Lock the subnet mutex only when trying to find peers, so the mutex is not locked when dialing peers.

prevent ConnManager from pruning peers excessively (#15681 )
* prevent ConnManager from pruning peers excessively * manu feedback --------- Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com> Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>
2026-01-10 05:47:59 -05:00 · 2025-09-14 21:18:11 +02:00 · 2025-09-14 00:03:48 +00:00 · 2025-09-12 16:03:54 +00:00 · 2025-09-12 13:58:00 +00:00 · 2025-09-12 13:29:08 +00:00
2076 changed files with 84560 additions and 28166 deletions
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -1,6 +1,6 @@
 name: 🐞 Bug report
 description: Report a bug or problem with running Prysm
-labels: ["Bug"]
+type: "Bug"
 body:
  - type: markdown
    attributes:
--- a/.github/workflows/changelog.yml
+++ b/.github/workflows/changelog.yml
@@ -18,7 +18,7 @@ jobs:
        uses: dsaltares/fetch-gh-release-asset@aa2ab1243d6e0d5b405b973c89fa4d06a2d0fff7 # 1.1.2
        with:
          repo: OffchainLabs/unclog
-          version: "tags/v0.1.3"
+          version: "tags/v0.1.5"
          file: "unclog"

      - name: Get new changelog files
--- a/.github/workflows/check-specrefs.yml
+++ b/.github/workflows/check-specrefs.yml
@@ -0,0 +1,43 @@
+name: Check Spec References
+on: [push, pull_request]
+
+jobs:
+  check-specrefs:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Check version consistency
+      run: |
+        WORKSPACE_VERSION=$(grep 'consensus_spec_version = ' WORKSPACE | sed 's/.*"\(.*\)"/\1/')
+        ETHSPECIFY_VERSION=$(grep '^version:' specrefs/.ethspecify.yml | sed 's/version: //')
+        if [ "$WORKSPACE_VERSION" != "$ETHSPECIFY_VERSION" ]; then
+          echo "Version mismatch between WORKSPACE and ethspecify"
+          echo "  WORKSPACE: $WORKSPACE_VERSION"
+          echo "  specrefs/.ethspecify.yml: $ETHSPECIFY_VERSION"
+          exit 1
+        else
+          echo "Versions match: $WORKSPACE_VERSION"
+        fi
+
+    - name: Install ethspecify
+      run: python3 -mpip install ethspecify
+
+    - name: Update spec references
+      run: ethspecify process --path=specrefs
+
+    - name: Check for differences
+      run: |
+        if ! git diff --exit-code specrefs >/dev/null; then
+          echo "Spec references are out-of-date!"
+          echo ""
+          git --no-pager diff specrefs
+          exit 1
+        else
+          echo "Spec references are up-to-date!"
+        fi
+
+    - name: Check spec references
+      run: ethspecify check --path=specrefs
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -194,6 +194,7 @@ nogo(
        "//tools/analyzers/gocognit:go_default_library",
        "//tools/analyzers/ineffassign:go_default_library",
        "//tools/analyzers/interfacechecker:go_default_library",
+        "//tools/analyzers/logcapitalization:go_default_library",
        "//tools/analyzers/logruswitherror:go_default_library",
        "//tools/analyzers/maligned:go_default_library",
        "//tools/analyzers/nop:go_default_library",
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,209 @@ All notable changes to this project will be documented in this file.

 The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

+## [v6.0.4](https://github.com/prysmaticlabs/prysm/compare/v6.0.3...v6.0.4) - 2025-06-05
+
+This release has more work on PeerDAS, and light client support. Additionally, we have a few bug fixes:
+- Blob cache size now correctly set at startup.
+- A fix for slashing protection history exports where the validator database was in a nested folder.
+- Corrected behavior of the API call for state committees with an invalid request.
+- `/bin/sh` is now symlinked to `/bin/bash` for Prysm docker images.
+
+In the [Hoodi](https://github.com/eth-clients/hoodi) testnet, the default gas limit is raised to 60M gas. 
+
+### Added
+
+- Add light client mainnet spec test. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15295)
+- Add support for light client req/resp domain. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15281)
+- Added /bin/sh simlink to docker images. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15294)
+- Added Prysm build data to otel tracing spans. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15302)
+- Add light client minimal spec test support for `update_ranking` tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15297)
+- Add fulu operation and epoch processing spec tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15284)
+- Updated e2e Beacon API evaluator to support more endpoints, including the ones introduced in Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15304)
+- Data column sidecars verification methods. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15232)
+- Implement data column sidecars filesystem. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15257)
+- Add blob schedule support from https://github.com/ethereum/consensus-specs/pull/4277. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15272)
+-  random forkchoice spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15287)
+- Add ability to download nightly test vectors. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15312)
+- PeerDAS: Validation pipeline for data column sidecars received via gossip. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15310)
+- PeerDAS: Implement P2P. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15347)
+- PeerDAS: Implement the blockchain package. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15350)
+
+### Changed
+
+- Update spec tests to v1.6.0-alpha.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15306)
+- PeerDAS: Refactor the reconstruction pipeline. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15309)
+- PeerDAS: `DataColumnStorage.Get` - Exit early no columns are available. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15309)
+- Default hoodi testnet builder gas limit to 60M. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15361)
+
+### Fixed
+
+- Fix cyclical dependencies issue when using testing/util package. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15248)
+- Set seen blob cache size correctly based on current slot time at start up. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15348)
+- Fix `slashing-protection-history export` failing when `validator.db` is in a nested folder like `data/direct/`. (#14954). [[PR]](https://github.com/prysmaticlabs/prysm/pull/15351)
+- Made `/eth/v1/beacon/states/{state_id}/committees` endpoint return `400` when slot does not belong to the specified epoch, aligning with the Beacon API spec (#15355). [[PR]](https://github.com/prysmaticlabs/prysm/pull/15356)
+- Removed eager validator context cancellation that was causing validator builder registrations to fail occasionally. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15369)
+
+## [v6.0.3](https://github.com/prysmaticlabs/prysm/compare/v6.0.2...v6.0.3) - 2025-05-21
+
+This release has important bugfixes for users of the [Beacon API](https://ethereum.github.io/beacon-APIs/). These fixes include:
+- Fixed pending consolidations endpoint to return the correct response.
+- Fixed incorrect field name from pending partial withdrawals response.
+- Fixed attester slashing to return an empty array instead of nil/null. 
+- Fixed validator participation and active set changes endpoints to accept a `{state_id}` parameter. 
+
+Other improvements include:
+- Disabled deposit log processing routine for Electra and beyond.
+
+Operators are encouraged to update at their own convenience.
+
+### Added
+
+- ssz static spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15279)
+- finality and merkle proof spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15286)
+- sanity and rewards spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15285)
+
+### Changed
+
+- Added more tracing spans to various helpers related to GetDuties. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15271)
+- Disable log processing after deposit requests are activated. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15274)
+
+### Fixed
+
+- fixed wrong handler for get pending consolidations endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15290)
+- Fixed /eth/v2/beacon/pool/attester_slashings no slashings returns empty array instead of nil. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15291)
+- Fix Prysm endpoints `/prysm/v1/validators/{state_id}/participation` and `/prysm/v1/validators/{state_id}/active_set_changes` to properly handle `{state_id}`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15245)
+
+## [v6.0.2](https://github.com/prysmaticlabs/prysm/compare/v6.0.1...v6.0.2) - 2025-05-12
+
+This is a patch release to fix a few important bugs. Most importantly, we have adjusted the index limit for field tries in the beacon state to better support Pectra states. This should alleviate memory issues that clients are seeing since Pectra mainnet fork.
+
+### Added
+
+- Enable light client gossip for optimistic and finality updates. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15220)
+- Implement peerDAS core functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15192)
+- Force duties start on received blocks. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15251)
+- Added additional tracing spans for the GetDuties routine. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15258)
+
+### Changed
+
+- Use otelgrpc for tracing grpc server and client. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15237)
+- Upgraded ristretto to v2.2.0, for RISC-V support. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15170)
+- Update spec to v1.5.0 compliance which changes minimal execution requests size. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15256)
+- Increase indices limit in field trie rebuilding. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15252)
+- Increase sepolia gas limit to 60M. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15253)
+
+### Fixed
+
+- Fixed wrong field name in pending partial withdrawals was returned on state json representation, described in https://github.com/ethereum/consensus-specs/blob/dev/specs/electra/beacon-chain.md#pendingpartialwithdrawal. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15254)
+- Fixed gocognit on propose block rest path. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15147)
+
+## [v6.0.1](https://github.com/prysmaticlabs/prysm/compare/v6.0.0...v6.0.1) - 2025-05-02
+
+This release fixes two bugs related to the `payload_attributes` [event stream](https://ethereum.github.io/beacon-APIs/#/Events/eventstream). If you are using or planning to use this endpoint, upgrading to version 6.0.1 is mandatory.  
+Also, a reminder: like other Beacon API endpoints, when a node is syncing, it may return historical data as `finalized` or `head`. Until the node is fully synced to the head of the chain, you should avoid using this data, depending on your application's needs.
+
+We currently recommend against using the `--enable-beacon-rest-api` flag on Mainnet. As you may have noticed, we put a deprecation notice on our gRPC code, in particular on gRPC-related flags. The reason for this is that we want to eventually remove gRPC and have REST HTTP as the standard way of communication between the validator client and the beacon node. That being said, the REST option is still unstable and thus marked as experimental in the flag's description (the flag is `--enable-beacon-rest-api`). Therefore we encourage everyone to keep using gRPC, which is currently the default. It is fine to test the REST option on testnets, but doing it on Mainnet can lead to missing attestations and even missing blocks.
+
+**Updating to v6.0.0 or later is required for Pectra Mainnet!**
+
+This patch release has a few important fixes from v6.0.0. Updating to this release is encouraged.
+
+### Added
+
+- `UpgradeToFulu` spectests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- PeerDAS related KZG wrappers. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15186)
+- Add light client p2p broadcaster functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15175)
+- Added immediate broadcasting of proposer slashings when equivocating blocks are detected during block processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Added 2 new errors: `HeadStateErr` and `ErrCouldNotVerifyBlockHeader`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Implement pending consolidations Beacon API endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15219)
+- PeerDAS: Add needed proto files and corresponding generated code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15187)
+- Add light client p2p validator and subscriber functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15214)
+
+### Changed
+
+- Refactored internal function `reValidateSubscriptions` to `pruneSubscriptions` in `beacon-chain/sync/subscriber.go` for improved clarity, addressing a TODO comment. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15160)
+- Updated geth to v1.15.9. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15216)
+- Removed the slot from `UpdateDuties`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15223)
+- Update hoodie bootnodes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15240)
+
+### Fixed
+
+- avoid nondeterministic default fork value when generate genesis. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15151)
+- `UpgradeToFulu`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- fixed underflow with balances in leaking edge case with expected withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15191)
+- Fixes our generated ssz files to have the correct package name. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15199)
+- Fixes our blob sidecar by root request lists for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15209)
+- Ensure that the `payload_attributes` event has a consistent view of the head state by passing the head block in the event and using stategen to retrieve the corresponding state. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15213)
+- Pass parent context to update duties when dependent roots change. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15221)
+- Process slots across epoch for payload attribute event. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15228)
+- extend the payload attribute computation deadline to the beginning of the proposal slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15230)
+
+### Security
+
+- Fix CVE-2025-22869. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22870. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22872. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-30204. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+
+## [v6.0.0](https://github.com/prysmaticlabs/prysm/compare/v5.3.2...v6.0.0) - 2025-04-21
+
+This release introduces Mainnet support for the upcoming Electra + Prague (Pectra) fork. The fork is scheduled for mainnet epoch 364032 (May 7, 2025, 10:05:11 UTC). You MUST update Prysm Beacon Node, Prysm Validator Client, and your execution layer client to the Pectra ready release prior to the fork to stay on the correct chain.
+
+Besides Pectra, we have more light client API support, cleanups, and a few bugfixes. Please review the changelog below and update your client as soon as practical before May 7.
+
+This release is **mandatory** for all operators before May 7.
+
+### Added
+
+- Implemented validator identities Beacon API endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15086)
+- Add SSZ support to light client updates by range API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15082)
+- Add light client ssz types to the spec test. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15097)
+- Added the ability for execution requests to be tested in e2e with electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14971)
+- Add warning messages for gas limit ranges that might be problematic. Low gas limits (≤10% of default) may cause transactions to fail, while high gas limits (>150% of default) could lead to block propagation issues. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15078)
+- Add light client store object to the beacon node object. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15120)
+- prysmctl option in wrapper script to generate devnet ssz. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15145)
+- Add support for Electra fork epoch. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15132)
+
+### Changed
+
+- The validator client will no longer use the full list of committee values but instead use the committee length and validator committee index. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15039)
+- Remove the header `Content-Disposition` from the `httputil.WriteSSZ` function. No `filename` parameter is needed anymore. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15092)
+- Sort attestations in proposer block by reward. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15093)
+- More efficient query method for stategen to retrieve blocks between a given state and the replay target block. This avoids attempting to look up blocks that are not needed for head replay queries, which may be missing due to a previous rollback bug. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15063)
+- removed old web3signer metrics in favor for a universal one. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14920)
+- Deprecated everything related with the gRPC API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14944)
+- Migrate Prysm repo to Offchain Labs organization ahead of Pectra upgrade v6. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15140)
+
+### Deprecated
+
+- deprecates and removes usage of the `--trace` flag and`--cpuprofile` flag in favor of just using `--pprof`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15083)
+
+### Removed
+
+- Remove /eth/v1/beacon/states/head/committees call when getting duties. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15039)
+- Removed unused hack scripts. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15157)
+- Remove `disable-committee-aware-packing` flag. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15162)
+- Remove deprecated flags for the major release. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15165)
+- Removed Beacon API endpoints which have been deprecated at the Deneb fork. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15166)
+
+### Fixed
+
+- The `--rpc` flag will now properly enable the keymanager APIs without web. The `--web` will enable both validator api endpoints and web. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15080)
+- Use latest state to pack attestation. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15113)
+- Clean up dangling block index entries for blocks that were previously deleted by incomplete cleanup code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15040)
+- Fixed to use io stream instead of stream read. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15089)
+- When using a DV, send all aggregations for a slot and committee. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15110)
+- Fixed a bug in consolidation request processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15122)
+- Fix State Getter for pending withdrawal balance. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15123)
+- Fixed a bug in checking for attestation lengths in our block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15134)
+- Fix Committee Index Check For Aggregates. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15146)
+- Fix filtering by committee index post-Electra in `ListAttestationsV2`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15148)
+- Peers giving invalid data in range syncing are now downscored. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15149)
+- Adding fork guard to attestation api endpoints so that it doesn't accidentally include wrong attestation types in the pool. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15161)
+- fixed underflow with balances in leaking edge case with expected withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15191)
+- Attribute block and blob issues to correct peers during range syncing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15173)
+
 ## [v5.3.2](https://github.com/prysmaticlabs/prysm/compare/v5.3.1...v5.3.2) - 2025-03-25

 This release introduces support for the `Hoodi` testnet.
@@ -2790,7 +2993,7 @@ There are two known issues with this release:

 ### Added

- Web3Signer support. See the [documentation](https://docs.prylabs.network/docs/next/wallet/web3signer) for more
+- Web3Signer support. See the [documentation](https://prysm.offchainlabs.com/docs/manage-wallet/web3signer/) for more
  details.
 - Bellatrix support. See [kiln testnet instructions](https://hackmd.io/OqIoTiQvS9KOIataIFksBQ?view)
 - Weak subjectivity sync / checkpoint sync. This is an experimental feature and may have unintended side effects for
@@ -3255,4 +3458,4 @@ There are no security updates in this release.

 # Older than v2.0.0

-For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases
+For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -4,7 +4,7 @@ Note: The latest and most up-to-date documentation can be found on our [docs por

 Excited by our work and want to get involved in building out our sharding releases? Or maybe you haven't learned as much about the Ethereum protocol but are a savvy developer? 

-You can explore our [Open Issues](https://github.com/OffchainLabs/prysm/issues) in-the works for our different releases. Feel free to fork our repo and start creating PR’s after assigning yourself to an issue of interest. We are always chatting on [Discord](https://discord.gg/CTYGPUJ) drop us a line there if you want to get more involved or have any questions on our implementation!
+You can explore our [Open Issues](https://github.com/OffchainLabs/prysm/issues) in-the works for our different releases. Feel free to fork our repo and start creating PR’s after assigning yourself to an issue of interest. We are always chatting on [Discord](https://discord.gg/prysm) drop us a line there if you want to get more involved or have any questions on our implementation!

 > [!IMPORTANT] 
 > Please, **do not send pull requests for trivial changes**, such as typos, these will be rejected. These types of pull requests incur a cost to reviewers and do not provide much value to the project. If you are unsure, please open an issue first to discuss the change.
--- a/DEPENDENCIES.md
+++ b/DEPENDENCIES.md
@@ -2,7 +2,7 @@

 Prysm is go project with many complicated dependencies, including some c++ based libraries. There
 are two parts to Prysm's dependency management. Go modules and bazel managed dependencies. Be sure 
-to read [Why Bazel?](https://github.com/OffchainLabs/documentation/issues/138) to fully
+to read [Why Bazel?](https://prysm.offchainlabs.com/docs/install-prysm/install-with-bazel/#why-bazel) to fully
 understand the reasoning behind an additional layer of build tooling via Bazel rather than a pure
 "go build" project.

--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/OffchainLabs/prysm)](https://goreportcard.com/report/github.com/OffchainLabs/prysm)
 [![Consensus_Spec_Version 1.4.0](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.4.0-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.4.0)
 [![Execution_API_Version 1.0.0-beta.2](https://img.shields.io/badge/Execution%20API%20Version-v1.0.0.beta.2-blue.svg)](https://github.com/ethereum/execution-apis/tree/v1.0.0-beta.2/src/engine)
-[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/OffchainLabs)
+[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysm)
 [![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/OffchainLabs/prysm/badge)](https://www.gitpoap.io/gh/OffchainLabs/prysm)

 </div>
@@ -25,7 +25,7 @@ See the [Changelog](https://github.com/OffchainLabs/prysm/releases) for details

 A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the **[official documentation portal](https://docs.prylabs.network)**.

-💬 **Need help?** Join our **[Discord Community](https://discord.gg/OffchainLabs)** for support.
+💬 **Need help?** Join our **[Discord Community](https://discord.gg/prysm)** for support.

 ---

--- a/70
+++ b/70
@@ -1,7 +1,7 @@
 workspace(name = "prysm")

-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

 http_archive(
    name = "rules_pkg",
@@ -16,8 +16,6 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")

 rules_pkg_dependencies()

-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
 http_archive(
    name = "toolchains_protoc",
    sha256 = "abb1540f8a9e045422730670ebb2f25b41fa56ca5a7cf795175a110a0a68f4ad",
@@ -192,7 +190,7 @@ load("@rules_oci//oci:pull.bzl", "oci_pull")
 # A multi-arch base image
 oci_pull(
    name = "linux_debian11_multiarch_base",  # Debian bullseye
-    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
+    digest = "sha256:55a5e011b2c4246b4c51e01fcc2b452d151e03df052e357465f0392fcd59fddf",
    image = "gcr.io/prysmaticlabs/distroless/cc-debian11",
    platforms = [
        "linux/amd64",
@@ -210,7 +208,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

 go_register_toolchains(
-    go_version = "1.24.0",
+    go_version = "1.24.6",
    nogo = "@//:nogo",
 )

@@ -255,56 +253,18 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.5.0-beta.5"
+consensus_spec_version = "v1.6.0-alpha.6"

-bls_test_version = "v0.1.1"
+load("@prysm//tools:download_spectests.bzl", "consensus_spec_tests")

-http_archive(
-    name = "consensus_spec_tests_general",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-H+Pt4z+HCVDnEBAv814yvsjR7f5l1IpumjFoTj2XnLE=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
-)
-
-http_archive(
-    name = "consensus_spec_tests_minimal",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-Dqiwf5BG7yYyURGf+i87AIdArAyztvcgjoi2kSxrGvo=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
-)
-
-http_archive(
-    name = "consensus_spec_tests_mainnet",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-xrmsFF243pzXHAjh1EQYKS9gtcwmtHK3wRZDSLlVVRk=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
+consensus_spec_tests(
+    name = "consensus_spec_tests",
+    flavors = {
+        "general": "sha256-7wkWuahuCO37uVYnxq8Badvi+jY907pBj68ixL8XDOI=",
+        "minimal": "sha256-Qy/f27N0LffS/ej7VhIubwDejD6LMK0VdenKkqtZVt4=",
+        "mainnet": "sha256-3H7mu5yE+FGz2Wr/nc8Nd9aEu93YoEpsYtn0zBSoeDE=",
+    },
+    version = consensus_spec_version,
 )

 http_archive(
@@ -318,11 +278,13 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-c+gGapqifCvFtmtxfhOwieBDO2Syxp13GECWEpWM/Ho=",
+    integrity = "sha256-uvz3XfMTGfy3/BtQQoEp5XQOgrWgcH/5Zo/gR0iiP+k=",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

+bls_test_version = "v0.1.1"
+
 http_archive(
    name = "bls_spec_tests",
    build_file_content = """
--- a/api/apiutil/BUILD.bazel
+++ b/api/apiutil/BUILD.bazel
@@ -2,18 +2,28 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")

 go_library(
    name = "go_default_library",
-    srcs = ["common.go"],
+    srcs = [
+        "common.go",
+        "header.go",
+    ],
    importpath = "github.com/OffchainLabs/prysm/v6/api/apiutil",
    visibility = ["//visibility:public"],
-    deps = ["//consensus-types/primitives:go_default_library"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
 )

 go_test(
    name = "go_default_test",
-    srcs = ["common_test.go"],
+    srcs = [
+        "common_test.go",
+        "header_test.go",
+    ],
    embed = [":go_default_library"],
    deps = [
        "//consensus-types/primitives:go_default_library",
        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
    ],
 )
--- a/api/apiutil/header.go
+++ b/api/apiutil/header.go
@@ -0,0 +1,122 @@
+package apiutil
+
+import (
+	"mime"
+	"sort"
+	"strconv"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type mediaRange struct {
+	mt   string  // canonicalised media‑type, e.g. "application/json"
+	q    float64 // quality factor (0‑1)
+	raw  string  // original string – useful for logging/debugging
+	spec int     // 2=exact, 1=type/*, 0=*/*
+}
+
+func parseMediaRange(field string) (mediaRange, bool) {
+	field = strings.TrimSpace(field)
+
+	mt, params, err := mime.ParseMediaType(field)
+	if err != nil {
+		log.WithError(err).Debug("Failed to parse header field")
+		return mediaRange{}, false
+	}
+
+	r := mediaRange{mt: mt, q: 1, spec: 2, raw: field}
+
+	if qs, ok := params["q"]; ok {
+		v, err := strconv.ParseFloat(qs, 64)
+		if err != nil || v < 0 || v > 1 {
+			log.WithField("q", qs).Debug("Invalid quality factor (0‑1)")
+			return mediaRange{}, false // skip invalid entry
+		}
+		r.q = v
+	}
+
+	switch {
+	case mt == "*/*":
+		r.spec = 0
+	case strings.HasSuffix(mt, "/*"):
+		r.spec = 1
+	}
+	return r, true
+}
+
+func hasExplicitQ(r mediaRange) bool {
+	return strings.Contains(strings.ToLower(r.raw), ";q=")
+}
+
+// ParseAccept returns media ranges sorted by q (desc) then specificity.
+func ParseAccept(header string) []mediaRange {
+	if header == "" {
+		return []mediaRange{{mt: "*/*", q: 1, spec: 0, raw: "*/*"}}
+	}
+
+	var out []mediaRange
+	for _, field := range strings.Split(header, ",") {
+		if r, ok := parseMediaRange(field); ok {
+			out = append(out, r)
+		}
+	}
+
+	sort.SliceStable(out, func(i, j int) bool {
+		ei, ej := hasExplicitQ(out[i]), hasExplicitQ(out[j])
+		if ei != ej {
+			return ei // explicit beats implicit
+		}
+		if out[i].q != out[j].q {
+			return out[i].q > out[j].q
+		}
+		return out[i].spec > out[j].spec
+	})
+	return out
+}
+
+// Matches reports whether content type is acceptable per the header.
+func Matches(header, ct string) bool {
+	for _, r := range ParseAccept(header) {
+		switch {
+		case r.q == 0:
+			continue
+		case r.mt == "*/*":
+			return true
+		case strings.HasSuffix(r.mt, "/*"):
+			if strings.HasPrefix(ct, r.mt[:len(r.mt)-1]) {
+				return true
+			}
+		case r.mt == ct:
+			return true
+		}
+	}
+	return false
+}
+
+// Negotiate selects the best server type according to the header.
+// Returns the chosen type and true, or "", false when nothing matches.
+func Negotiate(header string, serverTypes []string) (string, bool) {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue
+		}
+		for _, s := range serverTypes {
+			if Matches(r.mt, s) {
+				return s, true
+			}
+		}
+	}
+	return "", false
+}
+
+// PrimaryAcceptMatches only checks if the first accept matches
+func PrimaryAcceptMatches(header, produced string) bool {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue // explicitly unacceptable – skip
+		}
+		return Matches(r.mt, produced)
+	}
+	return false
+}
--- a/api/apiutil/header_test.go
+++ b/api/apiutil/header_test.go
@@ -0,0 +1,174 @@
+package apiutil
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestParseAccept(t *testing.T) {
+	type want struct {
+		mt   string
+		q    float64
+		spec int
+	}
+
+	cases := []struct {
+		name   string
+		header string
+		want   []want
+	}{
+		{
+			name:   "empty header becomes */*;q=1",
+			header: "",
+			want:   []want{{mt: "*/*", q: 1, spec: 0}},
+		},
+		{
+			name:   "quality ordering then specificity",
+			header: "application/json;q=0.2, */*;q=0.1, application/xml;q=0.5, text/*;q=0.5",
+			want: []want{
+				{mt: "application/xml", q: 0.5, spec: 2},
+				{mt: "text/*", q: 0.5, spec: 1},
+				{mt: "application/json", q: 0.2, spec: 2},
+				{mt: "*/*", q: 0.1, spec: 0},
+			},
+		},
+		{
+			name:   "invalid pieces are skipped",
+			header: "text/plain; q=boom, application/json",
+			want:   []want{{mt: "application/json", q: 1, spec: 2}},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := ParseAccept(tc.header)
+			gotProjected := make([]want, len(got))
+			for i, g := range got {
+				gotProjected[i] = want{mt: g.mt, q: g.q, spec: g.spec}
+			}
+			require.DeepEqual(t, gotProjected, tc.want)
+		})
+	}
+}
+
+func TestMatches(t *testing.T) {
+	cases := []struct {
+		name    string
+		accept  string
+		ct      string
+		matches bool
+	}{
+		{"exact match", "application/json", "application/json", true},
+		{"type wildcard", "application/*;q=0.8", "application/xml", true},
+		{"global wildcard", "*/*;q=0.1", "image/png", true},
+		{"explicitly unacceptable (q=0)", "text/*;q=0", "text/plain", false},
+		{"no match", "image/png", "application/json", false},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := Matches(tc.accept, tc.ct)
+			require.Equal(t, tc.matches, got)
+		})
+	}
+}
+
+func TestNegotiate(t *testing.T) {
+	cases := []struct {
+		name        string
+		accept      string
+		serverTypes []string
+		wantType    string
+		ok          bool
+	}{
+		{
+			name:        "highest quality wins",
+			accept:      "application/json;q=0.8,application/xml;q=0.9",
+			serverTypes: []string{"application/json", "application/xml"},
+			wantType:    "application/xml",
+			ok:          true,
+		},
+		{
+			name:        "wildcard matches first server type",
+			accept:      "*/*;q=0.5",
+			serverTypes: []string{"application/octet-stream", "application/json"},
+			wantType:    "application/octet-stream",
+			ok:          true,
+		},
+		{
+			name:        "no acceptable type",
+			accept:      "image/png",
+			serverTypes: []string{"application/json"},
+			wantType:    "",
+			ok:          false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := Negotiate(tc.accept, tc.serverTypes)
+			require.Equal(t, tc.ok, ok)
+			require.Equal(t, tc.wantType, got)
+		})
+	}
+}
+
+func TestPrimaryAcceptMatches(t *testing.T) {
+	tests := []struct {
+		name     string
+		accept   string
+		produced string
+		expect   bool
+	}{
+		{
+			name:     "prefers json",
+			accept:   "application/json;q=0.9,application/xml",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "wildcard application beats other wildcard",
+			accept:   "application/*;q=0.2,*/*;q=0.1",
+			produced: "application/xml",
+			expect:   true,
+		},
+		{
+			name:     "json wins",
+			accept:   "application/xml;q=0.8,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json loses",
+			accept:   "application/xml;q=0.8,application/json;q=0.9,application/octet-stream;q=0.99",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "json wins with non q option",
+			accept:   "application/xml;q=0.8,image/png,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json not primary",
+			accept:   "image/png,application/json",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "absent header",
+			accept:   "",
+			produced: "text/plain",
+			expect:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := PrimaryAcceptMatches(tc.accept, tc.produced)
+			require.Equal(t, got, tc.expect)
+		})
+	}
+}
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -16,7 +16,6 @@ go_library(
        "//api/server/structs:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
-        "//network/forks:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"path"
 	"regexp"
-	"sort"
 	"strconv"

 	"github.com/OffchainLabs/prysm/v6/api/client"
@@ -17,7 +16,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
@@ -137,24 +135,6 @@ func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fo
 	return fr.ToConsensus()
 }

-// GetForkSchedule retrieve all forks, past present and future, of which this node is aware.
-func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, error) {
-	body, err := c.Get(ctx, getForkSchedulePath)
-	if err != nil {
-		return nil, errors.Wrap(err, "error requesting fork schedule")
-	}
-	fsr := &forkScheduleResponse{}
-	err = json.Unmarshal(body, fsr)
-	if err != nil {
-		return nil, err
-	}
-	ofs, err := fsr.OrderedForkSchedule()
-	if err != nil {
-		return nil, errors.Wrap(err, fmt.Sprintf("problem unmarshaling %s response", getForkSchedulePath))
-	}
-	return ofs, nil
-}
-
 // GetConfigSpec retrieve the current configs of the network used by the beacon node.
 func (c *Client) GetConfigSpec(ctx context.Context) (*structs.GetSpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
@@ -334,31 +314,3 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToEx
 	}
 	return poolResponse, nil
 }
-
-type forkScheduleResponse struct {
-	Data []structs.Fork
-}
-
-func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, error) {
-	ofs := make(forks.OrderedSchedule, 0)
-	for _, d := range fsr.Data {
-		epoch, err := strconv.ParseUint(d.Epoch, 10, 64)
-		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing epoch %s", d.Epoch)
-		}
-		vSlice, err := hexutil.Decode(d.CurrentVersion)
-		if err != nil {
-			return nil, err
-		}
-		if len(vSlice) != 4 {
-			return nil, fmt.Errorf("got %d byte version, expected 4 bytes. version hex=%s", len(vSlice), d.CurrentVersion)
-		}
-		version := bytesutil.ToBytes4(vSlice)
-		ofs = append(ofs, forks.ForkScheduleEntry{
-			Version: version,
-			Epoch:   primitives.Epoch(epoch),
-		})
-	}
-	sort.Sort(ofs)
-	return ofs, nil
-}
--- a/api/client/beacon/health/BUILD.bazel
+++ b/api/client/beacon/health/BUILD.bazel
@@ -1,20 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "go_default_library",
-    srcs = [
-        "health.go",
-        "interfaces.go",
-        "mock.go",
-    ],
-    importpath = "github.com/OffchainLabs/prysm/v6/api/client/beacon/health",
-    visibility = ["//visibility:public"],
-    deps = ["@org_uber_go_mock//gomock:go_default_library"],
-)
-
-go_test(
-    name = "go_default_test",
-    srcs = ["health_test.go"],
-    embed = [":go_default_library"],
-    deps = ["@org_uber_go_mock//gomock:go_default_library"],
-)
--- a/api/client/beacon/health/health.go
+++ b/api/client/beacon/health/health.go
@@ -1,58 +0,0 @@
-package health
-
-import (
-	"context"
-	"sync"
-)
-
-type NodeHealthTracker struct {
-	isHealthy  *bool
-	healthChan chan bool
-	node       Node
-	sync.RWMutex
-}
-
-func NewTracker(node Node) Tracker {
-	return &NodeHealthTracker{
-		node:       node,
-		healthChan: make(chan bool, 1),
-	}
-}
-
-// HealthUpdates provides a read-only channel for health updates.
-func (n *NodeHealthTracker) HealthUpdates() <-chan bool {
-	return n.healthChan
-}
-
-func (n *NodeHealthTracker) IsHealthy(_ context.Context) bool {
-	n.RLock()
-	defer n.RUnlock()
-	if n.isHealthy == nil {
-		return false
-	}
-	return *n.isHealthy
-}
-
-func (n *NodeHealthTracker) CheckHealth(ctx context.Context) bool {
-	n.Lock()
-	defer n.Unlock()
-
-	newStatus := n.node.IsHealthy(ctx)
-	if n.isHealthy == nil {
-		n.isHealthy = &newStatus
-	}
-
-	isStatusChanged := newStatus != *n.isHealthy
-	if isStatusChanged {
-		// Update the health status
-		n.isHealthy = &newStatus
-		// Send the new status to the health channel, potentially overwriting the existing value
-		select {
-		case <-n.healthChan:
-			n.healthChan <- newStatus
-		default:
-			n.healthChan <- newStatus
-		}
-	}
-	return newStatus
-}
--- a/api/client/beacon/health/health_test.go
+++ b/api/client/beacon/health/health_test.go
@@ -1,111 +0,0 @@
-package health
-
-import (
-	"context"
-	"sync"
-	"testing"
-
-	"go.uber.org/mock/gomock"
-)
-
-func TestNodeHealth_IsHealthy(t *testing.T) {
-	tests := []struct {
-		name      string
-		isHealthy bool
-		want      bool
-	}{
-		{"initially healthy", true, true},
-		{"initially unhealthy", false, false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			n := &NodeHealthTracker{
-				isHealthy:  &tt.isHealthy,
-				healthChan: make(chan bool, 1),
-			}
-			if got := n.IsHealthy(context.Background()); got != tt.want {
-				t.Errorf("IsHealthy() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestNodeHealth_UpdateNodeHealth(t *testing.T) {
-	tests := []struct {
-		name       string
-		initial    bool // Initial health status
-		newStatus  bool // Status to update to
-		shouldSend bool // Should a message be sent through the channel
-	}{
-		{"healthy to unhealthy", true, false, true},
-		{"unhealthy to healthy", false, true, true},
-		{"remain healthy", true, true, false},
-		{"remain unhealthy", false, false, false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
-			client := NewMockHealthClient(ctrl)
-			client.EXPECT().IsHealthy(gomock.Any()).Return(tt.newStatus)
-			n := &NodeHealthTracker{
-				isHealthy:  &tt.initial,
-				node:       client,
-				healthChan: make(chan bool, 1),
-			}
-
-			s := n.CheckHealth(context.Background())
-			// Check if health status was updated
-			if s != tt.newStatus {
-				t.Errorf("UpdateNodeHealth() failed to update isHealthy from %v to %v", tt.initial, tt.newStatus)
-			}
-
-			select {
-			case status := <-n.HealthUpdates():
-				if !tt.shouldSend {
-					t.Errorf("UpdateNodeHealth() unexpectedly sent status %v to HealthCh", status)
-				} else if status != tt.newStatus {
-					t.Errorf("UpdateNodeHealth() sent wrong status %v, want %v", status, tt.newStatus)
-				}
-			default:
-				if tt.shouldSend {
-					t.Error("UpdateNodeHealth() did not send any status to HealthCh when expected")
-				}
-			}
-		})
-	}
-}
-
-func TestNodeHealth_Concurrency(t *testing.T) {
-	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
-	client := NewMockHealthClient(ctrl)
-	n := NewTracker(client)
-	var wg sync.WaitGroup
-
-	// Number of goroutines to spawn for both reading and writing
-	numGoroutines := 6
-
-	wg.Add(numGoroutines * 2) // for readers and writers
-
-	// Concurrently update health status
-	for i := 0; i < numGoroutines; i++ {
-		go func() {
-			defer wg.Done()
-			client.EXPECT().IsHealthy(gomock.Any()).Return(false).Times(1)
-			n.CheckHealth(context.Background())
-			client.EXPECT().IsHealthy(gomock.Any()).Return(true).Times(1)
-			n.CheckHealth(context.Background())
-		}()
-	}
-
-	// Concurrently read health status
-	for i := 0; i < numGoroutines; i++ {
-		go func() {
-			defer wg.Done()
-			_ = n.IsHealthy(context.Background()) // Just read the value
-		}()
-	}
-
-	wg.Wait() // Wait for all goroutines to finish
-}
--- a/api/client/beacon/health/interfaces.go
+++ b/api/client/beacon/health/interfaces.go
@@ -1,13 +0,0 @@
-package health
-
-import "context"
-
-type Tracker interface {
-	HealthUpdates() <-chan bool
-	CheckHealth(ctx context.Context) bool
-	Node
-}
-
-type Node interface {
-	IsHealthy(ctx context.Context) bool
-}
--- a/api/client/beacon/health/mock.go
+++ b/api/client/beacon/health/mock.go
@@ -1,58 +0,0 @@
-package health
-
-import (
-	"context"
-	"reflect"
-	"sync"
-
-	"go.uber.org/mock/gomock"
-)
-
-var (
-	_ = Node(&MockHealthClient{})
-)
-
-// MockHealthClient is a mock of HealthClient interface.
-type MockHealthClient struct {
-	ctrl     *gomock.Controller
-	recorder *MockHealthClientMockRecorder
-	sync.Mutex
-}
-
-// MockHealthClientMockRecorder is the mock recorder for MockHealthClient.
-type MockHealthClientMockRecorder struct {
-	mock *MockHealthClient
-}
-
-// IsHealthy mocks base method.
-func (m *MockHealthClient) IsHealthy(arg0 context.Context) bool {
-	m.Lock()
-	defer m.Unlock()
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "IsHealthy", arg0)
-	ret0, ok := ret[0].(bool)
-	if !ok {
-		return false
-	}
-	return ret0
-}
-
-// EXPECT returns an object that allows the caller to indicate expected use.
-func (m *MockHealthClient) EXPECT() *MockHealthClientMockRecorder {
-	return m.recorder
-}
-
-// IsHealthy indicates an expected call of IsHealthy.
-func (mr *MockHealthClientMockRecorder) IsHealthy(arg0 any) *gomock.Call {
-	mr.mock.Lock()
-	defer mr.mock.Unlock()
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IsHealthy", reflect.TypeOf((*MockHealthClient)(nil).IsHealthy), arg0)
-}
-
-// NewMockHealthClient creates a new mock instance.
-func NewMockHealthClient(ctrl *gomock.Controller) *MockHealthClient {
-	mock := &MockHealthClient{ctrl: ctrl}
-	mock.recorder = &MockHealthClientMockRecorder{mock}
-	return mock
-}
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -13,7 +13,6 @@ go_library(
    deps = [
        "//api:go_default_library",
        "//api/client:go_default_library",
-        "//api/server:go_default_library",
        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
@@ -28,7 +27,6 @@ go_library(
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
        "@com_github_prysmaticlabs_fastssz//:go_default_library",
@@ -52,6 +50,7 @@ go_test(
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -72,7 +72,7 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 		log.WithFields(log.Fields{
 			"bodyBase64": "(nil value)",
 			"url":        r.URL.String(),
-		}).Info("builder http request")
+		}).Info("Builder http request")
 		return nil
 	}
 	t := io.TeeReader(r.Body, b)
@@ -89,7 +89,7 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 	log.WithFields(log.Fields{
 		"bodyBase64": string(body),
 		"url":        r.URL.String(),
-	}).Info("builder http request")
+	}).Info("Builder http request")

 	return nil
 }
@@ -101,7 +101,8 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error
 	Status(ctx context.Context) error
 }

@@ -152,7 +153,8 @@ func (c *Client) NodeURL() string {
 type reqOption func(*http.Request)

 // do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder.
-func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, header http.Header, err error) {
+// It validates that the HTTP response status matches the expectedStatus parameter.
+func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, expectedStatus int, opts ...reqOption) (res []byte, header http.Header, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
 		tracing.AnnotateError(span, err)
@@ -187,8 +189,8 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 			log.WithError(closeErr).Error("Failed to close response body")
 		}
 	}()
-	if r.StatusCode != http.StatusOK {
-		err = non200Err(r)
+	if r.StatusCode != expectedStatus {
+		err = unexpectedStatusErr(r, expectedStatus)
 		return
 	}
 	res, err = io.ReadAll(io.LimitReader(r.Body, client.MaxBodySize))
@@ -236,12 +238,12 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 			r.Header.Set("Accept", api.JsonMediaType)
 		}
 	}
-	data, header, err := c.do(ctx, http.MethodGet, path, nil, getOpts)
+	data, header, err := c.do(ctx, http.MethodGet, path, nil, http.StatusOK, getOpts)
 	if err != nil {
 		return nil, errors.Wrap(err, "error getting header from builder server")
 	}

-	bid, err := c.parseHeaderResponse(data, header)
+	bid, err := c.parseHeaderResponse(data, header, slot)
 	if err != nil {
 		return nil, errors.Wrapf(
 			err,
@@ -254,7 +256,7 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 	return bid, nil
 }

-func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid, error) {
+func (c *Client) parseHeaderResponse(data []byte, header http.Header, slot primitives.Slot) (SignedBid, error) {
 	var versionHeader string
 	if c.sszEnabled || header.Get(api.VersionHeader) != "" {
 		versionHeader = header.Get(api.VersionHeader)
@@ -276,7 +278,7 @@ func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid
 	}

 	if ver >= version.Electra {
-		return c.parseHeaderElectra(data)
+		return c.parseHeaderElectra(data, slot)
 	}
 	if ver >= version.Deneb {
 		return c.parseHeaderDeneb(data)
@@ -291,7 +293,7 @@ func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid
 	return nil, fmt.Errorf("unsupported header version %s", versionHeader)
 }

-func (c *Client) parseHeaderElectra(data []byte) (SignedBid, error) {
+func (c *Client) parseHeaderElectra(data []byte, slot primitives.Slot) (SignedBid, error) {
 	if c.sszEnabled {
 		sb := &ethpb.SignedBuilderBidElectra{}
 		if err := sb.UnmarshalSSZ(data); err != nil {
@@ -303,7 +305,7 @@ func (c *Client) parseHeaderElectra(data []byte) (SignedBid, error) {
 	if err := json.Unmarshal(data, hr); err != nil {
 		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponseElectra JSON")
 	}
-	p, err := hr.ToProto()
+	p, err := hr.ToProto(slot)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not convert ExecHeaderResponseElectra to proto")
 	}
@@ -409,7 +411,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 		}
 	}

-	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), postOpts); err != nil {
+	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), http.StatusOK, postOpts); err != nil {
 		return errors.Wrap(err, "do")
 	}
 	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
@@ -446,6 +448,9 @@ func sszValidatorRegisterRequest(svr []*ethpb.SignedValidatorRegistrationV1) ([]
 var errResponseVersionMismatch = errors.New("builder API response uses a different version than requested in " + api.VersionHeader + " header")

 func getVersionsBlockToPayload(blockVersion int) (int, error) {
+	if blockVersion >= version.Fulu {
+		return version.Fulu, nil
+	}
 	if blockVersion >= version.Deneb {
 		return version.Deneb, nil
 	}
@@ -460,7 +465,7 @@ func getVersionsBlockToPayload(blockVersion int) (int, error) {

 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	body, postOpts, err := c.buildBlindedBlockRequest(sb)
 	if err != nil {
 		return nil, nil, err
@@ -468,7 +473,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS

 	// post the blinded block - the execution payload response should contain the unblinded payload, along with the
 	// blobs bundle if it is post deneb.
-	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), postOpts)
+	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), http.StatusOK, postOpts)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "error posting the blinded block to the builder api")
 	}
@@ -498,6 +503,24 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 	return ed, blobs, nil
 }

+// SubmitBlindedBlockPostFulu calls the builder API endpoint post-Fulu where relays only return status codes.
+// This method is used after the Fulu fork when MEV-boost relays no longer return execution payloads.
+func (c *Client) SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error {
+	body, postOpts, err := c.buildBlindedBlockRequest(sb)
+	if err != nil {
+		return err
+	}
+
+	// Post the blinded block - the response should only contain a status code (no payload)
+	_, _, err = c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), http.StatusAccepted, postOpts)
+	if err != nil {
+		return errors.Wrap(err, "error posting the blinded block to the builder api post-Fulu")
+	}
+
+	// Success is indicated by no error (status 202)
+	return nil
+}
+
 func (c *Client) checkBlockVersion(respBytes []byte, header http.Header) (int, error) {
 	var versionHeader string
 	if c.sszEnabled {
@@ -558,7 +581,7 @@ func (c *Client) buildBlindedBlockRequest(sb interfaces.ReadOnlySignedBeaconBloc
 func (c *Client) parseBlindedBlockResponse(
 	respBytes []byte,
 	forkVersion int,
-) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	if c.sszEnabled {
 		return c.parseBlindedBlockResponseSSZ(respBytes, forkVersion)
 	}
@@ -568,8 +591,18 @@ func (c *Client) parseBlindedBlockResponse(
 func (c *Client) parseBlindedBlockResponseSSZ(
 	respBytes []byte,
 	forkVersion int,
-) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
-	if forkVersion >= version.Deneb {
+) (interfaces.ExecutionData, v1.BlobsBundler, error) {
+	if forkVersion >= version.Fulu {
+		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundleV2{}
+		if err := payloadAndBlobs.UnmarshalSSZ(respBytes); err != nil {
+			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadDenebAndBlobsBundleV2 SSZ")
+		}
+		ed, err := blocks.NewWrappedExecutionData(payloadAndBlobs.Payload)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "unable to wrap execution data for %s", version.String(forkVersion))
+		}
+		return ed, payloadAndBlobs.BlobsBundle, nil
+	} else if forkVersion >= version.Deneb {
 		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundle{}
 		if err := payloadAndBlobs.UnmarshalSSZ(respBytes); err != nil {
 			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadDenebAndBlobsBundle SSZ")
@@ -644,11 +677,11 @@ func (c *Client) Status(ctx context.Context) error {
 	getOpts := func(r *http.Request) {
 		r.Header.Set("Accept", api.JsonMediaType)
 	}
-	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, getOpts)
+	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, http.StatusOK, getOpts)
 	return err
 }

-func non200Err(response *http.Response) error {
+func unexpectedStatusErr(response *http.Response, expected int) error {
 	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, client.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
@@ -657,7 +690,7 @@ func non200Err(response *http.Response) error {
 	} else {
 		body = "response body:\n" + string(bodyBytes)
 	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
+	msg := fmt.Sprintf("expected=%d, got=%d, url=%s, body=%s", expected, response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
 	case http.StatusUnsupportedMediaType:
 		log.WithError(ErrUnsupportedMediaType).Debug(msg)
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	v1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -31,7 +32,7 @@ func (fn roundtrip) RoundTrip(r *http.Request) (*http.Response, error) {
 }

 func TestClient_Status(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	statusPath := "/eth/v1/builder/status"
 	hc := &http.Client{
 		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -84,7 +85,7 @@ func TestClient_Status(t *testing.T) {
 }

 func TestClient_RegisterValidator(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	expectedBody := `[{"message":{"fee_recipient":"0x0000000000000000000000000000000000000000","gas_limit":"23","timestamp":"42","pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}]`
 	expectedPath := "/eth/v1/builder/validators"
 	t.Run("JSON success", func(t *testing.T) {
@@ -168,7 +169,7 @@ func TestClient_RegisterValidator(t *testing.T) {
 }

 func TestClient_GetHeader(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	expectedPath := "/eth/v1/builder/header/23/0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2/0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
 	var slot primitives.Slot = 23
 	parentHash := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
@@ -532,7 +533,7 @@ func TestClient_GetHeader(t *testing.T) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				epr := &ExecHeaderResponseElectra{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseElectra), epr))
-				pro, err := epr.ToProto()
+				pro, err := epr.ToProto(100)
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)
@@ -601,7 +602,7 @@ func TestClient_GetHeader(t *testing.T) {
 }

 func TestSubmitBlindedBlock(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

 	t.Run("bellatrix", func(t *testing.T) {
 		hc := &http.Client{
@@ -640,9 +641,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
 				epr := &ExecutionPayloadResponse{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
-				ep := &ExecutionPayload{}
+				ep := &structs.ExecutionPayload{}
 				require.NoError(t, json.Unmarshal(epr.Data, ep))
-				pro, err := ep.ToProto()
+				pro, err := ep.ToConsensus()
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)
@@ -710,9 +711,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
 				epr := &ExecutionPayloadResponse{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadCapella), epr))
-				ep := &ExecutionPayloadCapella{}
+				ep := &structs.ExecutionPayloadCapella{}
 				require.NoError(t, json.Unmarshal(epr.Data, ep))
-				pro, err := ep.ToProto()
+				pro, err := ep.ToConsensus()
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)
@@ -1554,12 +1555,95 @@ func testSignedBlindedBeaconBlockElectra(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }

+func TestSubmitBlindedBlockPostFulu(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("success", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("success_ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get(api.VersionHeader))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("error_response", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				message := ErrorMessage{
+					Code:    400,
+					Message: "Bad Request",
+				}
+				resp, err := json.Marshal(message)
+				require.NoError(t, err)
+				return &http.Response{
+					StatusCode: http.StatusBadRequest,
+					Body:       io.NopCloser(bytes.NewBuffer(resp)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.ErrorIs(t, err, ErrNotOK)
+	})
+}
+
 func TestRequestLogger(t *testing.T) {
 	wo := WithObserver(&requestLogger{})
 	c, err := NewClient("localhost:3500", wo)
 	require.NoError(t, err)

-	ctx := context.Background()
+	ctx := t.Context()
 	hc := &http.Client{
 		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 			require.Equal(t, getStatus, r.URL.Path)
@@ -1574,3 +1658,166 @@ func TestRequestLogger(t *testing.T) {
 	err = c.Status(ctx)
 	require.NoError(t, err)
 }
+
+func TestGetVersionsBlockToPayload(t *testing.T) {
+	tests := []struct {
+		name            string
+		blockVersion    int
+		expectedVersion int
+		expectedError   bool
+	}{
+		{
+			name:            "Fulu version",
+			blockVersion:    6, // version.Fulu
+			expectedVersion: 6,
+			expectedError:   false,
+		},
+		{
+			name:            "Deneb version",
+			blockVersion:    4, // version.Deneb
+			expectedVersion: 4,
+			expectedError:   false,
+		},
+		{
+			name:            "Capella version",
+			blockVersion:    3, // version.Capella
+			expectedVersion: 3,
+			expectedError:   false,
+		},
+		{
+			name:            "Bellatrix version",
+			blockVersion:    2, // version.Bellatrix
+			expectedVersion: 2,
+			expectedError:   false,
+		},
+		{
+			name:          "Unsupported version",
+			blockVersion:  0,
+			expectedError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			version, err := getVersionsBlockToPayload(tt.blockVersion)
+			if tt.expectedError {
+				assert.NotNil(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expectedVersion, version)
+			}
+		})
+	}
+}
+
+func TestParseBlindedBlockResponseSSZ_WithBlobsBundleV2(t *testing.T) {
+	c := &Client{sszEnabled: true}
+
+	// Create test payload
+	payload := &v1.ExecutionPayloadDeneb{
+		ParentHash:    make([]byte, 32),
+		FeeRecipient:  make([]byte, 20),
+		StateRoot:     make([]byte, 32),
+		ReceiptsRoot:  make([]byte, 32),
+		LogsBloom:     make([]byte, 256),
+		PrevRandao:    make([]byte, 32),
+		BlockNumber:   123456,
+		GasLimit:      30000000,
+		GasUsed:       21000,
+		Timestamp:     1234567890,
+		ExtraData:     []byte("test-extra-data"),
+		BaseFeePerGas: make([]byte, 32),
+		BlockHash:     make([]byte, 32),
+		Transactions:  [][]byte{},
+		Withdrawals:   []*v1.Withdrawal{},
+		BlobGasUsed:   1024,
+		ExcessBlobGas: 2048,
+	}
+
+	// Create test BlobsBundleV2
+	bundleV2 := &v1.BlobsBundleV2{
+		KzgCommitments: [][]byte{make([]byte, 48), make([]byte, 48)},
+		Proofs:         [][]byte{make([]byte, 48), make([]byte, 48)},
+		Blobs:          [][]byte{make([]byte, 131072), make([]byte, 131072)},
+	}
+
+	// Test Fulu version (should use ExecutionPayloadDenebAndBlobsBundleV2)
+	t.Run("Fulu version with BlobsBundleV2", func(t *testing.T) {
+		payloadAndBlobsV2 := &v1.ExecutionPayloadDenebAndBlobsBundleV2{
+			Payload:     payload,
+			BlobsBundle: bundleV2,
+		}
+
+		respBytes, err := payloadAndBlobsV2.MarshalSSZ()
+		require.NoError(t, err)
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(respBytes, 6) // version.Fulu
+		require.NoError(t, err)
+		require.NotNil(t, ed)
+		require.NotNil(t, bundle)
+
+		// Verify the bundle is BlobsBundleV2
+		bundleV2Result, ok := bundle.(*v1.BlobsBundleV2)
+		assert.Equal(t, true, ok, "Expected BlobsBundleV2 type")
+		require.Equal(t, len(bundleV2.KzgCommitments), len(bundleV2Result.KzgCommitments))
+		require.Equal(t, len(bundleV2.Proofs), len(bundleV2Result.Proofs))
+		require.Equal(t, len(bundleV2.Blobs), len(bundleV2Result.Blobs))
+	})
+
+	// Test Deneb version (should use regular BlobsBundle)
+	t.Run("Deneb version with regular BlobsBundle", func(t *testing.T) {
+		regularBundle := &v1.BlobsBundle{
+			KzgCommitments: bundleV2.KzgCommitments,
+			Proofs:         bundleV2.Proofs,
+			Blobs:          bundleV2.Blobs,
+		}
+
+		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundle{
+			Payload:     payload,
+			BlobsBundle: regularBundle,
+		}
+
+		respBytes, err := payloadAndBlobs.MarshalSSZ()
+		require.NoError(t, err)
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(respBytes, 4) // version.Deneb
+		require.NoError(t, err)
+		require.NotNil(t, ed)
+		require.NotNil(t, bundle)
+
+		// Verify the bundle is regular BlobsBundle
+		regularBundleResult, ok := bundle.(*v1.BlobsBundle)
+		assert.Equal(t, true, ok, "Expected BlobsBundle type")
+		require.Equal(t, len(regularBundle.KzgCommitments), len(regularBundleResult.KzgCommitments))
+	})
+
+	// Test invalid SSZ data
+	t.Run("Invalid SSZ data", func(t *testing.T) {
+		invalidBytes := []byte("invalid-ssz-data")
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(invalidBytes, 6)
+		assert.NotNil(t, err)
+		assert.Equal(t, true, ed == nil)
+		assert.Equal(t, true, bundle == nil)
+	})
+}
+
+func TestSubmitBlindedBlock_BlobsBundlerInterface(t *testing.T) {
+	// Note: The full integration test is complex due to version detection logic
+	// The key functionality is tested in the parseBlindedBlockResponseSSZ tests above
+	// and in the mock service tests which verify the interface changes work correctly
+
+	t.Run("Interface signature verification", func(t *testing.T) {
+		// This test verifies that the SubmitBlindedBlock method signature
+		// has been updated to return BlobsBundler interface
+
+		client := &Client{}
+
+		// Verify the method exists with the correct signature
+		// by using reflection or by checking it compiles with the interface
+		var _ func(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) = client.SubmitBlindedBlock
+
+		// This test passes if the signature is correct
+		assert.Equal(t, true, true)
+	})
+}
--- a/api/client/builder/testing/mock.go
+++ b/api/client/builder/testing/mock.go
@@ -41,10 +41,15 @@ func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedVali
 }

 // SubmitBlindedBlock --
-func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	return nil, nil, nil
 }

+// SubmitBlindedBlockPostFulu --
+func (MockClient) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return nil
+}
+
 // Status --
 func (MockClient) Status(_ context.Context) error {
 	return nil
--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
--- a/api/client/builder/types_test.go
+++ b/api/client/builder/types_test.go
@@ -328,72 +328,72 @@ func TestExecutionHeaderResponseUnmarshal(t *testing.T) {
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ParentHash),
+			actual:   hr.Data.Message.Header.ParentHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(hr.Data.Message.Header.FeeRecipient),
+			actual:   hr.Data.Message.Header.FeeRecipient,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.StateRoot),
+			actual:   hr.Data.Message.Header.StateRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ReceiptsRoot),
+			actual:   hr.Data.Message.Header.ReceiptsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(hr.Data.Message.Header.LogsBloom),
+			actual:   hr.Data.Message.Header.LogsBloom,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.PrevRandao),
+			actual:   hr.Data.Message.Header.PrevRandao,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BlockNumber),
+			actual:   hr.Data.Message.Header.BlockNumber,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasLimit),
+			actual:   hr.Data.Message.Header.GasLimit,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasUsed),
+			actual:   hr.Data.Message.Header.GasUsed,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.Timestamp),
+			actual:   hr.Data.Message.Header.Timestamp,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ExtraData),
+			actual:   hr.Data.Message.Header.ExtraData,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BaseFeePerGas),
+			actual:   hr.Data.Message.Header.BaseFeePerGas,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.BlockHash),
+			actual:   hr.Data.Message.Header.BlockHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockHash",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.TransactionsRoot),
+			actual:   hr.Data.Message.Header.TransactionsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.TransactionsRoot",
 		},
 	}
@@ -427,77 +427,77 @@ func TestExecutionHeaderResponseCapellaUnmarshal(t *testing.T) {
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ParentHash),
+			actual:   hr.Data.Message.Header.ParentHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(hr.Data.Message.Header.FeeRecipient),
+			actual:   hr.Data.Message.Header.FeeRecipient,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.StateRoot),
+			actual:   hr.Data.Message.Header.StateRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ReceiptsRoot),
+			actual:   hr.Data.Message.Header.ReceiptsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(hr.Data.Message.Header.LogsBloom),
+			actual:   hr.Data.Message.Header.LogsBloom,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.PrevRandao),
+			actual:   hr.Data.Message.Header.PrevRandao,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BlockNumber),
+			actual:   hr.Data.Message.Header.BlockNumber,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasLimit),
+			actual:   hr.Data.Message.Header.GasLimit,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasUsed),
+			actual:   hr.Data.Message.Header.GasUsed,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.Timestamp),
+			actual:   hr.Data.Message.Header.Timestamp,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ExtraData),
+			actual:   hr.Data.Message.Header.ExtraData,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BaseFeePerGas),
+			actual:   hr.Data.Message.Header.BaseFeePerGas,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.BlockHash),
+			actual:   hr.Data.Message.Header.BlockHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockHash",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.TransactionsRoot),
+			actual:   hr.Data.Message.Header.TransactionsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.TransactionsRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.WithdrawalsRoot),
+			actual:   hr.Data.Message.Header.WithdrawalsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.WithdrawalsRoot",
 		},
 	}
@@ -867,88 +867,6 @@ var testExampleExecutionPayloadDenebDifferentProofCount = fmt.Sprintf(`{
  }
 }`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))

-func TestExecutionPayloadResponseUnmarshal(t *testing.T) {
-	epr := &ExecPayloadResponse{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
-	cases := []struct {
-		expected string
-		actual   string
-		name     string
-	}{
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ParentHash),
-			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
-		},
-		{
-			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.FeeRecipient),
-			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.StateRoot),
-			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ReceiptsRoot),
-			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
-		},
-		{
-			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.LogsBloom),
-			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.PrevRandao),
-			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.BlockNumber),
-			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasLimit),
-			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasUsed),
-			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.Timestamp),
-			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExtraData),
-			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
-		},
-		{
-			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.BaseFeePerGas),
-			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.BlockHash),
-			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
-		},
-	}
-	for _, c := range cases {
-		require.Equal(t, c.expected, c.actual, fmt.Sprintf("unexpected value for field %s", c.name))
-	}
-	require.Equal(t, 1, len(epr.Data.Transactions))
-	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.Transactions[0]))
-}
-
 func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	epr := &ExecPayloadResponseCapella{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadCapella), epr))
@@ -959,67 +877,67 @@ func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	}{
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ParentHash),
+			actual:   epr.Data.ParentHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.FeeRecipient),
+			actual:   epr.Data.FeeRecipient,
 			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.StateRoot),
+			actual:   epr.Data.StateRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ReceiptsRoot),
+			actual:   epr.Data.ReceiptsRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.LogsBloom),
+			actual:   epr.Data.LogsBloom,
 			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.PrevRandao),
+			actual:   epr.Data.PrevRandao,
 			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.BlockNumber),
+			actual:   epr.Data.BlockNumber,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasLimit),
+			actual:   epr.Data.GasLimit,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasUsed),
+			actual:   epr.Data.GasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.Timestamp),
+			actual:   epr.Data.Timestamp,
 			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExtraData),
+			actual:   epr.Data.ExtraData,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.BaseFeePerGas),
+			actual:   epr.Data.BaseFeePerGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.BlockHash),
+			actual:   epr.Data.BlockHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
 		},
 	}
@@ -1028,14 +946,14 @@ func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	}
 	require.Equal(t, 1, len(epr.Data.Transactions))
 	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.Transactions[0]))
+	require.Equal(t, txHash, epr.Data.Transactions[0])

 	require.Equal(t, 1, len(epr.Data.Withdrawals))
 	w := epr.Data.Withdrawals[0]
-	assert.Equal(t, uint64(1), w.Index.Uint64())
-	assert.Equal(t, uint64(1), w.ValidatorIndex.Uint64())
-	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.Address.String())
-	assert.Equal(t, uint64(1), w.Amount.Uint64())
+	assert.Equal(t, "1", w.WithdrawalIndex)
+	assert.Equal(t, "1", w.ValidatorIndex)
+	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.ExecutionAddress)
+	assert.Equal(t, "1", w.Amount)
 }

 func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
@@ -1048,77 +966,77 @@ func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
 	}{
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ParentHash),
+			actual:   epr.Data.ExecutionPayload.ParentHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.FeeRecipient),
+			actual:   epr.Data.ExecutionPayload.FeeRecipient,
 			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.StateRoot),
+			actual:   epr.Data.ExecutionPayload.StateRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ReceiptsRoot),
+			actual:   epr.Data.ExecutionPayload.ReceiptsRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.LogsBloom),
+			actual:   epr.Data.ExecutionPayload.LogsBloom,
 			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.PrevRandao),
+			actual:   epr.Data.ExecutionPayload.PrevRandao,
 			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BlockNumber),
+			actual:   epr.Data.ExecutionPayload.BlockNumber,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasLimit),
+			actual:   epr.Data.ExecutionPayload.GasLimit,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasUsed),
+			actual:   epr.Data.ExecutionPayload.GasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.Timestamp),
+			actual:   epr.Data.ExecutionPayload.Timestamp,
 			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ExtraData),
+			actual:   epr.Data.ExecutionPayload.ExtraData,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BaseFeePerGas),
+			actual:   epr.Data.ExecutionPayload.BaseFeePerGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.BlockHash),
+			actual:   epr.Data.ExecutionPayload.BlockHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
 		},
 		{
 			expected: "2",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BlobGasUsed),
+			actual:   epr.Data.ExecutionPayload.BlobGasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlobGasUsed",
 		},
 		{
 			expected: "3",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.ExcessBlobGas),
+			actual:   epr.Data.ExecutionPayload.ExcessBlobGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExcessBlobGas",
 		},
 	}
@@ -1127,64 +1045,16 @@ func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
 	}
 	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Transactions))
 	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.ExecutionPayload.Transactions[0]))
+	require.Equal(t, txHash, epr.Data.ExecutionPayload.Transactions[0])

 	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Withdrawals))
 	w := epr.Data.ExecutionPayload.Withdrawals[0]
-	assert.Equal(t, uint64(1), w.Index.Uint64())
-	assert.Equal(t, uint64(1), w.ValidatorIndex.Uint64())
-	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.Address.String())
-	assert.Equal(t, uint64(1), w.Amount.Uint64())
-	assert.Equal(t, uint64(2), uint64(epr.Data.ExecutionPayload.BlobGasUsed))
-	assert.Equal(t, uint64(3), uint64(epr.Data.ExecutionPayload.ExcessBlobGas))
-}
-
-func TestExecutionPayloadResponseToProto(t *testing.T) {
-	hr := &ExecPayloadResponse{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), hr))
-	p, err := hr.ToProto()
-	require.NoError(t, err)
-
-	parentHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	feeRecipient, err := hexutil.Decode("0xabcf8e0d4e9587369b2301d0790347320302cc09")
-	require.NoError(t, err)
-	stateRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	receiptsRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	logsBloom, err := hexutil.Decode("0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")
-	require.NoError(t, err)
-	prevRandao, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	extraData, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	blockHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-
-	tx, err := hexutil.Decode("0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86")
-	require.NoError(t, err)
-	txList := [][]byte{tx}
-
-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
-	expected := &v1.ExecutionPayload{
-		ParentHash:    parentHash,
-		FeeRecipient:  feeRecipient,
-		StateRoot:     stateRoot,
-		ReceiptsRoot:  receiptsRoot,
-		LogsBloom:     logsBloom,
-		PrevRandao:    prevRandao,
-		BlockNumber:   1,
-		GasLimit:      1,
-		GasUsed:       1,
-		Timestamp:     1,
-		ExtraData:     extraData,
-		BaseFeePerGas: bfpg.SSZBytes(),
-		BlockHash:     blockHash,
-		Transactions:  txList,
-	}
-	require.DeepEqual(t, expected, p)
+	assert.Equal(t, "1", w.WithdrawalIndex)
+	assert.Equal(t, "1", w.ValidatorIndex)
+	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.ExecutionAddress)
+	assert.Equal(t, "1", w.Amount)
+	assert.Equal(t, "2", epr.Data.ExecutionPayload.BlobGasUsed)
+	assert.Equal(t, "3", epr.Data.ExecutionPayload.ExcessBlobGas)
 }

 func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {
@@ -1352,16 +1222,6 @@ func pbEth1Data() *eth.Eth1Data {
 	}
 }

-func TestEth1DataMarshal(t *testing.T) {
-	ed := &Eth1Data{
-		Eth1Data: pbEth1Data(),
-	}
-	b, err := json.Marshal(ed)
-	require.NoError(t, err)
-	expected := `{"deposit_root":"0x0000000000000000000000000000000000000000000000000000000000000000","deposit_count":"23","block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbSyncAggregate() *eth.SyncAggregate {
 	return &eth.SyncAggregate{
 		SyncCommitteeSignature: make([]byte, 48),
@@ -1369,14 +1229,6 @@ func pbSyncAggregate() *eth.SyncAggregate {
 	}
 }

-func TestSyncAggregate_MarshalJSON(t *testing.T) {
-	sa := &SyncAggregate{pbSyncAggregate()}
-	b, err := json.Marshal(sa)
-	require.NoError(t, err)
-	expected := `{"sync_committee_bits":"0x01","sync_committee_signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbDeposit(t *testing.T) *eth.Deposit {
 	return &eth.Deposit{
 		Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
@@ -1389,16 +1241,6 @@ func pbDeposit(t *testing.T) *eth.Deposit {
 	}
 }

-func TestDeposit_MarshalJSON(t *testing.T) {
-	d := &Deposit{
-		Deposit: pbDeposit(t),
-	}
-	b, err := json.Marshal(d)
-	require.NoError(t, err)
-	expected := `{"proof":["0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"],"data":{"pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a","withdrawal_credentials":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","amount":"1","signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbSignedVoluntaryExit(t *testing.T) *eth.SignedVoluntaryExit {
 	return &eth.SignedVoluntaryExit{
 		Exit: &eth.VoluntaryExit{
@@ -1409,16 +1251,6 @@ func pbSignedVoluntaryExit(t *testing.T) *eth.SignedVoluntaryExit {
 	}
 }

-func TestVoluntaryExit(t *testing.T) {
-	ve := &SignedVoluntaryExit{
-		SignedVoluntaryExit: pbSignedVoluntaryExit(t),
-	}
-	b, err := json.Marshal(ve)
-	require.NoError(t, err)
-	expected := `{"message":{"epoch":"1","validator_index":"1"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbAttestation(t *testing.T) *eth.Attestation {
 	return &eth.Attestation{
 		AggregationBits: bitfield.Bitlist{0x01},
@@ -1439,16 +1271,6 @@ func pbAttestation(t *testing.T) *eth.Attestation {
 	}
 }

-func TestAttestationMarshal(t *testing.T) {
-	a := &Attestation{
-		Attestation: pbAttestation(t),
-	}
-	b, err := json.Marshal(a)
-	require.NoError(t, err)
-	expected := `{"aggregation_bits":"0x01","data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbAttesterSlashing(t *testing.T) *eth.AttesterSlashing {
 	return &eth.AttesterSlashing{
 		Attestation_1: &eth.IndexedAttestation{
@@ -1489,9 +1311,7 @@ func pbAttesterSlashing(t *testing.T) *eth.AttesterSlashing {
 }

 func TestAttesterSlashing_MarshalJSON(t *testing.T) {
-	as := &AttesterSlashing{
-		AttesterSlashing: pbAttesterSlashing(t),
-	}
+	as := structs.AttesterSlashingFromConsensus(pbAttesterSlashing(t))
 	b, err := json.Marshal(as)
 	require.NoError(t, err)
 	expected := `{"attestation_1":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"},"attestation_2":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
@@ -1599,9 +1419,8 @@ func pbExecutionPayloadHeaderDeneb(t *testing.T) *v1.ExecutionPayloadHeaderDeneb
 }

 func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeader{
-		ExecutionPayloadHeader: pbExecutionPayloadHeader(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderFromConsensus(pbExecutionPayloadHeader(t))
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}`
@@ -1609,9 +1428,9 @@ func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
 }

 func TestExecutionPayloadHeaderCapella_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeaderCapella{
-		ExecutionPayloadHeaderCapella: pbExecutionPayloadHeaderCapella(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderCapellaFromConsensus(pbExecutionPayloadHeaderCapella(t))
+	require.NoError(t, err)
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","withdrawals_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}`
@@ -1619,9 +1438,8 @@ func TestExecutionPayloadHeaderCapella_MarshalJSON(t *testing.T) {
 }

 func TestExecutionPayloadHeaderDeneb_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeaderDeneb{
-		ExecutionPayloadHeaderDeneb: pbExecutionPayloadHeaderDeneb(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderDenebFromConsensus(pbExecutionPayloadHeaderDeneb(t))
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","withdrawals_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","blob_gas_used":"1","excess_blob_gas":"2"}`
@@ -1850,12 +1668,13 @@ func TestRoundTripUint256(t *testing.T) {
 func TestRoundTripProtoUint256(t *testing.T) {
 	h := pbExecutionPayloadHeader(t)
 	h.BaseFeePerGas = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}
-	hm := &ExecutionPayloadHeader{ExecutionPayloadHeader: h}
+	hm, err := structs.ExecutionPayloadHeaderFromConsensus(h)
+	require.NoError(t, err)
 	m, err := json.Marshal(hm)
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeader{}
+	hu := &structs.ExecutionPayloadHeader{}
 	require.NoError(t, json.Unmarshal(m, hu))
-	hp, err := hu.ToProto()
+	hp, err := hu.ToConsensus()
 	require.NoError(t, err)
 	require.DeepEqual(t, h.BaseFeePerGas, hp.BaseFeePerGas)
 }
@@ -1863,7 +1682,7 @@ func TestRoundTripProtoUint256(t *testing.T) {
 func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
 	expected, err := os.ReadFile("testdata/execution-payload.json")
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeader{}
+	hu := &structs.ExecutionPayloadHeader{}
 	require.NoError(t, json.Unmarshal(expected, hu))
 	m, err := json.Marshal(hu)
 	require.NoError(t, err)
@@ -1873,14 +1692,14 @@ func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
 func TestExecutionPayloadHeaderCapellaRoundtrip(t *testing.T) {
 	expected, err := os.ReadFile("testdata/execution-payload-capella.json")
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeaderCapella{}
+	hu := &structs.ExecutionPayloadHeaderCapella{}
 	require.NoError(t, json.Unmarshal(expected, hu))
 	m, err := json.Marshal(hu)
 	require.NoError(t, err)
 	require.DeepEqual(t, string(expected[0:len(expected)-1]), string(m))
 }

-func TestErrorMessage_non200Err(t *testing.T) {
+func TestErrorMessage_unexpectedStatusErr(t *testing.T) {
 	mockRequest := &http.Request{
 		URL: &url.URL{Path: "example.com"},
 	}
@@ -1960,7 +1779,7 @@ func TestErrorMessage_non200Err(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			err := non200Err(tt.args)
+			err := unexpectedStatusErr(tt.args, http.StatusOK)
 			if err != nil && tt.wantMessage != "" {
 				require.ErrorContains(t, tt.wantMessage, err)
 			}
@@ -1994,11 +1813,9 @@ func TestEmptyResponseBody(t *testing.T) {
 			epr := &ExecutionPayloadResponse{}
 			require.NoError(t, json.Unmarshal(encoded, epr))
 			pp, err := epr.ParsePayload()
-			require.NoError(t, err)
-			pb, err := pp.PayloadProto()
 			if err == nil {
 				require.NoError(t, err)
-				require.Equal(t, false, pb == nil)
+				require.Equal(t, false, pp == nil)
 			} else {
 				require.ErrorIs(t, err, consensusblocks.ErrNilObject)
 			}
--- a/api/client/event/event_stream.go
+++ b/api/client/event/event_stream.go
@@ -14,22 +14,10 @@ import (
 )

 const (
-	EventHead                        = "head"
-	EventBlock                       = "block"
-	EventAttestation                 = "attestation"
-	EventVoluntaryExit               = "voluntary_exit"
-	EventBlsToExecutionChange        = "bls_to_execution_change"
-	EventProposerSlashing            = "proposer_slashing"
-	EventAttesterSlashing            = "attester_slashing"
-	EventFinalizedCheckpoint         = "finalized_checkpoint"
-	EventChainReorg                  = "chain_reorg"
-	EventContributionAndProof        = "contribution_and_proof"
-	EventLightClientFinalityUpdate   = "light_client_finality_update"
-	EventLightClientOptimisticUpdate = "light_client_optimistic_update"
-	EventPayloadAttributes           = "payload_attributes"
-	EventBlobSidecar                 = "blob_sidecar"
-	EventError                       = "error"
-	EventConnectionError             = "connection_error"
+	EventHead = "head"
+
+	EventError           = "error"
+	EventConnectionError = "connection_error"
 )

 var (
--- a/api/client/event/event_stream_test.go
+++ b/api/client/event/event_stream_test.go
@@ -1,7 +1,6 @@
 package event

 import (
-	"context"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
@@ -30,7 +29,7 @@ func TestNewEventStream(t *testing.T) {

 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			_, err := NewEventStream(context.Background(), &http.Client{}, tt.host, tt.topics)
+			_, err := NewEventStream(t.Context(), &http.Client{}, tt.host, tt.topics)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("NewEventStream() error = %v, wantErr %v", err, tt.wantErr)
 			}
@@ -56,7 +55,7 @@ func TestEventStream(t *testing.T) {

 	topics := []string{"head"}
 	eventsChannel := make(chan *Event, 1)
-	stream, err := NewEventStream(context.Background(), http.DefaultClient, server.URL, topics)
+	stream, err := NewEventStream(t.Context(), http.DefaultClient, server.URL, topics)
 	require.NoError(t, err)
 	go stream.Subscribe(eventsChannel)

@@ -83,8 +82,7 @@ func TestEventStream(t *testing.T) {
 func TestEventStreamRequestError(t *testing.T) {
 	topics := []string{"head"}
 	eventsChannel := make(chan *Event, 1)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()

 	// use valid url that will result in failed request with nil body
 	stream, err := NewEventStream(ctx, http.DefaultClient, "http://badhost:1234", topics)
--- a/api/grpc/grpcutils_test.go
+++ b/api/grpc/grpcutils_test.go
@@ -1,7 +1,6 @@
 package grpc

 import (
-	"context"
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -16,7 +15,7 @@ type customErrorData struct {

 func TestAppendHeaders(t *testing.T) {
 	t.Run("one_header", func(t *testing.T) {
-		ctx := AppendHeaders(context.Background(), []string{"first=value1"})
+		ctx := AppendHeaders(t.Context(), []string{"first=value1"})
 		md, ok := metadata.FromOutgoingContext(ctx)
 		require.Equal(t, true, ok, "Failed to read context metadata")
 		require.Equal(t, 1, md.Len(), "MetadataV0 contains wrong number of values")
@@ -24,7 +23,7 @@ func TestAppendHeaders(t *testing.T) {
 	})

 	t.Run("multiple_headers", func(t *testing.T) {
-		ctx := AppendHeaders(context.Background(), []string{"first=value1", "second=value2"})
+		ctx := AppendHeaders(t.Context(), []string{"first=value1", "second=value2"})
 		md, ok := metadata.FromOutgoingContext(ctx)
 		require.Equal(t, true, ok, "Failed to read context metadata")
 		require.Equal(t, 2, md.Len(), "MetadataV0 contains wrong number of values")
@@ -33,7 +32,7 @@ func TestAppendHeaders(t *testing.T) {
 	})

 	t.Run("one_empty_header", func(t *testing.T) {
-		ctx := AppendHeaders(context.Background(), []string{"first=value1", ""})
+		ctx := AppendHeaders(t.Context(), []string{"first=value1", ""})
 		md, ok := metadata.FromOutgoingContext(ctx)
 		require.Equal(t, true, ok, "Failed to read context metadata")
 		require.Equal(t, 1, md.Len(), "MetadataV0 contains wrong number of values")
@@ -42,7 +41,7 @@ func TestAppendHeaders(t *testing.T) {

 	t.Run("incorrect_header", func(t *testing.T) {
 		logHook := logTest.NewGlobal()
-		ctx := AppendHeaders(context.Background(), []string{"first=value1", "second"})
+		ctx := AppendHeaders(t.Context(), []string{"first=value1", "second"})
 		md, ok := metadata.FromOutgoingContext(ctx)
 		require.Equal(t, true, ok, "Failed to read context metadata")
 		require.Equal(t, 1, md.Len(), "MetadataV0 contains wrong number of values")
@@ -51,7 +50,7 @@ func TestAppendHeaders(t *testing.T) {
 	})

 	t.Run("header_value_with_equal_sign", func(t *testing.T) {
-		ctx := AppendHeaders(context.Background(), []string{"first=value=1"})
+		ctx := AppendHeaders(t.Context(), []string{"first=value=1"})
 		md, ok := metadata.FromOutgoingContext(ctx)
 		require.Equal(t, true, ok, "Failed to read context metadata")
 		require.Equal(t, 1, md.Len(), "MetadataV0 contains wrong number of values")
--- a/api/server/httprest/options.go
+++ b/api/server/httprest/options.go
@@ -1,9 +1,8 @@
 package httprest

 import (
-	"time"
-
 	"net/http"
+	"time"

 	"github.com/OffchainLabs/prysm/v6/api/server/middleware"
 )
--- a/api/server/httprest/server_test.go
+++ b/api/server/httprest/server_test.go
@@ -1,7 +1,6 @@
 package httprest

 import (
-	"context"
 	"flag"
 	"fmt"
 	"net"
@@ -34,7 +33,7 @@ func TestServer_StartStop(t *testing.T) {
 		WithRouter(handler),
 	}

-	g, err := New(context.Background(), opts...)
+	g, err := New(t.Context(), opts...)
 	require.NoError(t, err)

 	g.Start()
@@ -62,7 +61,7 @@ func TestServer_NilHandler_NotFoundHandlerRegistered(t *testing.T) {
 		WithRouter(handler),
 	}

-	g, err := New(context.Background(), opts...)
+	g, err := New(t.Context(), opts...)
 	require.NoError(t, err)

 	writer := httptest.NewRecorder()
--- a/api/server/middleware/BUILD.bazel
+++ b/api/server/middleware/BUILD.bazel
@@ -8,7 +8,12 @@ go_library(
    ],
    importpath = "github.com/OffchainLabs/prysm/v6/api/server/middleware",
    visibility = ["//visibility:public"],
-    deps = ["@com_github_rs_cors//:go_default_library"],
+    deps = [
+        "//api:go_default_library",
+        "//api/apiutil:go_default_library",
+        "@com_github_rs_cors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
 )

 go_test(
@@ -22,5 +27,6 @@ go_test(
        "//api:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
    ],
 )
--- a/api/server/middleware/middleware.go
+++ b/api/server/middleware/middleware.go
@@ -1,11 +1,15 @@
 package middleware

 import (
+	"compress/gzip"
 	"fmt"
 	"net/http"
 	"strings"

+	"github.com/OffchainLabs/prysm/v6/api"
+	"github.com/OffchainLabs/prysm/v6/api/apiutil"
 	"github.com/rs/cors"
+	log "github.com/sirupsen/logrus"
 )

 type Middleware func(http.Handler) http.Handler
@@ -71,47 +75,64 @@ func ContentTypeHandler(acceptedMediaTypes []string) Middleware {
 func AcceptHeaderHandler(serverAcceptedTypes []string) Middleware {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			acceptHeader := r.Header.Get("Accept")
-			// header is optional and should skip if not provided
-			if acceptHeader == "" {
+			if _, ok := apiutil.Negotiate(r.Header.Get("Accept"), serverAcceptedTypes); !ok {
+				http.Error(w, "Not Acceptable", http.StatusNotAcceptable)
+				return
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// AcceptEncodingHeaderHandler compresses the response before sending it back to the client, if gzip is supported.
+func AcceptEncodingHeaderHandler() Middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 				next.ServeHTTP(w, r)
 				return
 			}

-			accepted := false
-			acceptTypes := strings.Split(acceptHeader, ",")
-			// follows rules defined in https://datatracker.ietf.org/doc/html/rfc2616#section-14.1
-			for _, acceptType := range acceptTypes {
-				acceptType = strings.TrimSpace(acceptType)
-				if acceptType == "*/*" {
-					accepted = true
-					break
+			gz := gzip.NewWriter(w)
+			gzipRW := &gzipResponseWriter{gz: gz, ResponseWriter: w}
+			defer func() {
+				if !gzipRW.zip {
+					return
 				}
-				for _, serverAcceptedType := range serverAcceptedTypes {
-					if strings.HasPrefix(acceptType, serverAcceptedType) {
-						accepted = true
-						break
-					}
-					if acceptType != "/*" && strings.HasSuffix(acceptType, "/*") && strings.HasPrefix(serverAcceptedType, acceptType[:len(acceptType)-2]) {
-						accepted = true
-						break
-					}
+				if err := gz.Close(); err != nil {
+					log.WithError(err).Error("Failed to close gzip writer")
 				}
-				if accepted {
-					break
-				}
-			}
+			}()

-			if !accepted {
-				http.Error(w, fmt.Sprintf("Not Acceptable: %s", acceptHeader), http.StatusNotAcceptable)
-				return
-			}
-
-			next.ServeHTTP(w, r)
+			next.ServeHTTP(gzipRW, r)
 		})
 	}
 }

+type gzipResponseWriter struct {
+	gz *gzip.Writer
+	http.ResponseWriter
+	zip bool
+}
+
+func (g *gzipResponseWriter) WriteHeader(statusCode int) {
+	if strings.Contains(g.Header().Get("Content-Type"), api.JsonMediaType) {
+		// Removing the current Content-Length because zipping will change it.
+		g.Header().Del("Content-Length")
+		g.Header().Set("Content-Encoding", "gzip")
+		g.zip = true
+	}
+
+	g.ResponseWriter.WriteHeader(statusCode)
+}
+
+func (g *gzipResponseWriter) Write(b []byte) (int, error) {
+	if g.zip {
+		return g.gz.Write(b)
+	}
+	return g.ResponseWriter.Write(b)
+}
+
 func MiddlewareChain(h http.Handler, mw []Middleware) http.Handler {
 	if len(mw) < 1 {
 		return h
--- a/api/server/middleware/middleware_test.go
+++ b/api/server/middleware/middleware_test.go
@@ -1,14 +1,35 @@
 package middleware

 import (
+	"bytes"
+	"compress/gzip"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	log "github.com/sirupsen/logrus"
 )

+// frozenHeaderRecorder allows asserting that response headers were not modified
+// after the call to WriteHeader.
+//
+// Its purpose is to have a regression test for https://github.com/OffchainLabs/prysm/pull/15499.
+type frozenHeaderRecorder struct {
+	*httptest.ResponseRecorder
+	frozenHeader http.Header
+}
+
+func (r *frozenHeaderRecorder) WriteHeader(code int) {
+	if r.frozenHeader != nil {
+		return
+	}
+	r.ResponseRecorder.WriteHeader(code)
+	r.frozenHeader = r.ResponseRecorder.Header().Clone()
+}
+
 func TestNormalizeQueryValuesHandler(t *testing.T) {
 	nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		_, err := w.Write([]byte("next handler"))
@@ -124,6 +145,90 @@ func TestContentTypeHandler(t *testing.T) {
 	}
 }

+func TestAcceptEncodingHeaderHandler(t *testing.T) {
+	dummyContent := "Test gzip middleware content"
+	nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", r.Header.Get("Accept"))
+		w.WriteHeader(http.StatusOK)
+		_, err := w.Write([]byte(dummyContent))
+		require.NoError(t, err)
+	})
+
+	handler := AcceptEncodingHeaderHandler()(nextHandler)
+
+	tests := []struct {
+		name             string
+		accept           string
+		acceptEncoding   string
+		expectCompressed bool
+	}{
+		{
+			name:             "Accept gzip",
+			accept:           api.JsonMediaType,
+			acceptEncoding:   "gzip",
+			expectCompressed: true,
+		},
+		{
+			name:             "Accept multiple encodings",
+			accept:           api.JsonMediaType,
+			acceptEncoding:   "deflate, gzip",
+			expectCompressed: true,
+		},
+		{
+			name:             "Accept unsupported encoding",
+			accept:           api.JsonMediaType,
+			acceptEncoding:   "deflate",
+			expectCompressed: false,
+		},
+		{
+			name:             "No accept encoding header",
+			accept:           api.JsonMediaType,
+			acceptEncoding:   "",
+			expectCompressed: false,
+		},
+		{
+			name:             "SSZ",
+			accept:           api.OctetStreamMediaType,
+			acceptEncoding:   "gzip",
+			expectCompressed: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest("GET", "/", nil)
+			req.Header.Set("Accept", tt.accept)
+			if tt.acceptEncoding != "" {
+				req.Header.Set("Accept-Encoding", tt.acceptEncoding)
+			}
+			rr := &frozenHeaderRecorder{ResponseRecorder: httptest.NewRecorder()}
+
+			handler.ServeHTTP(rr, req)
+
+			if tt.expectCompressed {
+				require.Equal(t, "gzip", rr.frozenHeader.Get("Content-Encoding"), "Expected Content-Encoding header to be 'gzip'")
+
+				compressedBody := rr.Body.Bytes()
+				require.NotEqual(t, dummyContent, string(compressedBody), "Response body should be compressed and differ from the original")
+
+				gzReader, err := gzip.NewReader(bytes.NewReader(compressedBody))
+				require.NoError(t, err, "Failed to create gzipReader")
+				defer func() {
+					if err := gzReader.Close(); err != nil {
+						log.WithError(err).Error("Failed to close gzip reader")
+					}
+				}()
+
+				decompressedBody, err := io.ReadAll(gzReader)
+				require.NoError(t, err, "Failed to decompress response body")
+				require.Equal(t, dummyContent, string(decompressedBody), "Decompressed content should match the original")
+			} else {
+				require.Equal(t, dummyContent, rr.Body.String(), "Response body should be uncompressed and match the original")
+			}
+		})
+	}
+}
+
 func TestAcceptHeaderHandler(t *testing.T) {
 	acceptedTypes := []string{"application/json", "application/octet-stream"}

--- a/api/server/structs/BUILD.bazel
+++ b/api/server/structs/BUILD.bazel
@@ -31,10 +31,12 @@ go_library(
        "//beacon-chain/state:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//consensus-types/validator:go_default_library",
        "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//proto/engine/v1:go_default_library",
@@ -44,6 +46,7 @@ go_library(
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
    ],
 )

@@ -57,6 +60,7 @@ go_test(
    deps = [
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
--- a/api/server/structs/conversions.go
+++ b/api/server/structs/conversions.go
@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/validator"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -699,6 +700,11 @@ func (m *SyncCommitteeMessage) ToConsensus() (*eth.SyncCommitteeMessage, error)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Signature")
 	}
+	// Add validation to check if the signature is valid BLS format
+	_, err = bls.SignatureFromBytes(sig)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}

 	return &eth.SyncCommitteeMessage{
 		Slot:           primitives.Slot(slot),
--- a/api/server/structs/conversions_block_execution.go
+++ b/api/server/structs/conversions_block_execution.go
@@ -7,12 +7,15 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	consensusblocks "github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
+	"google.golang.org/protobuf/proto"
 )

 // ----------------------------------------------------------------------------
@@ -132,6 +135,13 @@ func (e *ExecutionPayload) ToConsensus() (*enginev1.ExecutionPayload, error) {
 	}, nil
 }

+func (r *ExecutionPayload) PayloadProto() (proto.Message, error) {
+	if r == nil {
+		return nil, errors.Wrap(consensusblocks.ErrNilObject, "nil execution payload")
+	}
+	return r.ToConsensus()
+}
+
 func ExecutionPayloadHeaderFromConsensus(payload *enginev1.ExecutionPayloadHeader) (*ExecutionPayloadHeader, error) {
 	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
 	if err != nil {
@@ -383,6 +393,13 @@ func (e *ExecutionPayloadCapella) ToConsensus() (*enginev1.ExecutionPayloadCapel
 	}, nil
 }

+func (p *ExecutionPayloadCapella) PayloadProto() (proto.Message, error) {
+	if p == nil {
+		return nil, errors.Wrap(consensusblocks.ErrNilObject, "nil capella execution payload")
+	}
+	return p.ToConsensus()
+}
+
 func ExecutionPayloadHeaderCapellaFromConsensus(payload *enginev1.ExecutionPayloadHeaderCapella) (*ExecutionPayloadHeaderCapella, error) {
 	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
 	if err != nil {
--- a/api/server/structs/conversions_state.go
+++ b/api/server/structs/conversions_state.go
@@ -26,10 +26,7 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -77,7 +74,7 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	}

 	return &BeaconState{
-		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                        fmt.Sprintf("%d", st.Slot()),
 		Fork:                        ForkFromConsensus(st.Fork()),
@@ -116,10 +113,7 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -183,7 +177,7 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	}

 	return &BeaconStateAltair{
-		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                        fmt.Sprintf("%d", st.Slot()),
 		Fork:                        ForkFromConsensus(st.Fork()),
@@ -225,10 +219,7 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -304,7 +295,7 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	}

 	return &BeaconStateBellatrix{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                         fmt.Sprintf("%d", st.Slot()),
 		Fork:                         ForkFromConsensus(st.Fork()),
@@ -347,10 +338,7 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -442,7 +430,7 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	}

 	return &BeaconStateCapella{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                         fmt.Sprintf("%d", st.Slot()),
 		Fork:                         ForkFromConsensus(st.Fork()),
@@ -488,10 +476,7 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -583,7 +568,7 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	}

 	return &BeaconStateDeneb{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                         fmt.Sprintf("%d", st.Slot()),
 		Fork:                         ForkFromConsensus(st.Fork()),
@@ -629,10 +614,7 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -760,7 +742,7 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 	}

 	return &BeaconStateElectra{
-		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:         hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                          fmt.Sprintf("%d", st.Slot()),
 		Fork:                          ForkFromConsensus(st.Fork()),
@@ -815,10 +797,7 @@ func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu,
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -944,9 +923,16 @@ func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu,
 	if err != nil {
 		return nil, err
 	}
-
+	srcLookahead, err := st.ProposerLookahead()
+	if err != nil {
+		return nil, err
+	}
+	lookahead := make([]string, len(srcLookahead))
+	for i, v := range srcLookahead {
+		lookahead[i] = fmt.Sprintf("%d", uint64(v))
+	}
 	return &BeaconStateFulu{
-		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime().Unix()),
 		GenesisValidatorsRoot:         hexutil.Encode(st.GenesisValidatorsRoot()),
 		Slot:                          fmt.Sprintf("%d", st.Slot()),
 		Fork:                          ForkFromConsensus(st.Fork()),
@@ -983,5 +969,6 @@ func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu,
 		PendingDeposits:               PendingDepositsFromConsensus(pbd),
 		PendingPartialWithdrawals:     PendingPartialWithdrawalsFromConsensus(ppw),
 		PendingConsolidations:         PendingConsolidationsFromConsensus(pc),
+		ProposerLookahead:             lookahead,
 	}, nil
 }
--- a/api/server/structs/conversions_test.go
+++ b/api/server/structs/conversions_test.go
@@ -4,7 +4,9 @@ import (
 	"testing"

 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 )

 func TestDepositSnapshotFromConsensus(t *testing.T) {
@@ -102,12 +104,266 @@ func TestProposerSlashing_ToConsensus(t *testing.T) {
 	require.ErrorContains(t, errNilValue.Error(), err)
 }

+func TestProposerSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.ProposerSlashing{
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          1,
+					ProposerIndex: 2,
+					ParentRoot:    []byte{3},
+					StateRoot:     []byte{4},
+					BodyRoot:      []byte{5},
+				},
+				Signature: []byte{6},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          7,
+					ProposerIndex: 8,
+					ParentRoot:    []byte{9},
+					StateRoot:     []byte{10},
+					BodyRoot:      []byte{11},
+				},
+				Signature: []byte{12},
+			},
+		},
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          13,
+					ProposerIndex: 14,
+					ParentRoot:    []byte{15},
+					StateRoot:     []byte{16},
+					BodyRoot:      []byte{17},
+				},
+				Signature: []byte{18},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          19,
+					ProposerIndex: 20,
+					ParentRoot:    []byte{21},
+					StateRoot:     []byte{22},
+					BodyRoot:      []byte{23},
+				},
+				Signature: []byte{24},
+			},
+		},
+	}
+
+	expectedResult := []*ProposerSlashing{
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "1",
+					ProposerIndex: "2",
+					ParentRoot:    hexutil.Encode([]byte{3}),
+					StateRoot:     hexutil.Encode([]byte{4}),
+					BodyRoot:      hexutil.Encode([]byte{5}),
+				},
+				Signature: hexutil.Encode([]byte{6}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "7",
+					ProposerIndex: "8",
+					ParentRoot:    hexutil.Encode([]byte{9}),
+					StateRoot:     hexutil.Encode([]byte{10}),
+					BodyRoot:      hexutil.Encode([]byte{11}),
+				},
+				Signature: hexutil.Encode([]byte{12}),
+			},
+		},
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "13",
+					ProposerIndex: "14",
+					ParentRoot:    hexutil.Encode([]byte{15}),
+					StateRoot:     hexutil.Encode([]byte{16}),
+					BodyRoot:      hexutil.Encode([]byte{17}),
+				},
+				Signature: hexutil.Encode([]byte{18}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "19",
+					ProposerIndex: "20",
+					ParentRoot:    hexutil.Encode([]byte{21}),
+					StateRoot:     hexutil.Encode([]byte{22}),
+					BodyRoot:      hexutil.Encode([]byte{23}),
+				},
+				Signature: hexutil.Encode([]byte{24}),
+			},
+		},
+	}
+
+	result := ProposerSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestAttesterSlashing_ToConsensus(t *testing.T) {
 	a := &AttesterSlashing{Attestation1: nil, Attestation2: nil}
 	_, err := a.ToConsensus()
 	require.ErrorContains(t, errNilValue.Error(), err)
 }

+func TestAttesterSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.AttesterSlashing{
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{1, 2},
+				Data: &eth.AttestationData{
+					Slot:            3,
+					CommitteeIndex:  4,
+					BeaconBlockRoot: []byte{5},
+					Source: &eth.Checkpoint{
+						Epoch: 6,
+						Root:  []byte{7},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 8,
+						Root:  []byte{9},
+					},
+				},
+				Signature: []byte{10},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{11, 12},
+				Data: &eth.AttestationData{
+					Slot:            13,
+					CommitteeIndex:  14,
+					BeaconBlockRoot: []byte{15},
+					Source: &eth.Checkpoint{
+						Epoch: 16,
+						Root:  []byte{17},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 18,
+						Root:  []byte{19},
+					},
+				},
+				Signature: []byte{20},
+			},
+		},
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{21, 22},
+				Data: &eth.AttestationData{
+					Slot:            23,
+					CommitteeIndex:  24,
+					BeaconBlockRoot: []byte{25},
+					Source: &eth.Checkpoint{
+						Epoch: 26,
+						Root:  []byte{27},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 28,
+						Root:  []byte{29},
+					},
+				},
+				Signature: []byte{30},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{31, 32},
+				Data: &eth.AttestationData{
+					Slot:            33,
+					CommitteeIndex:  34,
+					BeaconBlockRoot: []byte{35},
+					Source: &eth.Checkpoint{
+						Epoch: 36,
+						Root:  []byte{37},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 38,
+						Root:  []byte{39},
+					},
+				},
+				Signature: []byte{40},
+			},
+		},
+	}
+
+	expectedResult := []*AttesterSlashing{
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"1", "2"},
+				Data: &AttestationData{
+					Slot:            "3",
+					CommitteeIndex:  "4",
+					BeaconBlockRoot: hexutil.Encode([]byte{5}),
+					Source: &Checkpoint{
+						Epoch: "6",
+						Root:  hexutil.Encode([]byte{7}),
+					},
+					Target: &Checkpoint{
+						Epoch: "8",
+						Root:  hexutil.Encode([]byte{9}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{10}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"11", "12"},
+				Data: &AttestationData{
+					Slot:            "13",
+					CommitteeIndex:  "14",
+					BeaconBlockRoot: hexutil.Encode([]byte{15}),
+					Source: &Checkpoint{
+						Epoch: "16",
+						Root:  hexutil.Encode([]byte{17}),
+					},
+					Target: &Checkpoint{
+						Epoch: "18",
+						Root:  hexutil.Encode([]byte{19}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{20}),
+			},
+		},
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"21", "22"},
+				Data: &AttestationData{
+					Slot:            "23",
+					CommitteeIndex:  "24",
+					BeaconBlockRoot: hexutil.Encode([]byte{25}),
+					Source: &Checkpoint{
+						Epoch: "26",
+						Root:  hexutil.Encode([]byte{27}),
+					},
+					Target: &Checkpoint{
+						Epoch: "28",
+						Root:  hexutil.Encode([]byte{29}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{30}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"31", "32"},
+				Data: &AttestationData{
+					Slot:            "33",
+					CommitteeIndex:  "34",
+					BeaconBlockRoot: hexutil.Encode([]byte{35}),
+					Source: &Checkpoint{
+						Epoch: "36",
+						Root:  hexutil.Encode([]byte{37}),
+					},
+					Target: &Checkpoint{
+						Epoch: "38",
+						Root:  hexutil.Encode([]byte{39}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{40}),
+			},
+		},
+	}
+
+	result := AttesterSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestIndexedAttestation_ToConsensus(t *testing.T) {
 	a := &IndexedAttestation{
 		AttestingIndices: []string{"1"},
--- a/api/server/structs/endpoints_beacon.go
+++ b/api/server/structs/endpoints_beacon.go
@@ -263,6 +263,13 @@ type ChainHead struct {
 	OptimisticStatus           bool   `json:"optimistic_status"`
 }

+type GetPendingConsolidationsResponse struct {
+	Version             string                  `json:"version"`
+	ExecutionOptimistic bool                    `json:"execution_optimistic"`
+	Finalized           bool                    `json:"finalized"`
+	Data                []*PendingConsolidation `json:"data"`
+}
+
 type GetPendingDepositsResponse struct {
 	Version             string            `json:"version"`
 	ExecutionOptimistic bool              `json:"execution_optimistic"`
@@ -276,3 +283,10 @@ type GetPendingPartialWithdrawalsResponse struct {
 	Finalized           bool                        `json:"finalized"`
 	Data                []*PendingPartialWithdrawal `json:"data"`
 }
+
+type GetProposerLookaheadResponse struct {
+	Version             string   `json:"version"`
+	ExecutionOptimistic bool     `json:"execution_optimistic"`
+	Finalized           bool     `json:"finalized"`
+	Data                []string `json:"data"` // validator indexes
+}
--- a/api/server/structs/endpoints_events.go
+++ b/api/server/structs/endpoints_events.go
@@ -25,6 +25,13 @@ type BlockGossipEvent struct {
 	Block string `json:"block"`
 }

+type DataColumnGossipEvent struct {
+	Slot           string   `json:"slot"`
+	Index          string   `json:"index"`
+	BlockRoot      string   `json:"block_root"`
+	KzgCommitments []string `json:"kzg_commitments"`
+}
+
 type AggregatedAttEventSource struct {
 	Aggregate *Attestation `json:"aggregate"`
 }
--- a/api/server/structs/endpoints_node.go
+++ b/api/server/structs/endpoints_node.go
@@ -27,14 +27,22 @@ type Identity struct {
 type Metadata struct {
 	SeqNumber string `json:"seq_number"`
 	Attnets   string `json:"attnets"`
+	Syncnets  string `json:"syncnets,omitempty"`
+	Cgc       string `json:"custody_group_count,omitempty"`
 }

 type GetPeerResponse struct {
 	Data *Peer `json:"data"`
 }

+// Added Meta to align with beacon-api: https://ethereum.github.io/beacon-APIs/#/Node/getPeers
+type Meta struct {
+	Count int `json:"count"`
+}
+
 type GetPeersResponse struct {
 	Data []*Peer `json:"data"`
+	Meta Meta    `json:"meta"`
 }

 type Peer struct {
--- a/api/server/structs/other.go
+++ b/api/server/structs/other.go
@@ -253,7 +253,7 @@ type PendingDeposit struct {
 }

 type PendingPartialWithdrawal struct {
-	Index             string `json:"index"`
+	Index             string `json:"validator_index"`
 	Amount            string `json:"amount"`
 	WithdrawableEpoch string `json:"withdrawable_epoch"`
 }
--- a/api/server/structs/state.go
+++ b/api/server/structs/state.go
@@ -219,4 +219,5 @@ type BeaconStateFulu struct {
 	PendingDeposits               []*PendingDeposit            `json:"pending_deposits"`
 	PendingPartialWithdrawals     []*PendingPartialWithdrawal  `json:"pending_partial_withdrawals"`
 	PendingConsolidations         []*PendingConsolidation      `json:"pending_consolidations"`
+	ProposerLookahead             []string                     `json:"proposer_lookahead"`
 }
--- a/async/debounce_test.go
+++ b/async/debounce_test.go
@@ -15,7 +15,7 @@ import (

 func TestDebounce_NoEvents(t *testing.T) {
 	eventsChan := make(chan interface{}, 100)
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
 	wg := &sync.WaitGroup{}
@@ -39,7 +39,7 @@ func TestDebounce_NoEvents(t *testing.T) {

 func TestDebounce_CtxClosing(t *testing.T) {
 	eventsChan := make(chan interface{}, 100)
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
 	wg := &sync.WaitGroup{}
@@ -75,7 +75,7 @@ func TestDebounce_CtxClosing(t *testing.T) {

 func TestDebounce_SingleHandlerInvocation(t *testing.T) {
 	eventsChan := make(chan interface{}, 100)
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
 	go async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
@@ -93,7 +93,7 @@ func TestDebounce_SingleHandlerInvocation(t *testing.T) {

 func TestDebounce_MultipleHandlerInvocation(t *testing.T) {
 	eventsChan := make(chan interface{}, 100)
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	interval := time.Second
 	timesHandled := int32(0)
 	go async.Debounce(ctx, interval, eventsChan, func(event interface{}) {
--- a/async/every.go
+++ b/async/every.go
@@ -19,10 +19,10 @@ func RunEvery(ctx context.Context, period time.Duration, f func()) {
 		for {
 			select {
 			case <-ticker.C:
-				log.WithField("function", funcName).Trace("running")
+				log.WithField("function", funcName).Trace("Running")
 				f()
 			case <-ctx.Done():
-				log.WithField("function", funcName).Debug("context is closed, exiting")
+				log.WithField("function", funcName).Debug("Context is closed, exiting")
 				ticker.Stop()
 				return
 			}
--- a/async/every_test.go
+++ b/async/every_test.go
@@ -10,7 +10,7 @@ import (
 )

 func TestEveryRuns(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())

 	i := int32(0)
 	async.RunEvery(ctx, 100*time.Millisecond, func() {
--- a/beacon-chain/README.md
+++ b/beacon-chain/README.md
@@ -4,6 +4,6 @@ This is the main project folder for the beacon chain implementation of Ethereum

 You can also read our main [README](https://github.com/prysmaticlabs/prysm/blob/master/README.md) and join our active chat room on Discord.

-[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/CTYGPUJ)
+[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysm)

 Also, read the official beacon chain [specification](https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/beacon-chain.md), this design spec serves as a source of truth for the beacon chain implementation we follow at Prysmatic Labs.
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -25,8 +25,9 @@ go_library(
        "receive_attestation.go",
        "receive_blob.go",
        "receive_block.go",
+        "receive_data_column.go",
        "service.go",
-        "setup_forchoice.go",
+        "setup_forkchoice.go",
        "tracked_proposer.go",
        "weak_subjectivity_checks.go",
    ],
@@ -50,6 +51,7 @@ go_library(
        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/time:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
@@ -71,6 +73,7 @@ go_library(
        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/stategen:go_default_library",
        "//beacon-chain/verification:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
        "//config/features:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
@@ -146,6 +149,7 @@ go_test(
        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
        "//beacon-chain/das:go_default_library",
@@ -163,6 +167,7 @@ go_test(
        "//beacon-chain/operations/slashings:go_default_library",
        "//beacon-chain/operations/voluntaryexits:go_default_library",
        "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
        "//beacon-chain/startup:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
@@ -177,6 +182,7 @@ go_test(
        "//container/trie:go_default_library",
        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
+        "//genesis:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/eth/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
@@ -190,6 +196,7 @@ go_test(
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
        "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -41,7 +41,7 @@ type ForkchoiceFetcher interface {
 	Ancestor(context.Context, []byte, primitives.Slot) ([]byte, error)
 	CachedHeadRoot() [32]byte
 	GetProposerHead() [32]byte
-	SetForkChoiceGenesisTime(uint64)
+	SetForkChoiceGenesisTime(time.Time)
 	UpdateHead(context.Context, primitives.Slot)
 	HighestReceivedBlockSlot() primitives.Slot
 	ReceivedBlocksLastEpoch() (uint64, error)
@@ -514,7 +514,7 @@ func (s *Service) Ancestor(ctx context.Context, root []byte, slot primitives.Slo

 // SetGenesisTime sets the genesis time of beacon chain.
 func (s *Service) SetGenesisTime(t time.Time) {
-	s.genesisTime = t
+	s.genesisTime = t.Truncate(time.Second) // Genesis time has a precision of 1 second.
 }

 func (s *Service) recoverStateSummary(ctx context.Context, blockRoot [32]byte) (*ethpb.StateSummary, error) {
--- a/beacon-chain/blockchain/chain_info_forkchoice.go
+++ b/beacon-chain/blockchain/chain_info_forkchoice.go
@@ -2,6 +2,7 @@ package blockchain

 import (
 	"context"
+	"time"

 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	consensus_blocks "github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -27,7 +28,7 @@ func (s *Service) GetProposerHead() [32]byte {
 }

 // SetForkChoiceGenesisTime sets the genesis time in Forkchoice
-func (s *Service) SetForkChoiceGenesisTime(timestamp uint64) {
+func (s *Service) SetForkChoiceGenesisTime(timestamp time.Time) {
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
 	s.cfg.ForkChoiceStore.SetGenesisTime(timestamp)
--- a/beacon-chain/blockchain/chain_info_norace_test.go
+++ b/beacon-chain/blockchain/chain_info_norace_test.go
@@ -1,12 +1,8 @@
 package blockchain

 import (
-	"context"
 	"testing"

-	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -15,82 +11,71 @@ import (
 )

 func TestHeadSlot_DataRace(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg: &config{BeaconDB: beaconDB},
-	}
+	s := testServiceWithDB(t)
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	st, _ := util.DeterministicGenesisState(t, 1)
 	wait := make(chan struct{})
 	go func() {
 		defer close(wait)
-		require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+		require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))
 	}()
 	s.HeadSlot()
 	<-wait
 }

 func TestHeadRoot_DataRace(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
-		head: &head{root: [32]byte{'A'}},
-	}
+	s := testServiceWithDB(t)
+	s.head = &head{root: [32]byte{'A'}}
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
 	go func() {
 		defer close(wait)
-		require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+		require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))

 	}()
-	_, err = s.HeadRoot(context.Background())
+	_, err = s.HeadRoot(t.Context())
 	require.NoError(t, err)
 	<-wait
 }

 func TestHeadBlock_DataRace(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
 	wsb, err := blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlock{Block: &ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}}})
 	require.NoError(t, err)
-	s := &Service{
-		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
-		head: &head{block: wsb},
-	}
+	s := testServiceWithDB(t)
+	s.head = &head{block: wsb}
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
 	go func() {
 		defer close(wait)
-		require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+		require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))

 	}()
-	_, err = s.HeadBlock(context.Background())
+	_, err = s.HeadBlock(t.Context())
 	require.NoError(t, err)
 	<-wait
 }

 func TestHeadState_DataRace(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
-	}
+	s := testServiceWithDB(t)
+	beaconDB := s.cfg.BeaconDB
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
 	root := bytesutil.ToBytes32(bytesutil.PadTo([]byte{'s'}, 32))
-	require.NoError(t, beaconDB.SaveGenesisBlockRoot(context.Background(), root))
-	require.NoError(t, beaconDB.SaveState(context.Background(), st, root))
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(t.Context(), root))
+	require.NoError(t, beaconDB.SaveState(t.Context(), st, root))
 	go func() {
 		defer close(wait)
-		require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+		require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))

 	}()
-	_, err = s.HeadState(context.Background())
+	_, err = s.HeadState(t.Context())
 	require.NoError(t, err)
 	<-wait
 }
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -6,7 +6,6 @@ import (
 	"time"

 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
@@ -15,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -84,7 +84,7 @@ func prepareForkchoiceState(
 func TestHeadRoot_Nil(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	c := setupBeaconChain(t, beaconDB)
-	headRoot, err := c.HeadRoot(context.Background())
+	headRoot, err := c.HeadRoot(t.Context())
 	require.NoError(t, err)
 	assert.DeepEqual(t, params.BeaconConfig().ZeroHash[:], headRoot, "Incorrect pre chain start value")
 }
@@ -137,8 +137,8 @@ func TestFinalizedBlockHash(t *testing.T) {
 }

 func TestUnrealizedJustifiedBlockHash(t *testing.T) {
-	ctx := context.Background()
-	service := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
+	ctx := t.Context()
+	service := testServiceWithDB(t)
 	ojc := &ethpb.Checkpoint{Root: []byte{'j'}}
 	ofc := &ethpb.Checkpoint{Root: []byte{'f'}}
 	st, roblock, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -153,7 +153,7 @@ func TestUnrealizedJustifiedBlockHash(t *testing.T) {
 }

 func TestHeadSlot_CanRetrieve(t *testing.T) {
-	c := &Service{}
+	c := testServiceNoDB(t)
 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
 	require.NoError(t, err)
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
@@ -200,10 +200,10 @@ func TestHeadBlock_CanRetrieve(t *testing.T) {
 	require.NoError(t, err)
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{block: wsb, state: s}

-	received, err := c.HeadBlock(context.Background())
+	received, err := c.HeadBlock(t.Context())
 	require.NoError(t, err)
 	pb, err := received.Proto()
 	require.NoError(t, err)
@@ -213,15 +213,16 @@ func TestHeadBlock_CanRetrieve(t *testing.T) {
 func TestHeadState_CanRetrieve(t *testing.T) {
 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: 2, GenesisValidatorsRoot: params.BeaconConfig().ZeroHash[:]})
 	require.NoError(t, err)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{state: s}
-	headState, err := c.HeadState(context.Background())
+	headState, err := c.HeadState(t.Context())
 	require.NoError(t, err)
 	assert.DeepEqual(t, headState.ToProtoUnsafe(), s.ToProtoUnsafe(), "Incorrect head state received")
 }

 func TestGenesisTime_CanRetrieve(t *testing.T) {
-	c := &Service{genesisTime: time.Unix(999, 0)}
+	c := testServiceNoDB(t)
+	c.genesisTime = time.Unix(999, 0)
 	wanted := time.Unix(999, 0)
 	assert.Equal(t, wanted, c.GenesisTime(), "Did not get wanted genesis time")
 }
@@ -230,7 +231,7 @@ func TestCurrentFork_CanRetrieve(t *testing.T) {
 	f := &ethpb.Fork{Epoch: 999}
 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Fork: f})
 	require.NoError(t, err)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{state: s}
 	if !proto.Equal(c.CurrentFork(), f) {
 		t.Error("Received incorrect fork version")
@@ -242,7 +243,7 @@ func TestCurrentFork_NilHeadSTate(t *testing.T) {
 		PreviousVersion: params.BeaconConfig().GenesisForkVersion,
 		CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
 	}
-	c := &Service{}
+	c := testServiceNoDB(t)
 	if !proto.Equal(c.CurrentFork(), f) {
 		t.Error("Received incorrect fork version")
 	}
@@ -250,7 +251,7 @@ func TestCurrentFork_NilHeadSTate(t *testing.T) {

 func TestGenesisValidatorsRoot_CanRetrieve(t *testing.T) {
 	// Should not panic if head state is nil.
-	c := &Service{}
+	c := testServiceNoDB(t)
 	assert.Equal(t, [32]byte{}, c.GenesisValidatorsRoot(), "Did not get correct genesis validators root")

 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{GenesisValidatorsRoot: []byte{'a'}})
@@ -269,7 +270,7 @@ func TestHeadETH1Data_CanRetrieve(t *testing.T) {
 	d := &ethpb.Eth1Data{DepositCount: 999}
 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Eth1Data: d})
 	require.NoError(t, err)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{state: s}
 	if !proto.Equal(c.HeadETH1Data(), d) {
 		t.Error("Received incorrect eth1 data")
@@ -277,7 +278,7 @@ func TestHeadETH1Data_CanRetrieve(t *testing.T) {
 }

 func TestIsCanonical_Ok(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	c := setupBeaconChain(t, beaconDB)

@@ -298,22 +299,22 @@ func TestIsCanonical_Ok(t *testing.T) {

 func TestService_HeadValidatorsIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 10)
-	c := &Service{}
+	c := testServiceNoDB(t)

 	c.head = &head{}
-	indices, err := c.HeadValidatorsIndices(context.Background(), 0)
+	indices, err := c.HeadValidatorsIndices(t.Context(), 0)
 	require.NoError(t, err)
 	require.Equal(t, 0, len(indices))

 	c.head = &head{state: s}
-	indices, err = c.HeadValidatorsIndices(context.Background(), 0)
+	indices, err = c.HeadValidatorsIndices(t.Context(), 0)
 	require.NoError(t, err)
 	require.Equal(t, 10, len(indices))
 }

 func TestService_HeadGenesisValidatorsRoot(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 1)
-	c := &Service{}
+	c := testServiceNoDB(t)

 	c.head = &head{}
 	root := c.HeadGenesisValidatorsRoot()
@@ -331,8 +332,8 @@ func TestService_HeadGenesisValidatorsRoot(t *testing.T) {
 //     ---------- D

 func TestService_ChainHeads(t *testing.T) {
-	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	st, roblock, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -366,7 +367,7 @@ func TestService_ChainHeads(t *testing.T) {

 func TestService_HeadPublicKeyToValidatorIndex(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 10)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{state: s}

 	_, e := c.HeadPublicKeyToValidatorIndex([fieldparams.BLSPubkeyLength]byte{})
@@ -381,7 +382,7 @@ func TestService_HeadPublicKeyToValidatorIndex(t *testing.T) {
 }

 func TestService_HeadPublicKeyToValidatorIndexNil(t *testing.T) {
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = nil

 	idx, e := c.HeadPublicKeyToValidatorIndex([fieldparams.BLSPubkeyLength]byte{})
@@ -396,10 +397,10 @@ func TestService_HeadPublicKeyToValidatorIndexNil(t *testing.T) {

 func TestService_HeadValidatorIndexToPublicKey(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 10)
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = &head{state: s}

-	p, err := c.HeadValidatorIndexToPublicKey(context.Background(), 0)
+	p, err := c.HeadValidatorIndexToPublicKey(t.Context(), 0)
 	require.NoError(t, err)

 	v, err := s.ValidatorAtIndex(0)
@@ -409,15 +410,15 @@ func TestService_HeadValidatorIndexToPublicKey(t *testing.T) {
 }

 func TestService_HeadValidatorIndexToPublicKeyNil(t *testing.T) {
-	c := &Service{}
+	c := testServiceNoDB(t)
 	c.head = nil

-	p, err := c.HeadValidatorIndexToPublicKey(context.Background(), 0)
+	p, err := c.HeadValidatorIndexToPublicKey(t.Context(), 0)
 	require.NoError(t, err)
 	require.Equal(t, [fieldparams.BLSPubkeyLength]byte{}, p)

 	c.head = &head{state: nil}
-	p, err = c.HeadValidatorIndexToPublicKey(context.Background(), 0)
+	p, err = c.HeadValidatorIndexToPublicKey(t.Context(), 0)
 	require.NoError(t, err)
 	require.Equal(t, [fieldparams.BLSPubkeyLength]byte{}, p)
 }
@@ -428,10 +429,12 @@ func TestService_IsOptimistic(t *testing.T) {
 	cfg.BellatrixForkEpoch = 0
 	params.OverrideBeaconConfig(cfg)

-	ctx := context.Background()
+	ctx := t.Context()
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	c := testServiceWithDB(t)
+	c.SetGenesisTime(time.Now())
+	c.head = &head{root: [32]byte{'b'}}
 	st, roblock, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, roblock))
@@ -450,22 +453,24 @@ func TestService_IsOptimistic(t *testing.T) {
 	require.Equal(t, true, opt)

 	// If head is nil, for some reason, an error should be returned rather than panic.
-	c = &Service{}
+	c = testServiceNoDB(t)
 	_, err = c.IsOptimistic(ctx)
 	require.ErrorIs(t, err, ErrNilHead)
 }

 func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
-	ctx := context.Background()
-	c := &Service{genesisTime: time.Now()}
+	ctx := t.Context()
+	c := testServiceNoDB(t)
+	c.genesisTime = time.Now()
 	opt, err := c.IsOptimistic(ctx)
 	require.NoError(t, err)
 	require.Equal(t, false, opt)
 }

 func TestService_IsOptimisticForRoot(t *testing.T) {
-	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
+	c.head = &head{root: [32]byte{'b'}}
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	st, roblock, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -481,28 +486,29 @@ func TestService_IsOptimisticForRoot(t *testing.T) {
 }

 func TestService_IsOptimisticForRoot_DB(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
+	c.head = &head{root: [32]byte{'b'}}
+	beaconDB := c.cfg.BeaconDB
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
 	br, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, b)
-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: br[:], Slot: 10}))
+	util.SaveBlock(t, t.Context(), beaconDB, b)
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: br[:], Slot: 10}))

 	optimisticBlock := util.NewBeaconBlock()
 	optimisticBlock.Block.Slot = 97
 	optimisticRoot, err := optimisticBlock.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, optimisticBlock)
+	util.SaveBlock(t, t.Context(), beaconDB, optimisticBlock)

 	validatedBlock := util.NewBeaconBlock()
 	validatedBlock.Block.Slot = 9
 	validatedRoot, err := validatedBlock.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, validatedBlock)
+	util.SaveBlock(t, t.Context(), beaconDB, validatedBlock)

 	validatedCheckpoint := &ethpb.Checkpoint{Root: br[:]}
 	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, validatedCheckpoint))
@@ -524,48 +530,48 @@ func TestService_IsOptimisticForRoot_DB(t *testing.T) {
 	// Before the first finalized epoch, finalized root could be zeros.
 	validatedCheckpoint = &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, br))
-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: params.BeaconConfig().ZeroHash[:], Slot: 10}))
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: params.BeaconConfig().ZeroHash[:], Slot: 10}))
 	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, validatedCheckpoint))

-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
 	optimistic, err = c.IsOptimisticForRoot(ctx, optimisticRoot)
 	require.NoError(t, err)
 	require.Equal(t, true, optimistic)
 }

 func TestService_IsOptimisticForRoot_DB_non_canonical(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
+	beaconDB := c.cfg.BeaconDB
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
 	br, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, b)
-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: br[:], Slot: 10}))
+	util.SaveBlock(t, t.Context(), beaconDB, b)
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: br[:], Slot: 10}))

 	optimisticBlock := util.NewBeaconBlock()
 	optimisticBlock.Block.Slot = 97
 	optimisticRoot, err := optimisticBlock.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, optimisticBlock)
+	util.SaveBlock(t, t.Context(), beaconDB, optimisticBlock)

 	validatedBlock := util.NewBeaconBlock()
 	validatedBlock.Block.Slot = 9
 	validatedRoot, err := validatedBlock.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, validatedBlock)
+	util.SaveBlock(t, t.Context(), beaconDB, validatedBlock)

 	validatedCheckpoint := &ethpb.Checkpoint{Root: br[:]}
 	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, validatedCheckpoint))

-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
 	optimistic, err := c.IsOptimisticForRoot(ctx, optimisticRoot)
 	require.NoError(t, err)
 	require.Equal(t, true, optimistic)

-	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: validatedRoot[:], Slot: 9}))
+	require.NoError(t, beaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Root: validatedRoot[:], Slot: 9}))
 	validated, err := c.IsOptimisticForRoot(ctx, validatedRoot)
 	require.NoError(t, err)
 	require.Equal(t, true, validated)
@@ -573,15 +579,15 @@ func TestService_IsOptimisticForRoot_DB_non_canonical(t *testing.T) {
 }

 func TestService_IsOptimisticForRoot_StateSummaryRecovered(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
+	beaconDB := c.cfg.BeaconDB
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
 	br, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	util.SaveBlock(t, context.Background(), beaconDB, b)
+	util.SaveBlock(t, t.Context(), beaconDB, b)
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, [32]byte{}))
 	_, err = c.IsOptimisticForRoot(ctx, br)
 	assert.NoError(t, err)
@@ -593,9 +599,9 @@ func TestService_IsOptimisticForRoot_StateSummaryRecovered(t *testing.T) {
 }

 func TestService_IsFinalized(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}}
+	ctx := t.Context()
+	c := testServiceWithDB(t)
+	beaconDB := c.cfg.BeaconDB
 	r1 := [32]byte{'a'}
 	require.NoError(t, c.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{
 		Root: r1,
@@ -616,9 +622,10 @@ func TestService_IsFinalized(t *testing.T) {

 func Test_hashForGenesisRoot(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
+	ctx := t.Context()
 	c := setupBeaconChain(t, beaconDB)
 	st, _ := util.DeterministicGenesisStateElectra(t, 10)
+	genesis.StoreDuringTest(t, genesis.GenesisData{State: st})
 	require.NoError(t, c.cfg.BeaconDB.SaveGenesisData(ctx, st))
 	root, err := beaconDB.GenesisBlockRoot(ctx)
 	require.NoError(t, err)
--- a/beacon-chain/blockchain/currently_syncing_block.go
+++ b/beacon-chain/blockchain/currently_syncing_block.go
@@ -7,10 +7,15 @@ type currentlySyncingBlock struct {
 	roots map[[32]byte]struct{}
 }

-func (b *currentlySyncingBlock) set(root [32]byte) {
+func (b *currentlySyncingBlock) set(root [32]byte) error {
 	b.Lock()
 	defer b.Unlock()
+	_, ok := b.roots[root]
+	if ok {
+		return errBlockBeingSynced
+	}
 	b.roots[root] = struct{}{}
+	return nil
 }

 func (b *currentlySyncingBlock) unset(root [32]byte) {
--- a/beacon-chain/blockchain/defragment.go
+++ b/beacon-chain/blockchain/defragment.go
@@ -2,7 +2,6 @@ package blockchain

 import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
-	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/time"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -17,9 +16,6 @@ var stateDefragmentationTime = promauto.NewSummary(prometheus.SummaryOpts{
 // a higher number of fragmented indexes are reallocated to a new separate slice for
 // that field.
 func (s *Service) defragmentState(st state.BeaconState) {
-	if !features.Get().EnableExperimentalState {
-		return
-	}
 	startTime := time.Now()
 	st.Defragment()
 	elapsedTime := time.Since(startTime)
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -40,10 +40,14 @@ var (
 	errNotGenesisRoot = errors.New("root is not the genesis block root")
 	// errBlacklistedBlock is returned when a block is blacklisted as invalid.
 	errBlacklistedRoot = verification.AsVerificationFailure(errors.New("block root is blacklisted"))
+	// errMaxBlobsExceeded is returned when the number of blobs in a block exceeds the maximum allowed.
+	errMaxBlobsExceeded = verification.AsVerificationFailure(errors.New("expected commitments in block exceeds MAX_BLOBS_PER_BLOCK"))
+	// errMaxDataColumnsExceeded is returned when the number of data columns exceeds the maximum allowed.
+	errMaxDataColumnsExceeded = verification.AsVerificationFailure(errors.New("expected data columns for node exceeds NUMBER_OF_COLUMNS"))
+	// errBlockBeingSynced is returned when a block is being synced.
+	errBlockBeingSynced = errors.New("block is being synced")
 )

-var errMaxBlobsExceeded = verification.AsVerificationFailure(errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK"))
-
 // An invalid block is the block that fails state transition based on the core protocol rules.
 // The beacon node shall not be accepting nor building blocks that branch off from an invalid block.
 // Some examples of invalid blocks are:
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -141,7 +141,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			}

 			if err := s.saveHead(ctx, r, b, st); err != nil {
-				log.WithError(err).Error("could not save head after pruning invalid blocks")
+				log.WithError(err).Error("Could not save head after pruning invalid blocks")
 			}

 			log.WithFields(logrus.Fields{
@@ -174,6 +174,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
 		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), arg.headBlock, arg.headRoot, nextSlot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -184,13 +185,17 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 	return payloadID, nil
 }

-func firePayloadAttributesEvent(_ context.Context, f event.SubscriberSender, nextSlot primitives.Slot) {
+func (s *Service) firePayloadAttributesEvent(f event.SubscriberSender, block interfaces.ReadOnlySignedBeaconBlock, root [32]byte, nextSlot primitives.Slot) {
+	// If we're syncing a block in the past and init-sync is still running, we shouldn't fire this event.
+	if !s.cfg.SyncChecker.Synced() {
+		return
+	}
 	// the fcu args have differing amounts of completeness based on the code path,
 	// and there is work we only want to do if a client is actually listening to the events beacon api endpoint.
 	// temporary solution: just fire a blank event and fill in the details in the api handler.
 	f.Send(&feed.Event{
 		Type: statefeed.PayloadAttributes,
-		Data: payloadattribute.EventData{ProposalSlot: nextSlot},
+		Data: payloadattribute.EventData{HeadBlock: block, HeadRoot: root, ProposalSlot: nextSlot},
 	})
 }

@@ -350,7 +355,7 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 	}

 	// Get timestamp.
-	t, err := slots.ToTime(uint64(s.genesisTime.Unix()), slot)
+	t, err := slots.StartTime(s.genesisTime, slot)
 	if err != nil {
 		log.WithError(err).Error("Could not get timestamp to get payload attribute")
 		return emptyAttri
@@ -435,6 +440,9 @@ func (s *Service) removeInvalidBlockAndState(ctx context.Context, blkRoots [][32
 			// Blobs may not exist for some blocks, leading to deletion failures. Log such errors at debug level.
 			log.WithError(err).Debug("Could not remove blob from blob storage")
 		}
+		if err := s.dataColumnStorage.Remove(root); err != nil {
+			log.WithError(err).Errorf("Could not remove data columns from data column storage for root %#x", root)
+		}
 	}
 	return nil
 }
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -19,6 +19,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	v1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -309,6 +310,7 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 		block: wba,
 	}

+	genesis.StoreStateDuringTest(t, st)
 	require.NoError(t, beaconDB.SaveState(ctx, st, bra))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
 	a := &fcuConfig{
@@ -403,6 +405,7 @@ func Test_NotifyForkchoiceUpdateRecursive_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)

 	bState, _ := util.DeterministicGenesisState(t, 10)
+	genesis.StoreStateDuringTest(t, bState)
 	require.NoError(t, beaconDB.SaveState(ctx, bState, bra))
 	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
 	state, blkRoot, err = prepareForkchoiceState(ctx, 2, brb, bra, [32]byte{'B'}, ojc, ofc)
--- a/beacon-chain/blockchain/forkchoice_update_execution.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution.go
@@ -76,14 +76,14 @@ func (s *Service) sendFCUWithAttributes(cfg *postBlockProcessConfig, fcuArgs *fc
 	s.cfg.ForkChoiceStore.RLock()
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	if err := s.computePayloadAttributes(cfg, fcuArgs); err != nil {
-		log.WithError(err).Error("could not compute payload attributes")
+		log.WithError(err).Error("Could not compute payload attributes")
 		return
 	}
 	if fcuArgs.attributes.IsEmpty() {
 		return
 	}
 	if _, err := s.notifyForkchoiceUpdate(cfg.ctx, fcuArgs); err != nil {
-		log.WithError(err).Error("could not update forkchoice with payload attributes for proposal")
+		log.WithError(err).Error("Could not update forkchoice with payload attributes for proposal")
 	}
 }

@@ -99,11 +99,9 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 	}

 	if err := s.saveHead(ctx, args.headRoot, args.headBlock, args.headState); err != nil {
-		log.WithError(err).Error("could not save head")
+		log.WithError(err).Error("Could not save head")
 	}

-	go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
-
 	// Only need to prune attestations from pool if the head has changed.
 	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)
 	return nil
@@ -114,7 +112,7 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 func (s *Service) shouldOverrideFCU(newHeadRoot [32]byte, proposingSlot primitives.Slot) bool {
 	headWeight, err := s.cfg.ForkChoiceStore.Weight(newHeadRoot)
 	if err != nil {
-		log.WithError(err).WithField("root", fmt.Sprintf("%#x", newHeadRoot)).Warn("could not determine node weight")
+		log.WithError(err).WithField("root", fmt.Sprintf("%#x", newHeadRoot)).Warn("Could not determine node weight")
 	}
 	currentSlot := s.CurrentSlot()
 	if proposingSlot == currentSlot {
@@ -132,17 +130,17 @@ func (s *Service) shouldOverrideFCU(newHeadRoot [32]byte, proposingSlot primitiv
 		if s.cfg.ForkChoiceStore.ShouldOverrideFCU() {
 			return true
 		}
-		secs, err := slots.SecondsSinceSlotStart(currentSlot,
-			uint64(s.genesisTime.Unix()), uint64(time.Now().Unix()))
+		sss, err := slots.SinceSlotStart(currentSlot, s.genesisTime, time.Now())
 		if err != nil {
-			log.WithError(err).Error("could not compute seconds since slot start")
+			log.WithError(err).Error("Could not compute seconds since slot start")
 		}
-		if secs >= doublylinkedtree.ProcessAttestationsThreshold {
+		if sss >= doublylinkedtree.ProcessAttestationsThreshold {
 			log.WithFields(logrus.Fields{
-				"root":   fmt.Sprintf("%#x", newHeadRoot),
-				"weight": headWeight,
-			}).Infof("Attempted late block reorg aborted due to attestations at %d seconds",
-				doublylinkedtree.ProcessAttestationsThreshold)
+				"root":           fmt.Sprintf("%#x", newHeadRoot),
+				"weight":         headWeight,
+				"sinceSlotStart": sss,
+				"threshold":      doublylinkedtree.ProcessAttestationsThreshold,
+			}).Info("Attempted late block reorg aborted due to attestations after threshold")
 			lateBlockFailedAttemptFirstThreshold.Inc()
 		}
 	}
--- a/beacon-chain/blockchain/forkchoice_update_execution_test.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"context"
 	"testing"
 	"time"

@@ -36,29 +35,29 @@ func TestService_isNewHead(t *testing.T) {
 func TestService_getHeadStateAndBlock(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	_, _, err := service.getStateAndBlock(context.Background(), [32]byte{})
+	_, _, err := service.getStateAndBlock(t.Context(), [32]byte{})
 	require.ErrorContains(t, "block does not exist", err)

 	blk, err := blocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlock(&ethpb.SignedBeaconBlock{Signature: []byte{1}}))
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.BeaconDB.SaveBlock(context.Background(), blk))
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(t.Context(), blk))

 	st, _ := util.DeterministicGenesisState(t, 1)
 	r, err := blk.Block().HashTreeRoot()
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.BeaconDB.SaveState(context.Background(), st, r))
+	require.NoError(t, service.cfg.BeaconDB.SaveState(t.Context(), st, r))

-	gotState, err := service.cfg.BeaconDB.State(context.Background(), r)
+	gotState, err := service.cfg.BeaconDB.State(t.Context(), r)
 	require.NoError(t, err)
 	require.DeepEqual(t, st.ToProto(), gotState.ToProto())

-	gotBlk, err := service.cfg.BeaconDB.Block(context.Background(), r)
+	gotBlk, err := service.cfg.BeaconDB.Block(t.Context(), r)
 	require.NoError(t, err)
 	require.DeepEqual(t, blk, gotBlk)
 }

 func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	opts := testServiceOptsWithDB(t)

 	service, err := NewService(ctx, opts...)
@@ -161,6 +160,7 @@ func TestShouldOverrideFCU(t *testing.T) {
 	ctx, fcs := tr.ctx, tr.fcs

 	service.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot) * time.Second))
+	fcs.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot) * time.Second))
 	headRoot := [32]byte{'b'}
 	parentRoot := [32]byte{'a'}
 	ojc := &ethpb.Checkpoint{}
@@ -181,11 +181,12 @@ func TestShouldOverrideFCU(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, headRoot, head)

-	fcs.SetGenesisTime(uint64(time.Now().Unix()) - 29)
+	wantLog := "aborted due to attestations after threshold"
+	fcs.SetGenesisTime(time.Now().Add(-29 * time.Second))
 	require.Equal(t, true, service.shouldOverrideFCU(parentRoot, 3))
-	require.LogsDoNotContain(t, hook, "10 seconds")
-	fcs.SetGenesisTime(uint64(time.Now().Unix()) - 24)
+	require.LogsDoNotContain(t, hook, wantLog)
+	fcs.SetGenesisTime(time.Now().Add(-24 * time.Second))
 	service.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot+10) * time.Second))
 	require.Equal(t, false, service.shouldOverrideFCU(parentRoot, 3))
-	require.LogsContain(t, hook, "10 seconds")
+	require.LogsContain(t, hook, wantLog)
 }
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -98,7 +98,7 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 	oldHeadRoot := bytesutil.ToBytes32(r)
 	isOptimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(newHeadRoot)
 	if err != nil {
-		log.WithError(err).Error("could not check if node is optimistically synced")
+		log.WithError(err).Error("Could not check if node is optimistically synced")
 	}
 	if headBlock.Block().ParentRoot() != oldHeadRoot {
 		// A chain re-org occurred, so we fire an event notifying the rest of the services.
@@ -111,11 +111,11 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 		dep := math.Max(uint64(headSlot-forkSlot), uint64(newHeadSlot-forkSlot))
 		oldWeight, err := s.cfg.ForkChoiceStore.Weight(oldHeadRoot)
 		if err != nil {
-			log.WithField("root", fmt.Sprintf("%#x", oldHeadRoot)).Warn("could not determine node weight")
+			log.WithField("root", fmt.Sprintf("%#x", oldHeadRoot)).Warn("Could not determine node weight")
 		}
 		newWeight, err := s.cfg.ForkChoiceStore.Weight(newHeadRoot)
 		if err != nil {
-			log.WithField("root", fmt.Sprintf("%#x", newHeadRoot)).Warn("could not determine node weight")
+			log.WithField("root", fmt.Sprintf("%#x", newHeadRoot)).Warn("Could not determine node weight")
 		}
 		log.WithFields(logrus.Fields{
 			"newSlot":            fmt.Sprintf("%d", newHeadSlot),
--- a/beacon-chain/blockchain/head_sync_committee_info.go
+++ b/beacon-chain/blockchain/head_sync_committee_info.go
@@ -18,9 +18,6 @@ import (
 	"github.com/pkg/errors"
 )

-// Initialize the state cache for sync committees.
-var syncCommitteeHeadStateCache = cache.NewSyncCommitteeHeadState()
-
 // HeadSyncCommitteeFetcher is the interface that wraps the head sync committee related functions.
 // The head sync committee functions return callers sync committee indices and public keys with respect to current head state.
 type HeadSyncCommitteeFetcher interface {
@@ -143,7 +140,7 @@ func (s *Service) getSyncCommitteeHeadState(ctx context.Context, slot primitives
 	defer mLock.Unlock()

 	// If there's already a head state exists with the request slot, we don't need to process slots.
-	cachedState, err := syncCommitteeHeadStateCache.Get(slot)
+	cachedState, err := s.syncCommitteeHeadState.Get(slot)
 	switch {
 	case err == nil:
 		syncHeadStateHit.Inc()
@@ -166,7 +163,7 @@ func (s *Service) getSyncCommitteeHeadState(ctx context.Context, slot primitives
 			return nil, err
 		}
 		syncHeadStateMiss.Inc()
-		err = syncCommitteeHeadStateCache.Put(slot, headState)
+		err = s.syncCommitteeHeadState.Put(slot, headState)
 		return headState, err
 	default:
 		// In the event, we encounter another error
--- a/beacon-chain/blockchain/head_sync_committee_info_test.go
+++ b/beacon-chain/blockchain/head_sync_committee_info_test.go
@@ -1,12 +1,10 @@
 package blockchain

 import (
-	"context"
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
-	dbTest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -16,35 +14,35 @@ import (

 func TestService_HeadSyncCommitteeIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	// Current period
 	slot := 2*uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) + 1
-	a, err := c.HeadSyncCommitteeIndices(context.Background(), 0, primitives.Slot(slot))
+	a, err := c.HeadSyncCommitteeIndices(t.Context(), 0, primitives.Slot(slot))
 	require.NoError(t, err)

 	// Current period where slot-2 across EPOCHS_PER_SYNC_COMMITTEE_PERIOD
 	slot = 3*uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) - 2
-	b, err := c.HeadSyncCommitteeIndices(context.Background(), 0, primitives.Slot(slot))
+	b, err := c.HeadSyncCommitteeIndices(t.Context(), 0, primitives.Slot(slot))
 	require.NoError(t, err)
 	require.DeepEqual(t, a, b)

 	// Next period where slot-1 across EPOCHS_PER_SYNC_COMMITTEE_PERIOD
 	slot = 3*uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) - 1
-	b, err = c.HeadSyncCommitteeIndices(context.Background(), 0, primitives.Slot(slot))
+	b, err = c.HeadSyncCommitteeIndices(t.Context(), 0, primitives.Slot(slot))
 	require.NoError(t, err)
 	require.DeepNotEqual(t, a, b)
 }

 func TestService_headCurrentSyncCommitteeIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	// Process slot up to `EpochsPerSyncCommitteePeriod` so it can `ProcessSyncCommitteeUpdates`.
 	slot := uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) + 1
-	indices, err := c.headCurrentSyncCommitteeIndices(context.Background(), 0, primitives.Slot(slot))
+	indices, err := c.headCurrentSyncCommitteeIndices(t.Context(), 0, primitives.Slot(slot))
 	require.NoError(t, err)

 	// NextSyncCommittee becomes CurrentSyncCommittee so it should be empty by default.
@@ -53,12 +51,12 @@ func TestService_headCurrentSyncCommitteeIndices(t *testing.T) {

 func TestService_headNextSyncCommitteeIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	// Process slot up to `EpochsPerSyncCommitteePeriod` so it can `ProcessSyncCommitteeUpdates`.
 	slot := uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) + 1
-	indices, err := c.headNextSyncCommitteeIndices(context.Background(), 0, primitives.Slot(slot))
+	indices, err := c.headNextSyncCommitteeIndices(t.Context(), 0, primitives.Slot(slot))
 	require.NoError(t, err)

 	// NextSyncCommittee should be empty after `ProcessSyncCommitteeUpdates`. Validator should get indices.
@@ -67,12 +65,12 @@ func TestService_headNextSyncCommitteeIndices(t *testing.T) {

 func TestService_HeadSyncCommitteePubKeys(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	// Process slot up to 2 * `EpochsPerSyncCommitteePeriod` so it can run `ProcessSyncCommitteeUpdates` twice.
 	slot := uint64(2*params.BeaconConfig().EpochsPerSyncCommitteePeriod)*uint64(params.BeaconConfig().SlotsPerEpoch) + 1
-	pubkeys, err := c.HeadSyncCommitteePubKeys(context.Background(), primitives.Slot(slot), 0)
+	pubkeys, err := c.HeadSyncCommitteePubKeys(t.Context(), primitives.Slot(slot), 0)
 	require.NoError(t, err)

 	// Any subcommittee should match the subcommittee size.
@@ -82,13 +80,13 @@ func TestService_HeadSyncCommitteePubKeys(t *testing.T) {

 func TestService_HeadSyncCommitteeDomain(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorsRoot())
 	require.NoError(t, err)

-	d, err := c.HeadSyncCommitteeDomain(context.Background(), 0)
+	d, err := c.HeadSyncCommitteeDomain(t.Context(), 0)
 	require.NoError(t, err)

 	require.DeepEqual(t, wanted, d)
@@ -96,13 +94,13 @@ func TestService_HeadSyncCommitteeDomain(t *testing.T) {

 func TestService_HeadSyncContributionProofDomain(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainContributionAndProof, s.GenesisValidatorsRoot())
 	require.NoError(t, err)

-	d, err := c.HeadSyncContributionProofDomain(context.Background(), 0)
+	d, err := c.HeadSyncContributionProofDomain(t.Context(), 0)
 	require.NoError(t, err)

 	require.DeepEqual(t, wanted, d)
@@ -110,30 +108,27 @@ func TestService_HeadSyncContributionProofDomain(t *testing.T) {

 func TestService_HeadSyncSelectionProofDomain(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := testServiceWithDB(t)
 	c.head = &head{state: s}

 	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommitteeSelectionProof, s.GenesisValidatorsRoot())
 	require.NoError(t, err)

-	d, err := c.HeadSyncSelectionProofDomain(context.Background(), 0)
+	d, err := c.HeadSyncSelectionProofDomain(t.Context(), 0)
 	require.NoError(t, err)

 	require.DeepEqual(t, wanted, d)
 }

 func TestSyncCommitteeHeadStateCache_RoundTrip(t *testing.T) {
-	c := syncCommitteeHeadStateCache
-	t.Cleanup(func() {
-		syncCommitteeHeadStateCache = cache.NewSyncCommitteeHeadState()
-	})
+	s := testServiceNoDB(t)
 	beaconState, _ := util.DeterministicGenesisStateAltair(t, 100)
 	require.NoError(t, beaconState.SetSlot(100))
-	cachedState, err := c.Get(101)
+	cachedState, err := s.syncCommitteeHeadState.Get(101)
 	require.ErrorContains(t, cache.ErrNotFound.Error(), err)
 	require.Equal(t, nil, cachedState)
-	require.NoError(t, c.Put(101, beaconState))
-	cachedState, err = c.Get(101)
+	require.NoError(t, s.syncCommitteeHeadState.Put(101, beaconState))
+	cachedState, err = s.syncCommitteeHeadState.Get(101)
 	require.NoError(t, err)
 	require.DeepEqual(t, beaconState, cachedState)
 }
--- a/beacon-chain/blockchain/head_test.go
+++ b/beacon-chain/blockchain/head_test.go
@@ -9,7 +9,6 @@ import (

 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -34,17 +33,17 @@ func TestSaveHead_Same(t *testing.T) {
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	st, _ := util.DeterministicGenesisState(t, 1)
-	require.NoError(t, service.saveHead(context.Background(), r, b, st))
+	require.NoError(t, service.saveHead(t.Context(), r, b, st))
 	assert.Equal(t, primitives.Slot(0), service.headSlot(), "Head did not stay the same")
 	assert.Equal(t, r, service.headRoot(), "Head did not stay the same")
 }

 func TestSaveHead_Different(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)

-	oldBlock := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, util.NewBeaconBlock())
+	oldBlock := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, util.NewBeaconBlock())
 	oldRoot, err := oldBlock.Block().HashTreeRoot()
 	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
@@ -61,7 +60,7 @@ func TestSaveHead_Different(t *testing.T) {
 	newHeadSignedBlock.Block.Slot = 1
 	newHeadBlock := newHeadSignedBlock.Block

-	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
+	wsb := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
 	state, blkRoot, err = prepareForkchoiceState(ctx, slots.PrevSlot(wsb.Block().Slot()), wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
@@ -74,13 +73,13 @@ func TestSaveHead_Different(t *testing.T) {
 	headState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, headState.SetSlot(1))
-	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
-	require.NoError(t, service.cfg.BeaconDB.SaveState(context.Background(), headState, newRoot))
-	require.NoError(t, service.saveHead(context.Background(), newRoot, wsb, headState))
+	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveState(t.Context(), headState, newRoot))
+	require.NoError(t, service.saveHead(t.Context(), newRoot, wsb, headState))

 	assert.Equal(t, primitives.Slot(1), service.HeadSlot(), "Head did not change")

-	cachedRoot, err := service.HeadRoot(context.Background())
+	cachedRoot, err := service.HeadRoot(t.Context())
 	require.NoError(t, err)
 	assert.DeepEqual(t, cachedRoot, newRoot[:], "Head did not change")
 	headBlock, err := service.headBlock()
@@ -92,12 +91,12 @@ func TestSaveHead_Different(t *testing.T) {
 }

 func TestSaveHead_Different_Reorg(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	hook := logTest.NewGlobal()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)

-	oldBlock := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, util.NewBeaconBlock())
+	oldBlock := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, util.NewBeaconBlock())
 	oldRoot, err := oldBlock.Block().HashTreeRoot()
 	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
@@ -120,7 +119,7 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	newHeadSignedBlock.Block.ParentRoot = reorgChainParent[:]
 	newHeadBlock := newHeadSignedBlock.Block

-	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
+	wsb := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
 	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot(), newRoot, wsb.Block().ParentRoot(), [32]byte{}, ojc, ofc)
@@ -129,13 +128,13 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	headState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, headState.SetSlot(1))
-	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
-	require.NoError(t, service.cfg.BeaconDB.SaveState(context.Background(), headState, newRoot))
-	require.NoError(t, service.saveHead(context.Background(), newRoot, wsb, headState))
+	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveState(t.Context(), headState, newRoot))
+	require.NoError(t, service.saveHead(t.Context(), newRoot, wsb, headState))

 	assert.Equal(t, primitives.Slot(1), service.HeadSlot(), "Head did not change")

-	cachedRoot, err := service.HeadRoot(context.Background())
+	cachedRoot, err := service.HeadRoot(t.Context())
 	require.NoError(t, err)
 	if !bytes.Equal(cachedRoot, newRoot[:]) {
 		t.Error("Head did not change")
@@ -154,20 +153,16 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 func Test_notifyNewHeadEvent(t *testing.T) {
 	t.Run("genesis_state_root", func(t *testing.T) {
 		bState, _ := util.DeterministicGenesisState(t, 10)
-		notifier := &mock.MockStateNotifier{RecordEvents: true}
-		srv := &Service{
-			cfg: &config{
-				StateNotifier:   notifier,
-				ForkChoiceStore: doublylinkedtree.New(),
-			},
-			originBlockRoot: [32]byte{1},
-		}
-		st, blk, err := prepareForkchoiceState(context.Background(), 0, [32]byte{}, [32]byte{}, [32]byte{}, &ethpb.Checkpoint{}, &ethpb.Checkpoint{})
+		srv := testServiceWithDB(t)
+		srv.SetGenesisTime(time.Now())
+		notifier := srv.cfg.StateNotifier.(*mock.MockStateNotifier)
+		srv.originBlockRoot = [32]byte{1}
+		st, blk, err := prepareForkchoiceState(t.Context(), 0, [32]byte{}, [32]byte{}, [32]byte{}, &ethpb.Checkpoint{}, &ethpb.Checkpoint{})
 		require.NoError(t, err)
-		require.NoError(t, srv.cfg.ForkChoiceStore.InsertNode(context.Background(), st, blk))
+		require.NoError(t, srv.cfg.ForkChoiceStore.InsertNode(t.Context(), st, blk))
 		newHeadStateRoot := [32]byte{2}
 		newHeadRoot := [32]byte{3}
-		require.NoError(t, srv.notifyNewHeadEvent(context.Background(), 1, bState, newHeadStateRoot[:], newHeadRoot[:]))
+		require.NoError(t, srv.notifyNewHeadEvent(t.Context(), 1, bState, newHeadStateRoot[:], newHeadRoot[:]))
 		events := notifier.ReceivedEvents()
 		require.Equal(t, 1, len(events))

@@ -185,18 +180,14 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 	})
 	t.Run("non_genesis_values", func(t *testing.T) {
 		bState, _ := util.DeterministicGenesisState(t, 10)
-		notifier := &mock.MockStateNotifier{RecordEvents: true}
 		genesisRoot := [32]byte{1}
-		srv := &Service{
-			cfg: &config{
-				StateNotifier:   notifier,
-				ForkChoiceStore: doublylinkedtree.New(),
-			},
-			originBlockRoot: genesisRoot,
-		}
-		st, blk, err := prepareForkchoiceState(context.Background(), 0, [32]byte{}, [32]byte{}, [32]byte{}, &ethpb.Checkpoint{}, &ethpb.Checkpoint{})
+		srv := testServiceWithDB(t)
+		srv.SetGenesisTime(time.Now())
+		srv.originBlockRoot = genesisRoot
+		notifier := srv.cfg.StateNotifier.(*mock.MockStateNotifier)
+		st, blk, err := prepareForkchoiceState(t.Context(), 0, [32]byte{}, [32]byte{}, [32]byte{}, &ethpb.Checkpoint{}, &ethpb.Checkpoint{})
 		require.NoError(t, err)
-		require.NoError(t, srv.cfg.ForkChoiceStore.InsertNode(context.Background(), st, blk))
+		require.NoError(t, srv.cfg.ForkChoiceStore.InsertNode(t.Context(), st, blk))
 		epoch1Start, err := slots.EpochStart(1)
 		require.NoError(t, err)
 		epoch2Start, err := slots.EpochStart(1)
@@ -205,7 +196,7 @@ func Test_notifyNewHeadEvent(t *testing.T) {

 		newHeadStateRoot := [32]byte{2}
 		newHeadRoot := [32]byte{3}
-		err = srv.notifyNewHeadEvent(context.Background(), epoch2Start, bState, newHeadStateRoot[:], newHeadRoot[:])
+		err = srv.notifyNewHeadEvent(t.Context(), epoch2Start, bState, newHeadStateRoot[:], newHeadRoot[:])
 		require.NoError(t, err)
 		events := notifier.ReceivedEvents()
 		require.Equal(t, 1, len(events))
@@ -225,11 +216,11 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 }

 func TestRetrieveHead_ReadOnly(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)

-	oldBlock := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, util.NewBeaconBlock())
+	oldBlock := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, util.NewBeaconBlock())
 	oldRoot, err := oldBlock.Block().HashTreeRoot()
 	require.NoError(t, err)
 	service.head = &head{
@@ -243,7 +234,7 @@ func TestRetrieveHead_ReadOnly(t *testing.T) {
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}

-	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
+	wsb := util.SaveBlock(t, t.Context(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
 	state, blkRoot, err := prepareForkchoiceState(ctx, slots.PrevSlot(wsb.Block().Slot()), wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
@@ -256,9 +247,9 @@ func TestRetrieveHead_ReadOnly(t *testing.T) {
 	headState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, headState.SetSlot(1))
-	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
-	require.NoError(t, service.cfg.BeaconDB.SaveState(context.Background(), headState, newRoot))
-	require.NoError(t, service.saveHead(context.Background(), newRoot, wsb, headState))
+	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(t.Context(), &ethpb.StateSummary{Slot: 1, Root: newRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveState(t.Context(), headState, newRoot))
+	require.NoError(t, service.saveHead(t.Context(), newRoot, wsb, headState))

 	rOnlyState, err := service.HeadStateReadOnly(ctx)
 	require.NoError(t, err)
@@ -267,7 +258,7 @@ func TestRetrieveHead_ReadOnly(t *testing.T) {
 }

 func TestSaveOrphanedAtts(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
@@ -333,7 +324,7 @@ func TestSaveOrphanedAtts(t *testing.T) {
 }

 func TestSaveOrphanedAttsElectra(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
@@ -404,10 +395,10 @@ func TestSaveOrphanedOps(t *testing.T) {
 	config.ShardCommitteePeriod = 0
 	params.OverrideBeaconConfig(config)

-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	service.SetGenesisTime(time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second))

 	// Chain setup
 	// 0 -- 1 -- 2 -- 3
@@ -481,7 +472,7 @@ func TestSaveOrphanedOps(t *testing.T) {
 }

 func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.cfg.BLSToExecPool = blstoexec.NewPool()
@@ -539,7 +530,7 @@ func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
 }

 func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
@@ -604,7 +595,7 @@ func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
 }

 func TestSaveOrphanedAtts_CanFilter_DoublyLinkedTrie(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
--- a/beacon-chain/blockchain/init_sync_process_block_test.go
+++ b/beacon-chain/blockchain/init_sync_process_block_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"context"
 	"testing"

 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
@@ -11,7 +10,7 @@ import (
 )

 func TestService_getBlock(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	s := setupBeaconChain(t, beaconDB)
 	b1 := util.NewBeaconBlock()
@@ -42,7 +41,7 @@ func TestService_getBlock(t *testing.T) {
 }

 func TestService_hasBlockInInitSyncOrDB(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	s := setupBeaconChain(t, beaconDB)
 	b1 := util.NewBeaconBlock()
--- a/beacon-chain/blockchain/kzg/BUILD.bazel
+++ b/beacon-chain/blockchain/kzg/BUILD.bazel
@@ -3,15 +3,19 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = [
+        "kzg.go",
        "trusted_setup.go",
        "validation.go",
    ],
-    embedsrcs = ["trusted_setup.json"],
+    embedsrcs = ["trusted_setup_4096.json"],
    importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg",
    visibility = ["//visibility:public"],
    deps = [
        "//consensus-types/blocks:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_c_kzg_4844//bindings/go:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//crypto/kzg4844:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
 )
@@ -25,8 +29,8 @@ go_test(
    embed = [":go_default_library"],
    deps = [
        "//consensus-types/blocks:go_default_library",
+        "//crypto/random:go_default_library",
        "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/kzg/kzg.go
+++ b/beacon-chain/blockchain/kzg/kzg.go
@@ -0,0 +1,142 @@
+package kzg
+
+import (
+	"github.com/pkg/errors"
+
+	ckzg4844 "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+)
+
+// BytesPerBlob is the number of bytes in a single blob.
+const BytesPerBlob = ckzg4844.BytesPerBlob
+
+// Blob represents a serialized chunk of data.
+type Blob [BytesPerBlob]byte
+
+// BytesPerCell is the number of bytes in a single cell.
+const BytesPerCell = ckzg4844.BytesPerCell
+
+// Cell represents a chunk of an encoded Blob.
+type Cell [BytesPerCell]byte
+
+// Commitment represent a KZG commitment to a Blob.
+type Commitment [48]byte
+
+// Proof represents a KZG proof that attests to the validity of a Blob or parts of it.
+type Proof [48]byte
+
+// Bytes48 is a 48-byte array.
+type Bytes48 = ckzg4844.Bytes48
+
+// Bytes32 is a 32-byte array.
+type Bytes32 = ckzg4844.Bytes32
+
+// CellsAndProofs represents the Cells and Proofs corresponding to a single blob.
+type CellsAndProofs struct {
+	Cells  []Cell
+	Proofs []Proof
+}
+
+// BlobToKZGCommitment computes a KZG commitment from a given blob.
+func BlobToKZGCommitment(blob *Blob) (Commitment, error) {
+	var kzgBlob kzg4844.Blob
+	copy(kzgBlob[:], blob[:])
+
+	commitment, err := kzg4844.BlobToCommitment(&kzgBlob)
+	if err != nil {
+		return Commitment{}, err
+	}
+
+	return Commitment(commitment), nil
+}
+
+// ComputeCells computes the (extended) cells from a given blob.
+func ComputeCells(blob *Blob) ([]Cell, error) {
+	var ckzgBlob ckzg4844.Blob
+	copy(ckzgBlob[:], blob[:])
+
+	ckzgCells, err := ckzg4844.ComputeCells(&ckzgBlob)
+	if err != nil {
+		return nil, errors.Wrap(err, "compute cells")
+	}
+
+	cells := make([]Cell, len(ckzgCells))
+	for i := range ckzgCells {
+		cells[i] = Cell(ckzgCells[i])
+	}
+
+	return cells, nil
+}
+
+// ComputeBlobKZGProof computes the blob KZG proof from a given blob and its commitment.
+func ComputeBlobKZGProof(blob *Blob, commitment Commitment) (Proof, error) {
+	var kzgBlob kzg4844.Blob
+	copy(kzgBlob[:], blob[:])
+
+	proof, err := kzg4844.ComputeBlobProof(&kzgBlob, kzg4844.Commitment(commitment))
+	if err != nil {
+		return [48]byte{}, err
+	}
+	return Proof(proof), nil
+}
+
+// ComputeCellsAndKZGProofs computes the cells and cells KZG proofs from a given blob.
+func ComputeCellsAndKZGProofs(blob *Blob) (CellsAndProofs, error) {
+	var ckzgBlob ckzg4844.Blob
+	copy(ckzgBlob[:], blob[:])
+
+	ckzgCells, ckzgProofs, err := ckzg4844.ComputeCellsAndKZGProofs(&ckzgBlob)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// VerifyCellKZGProofBatch verifies the KZG proofs for a given slice of commitments, cells indices, cells and proofs.
+// Note: It is way more efficient to call once this function with big slices than calling it multiple times with small slices.
+func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, cells []Cell, proofsBytes []Bytes48) (bool, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgCells := make([]ckzg4844.Cell, len(cells))
+
+	for i := range cells {
+		ckzgCells[i] = ckzg4844.Cell(cells[i])
+	}
+	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
+}
+
+// RecoverCellsAndKZGProofs recovers the complete cells and KZG proofs from a given set of cell indices and partial cells.
+func RecoverCellsAndKZGProofs(cellIndices []uint64, partialCells []Cell) (CellsAndProofs, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgPartialCells := make([]ckzg4844.Cell, len(partialCells))
+	for i := range partialCells {
+		ckzgPartialCells[i] = ckzg4844.Cell(partialCells[i])
+	}
+
+	ckzgCells, ckzgProofs, err := ckzg4844.RecoverCellsAndKZGProofs(cellIndices, ckzgPartialCells)
+	if err != nil {
+		return CellsAndProofs{}, errors.Wrap(err, "recover cells and KZG proofs")
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// makeCellsAndProofs converts cells/proofs to the CellsAndProofs type defined in this package.
+func makeCellsAndProofs(ckzgCells []ckzg4844.Cell, ckzgProofs []ckzg4844.KZGProof) (CellsAndProofs, error) {
+	if len(ckzgCells) != len(ckzgProofs) {
+		return CellsAndProofs{}, errors.New("different number of cells/proofs")
+	}
+
+	cells := make([]Cell, 0, len(ckzgCells))
+	proofs := make([]Proof, 0, len(ckzgProofs))
+
+	for i := range ckzgCells {
+		cells = append(cells, Cell(ckzgCells[i]))
+		proofs = append(proofs, Proof(ckzgProofs[i]))
+	}
+
+	return CellsAndProofs{
+		Cells:  cells,
+		Proofs: proofs,
+	}, nil
+}
--- a/beacon-chain/blockchain/kzg/trusted_setup.go
+++ b/beacon-chain/blockchain/kzg/trusted_setup.go
@@ -5,24 +5,69 @@ import (
 	"encoding/json"

 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	CKZG "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 )

 var (
-	//go:embed trusted_setup.json
+	// https://github.com/ethereum/consensus-specs/blob/master/presets/mainnet/trusted_setups/trusted_setup_4096.json
+	//go:embed trusted_setup_4096.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context
+	kzgLoaded            bool
 )

+type TrustedSetup struct {
+	G1Monomial [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_monomial"`
+	G1Lagrange [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_lagrange"`
+	G2Monomial [65]GoKZG.G2CompressedHexStr                   `json:"g2_monomial"`
+}
+
 func Start() error {
-	parsedSetup := GoKZG.JSONTrustedSetup{}
-	err := json.Unmarshal(embeddedTrustedSetup, &parsedSetup)
+	trustedSetup := &TrustedSetup{}
+	err := json.Unmarshal(embeddedTrustedSetup, trustedSetup)
 	if err != nil {
 		return errors.Wrap(err, "could not parse trusted setup JSON")
 	}
-	kzgContext, err = GoKZG.NewContext4096(&parsedSetup)
+
+	kzgContext, err = GoKZG.NewContext4096(&GoKZG.JSONTrustedSetup{
+		SetupG2:         trustedSetup.G2Monomial[:],
+		SetupG1Lagrange: trustedSetup.G1Lagrange,
+	})
 	if err != nil {
 		return errors.Wrap(err, "could not initialize go-kzg context")
 	}
+
+	// Length of a G1 point, converted from hex to binary.
+	g1MonomialBytes := make([]byte, len(trustedSetup.G1Monomial)*(len(trustedSetup.G1Monomial[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Monomial {
+		copy(g1MonomialBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+
+	// Length of a G1 point, converted from hex to binary.
+	g1LagrangeBytes := make([]byte, len(trustedSetup.G1Lagrange)*(len(trustedSetup.G1Lagrange[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Lagrange {
+		copy(g1LagrangeBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+
+	// Length of a G2 point, converted from hex to binary.
+	g2MonomialBytes := make([]byte, len(trustedSetup.G2Monomial)*(len(trustedSetup.G2Monomial[0])-2)/2)
+	for i, g2 := range &trustedSetup.G2Monomial {
+		copy(g2MonomialBytes[i*(len(g2)-2)/2:], hexutil.MustDecode(g2))
+	}
+
+	if !kzgLoaded {
+		const precompute uint = 8
+
+		kzgLoaded = true
+
+		// Free the current trusted setup before running this method.
+		// CKZG panics if the same setup is run multiple times.
+		if err = CKZG.LoadTrustedSetup(g1MonomialBytes, g1LagrangeBytes, g2MonomialBytes, precompute); err != nil {
+			return errors.Wrap(err, "load trust setup")
+		}
+	}
+
 	return nil
 }
--- a/beacon-chain/blockchain/kzg/trusted_setup_4096.json
+++ b/beacon-chain/blockchain/kzg/trusted_setup_4096.json
--- a/beacon-chain/blockchain/kzg/validation.go
+++ b/beacon-chain/blockchain/kzg/validation.go
@@ -1,32 +1,14 @@
 package kzg

 import (
+	"fmt"
+
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	ckzg4844 "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/pkg/errors"
 )

-// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
-func Verify(sidecars ...blocks.ROBlob) error {
-	if len(sidecars) == 0 {
-		return nil
-	}
-	if len(sidecars) == 1 {
-		return kzgContext.VerifyBlobKZGProof(
-			bytesToBlob(sidecars[0].Blob),
-			bytesToCommitment(sidecars[0].KzgCommitment),
-			bytesToKZGProof(sidecars[0].KzgProof))
-	}
-	blobs := make([]GoKZG.Blob, len(sidecars))
-	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
-	proofs := make([]GoKZG.KZGProof, len(sidecars))
-	for i, sidecar := range sidecars {
-		blobs[i] = *bytesToBlob(sidecar.Blob)
-		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
-		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
-	}
-	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
-}
-
 func bytesToBlob(blob []byte) *GoKZG.Blob {
 	var ret GoKZG.Blob
 	copy(ret[:], blob)
@@ -42,3 +24,144 @@ func bytesToKZGProof(proof []byte) (ret GoKZG.KZGProof) {
 	copy(ret[:], proof)
 	return
 }
+
+// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
+func Verify(blobSidecars ...blocks.ROBlob) error {
+	if len(blobSidecars) == 0 {
+		return nil
+	}
+	if len(blobSidecars) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobSidecars[0].Blob),
+			bytesToCommitment(blobSidecars[0].KzgCommitment),
+			bytesToKZGProof(blobSidecars[0].KzgProof))
+	}
+	blobs := make([]GoKZG.Blob, len(blobSidecars))
+	cmts := make([]GoKZG.KZGCommitment, len(blobSidecars))
+	proofs := make([]GoKZG.KZGProof, len(blobSidecars))
+	for i, sidecar := range blobSidecars {
+		blobs[i] = *bytesToBlob(sidecar.Blob)
+		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
+		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
+	}
+	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
+}
+
+// VerifyBlobKZGProofBatch verifies KZG proofs for multiple blobs using batch verification.
+// This is more efficient than verifying each blob individually when len(blobs) > 1.
+// For single blob verification, it uses the optimized single verification path.
+func VerifyBlobKZGProofBatch(blobs [][]byte, commitments [][]byte, proofs [][]byte) error {
+	if len(blobs) != len(commitments) || len(blobs) != len(proofs) {
+		return errors.Errorf("number of blobs (%d), commitments (%d), and proofs (%d) must match", len(blobs), len(commitments), len(proofs))
+	}
+
+	if len(blobs) == 0 {
+		return nil
+	}
+
+	// Optimize for single blob case - use single verification to avoid batch overhead
+	if len(blobs) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobs[0]),
+			bytesToCommitment(commitments[0]),
+			bytesToKZGProof(proofs[0]))
+	}
+
+	// Use batch verification for multiple blobs
+	ckzgBlobs := make([]ckzg4844.Blob, len(blobs))
+	ckzgCommitments := make([]ckzg4844.Bytes48, len(commitments))
+	ckzgProofs := make([]ckzg4844.Bytes48, len(proofs))
+
+	for i := range blobs {
+		if len(blobs[i]) != len(ckzg4844.Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[i]), len(ckzg4844.Blob{}))
+		}
+		if len(commitments[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[i]), len(ckzg4844.Blob{}))
+		}
+		if len(proofs[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(proofs[i]), len(ckzg4844.Blob{}))
+		}
+		ckzgBlobs[i] = ckzg4844.Blob(blobs[i])
+		ckzgCommitments[i] = ckzg4844.Bytes48(commitments[i])
+		ckzgProofs[i] = ckzg4844.Bytes48(proofs[i])
+	}
+
+	valid, err := ckzg4844.VerifyBlobKZGProofBatch(ckzgBlobs, ckzgCommitments, ckzgProofs)
+	if err != nil {
+		return errors.Wrap(err, "batch verification")
+	}
+	if !valid {
+		return errors.New("batch KZG proof verification failed")
+	}
+
+	return nil
+}
+
+// VerifyCellKZGProofBatchFromBlobData verifies cell KZG proofs in batch format directly from blob data.
+// This is more efficient than reconstructing data column sidecars when you have the raw blob data and cell proofs.
+// For PeerDAS/Fulu, the execution client provides cell proofs in flattened format via BlobsBundleV2.
+// For single blob verification, it optimizes by computing cells once and verifying efficiently.
+func VerifyCellKZGProofBatchFromBlobData(blobs [][]byte, commitments [][]byte, cellProofs [][]byte, numberOfColumns uint64) error {
+	blobCount := uint64(len(blobs))
+	expectedCellProofs := blobCount * numberOfColumns
+
+	if uint64(len(cellProofs)) != expectedCellProofs {
+		return errors.Errorf("expected %d cell proofs, got %d", expectedCellProofs, len(cellProofs))
+	}
+
+	if len(commitments) != len(blobs) {
+		return errors.Errorf("number of commitments (%d) must match number of blobs (%d)", len(commitments), len(blobs))
+	}
+
+	if blobCount == 0 {
+		return nil
+	}
+
+	// Handle multiple blobs - compute cells for all blobs
+	allCells := make([]Cell, 0, expectedCellProofs)
+	allCommitments := make([]Bytes48, 0, expectedCellProofs)
+	allIndices := make([]uint64, 0, expectedCellProofs)
+	allProofs := make([]Bytes48, 0, expectedCellProofs)
+
+	for blobIndex := range blobs {
+		if len(blobs[blobIndex]) != len(Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[blobIndex]), len(Blob{}))
+		}
+		// Convert blob to kzg.Blob type
+		blob := Blob(blobs[blobIndex])
+
+		// Compute cells for this blob
+		cells, err := ComputeCells(&blob)
+		if err != nil {
+			return errors.Wrapf(err, "failed to compute cells for blob %d", blobIndex)
+		}
+
+		// Add cells and corresponding data for each column
+		for columnIndex := range numberOfColumns {
+			cellProofIndex := uint64(blobIndex)*numberOfColumns + columnIndex
+			if len(commitments[blobIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[blobIndex]), len(Bytes48{}))
+			}
+			if len(cellProofs[cellProofIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(cellProofs[cellProofIndex]), len(Bytes48{}))
+			}
+			allCells = append(allCells, cells[columnIndex])
+			allCommitments = append(allCommitments, Bytes48(commitments[blobIndex]))
+			allIndices = append(allIndices, columnIndex)
+
+			allProofs = append(allProofs, Bytes48(cellProofs[cellProofIndex]))
+		}
+	}
+
+	// Batch verify all cells
+	valid, err := VerifyCellKZGProofBatch(allCommitments, allIndices, allCells, allProofs)
+	if err != nil {
+		return errors.Wrap(err, "cell batch verification")
+	}
+	if !valid {
+		return errors.New("cell KZG proof batch verification failed")
+	}
+
+	return nil
+}
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -4,8 +4,8 @@ import (
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/crypto/random"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 )

@@ -22,8 +22,8 @@ func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZG
 }

 func TestVerify(t *testing.T) {
-	sidecars := make([]blocks.ROBlob, 0)
-	require.NoError(t, Verify(sidecars...))
+	blobSidecars := make([]blocks.ROBlob, 0)
+	require.NoError(t, Verify(blobSidecars...))
 }

 func TestBytesToAny(t *testing.T) {
@@ -37,7 +37,8 @@ func TestBytesToAny(t *testing.T) {
 }

 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := util.GetRandBlob(123)
+	require.NoError(t, Start())
+	blob := random.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
 	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}
@@ -45,3 +46,432 @@ func TestGenerateCommitmentAndProof(t *testing.T) {
 	require.Equal(t, expectedCommitment, commitment)
 	require.Equal(t, expectedProof, proof)
 }
+
+func TestVerifyBlobKZGProofBatch(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob batch", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob batch", func(t *testing.T) {
+		blobCount := 3
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		proofs := make([][]byte, blobCount)
+
+		for i := 0; i < blobCount; i++ {
+			blob := random.GetRandBlob(int64(i))
+			commitment, proof, err := GenerateCommitmentAndProof(blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+			proofs[i] = proof[:]
+		}
+
+		err := VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyBlobKZGProofBatch([][]byte{}, [][]byte{}, [][]byte{})
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched input lengths", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Test different mismatch scenarios
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:]},
+			[][]byte{},
+			[][]byte{proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (1), commitments (0), and proofs (1) must match", err)
+
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:], blob[:]},
+			[][]byte{commitment[:]},
+			[][]byte{proof[:], proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (2), commitments (1), and proofs (2) must match", err)
+	})
+
+	t.Run("invalid commitment should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		_, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use a different blob's commitment (mismatch)
+		differentBlob := random.GetRandBlob(456)
+		wrongCommitment, _, err := GenerateCommitmentAndProof(differentBlob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		// Single blob optimization uses different error message
+		require.ErrorContains(t, "can't verify opening proof", err)
+	})
+
+	t.Run("invalid proof should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, _, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use wrong proof
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "short buffer", err)
+	})
+
+	t.Run("mixed valid and invalid proofs should fail", func(t *testing.T) {
+		// First blob - valid
+		blob1 := random.GetRandBlob(123)
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Second blob - invalid proof
+		blob2 := random.GetRandBlob(456)
+		commitment2, _, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment2[:]}
+		proofs := [][]byte{proof1[:], invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch verification", err)
+	})
+
+	t.Run("batch KZG proof verification failed", func(t *testing.T) {
+		// Create multiple blobs with mismatched commitments and proofs to trigger batch verification failure
+		blob1 := random.GetRandBlob(123)
+		blob2 := random.GetRandBlob(456)
+
+		// Generate valid proof for blob1
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Generate valid proof for blob2 but use wrong commitment (from blob1)
+		_, proof2, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+
+		// Use blob2 data with blob1's commitment and blob2's proof - this should cause batch verification to fail
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment1[:]} // Wrong commitment for blob2
+		proofs := [][]byte{proof1[:], proof2[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch KZG proof verification failed", err)
+	})
+}
+
+func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and commitment
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Compute cells and proofs
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Create flattened cell proofs (like execution client format)
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := range blobCount {
+			// Generate blob and commitment
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+
+			// Compute cells and proofs
+			cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+
+			// Add cell proofs for this blob
+			for j := range numberOfColumns {
+				allCellProofs = append(allCellProofs, cellsAndProofs.Proofs[j][:])
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyCellKZGProofBatchFromBlobData([][]byte{}, [][]byte{}, [][]byte{}, 128)
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched blob and commitment count", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		err := VerifyCellKZGProofBatchFromBlobData(
+			[][]byte{blob[:]},
+			[][]byte{}, // Empty commitments
+			[][]byte{},
+			128,
+		)
+		require.ErrorContains(t, "expected 128 cell proofs", err)
+	})
+
+	t.Run("wrong cell proof count", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Wrong number of cell proofs - should be 128 for 1 blob, but provide 10
+		wrongCellProofs := make([][]byte, 10)
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, wrongCellProofs, numberOfColumns)
+		require.ErrorContains(t, "expected 128 cell proofs, got 10", err)
+	})
+
+	t.Run("invalid cell proofs should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Create invalid cell proofs (all zeros)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			invalidCellProofs[i] = make([]byte, 48) // All zeros
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell batch verification", err)
+	})
+
+	t.Run("mismatched commitment should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and correct cell proofs
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Generate wrong commitment from different blob
+		randBlob2 := random.GetRandBlob(456)
+		var differentBlob Blob
+		copy(differentBlob[:], randBlob2[:])
+		wrongCommitment, err := BlobToKZGCommitment(&differentBlob)
+		require.NoError(t, err)
+
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell KZG proof batch verification failed", err)
+	})
+
+	t.Run("invalid blob data that should cause ComputeCells to fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Create invalid blob (not properly formatted)
+		invalidBlobData := make([]byte, 10) // Too short
+		commitment := make([]byte, 48)      // Dummy commitment
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{invalidBlobData}
+		commitments := [][]byte{commitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NotNil(t, err)
+		require.ErrorContains(t, "blobs len (10) differs from expected (131072)", err)
+	})
+
+	t.Run("invalid commitment size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		// Create invalid commitment (wrong size)
+		invalidCommitment := make([]byte, 32) // Should be 48 bytes
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{invalidCommitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("invalid cell proof size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Create invalid cell proofs (wrong size)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			if i == 0 {
+				invalidCellProofs[i] = make([]byte, 32) // Wrong size - should be 48
+			} else {
+				invalidCellProofs[i] = make([]byte, 48)
+			}
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid commitments", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		// First blob - valid
+		randBlob1 := random.GetRandBlob(123)
+		var blob1 Blob
+		copy(blob1[:], randBlob1[:])
+		commitment1, err := BlobToKZGCommitment(&blob1)
+		require.NoError(t, err)
+		blobs[0] = blob1[:]
+		commitments[0] = commitment1[:]
+
+		// Second blob - use invalid commitment size
+		randBlob2 := random.GetRandBlob(456)
+		var blob2 Blob
+		copy(blob2[:], randBlob2[:])
+		blobs[1] = blob2[:]
+		commitments[1] = make([]byte, 32) // Wrong size
+
+		// Add cell proofs for both blobs
+		for i := 0; i < blobCount; i++ {
+			for j := uint64(0); j < numberOfColumns; j++ {
+				allCellProofs = append(allCellProofs, make([]byte, 48))
+			}
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid cell proof sizes", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := 0; i < blobCount; i++ {
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+
+			// Add cell proofs - make some invalid in the second blob
+			for j := uint64(0); j < numberOfColumns; j++ {
+				if i == 1 && j == 64 {
+					// Invalid proof size in middle of second blob's proofs
+					allCellProofs = append(allCellProofs, make([]byte, 20))
+				} else {
+					allCellProofs = append(allCellProofs, make([]byte, 48))
+				}
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (20) differs from expected (48)", err)
+	})
+}
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -26,9 +26,6 @@ func logStateTransitionData(b interfaces.ReadOnlyBeaconBlock) error {
 	if len(b.Body().Attestations()) > 0 {
 		log = log.WithField("attestations", len(b.Body().Attestations()))
 	}
-	if len(b.Body().Deposits()) > 0 {
-		log = log.WithField("deposits", len(b.Body().Deposits()))
-	}
 	if len(b.Body().AttesterSlashings()) > 0 {
 		log = log.WithField("attesterSlashings", len(b.Body().AttesterSlashings()))
 	}
@@ -89,8 +86,8 @@ func logStateTransitionData(b interfaces.ReadOnlyBeaconBlock) error {
 	return nil
 }

-func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64, daWaitedTime time.Duration) error {
-	startTime, err := slots.ToTime(genesisTime, block.Slot())
+func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesis time.Time, daWaitedTime time.Duration) error {
+	startTime, err := slots.StartTime(genesis, block.Slot())
 	if err != nil {
 		return err
 	}
@@ -111,7 +108,6 @@ func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte
 			"sinceSlotStartTime":         prysmTime.Now().Sub(startTime),
 			"chainServiceProcessedTime":  prysmTime.Now().Sub(receivedTime) - daWaitedTime,
 			"dataAvailabilityWaitedTime": daWaitedTime,
-			"deposits":                   len(block.Body().Deposits()),
 		}
 		log.WithFields(lf).Debug("Synced new block")
 	} else {
@@ -159,7 +155,9 @@ func logPayload(block interfaces.ReadOnlyBeaconBlock) error {
 		if err != nil {
 			return errors.Wrap(err, "could not get BLSToExecutionChanges")
 		}
-		fields["blsToExecutionChanges"] = len(changes)
+		if len(changes) > 0 {
+			fields["blsToExecutionChanges"] = len(changes)
+		}
 	}
 	log.WithFields(fields).Debug("Synced new payload")
 	return nil
--- a/beacon-chain/blockchain/log_test.go
+++ b/beacon-chain/blockchain/log_test.go
@@ -53,7 +53,7 @@ func Test_logStateTransitionData(t *testing.T) {
 				require.NoError(t, err)
 				return wb
 			},
-			want: "\"Finished applying state transition\" attestations=1 deposits=1 prefix=blockchain slot=0",
+			want: "\"Finished applying state transition\" attestations=1 prefix=blockchain slot=0",
 		},
 		{name: "has attester slashing",
 			b: func() interfaces.ReadOnlyBeaconBlock {
@@ -93,7 +93,7 @@ func Test_logStateTransitionData(t *testing.T) {
 				require.NoError(t, err)
 				return wb
 			},
-			want: "\"Finished applying state transition\" attestations=1 attesterSlashings=1 deposits=1 prefix=blockchain proposerSlashings=1 slot=0 voluntaryExits=1",
+			want: "\"Finished applying state transition\" attestations=1 attesterSlashings=1 prefix=blockchain proposerSlashings=1 slot=0 voluntaryExits=1",
 		},
 		{name: "has payload",
 			b:    func() interfaces.ReadOnlyBeaconBlock { return wrappedPayloadBlk },
--- a/beacon-chain/blockchain/metrics_test.go
+++ b/beacon-chain/blockchain/metrics_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"context"
 	"testing"

 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -9,23 +8,13 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 )

-func TestReportEpochMetrics_BadHeadState(t *testing.T) {
-	s, err := util.NewBeaconState()
-	require.NoError(t, err)
-	h, err := util.NewBeaconState()
-	require.NoError(t, err)
-	require.NoError(t, h.SetValidators(nil))
-	err = reportEpochMetrics(context.Background(), s, h)
-	require.ErrorContains(t, "failed to initialize precompute: state has nil validator slice", err)
-}
-
 func TestReportEpochMetrics_BadAttestation(t *testing.T) {
 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
 	h, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, h.AppendCurrentEpochAttestations(&eth.PendingAttestation{InclusionDelay: 0}))
-	err = reportEpochMetrics(context.Background(), s, h)
+	err = reportEpochMetrics(t.Context(), s, h)
 	require.ErrorContains(t, "attestation with inclusion delay of 0", err)
 }

@@ -36,6 +25,6 @@ func TestReportEpochMetrics_SlashedValidatorOutOfBound(t *testing.T) {
 	v.Slashed = true
 	require.NoError(t, h.UpdateValidatorAtIndex(0, v))
 	require.NoError(t, h.AppendCurrentEpochAttestations(&eth.PendingAttestation{InclusionDelay: 1, Data: util.HydrateAttestationData(&eth.AttestationData{})}))
-	err = reportEpochMetrics(context.Background(), h, h)
+	err = reportEpochMetrics(t.Context(), h, h)
 	require.ErrorContains(t, "slot 0 out of bounds", err)
 }
--- a/beacon-chain/blockchain/mock_test.go
+++ b/beacon-chain/blockchain/mock_test.go
@@ -8,9 +8,10 @@ import (
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
 )

-func testServiceOptsWithDB(t *testing.T) []Option {
+func testServiceOptsWithDB(t testing.TB) []Option {
 	beaconDB := testDB.SetupDB(t)
 	fcs := doublylinkedtree.New()
 	cs := startup.NewClockSynchronizer()
@@ -20,6 +21,7 @@ func testServiceOptsWithDB(t *testing.T) []Option {
 		WithForkChoiceStore(fcs),
 		WithClockSynchronizer(cs),
 		WithStateNotifier(&mock.MockStateNotifier{RecordEvents: true}),
+		WithSyncChecker(&mock.MockSyncChecker{}),
 	}
 }

@@ -30,3 +32,15 @@ func testServiceOptsNoDB() []Option {
 	cs := startup.NewClockSynchronizer()
 	return []Option{WithClockSynchronizer(cs)}
 }
+
+func testServiceNoDB(t testing.TB) *Service {
+	s, err := NewService(t.Context(), testServiceOptsNoDB()...)
+	require.NoError(t, err)
+	return s
+}
+
+func testServiceWithDB(t testing.TB) *Service {
+	s, err := NewService(t.Context(), testServiceOptsWithDB(t)...)
+	require.NoError(t, err)
+	return s
+}
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -1,6 +1,8 @@
 package blockchain

 import (
+	"time"
+
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
@@ -30,6 +32,14 @@ func WithMaxGoroutines(x int) Option {
 	}
 }

+// WithLCStore for light client store access.
+func WithLCStore() Option {
+	return func(s *Service) error {
+		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
+		return nil
+	}
+}
+
 // WithWeakSubjectivityCheckpoint for checkpoint sync.
 func WithWeakSubjectivityCheckpoint(c *ethpb.Checkpoint) Option {
 	return func(s *Service) error {
@@ -127,9 +137,9 @@ func WithBLSToExecPool(p blstoexec.PoolManager) Option {
 }

 // WithP2PBroadcaster to broadcast messages after appropriate processing.
-func WithP2PBroadcaster(p p2p.Broadcaster) Option {
+func WithP2PBroadcaster(p p2p.Accessor) Option {
 	return func(s *Service) error {
-		s.cfg.P2p = p
+		s.cfg.P2P = p
 		return nil
 	}
 }
@@ -208,6 +218,15 @@ func WithBlobStorage(b *filesystem.BlobStorage) Option {
 	}
 }

+// WithDataColumnStorage sets the data column storage backend for the blockchain service.
+func WithDataColumnStorage(b *filesystem.DataColumnStorage) Option {
+	return func(s *Service) error {
+		s.dataColumnStorage = b
+		return nil
+	}
+}
+
+// WithSyncChecker sets the sync checker for the blockchain service.
 func WithSyncChecker(checker Checker) Option {
 	return func(s *Service) error {
 		s.cfg.SyncChecker = checker
@@ -215,6 +234,7 @@ func WithSyncChecker(checker Checker) Option {
 	}
 }

+// WithSlasherEnabled sets whether the slasher is enabled or not.
 func WithSlasherEnabled(enabled bool) Option {
 	return func(s *Service) error {
 		s.slasherEnabled = enabled
@@ -222,9 +242,27 @@ func WithSlasherEnabled(enabled bool) Option {
 	}
 }

+// WithGenesisTime sets the genesis time for the blockchain service.
+func WithGenesisTime(genesisTime time.Time) Option {
+	return func(s *Service) error {
+		s.genesisTime = genesisTime.Truncate(time.Second) // Genesis time has a precision of 1 second.
+		return nil
+	}
+}
+
+// WithLightClientStore sets the light client store for the blockchain service.
 func WithLightClientStore(lcs *lightclient.Store) Option {
 	return func(s *Service) error {
 		s.lcStore = lcs
 		return nil
 	}
 }
+
+// WithStartWaitingDataColumnSidecars sets a channel that the `areDataColumnsAvailable` function will fill
+// in when starting to wait for additional data columns.
+func WithStartWaitingDataColumnSidecars(c chan bool) Option {
+	return func(s *Service) error {
+		s.startWaitingDataColumnSidecars = c
+		return nil
+	}
+}
--- a/beacon-chain/blockchain/process_attestation.go
+++ b/beacon-chain/blockchain/process_attestation.go
@@ -5,6 +5,7 @@ import (
 	"time"

 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -59,10 +60,8 @@ func (s *Service) OnAttestation(ctx context.Context, a ethpb.Att, disparity time
 		return err
 	}

-	genesisTime := uint64(s.genesisTime.Unix())
-
 	// Verify attestation target is from current epoch or previous epoch.
-	if err := verifyAttTargetEpoch(ctx, genesisTime, uint64(time.Now().Add(disparity).Unix()), tgt); err != nil {
+	if err := verifyAttTargetEpoch(ctx, s.genesisTime, time.Now().Add(disparity), tgt); err != nil {
 		return err
 	}

@@ -75,7 +74,7 @@ func (s *Service) OnAttestation(ctx context.Context, a ethpb.Att, disparity time
 	// validate_aggregate_proof.go and validate_beacon_attestation.go

 	// Verify attestations can only affect the fork choice of subsequent slots.
-	if err := slots.VerifyTime(genesisTime, a.GetData().Slot+1, disparity); err != nil {
+	if err := slots.VerifyTime(s.genesisTime, a.GetData().Slot+1, disparity); err != nil {
 		return err
 	}

@@ -88,7 +87,7 @@ func (s *Service) OnAttestation(ctx context.Context, a ethpb.Att, disparity time
 	if err != nil {
 		return err
 	}
-	if err := attestation.IsValidAttestationIndices(ctx, indexedAtt); err != nil {
+	if err := attestation.IsValidAttestationIndices(ctx, indexedAtt, params.BeaconConfig().MaxValidatorsPerCommittee, params.BeaconConfig().MaxCommitteesPerSlot); err != nil {
 		return err
 	}

--- a/beacon-chain/blockchain/process_attestation_helpers.go
+++ b/beacon-chain/blockchain/process_attestation_helpers.go
@@ -4,12 +4,12 @@ import (
 	"context"
 	"fmt"
 	"strconv"
+	"time"

 	"github.com/OffchainLabs/prysm/v6/async"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
-	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -139,8 +139,8 @@ func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (stat
 }

 // verifyAttTargetEpoch validates attestation is from the current or previous epoch.
-func verifyAttTargetEpoch(_ context.Context, genesisTime, nowTime uint64, c *ethpb.Checkpoint) error {
-	currentSlot := primitives.Slot((nowTime - genesisTime) / params.BeaconConfig().SecondsPerSlot)
+func verifyAttTargetEpoch(_ context.Context, genesis, now time.Time, c *ethpb.Checkpoint) error {
+	currentSlot := slots.At(genesis, now)
 	currentEpoch := slots.ToEpoch(currentSlot)
 	var prevEpoch primitives.Epoch
 	// Prevents previous epoch under flow
--- a/beacon-chain/blockchain/process_attestation_test.go
+++ b/beacon-chain/blockchain/process_attestation_test.go
@@ -161,7 +161,7 @@ func TestStore_OnAttestation_Ok_DoublyLinkedTree(t *testing.T) {

 func TestService_GetRecentPreState(t *testing.T) {
 	service, _ := minimalTestService(t)
-	ctx := context.Background()
+	ctx := t.Context()

 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
@@ -183,7 +183,7 @@ func TestService_GetRecentPreState(t *testing.T) {

 func TestService_GetAttPreState_Concurrency(t *testing.T) {
 	service, _ := minimalTestService(t)
-	ctx := context.Background()
+	ctx := t.Context()

 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
@@ -353,29 +353,29 @@ func TestStore_UpdateCheckpointState(t *testing.T) {
 }

 func TestAttEpoch_MatchPrevEpoch(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

-	nowTime := uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	require.NoError(t, verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)}))
+	nowTime := time.Unix(int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
+	require.NoError(t, verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)}))
 }

 func TestAttEpoch_MatchCurrentEpoch(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

-	nowTime := uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	require.NoError(t, verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Epoch: 1}))
+	nowTime := time.Unix(int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
+	require.NoError(t, verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Epoch: 1}))
 }

 func TestAttEpoch_NotMatch(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

-	nowTime := 2 * uint64(params.BeaconConfig().SlotsPerEpoch) * params.BeaconConfig().SecondsPerSlot
-	err := verifyAttTargetEpoch(ctx, 0, nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)})
+	nowTime := time.Unix(2*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
+	err := verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)})
 	assert.ErrorContains(t, "target epoch 0 does not match current epoch 2 or prev epoch 1", err)
 }

 func TestVerifyBeaconBlock_NoBlock(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	opts := testServiceOptsWithDB(t)
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -385,7 +385,7 @@ func TestVerifyBeaconBlock_NoBlock(t *testing.T) {
 }

 func TestVerifyBeaconBlock_futureBlock(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

 	opts := testServiceOptsWithDB(t)
 	service, err := NewService(ctx, opts...)
@@ -402,7 +402,7 @@ func TestVerifyBeaconBlock_futureBlock(t *testing.T) {
 }

 func TestVerifyBeaconBlock_OK(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

 	opts := testServiceOptsWithDB(t)
 	service, err := NewService(ctx, opts...)
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -3,10 +3,12 @@ package blockchain
 import (
 	"context"
 	"fmt"
+	"slices"
 	"time"

 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
@@ -70,8 +72,6 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	}
 	if features.Get().EnableLightClient && slots.ToEpoch(s.CurrentSlot()) >= params.BeaconConfig().AltairForkEpoch {
 		defer s.processLightClientUpdates(cfg)
-		defer s.saveLightClientUpdate(cfg)
-		defer s.saveLightClientBootstrap(cfg)
 	}
 	defer s.sendStateFeedOnBlock(cfg)
 	defer reportProcessingTime(startTime)
@@ -159,7 +159,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	}

 	// Fill in missing blocks
-	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.CurrentJustifiedCheckpoint(), preState.FinalizedCheckpoint()); err != nil {
+	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.FinalizedCheckpoint(), preState.CurrentJustifiedCheckpoint()); err != nil {
 		return errors.Wrap(err, "could not fill in missing blocks to forkchoice")
 	}

@@ -239,9 +239,11 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate blob data availability at slot %d", b.Block().Slot())
+
+		if err := s.areSidecarsAvailable(ctx, avs, b); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability for block %#x at slot %d", b.Root(), b.Block().Slot())
 		}
+
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b,
 			JustifiedCheckpoint: jCheckpoints[i],
 			FinalizedCheckpoint: fCheckpoints[i]}
@@ -307,6 +309,30 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }

+func (s *Service) areSidecarsAvailable(ctx context.Context, avs das.AvailabilityStore, roBlock consensusblocks.ROBlock) error {
+	blockVersion := roBlock.Version()
+	block := roBlock.Block()
+	slot := block.Slot()
+
+	if blockVersion >= version.Fulu {
+		if err := s.areDataColumnsAvailable(ctx, roBlock.Root(), block); err != nil {
+			return errors.Wrapf(err, "are data columns available for block %#x with slot %d", roBlock.Root(), slot)
+		}
+
+		return nil
+	}
+
+	if blockVersion >= version.Deneb {
+		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), roBlock); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", slot)
+		}
+
+		return nil
+	}
+
+	return nil
+}
+
 func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.BeaconState) error {
 	e := coreTime.CurrentEpoch(st)
 	if err := helpers.UpdateCommitteeCache(ctx, st, e); err != nil {
@@ -328,7 +354,7 @@ func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.Beacon
 	// The latest block header is from the previous epoch
 	r, err := st.LatestBlockHeader().HashTreeRoot()
 	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
+		log.WithError(err).Error("Could not update proposer index state-root map")
 		return nil
 	}
 	// The proposer indices cache takes the target root for the previous
@@ -338,12 +364,12 @@ func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.Beacon
 	}
 	target, err := s.cfg.ForkChoiceStore.TargetRootForEpoch(r, e)
 	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
+		log.WithError(err).Error("Could not update proposer index state-root map")
 		return nil
 	}
 	err = helpers.UpdateCachedCheckpointToStateRoot(st, &forkchoicetypes.Checkpoint{Epoch: e, Root: target})
 	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
+		log.WithError(err).Error("Could not update proposer index state-root map")
 	}
 	return nil
 }
@@ -561,7 +587,7 @@ func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion
 // If there is not, it will call forkchoice updated with the correct payload attribute then cache the payload ID.
 func (s *Service) runLateBlockTasks() {
 	if err := s.waitForSync(); err != nil {
-		log.WithError(err).Error("failed to wait for initial sync")
+		log.WithError(err).Error("Failed to wait for initial sync")
 		return
 	}

@@ -578,12 +604,12 @@ func (s *Service) runLateBlockTasks() {
 	}
 }

-// missingIndices uses the expected commitments from the block to determine
+// missingBlobIndices uses the expected commitments from the block to determine
 // which BlobSidecar indices would need to be in the database for DA success.
 // It returns a map where each key represents a missing BlobSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // BlobSidecars against the set of known missing sidecars.
-func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte, slot primitives.Slot) (map[uint64]struct{}, error) {
+func missingBlobIndices(store *filesystem.BlobStorage, root [fieldparams.RootLength]byte, expected [][]byte, slot primitives.Slot) (map[uint64]bool, error) {
 	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	if len(expected) == 0 {
 		return nil, nil
@@ -591,30 +617,244 @@ func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte
 	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices := bs.Summary(root)
-	missing := make(map[uint64]struct{}, len(expected))
+	indices := store.Summary(root)
+	missing := make(map[uint64]bool, len(expected))
 	for i := range expected {
 		if len(expected[i]) > 0 && !indices.HasIndex(uint64(i)) {
-			missing[uint64(i)] = struct{}{}
+			missing[uint64(i)] = true
 		}
 	}
 	return missing, nil
 }

-// isDataAvailable blocks until all BlobSidecars committed to in the block are available,
-// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
-// The function will first check the database to see if all sidecars have been persisted. If any
-// sidecars are missing, it will then read from the blobNotifier channel for the given root until the channel is
-// closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
-func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed interfaces.ReadOnlySignedBeaconBlock) error {
-	if signed.Version() < version.Deneb {
-		return nil
+// missingDataColumnIndices uses the expected data columns from the block to determine
+// which DataColumnSidecar indices would need to be in the database for DA success.
+// It returns a map where each key represents a missing DataColumnSidecar index.
+// An empty map means we have all indices; a non-empty map can be used to compare incoming
+// DataColumns against the set of known missing sidecars.
+func missingDataColumnIndices(store *filesystem.DataColumnStorage, root [fieldparams.RootLength]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+	if len(expected) == 0 {
+		return nil, nil
 	}

-	block := signed.Block()
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	if uint64(len(expected)) > numberOfColumns {
+		return nil, errMaxDataColumnsExceeded
+	}
+
+	// Get a summary of the data columns stored in the database.
+	summary := store.Summary(root)
+
+	// Check all expected data columns against the summary.
+	missing := make(map[uint64]bool)
+	for column := range expected {
+		if !summary.HasIndex(column) {
+			missing[column] = true
+		}
+	}
+
+	return missing, nil
+}
+
+// isDataAvailable blocks until all sidecars committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+// The function will first check the database to see if all sidecars have been persisted. If any
+// sidecars are missing, it will then read from the sidecar notifier channel for the given root until the channel is
+// closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
+func (s *Service) isDataAvailable(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	signedBlock interfaces.ReadOnlySignedBeaconBlock,
+) error {
+	block := signedBlock.Block()
 	if block == nil {
 		return errors.New("invalid nil beacon block")
 	}
+
+	blockVersion := block.Version()
+	if blockVersion >= version.Fulu {
+		return s.areDataColumnsAvailable(ctx, root, block)
+	}
+
+	if blockVersion >= version.Deneb {
+		return s.areBlobsAvailable(ctx, root, block)
+	}
+
+	return nil
+}
+
+// areDataColumnsAvailable blocks until all data columns committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+func (s *Service) areDataColumnsAvailable(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	block interfaces.ReadOnlyBeaconBlock,
+) error {
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+
+	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS
+	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
+	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return nil
+	}
+
+	body := block.Body()
+	if body == nil {
+		return errors.New("invalid nil beacon block body")
+	}
+
+	kzgCommitments, err := body.BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// If block has not commitments there is nothing to wait for.
+	if len(kzgCommitments) == 0 {
+		return nil
+	}
+
+	// All columns to sample need to be available for the block to be considered available.
+	nodeID := s.cfg.P2P.NodeID()
+
+	// Get the custody group sampling size for the node.
+	custodyGroupCount, err := s.cfg.P2P.CustodyGroupCount()
+	if err != nil {
+		return errors.Wrap(err, "custody group count")
+	}
+
+	// Compute the sampling size.
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#custody-sampling
+	samplingSize := max(samplesPerSlot, custodyGroupCount)
+
+	// Get the peer info for the node.
+	peerInfo, _, err := peerdas.Info(nodeID, samplingSize)
+	if err != nil {
+		return errors.Wrap(err, "peer info")
+	}
+
+	// Subscribe to newly data columns stored in the database.
+	subscription, identsChan := s.dataColumnStorage.Subscribe()
+	defer subscription.Unsubscribe()
+
+	// Get the count of data columns we already have in the store.
+	summary := s.dataColumnStorage.Summary(root)
+	storedDataColumnsCount := summary.Count()
+
+	minimumColumnCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
+
+	// As soon as we have enough data column sidecars, we can reconstruct the missing ones.
+	// We don't need to wait for the rest of the data columns to declare the block as available.
+	if storedDataColumnsCount >= minimumColumnCountToReconstruct {
+		return nil
+	}
+
+	// Get a map of data column indices that are not currently available.
+	missingMap, err := missingDataColumnIndices(s.dataColumnStorage, root, peerInfo.CustodyColumns)
+	if err != nil {
+		return errors.Wrap(err, "missing data columns")
+	}
+
+	// If there are no missing indices, all data column sidecars are available.
+	// This is the happy path.
+	if len(missingMap) == 0 {
+		return nil
+	}
+
+	if s.startWaitingDataColumnSidecars != nil {
+		s.startWaitingDataColumnSidecars <- true
+	}
+
+	// Log for DA checks that cross over into the next slot; helpful for debugging.
+	nextSlot, err := slots.StartTime(s.genesisTime, block.Slot()+1)
+	if err != nil {
+		return fmt.Errorf("unable to determine slot start time: %w", err)
+	}
+
+	// Avoid logging if DA check is called after next slot start.
+	if nextSlot.After(time.Now()) {
+		timer := time.AfterFunc(time.Until(nextSlot), func() {
+			missingMapCount := uint64(len(missingMap))
+
+			if missingMapCount == 0 {
+				return
+			}
+
+			var (
+				expected interface{} = "all"
+				missing  interface{} = "all"
+			)
+
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			colMapCount := uint64(len(peerInfo.CustodyColumns))
+
+			if colMapCount < numberOfColumns {
+				expected = uint64MapToSortedSlice(peerInfo.CustodyColumns)
+			}
+
+			if missingMapCount < numberOfColumns {
+				missing = uint64MapToSortedSlice(missingMap)
+			}
+
+			log.WithFields(logrus.Fields{
+				"slot":            block.Slot(),
+				"root":            fmt.Sprintf("%#x", root),
+				"columnsExpected": expected,
+				"columnsWaiting":  missing,
+			}).Warning("Data columns still missing at slot end")
+		})
+		defer timer.Stop()
+	}
+
+	for {
+		select {
+		case idents := <-identsChan:
+			if idents.Root != root {
+				// This is not the root we are looking for.
+				continue
+			}
+
+			for _, index := range idents.Indices {
+				// This is a data column we are expecting.
+				if _, ok := missingMap[index]; ok {
+					storedDataColumnsCount++
+				}
+
+				// As soon as we have more than half of the data columns, we can reconstruct the missing ones.
+				// We don't need to wait for the rest of the data columns to declare the block as available.
+				if storedDataColumnsCount >= minimumColumnCountToReconstruct {
+					return nil
+				}
+
+				// Remove the index from the missing map.
+				delete(missingMap, index)
+
+				// Return if there is no more missing data columns.
+				if len(missingMap) == 0 {
+					return nil
+				}
+			}
+
+		case <-ctx.Done():
+			var missingIndices interface{} = "all"
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			missingIndicesCount := uint64(len(missingMap))
+
+			if missingIndicesCount < numberOfColumns {
+				missingIndices = uint64MapToSortedSlice(missingMap)
+			}
+
+			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing: %v", block.Slot(), root, missingIndices)
+		}
+	}
+}
+
+// areBlobsAvailable blocks until all BlobSidecars committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+func (s *Service) areBlobsAvailable(ctx context.Context, root [fieldparams.RootLength]byte, block interfaces.ReadOnlyBeaconBlock) error {
+	blockSlot := block.Slot()
+
 	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
 	if !params.WithinDAPeriod(slots.ToEpoch(block.Slot()), slots.ToEpoch(s.CurrentSlot())) {
 		return nil
@@ -634,9 +874,9 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 		return nil
 	}
 	// get a map of BlobSidecar indices that are not currently available.
-	missing, err := missingIndices(s.blobStorage, root, kzgCommitments, block.Slot())
+	missing, err := missingBlobIndices(s.blobStorage, root, kzgCommitments, block.Slot())
 	if err != nil {
-		return err
+		return errors.Wrap(err, "missing indices")
 	}
 	// If there are no missing indices, all BlobSidecars are available.
 	if len(missing) == 0 {
@@ -648,15 +888,23 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	nc := s.blobNotifiers.forRoot(root, block.Slot())

 	// Log for DA checks that cross over into the next slot; helpful for debugging.
-	nextSlot := slots.BeginsAt(signed.Block().Slot()+1, s.genesisTime)
+	nextSlot, err := slots.StartTime(s.genesisTime, block.Slot()+1)
+	if err != nil {
+		return fmt.Errorf("unable to determine slot start time: %w", err)
+	}
 	// Avoid logging if DA check is called after next slot start.
 	if nextSlot.After(time.Now()) {
 		nst := time.AfterFunc(time.Until(nextSlot), func() {
 			if len(missing) == 0 {
 				return
 			}
-			log.WithFields(daCheckLogFields(root, signed.Block().Slot(), expected, len(missing))).
-				Error("Still waiting for DA check at slot end.")
+
+			log.WithFields(logrus.Fields{
+				"slot":          blockSlot,
+				"root":          fmt.Sprintf("%#x", root),
+				"blobsExpected": expected,
+				"blobsWaiting":  len(missing),
+			}).Error("Still waiting for blobs DA check at slot end.")
 		})
 		defer nst.Stop()
 	}
@@ -678,13 +926,14 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	}
 }

-func daCheckLogFields(root [32]byte, slot primitives.Slot, expected, missing int) logrus.Fields {
-	return logrus.Fields{
-		"slot":          slot,
-		"root":          fmt.Sprintf("%#x", root),
-		"blobsExpected": expected,
-		"blobsWaiting":  missing,
+// uint64MapToSortedSlice produces a sorted uint64 slice from a map.
+func uint64MapToSortedSlice(input map[uint64]bool) []uint64 {
+	output := make([]uint64, 0, len(input))
+	for idx := range input {
+		output = append(output, idx)
 	}
+	slices.Sort[[]uint64](output)
+	return output
 }

 // lateBlockTasks  is called 4 seconds into the slot and performs tasks
@@ -693,7 +942,7 @@ func daCheckLogFields(root [32]byte, slot primitives.Slot, expected, missing int
 // it also updates the next slot cache and the proposer index cache to deal with skipped slots.
 func (s *Service) lateBlockTasks(ctx context.Context) {
 	currentSlot := s.CurrentSlot()
-	if s.CurrentSlot() == s.HeadSlot() {
+	if currentSlot == s.HeadSlot() {
 		return
 	}
 	s.cfg.ForkChoiceStore.RLock()
@@ -714,10 +963,10 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	// blocks.
 	lastState.CopyAllTries()
 	if err := transition.UpdateNextSlotCache(ctx, lastRoot, lastState); err != nil {
-		log.WithError(err).Debug("could not update next slot state cache")
+		log.WithError(err).Debug("Could not update next slot state cache")
 	}
 	if err := s.handleEpochBoundary(ctx, currentSlot, headState, headRoot[:]); err != nil {
-		log.WithError(err).Error("lateBlockTasks: could not update epoch boundary caches")
+		log.WithError(err).Error("Could not update epoch boundary caches")
 	}
 	// return early if we already started building a block for the current
 	// head root
@@ -729,9 +978,13 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
 	// return early if we are not proposing next slot
 	if attribute.IsEmpty() {
+		headBlock, err := s.headBlock()
+		if err != nil {
+			log.WithError(err).WithField("head_root", headRoot).Error("Unable to retrieve head block to fire payload attributes event")
+		}
 		// notifyForkchoiceUpdate fires the payload attribute event. But in this case, we won't
 		// call notifyForkchoiceUpdate, so the event is fired here.
-		go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), headBlock, headRoot, s.CurrentSlot()+1)
 		return
 	}

@@ -766,7 +1019,7 @@ func (s *Service) waitForSync() error {
 	}
 }

-func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot [32]byte, parentRoot [32]byte) error {
+func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot, parentRoot [fieldparams.RootLength]byte) error {
 	if IsInvalidBlock(err) && InvalidBlockLVH(err) != [32]byte{} {
 		return s.pruneInvalidBlock(ctx, blockRoot, parentRoot, InvalidBlockLVH(err))
 	}
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"bytes"
 	"context"
 	"fmt"
 	"strings"
@@ -31,9 +30,13 @@ import (
 	"github.com/sirupsen/logrus"
 )

+// ErrInvalidCheckpointArgs may be returned when the finalized checkpoint has an epoch greater than the justified checkpoint epoch.
+// If you are seeing this error, make sure you haven't mixed up the order of the arguments in the method you are calling.
+var ErrInvalidCheckpointArgs = errors.New("finalized checkpoint cannot be greater than justified checkpoint")
+
 // CurrentSlot returns the current slot based on time.
 func (s *Service) CurrentSlot() primitives.Slot {
-	return slots.CurrentSlot(uint64(s.genesisTime.Unix()))
+	return slots.CurrentSlot(s.genesisTime)
 }

 // getFCUArgs returns the arguments to call forkchoice update
@@ -45,7 +48,7 @@ func (s *Service) getFCUArgs(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) er
 		return nil
 	}
 	slot := cfg.roblock.Block().Slot()
-	if slots.WithinVotingWindow(uint64(s.genesisTime.Unix()), slot) {
+	if slots.WithinVotingWindow(s.genesisTime, slot) {
 		return nil
 	}
 	return s.computePayloadAttributes(cfg, fcuArgs)
@@ -68,11 +71,11 @@ func (s *Service) getFCUArgsEarlyBlock(cfg *postBlockProcessConfig, fcuArgs *fcu
 func (s *Service) logNonCanonicalBlockReceived(blockRoot [32]byte, headRoot [32]byte) {
 	receivedWeight, err := s.cfg.ForkChoiceStore.Weight(blockRoot)
 	if err != nil {
-		log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Warn("could not determine node weight")
+		log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Warn("Could not determine node weight")
 	}
 	headWeight, err := s.cfg.ForkChoiceStore.Weight(headRoot)
 	if err != nil {
-		log.WithField("root", fmt.Sprintf("%#x", headRoot)).Warn("could not determine node weight")
+		log.WithField("root", fmt.Sprintf("%#x", headRoot)).Warn("Could not determine node weight")
 	}
 	log.WithFields(logrus.Fields{
 		"receivedRoot":   fmt.Sprintf("%#x", blockRoot),
@@ -103,20 +106,37 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 		log.WithError(err).Debug("Could not check if block is optimistic")
 		optimistic = true
 	}
+	currEpoch := slots.ToEpoch(s.CurrentSlot())
+	currDependenRoot, err := s.cfg.ForkChoiceStore.DependentRoot(currEpoch)
+	if err != nil {
+		log.WithError(err).Debug("Could not get dependent root")
+	}
+	prevDependentRoot := [32]byte{}
+	if currEpoch > 0 {
+		prevDependentRoot, err = s.cfg.ForkChoiceStore.DependentRoot(currEpoch - 1)
+		if err != nil {
+			log.WithError(err).Debug("Could not get previous dependent root")
+		}
+	}
 	// Send notification of the processed block to the state feed.
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.BlockProcessed,
 		Data: &statefeed.BlockProcessedData{
-			Slot:        cfg.roblock.Block().Slot(),
-			BlockRoot:   cfg.roblock.Root(),
-			SignedBlock: cfg.roblock,
-			Verified:    true,
-			Optimistic:  optimistic,
+			Slot:              cfg.roblock.Block().Slot(),
+			BlockRoot:         cfg.roblock.Root(),
+			SignedBlock:       cfg.roblock,
+			CurrDependentRoot: currDependenRoot,
+			PrevDependentRoot: prevDependentRoot,
+			Verified:          true,
+			Optimistic:        optimistic,
 		},
 	})
 }

 func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
+	if err := s.processLightClientUpdate(cfg); err != nil {
+		log.WithError(err).Error("Failed to process light client update")
+	}
 	if err := s.processLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
 		log.WithError(err).Error("Failed to process light client optimistic update")
 	}
@@ -125,101 +145,43 @@ func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
 	}
 }

-// saveLightClientUpdate saves the light client update for this block
+// processLightClientUpdate saves the light client update for this block
 // if it's better than the already saved one, when feature flag is enabled.
-func (s *Service) saveLightClientUpdate(cfg *postBlockProcessConfig) {
+func (s *Service) processLightClientUpdate(cfg *postBlockProcessConfig) error {
 	attestedRoot := cfg.roblock.Block().ParentRoot()
 	attestedBlock, err := s.getBlock(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Errorf("Saving light client update failed: Could not get attested block for root %#x", attestedRoot)
-		return
+		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
 	}
 	if attestedBlock == nil || attestedBlock.IsNil() {
-		log.Error("Saving light client update failed: Attested block is nil")
-		return
+		return errors.New("attested block is nil")
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Errorf("Saving light client update failed: Could not get attested state for root %#x", attestedRoot)
-		return
+		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}
 	if attestedState == nil || attestedState.IsNil() {
-		log.Error("Saving light client update failed: Attested state is nil")
-		return
+		return errors.New("attested state is nil")
 	}

 	finalizedRoot := attestedState.FinalizedCheckpoint().Root
 	finalizedBlock, err := s.getBlock(cfg.ctx, [32]byte(finalizedRoot))
 	if err != nil {
 		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
-			log.Debugf("Skipping saving light client update: Finalized block is nil for root %#x", finalizedRoot)
-		} else {
-			log.WithError(err).Errorf("Saving light client update failed: Could not get finalized block for root %#x", finalizedRoot)
+			log.Debugf("Skipping saving light client update because finalized block is nil for root %#x", finalizedRoot)
+			return nil
 		}
-		return
+		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}

-	update, err := lightclient.NewLightClientUpdateFromBeaconState(
-		cfg.ctx,
-		s.CurrentSlot(),
-		cfg.postState,
-		cfg.roblock,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
+	update, err := lightclient.NewLightClientUpdateFromBeaconState(cfg.ctx, cfg.postState, cfg.roblock, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not create light client update")
-		return
+		return errors.Wrapf(err, "could not create light client update")
 	}

 	period := slots.SyncCommitteePeriod(slots.ToEpoch(attestedState.Slot()))

-	oldUpdate, err := s.cfg.BeaconDB.LightClientUpdate(cfg.ctx, period)
-	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not get current light client update")
-		return
-	}
-
-	if oldUpdate == nil {
-		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
-			log.WithError(err).Error("Saving light client update failed: Could not save light client update")
-		} else {
-			log.WithField("period", period).Debug("Saving light client update: Saved new update")
-		}
-		return
-	}
-
-	isNewUpdateBetter, err := lightclient.IsBetterUpdate(update, oldUpdate)
-	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not compare light client updates")
-		return
-	}
-
-	if isNewUpdateBetter {
-		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
-			log.WithError(err).Error("Saving light client update failed: Could not save light client update")
-		} else {
-			log.WithField("period", period).Debug("Saving light client update: Saved new update")
-		}
-	} else {
-		log.WithField("period", period).Debug("Saving light client update: New update is not better than the current one. Skipping save.")
-	}
-}
-
-// saveLightClientBootstrap saves a light client bootstrap for this block
-// when feature flag is enabled.
-func (s *Service) saveLightClientBootstrap(cfg *postBlockProcessConfig) {
-	blockRoot := cfg.roblock.Root()
-	bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(cfg.ctx, s.CurrentSlot(), cfg.postState, cfg.roblock)
-	if err != nil {
-		log.WithError(err).Error("Saving light client bootstrap failed: Could not create light client bootstrap")
-		return
-	}
-	err = s.cfg.BeaconDB.SaveLightClientBootstrap(cfg.ctx, blockRoot[:], bootstrap)
-	if err != nil {
-		log.WithError(err).Error("Saving light client bootstrap failed: Could not save light client bootstrap in DB")
-	}
+	return s.lcStore.SaveLightClientUpdate(cfg.ctx, period, update)
 }

 func (s *Service) processLightClientFinalityUpdate(
@@ -239,8 +201,7 @@ func (s *Service) processLightClientFinalityUpdate(

 	finalizedCheckpoint := attestedState.FinalizedCheckpoint()

-	// Check if the finalized checkpoint has changed
-	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+	if finalizedCheckpoint == nil {
 		return nil
 	}

@@ -254,47 +215,19 @@ func (s *Service) processLightClientFinalityUpdate(
 		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}

-	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
+	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, postState, signed, attestedState, attestedBlock, finalizedBlock)

 	if err != nil {
 		return errors.Wrap(err, "could not create light client finality update")
 	}

-	lastUpdate := s.lcStore.LastFinalityUpdate()
-	if lastUpdate != nil {
-		// The finalized_header.beacon.lastUpdateSlot is greater than that of all previously forwarded finality_updates,
-		// or it matches the highest previously forwarded lastUpdateSlot and also has a sync_aggregate indicating supermajority (> 2/3)
-		// sync committee participation while the previously forwarded finality_update for that lastUpdateSlot did not indicate supermajority
-		newUpdateSlot := newUpdate.FinalizedHeader().Beacon().Slot
-		newHasSupermajority := lightclient.UpdateHasSupermajority(newUpdate.SyncAggregate())
-
-		lastUpdateSlot := lastUpdate.FinalizedHeader().Beacon().Slot
-		lastHasSupermajority := lightclient.UpdateHasSupermajority(lastUpdate.SyncAggregate())
-
-		if newUpdateSlot < lastUpdateSlot {
-			log.Debug("Skip saving light client finality newUpdate: Older than local newUpdate")
-			return nil
-		}
-		if newUpdateSlot == lastUpdateSlot && (lastHasSupermajority || !newHasSupermajority) {
-			log.Debug("Skip saving light client finality update: No supermajority advantage")
-			return nil
-		}
+	if !lightclient.IsBetterFinalityUpdate(newUpdate, s.lcStore.LastFinalityUpdate()) {
+		log.Debug("Skip saving light client finality update: current update is better")
+		return nil
 	}
-	log.Debug("Saving new light client finality update")
-	s.lcStore.SetLastFinalityUpdate(newUpdate)

-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientFinalityUpdate,
-		Data: newUpdate,
-	})
+	s.lcStore.SetLastFinalityUpdate(newUpdate, true)
+
 	return nil
 }

@@ -310,14 +243,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}

-	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-	)
+	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, postState, signed, attestedState, attestedBlock)

 	if err != nil {
 		if strings.Contains(err.Error(), lightclient.ErrNotEnoughSyncCommitteeBits) {
@@ -327,22 +253,12 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrap(err, "could not create light client optimistic update")
 	}

-	lastUpdate := s.lcStore.LastOptimisticUpdate()
-	if lastUpdate != nil {
-		// The attested_header.beacon.slot is greater than that of all previously forwarded optimistic updates
-		if newUpdate.AttestedHeader().Beacon().Slot <= lastUpdate.AttestedHeader().Beacon().Slot {
-			log.Debug("Skip saving light client optimistic update: Older than local update")
-			return nil
-		}
+	if !lightclient.IsBetterOptimisticUpdate(newUpdate, s.lcStore.LastOptimisticUpdate()) {
+		log.Debug("Skip saving light client optimistic update: current update is better")
+		return nil
 	}

-	log.Debug("Saving new light client optimistic update")
-	s.lcStore.SetLastOptimisticUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientOptimisticUpdate,
-		Data: newUpdate,
-	})
+	s.lcStore.SetLastOptimisticUpdate(newUpdate, true)

 	return nil
 }
@@ -413,7 +329,7 @@ func (s *Service) getBlockPreState(ctx context.Context, b interfaces.ReadOnlyBea
 	}

 	// Verify block slot time is not from the future.
-	if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), b.Slot(), params.BeaconConfig().MaximumGossipClockDisparityDuration()); err != nil {
+	if err := slots.VerifyTime(s.genesisTime, b.Slot(), params.BeaconConfig().MaximumGossipClockDisparityDuration()); err != nil {
 		return nil, err
 	}

@@ -508,7 +424,7 @@ func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) err
 		// is meant to be asynchronous and run in the background rather than being
 		// tied to the execution of a block.
 		if err := s.cfg.StateGen.MigrateToCold(s.ctx, fRoot); err != nil {
-			log.WithError(err).Error("could not migrate to cold")
+			log.WithError(err).Error("Could not migrate to cold")
 		}
 	}()
 	return nil
@@ -542,6 +458,9 @@ func (s *Service) ancestorByDB(ctx context.Context, r [32]byte, slot primitives.
 // This is useful for block tree visualizer and additional vote accounting.
 func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
 	fCheckpoint, jCheckpoint *ethpb.Checkpoint) error {
+	if fCheckpoint.Epoch > jCheckpoint.Epoch {
+		return ErrInvalidCheckpointArgs
+	}
 	pendingNodes := make([]*forkchoicetypes.BlockAndCheckpoints, 0)

 	// Fork choice only matters from last finalized slot.
@@ -597,7 +516,7 @@ func (s *Service) insertFinalizedDepositsAndPrune(ctx context.Context, fRoot [32
 	// Update deposit cache.
 	finalizedState, err := s.cfg.StateGen.StateByRoot(ctx, fRoot)
 	if err != nil {
-		log.WithError(err).Error("could not fetch finalized state")
+		log.WithError(err).Error("Could not fetch finalized state")
 		return
 	}

@@ -615,7 +534,7 @@ func (s *Service) insertFinalizedDepositsAndPrune(ctx context.Context, fRoot [32
 	// because the Eth1 follow distance makes such long-range reorgs extremely unlikely.
 	eth1DepositIndex, err := mathutil.Int(finalizedState.Eth1DepositIndex())
 	if err != nil {
-		log.WithError(err).Error("could not cast eth1 deposit index")
+		log.WithError(err).Error("Could not cast eth1 deposit index")
 		return
 	}
 	// The deposit index in the state is always the index of the next deposit
@@ -624,12 +543,12 @@ func (s *Service) insertFinalizedDepositsAndPrune(ctx context.Context, fRoot [32
 	finalizedEth1DepIdx := eth1DepositIndex - 1
 	if err = s.cfg.DepositCache.InsertFinalizedDeposits(ctx, int64(finalizedEth1DepIdx), common.Hash(finalizedState.Eth1Data().BlockHash),
 		0 /* Setting a zero value as we have no access to block height */); err != nil {
-		log.WithError(err).Error("could not insert finalized deposits")
+		log.WithError(err).Error("Could not insert finalized deposits")
 		return
 	}
 	// Deposit proofs are only used during state transition and can be safely removed to save space.
 	if err = s.cfg.DepositCache.PruneProofs(ctx, int64(finalizedEth1DepIdx)); err != nil {
-		log.WithError(err).Error("could not prune deposit proofs")
+		log.WithError(err).Error("Could not prune deposit proofs")
 	}
 	// Prune deposits which have already been finalized, the below method prunes all pending deposits (non-inclusive) up
 	// to the provided eth1 deposit index.
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -43,7 +43,7 @@ func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Chec
 	if err != nil {
 		return nil, err
 	}
-	if err := slots.ValidateClock(ss, uint64(s.genesisTime.Unix())); err != nil {
+	if err := slots.ValidateClock(ss, s.genesisTime); err != nil {
 		return nil, err
 	}
 	// We acquire the lock here instead than on gettAttPreState because that function gets called from UpdateHead that holds a write lock
@@ -69,7 +69,7 @@ func (s *Service) spawnProcessAttestationsRoutine() {
 	go func() {
 		_, err := s.clockWaiter.WaitForClock(s.ctx)
 		if err != nil {
-			log.WithError(err).Error("spawnProcessAttestationsRoutine failed to receive genesis data")
+			log.WithError(err).Error("Failed to receive genesis data")
 			return
 		}
 		if s.genesisTime.IsZero() {
@@ -103,7 +103,7 @@ func (s *Service) spawnProcessAttestationsRoutine() {
 				} else {
 					s.cfg.ForkChoiceStore.Lock()
 					if err := s.cfg.ForkChoiceStore.NewSlot(s.ctx, slotInterval.Slot); err != nil {
-						log.WithError(err).Error("could not process new slot")
+						log.WithError(err).Error("Could not process new slot")
 					}
 					s.cfg.ForkChoiceStore.Unlock()

@@ -144,7 +144,7 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
 	log.WithField("newHeadRoot", fmt.Sprintf("%#x", newHeadRoot)).Debug("Head changed due to attestations")
 	headState, headBlock, err := s.getStateAndBlock(ctx, newHeadRoot)
 	if err != nil {
-		log.WithError(err).Error("could not get head block")
+		log.WithError(err).Error("Could not get head block")
 		return
 	}
 	newAttHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
@@ -161,7 +161,7 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
 		return
 	}
 	if err := s.forkchoiceUpdateWithExecution(s.ctx, fcuArgs); err != nil {
-		log.WithError(err).Error("could not update forkchoice")
+		log.WithError(err).Error("Could not update forkchoice")
 	}
 }

@@ -177,9 +177,9 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
-		// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/fork-choice.md#validate_on_attestation
+		// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/fork-choice.md#validate_on_attestation
 		nextSlot := a.GetData().Slot + 1
-		if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), nextSlot, disparity); err != nil {
+		if err := slots.VerifyTime(s.genesisTime, nextSlot, disparity); err != nil {
 			continue
 		}

--- a/beacon-chain/blockchain/receive_attestation_test.go
+++ b/beacon-chain/blockchain/receive_attestation_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"context"
 	"testing"
 	"time"

@@ -32,7 +31,7 @@ func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
 	service.genesisTime = time.Now()

 	e := primitives.Epoch(slots.MaxSlotBuffer/uint64(params.BeaconConfig().SlotsPerEpoch) + 1)
-	_, err := service.AttestationTargetState(context.Background(), &ethpb.Checkpoint{Epoch: e})
+	_, err := service.AttestationTargetState(t.Context(), &ethpb.Checkpoint{Epoch: e})
 	require.ErrorContains(t, "exceeds max allowed value relative to the local clock", err)
 }

@@ -56,11 +55,11 @@ func TestVerifyLMDFFGConsistent(t *testing.T) {
 	a.Data.Target.Root = []byte{'c'}
 	r33Root := r33.Root()
 	a.Data.BeaconBlockRoot = r33Root[:]
-	require.ErrorContains(t, wanted, service.VerifyLmdFfgConsistency(context.Background(), a))
+	require.ErrorContains(t, wanted, service.VerifyLmdFfgConsistency(t.Context(), a))

 	r32Root := r32.Root()
 	a.Data.Target.Root = r32Root[:]
-	err = service.VerifyLmdFfgConsistency(context.Background(), a)
+	err = service.VerifyLmdFfgConsistency(t.Context(), a)
 	require.NoError(t, err, "Could not verify LMD and FFG votes to be consistent")
 }

@@ -71,7 +70,7 @@ func TestProcessAttestations_Ok(t *testing.T) {

 	service.genesisTime = prysmTime.Now().Add(-1 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
 	genesisState, pks := util.DeterministicGenesisState(t, 64)
-	require.NoError(t, genesisState.SetGenesisTime(uint64(prysmTime.Now().Unix())-params.BeaconConfig().SecondsPerSlot))
+	require.NoError(t, genesisState.SetGenesisTime(time.Now().Add(-1*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second)))
 	require.NoError(t, service.saveGenesisData(ctx, genesisState))
 	atts, err := util.GenerateAttestations(genesisState, pks, 1, 0, false)
 	require.NoError(t, err)
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -16,6 +16,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/slasher/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -52,6 +53,13 @@ type BlobReceiver interface {
 	ReceiveBlob(context.Context, blocks.VerifiedROBlob) error
 }

+// DataColumnReceiver interface defines the methods of chain service for receiving new
+// data columns
+type DataColumnReceiver interface {
+	ReceiveDataColumn(blocks.VerifiedRODataColumn) error
+	ReceiveDataColumns([]blocks.VerifiedRODataColumn) error
+}
+
 // SlashingReceiver interface defines the methods of chain service for receiving validated slashing over the wire.
 type SlashingReceiver interface {
 	ReceiveAttesterSlashing(ctx context.Context, slashing ethpb.AttSlashing)
@@ -74,14 +82,20 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring already synced block")
 		return nil
 	}
+
 	receivedTime := time.Now()
-	s.blockBeingSynced.set(blockRoot)
+	err := s.blockBeingSynced.set(blockRoot)
+	if errors.Is(err, errBlockBeingSynced) {
+		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring block currently being synced")
+		return nil
+	}
 	defer s.blockBeingSynced.unset(blockRoot)

 	blockCopy, err := block.Copy()
 	if err != nil {
 		return err
 	}
+
 	preState, err := s.getBlockPreState(ctx, blockCopy.Block())
 	if err != nil {
 		return errors.Wrap(err, "could not get block's prestate")
@@ -97,10 +111,12 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+
 	daWaitedTime, err := s.handleDA(ctx, blockCopy, blockRoot, avs)
 	if err != nil {
 		return err
 	}
+
 	// Defragment the state before continuing block processing.
 	s.defragmentState(postState)

@@ -171,7 +187,7 @@ func (s *Service) updateCheckpoints(
 			return errors.Wrap(err, "could not get head state")
 		}
 		if err := reportEpochMetrics(ctx, postState, headSt); err != nil {
-			log.WithError(err).Error("could not report epoch metrics")
+			log.WithError(err).Error("Could not report epoch metrics")
 		}
 	}
 	if err := s.updateJustificationOnBlock(ctx, preState, postState, cp.j); err != nil {
@@ -227,26 +243,34 @@ func (s *Service) validateExecutionAndConsensus(
 func (s *Service) handleDA(
 	ctx context.Context,
 	block interfaces.SignedBeaconBlock,
-	blockRoot [32]byte,
+	blockRoot [fieldparams.RootLength]byte,
 	avs das.AvailabilityStore,
-) (time.Duration, error) {
-	daStartTime := time.Now()
-	if avs != nil {
-		rob, err := blocks.NewROBlockWithRoot(block, blockRoot)
-		if err != nil {
-			return 0, err
+) (elapsed time.Duration, err error) {
+	defer func(start time.Time) {
+		elapsed = time.Since(start)
+
+		if err == nil {
+			dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), rob); err != nil {
-			return 0, errors.Wrap(err, "could not validate blob data availability (AvailabilityStore.IsDataAvailable)")
-		}
-	} else {
-		if err := s.isDataAvailable(ctx, blockRoot, block); err != nil {
-			return 0, errors.Wrap(err, "could not validate blob data availability")
+	}(time.Now())
+
+	if avs == nil {
+		if err = s.isDataAvailable(ctx, blockRoot, block); err != nil {
+			return
 		}
+
+		return
 	}
-	daWaitedTime := time.Since(daStartTime)
-	dataAvailWaitedTime.Observe(float64(daWaitedTime.Milliseconds()))
-	return daWaitedTime, nil
+
+	var rob blocks.ROBlock
+	rob, err = blocks.NewROBlockWithRoot(block, blockRoot)
+	if err != nil {
+		return
+	}
+
+	err = avs.IsDataAvailable(ctx, s.CurrentSlot(), rob)
+
+	return
 }

 func (s *Service) reportPostBlockProcessing(
@@ -263,7 +287,7 @@ func (s *Service) reportPostBlockProcessing(
 	// Log block sync status.
 	cp = s.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	justified := &ethpb.Checkpoint{Epoch: cp.Epoch, Root: bytesutil.SafeCopyBytes(cp.Root[:])}
-	if err := logBlockSyncStatus(block.Block(), blockRoot, justified, finalized, receivedTime, uint64(s.genesisTime.Unix()), daWaitedTime); err != nil {
+	if err := logBlockSyncStatus(block.Block(), blockRoot, justified, finalized, receivedTime, s.genesisTime, daWaitedTime); err != nil {
 		log.WithError(err).Error("Unable to log block sync status")
 	}
 	// Log payload data
@@ -280,15 +304,30 @@ func (s *Service) reportPostBlockProcessing(

 func (s *Service) executePostFinalizationTasks(ctx context.Context, finalizedState state.BeaconState) {
 	finalized := s.cfg.ForkChoiceStore.FinalizedCheckpoint()
+
+	// Send finalization event
 	go func() {
 		s.sendNewFinalizedEvent(ctx, finalizedState)
 	}()

+	// Insert finalized deposits into finalized deposit trie
 	depCtx, cancel := context.WithTimeout(context.Background(), depositDeadline)
 	go func() {
 		s.insertFinalizedDepositsAndPrune(depCtx, finalized.Root)
 		cancel()
 	}()
+
+	if features.Get().EnableLightClient {
+		// Save a light client bootstrap for the finalized checkpoint
+		go func() {
+			err := s.lcStore.SaveLightClientBootstrap(s.ctx, finalized.Root)
+			if err != nil {
+				log.WithError(err).Error("Could not save light client bootstrap by block root")
+			} else {
+				log.Debugf("Saved light client bootstrap for finalized root %#x", finalized.Root)
+			}
+		}()
+	}
 }

 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/beacon-chain/blockchain/receive_block_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"context"
 	"sync"
 	"testing"
 	"time"
@@ -9,7 +8,10 @@ import (
 	blockchainTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
+	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/voluntaryexits"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -19,6 +21,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	ethpbv1 "github.com/OffchainLabs/prysm/v6/proto/eth/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -28,7 +31,7 @@ import (
 )

 func TestService_ReceiveBlock(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

 	genesis, keys := util.DeterministicGenesisState(t, 64)
 	copiedGen := genesis.Copy()
@@ -180,6 +183,19 @@ func TestService_ReceiveBlock(t *testing.T) {
 	}
 	wg.Wait()
 }
+func TestHandleDA(t *testing.T) {
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlock{
+		Block: &ethpb.BeaconBlock{
+			Body: &ethpb.BeaconBlockBody{},
+		},
+	})
+	require.NoError(t, err)
+
+	s, _ := minimalTestService(t)
+	elapsed, err := s.handleDA(t.Context(), signedBeaconBlock, [fieldparams.RootLength]byte{}, nil)
+	require.NoError(t, err)
+	require.Equal(t, true, elapsed > 0, "Elapsed time should be greater than 0")
+}

 func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 	s, tr := minimalTestService(t,
@@ -215,7 +231,7 @@ func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 }

 func TestService_ReceiveBlockBatch(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()

 	genesis, keys := util.DeterministicGenesisState(t, 64)
 	genFullBlock := func(t *testing.T, conf *util.BlockGenConfig, slot primitives.Slot) *ethpb.SignedBeaconBlock {
@@ -280,23 +296,26 @@ func TestService_ReceiveBlockBatch(t *testing.T) {
 func TestService_HasBlock(t *testing.T) {
 	s, _ := minimalTestService(t)
 	r := [32]byte{'a'}
-	if s.HasBlock(context.Background(), r) {
+	if s.HasBlock(t.Context(), r) {
 		t.Error("Should not have block")
 	}
 	wsb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
-	require.NoError(t, s.saveInitSyncBlock(context.Background(), r, wsb))
-	if !s.HasBlock(context.Background(), r) {
+	require.NoError(t, s.saveInitSyncBlock(t.Context(), r, wsb))
+	if !s.HasBlock(t.Context(), r) {
 		t.Error("Should have block")
 	}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 1
-	util.SaveBlock(t, context.Background(), s.cfg.BeaconDB, b)
+	util.SaveBlock(t, t.Context(), s.cfg.BeaconDB, b)
 	r, err = b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	require.Equal(t, true, s.HasBlock(context.Background(), r))
-	s.blockBeingSynced.set(r)
-	require.Equal(t, false, s.HasBlock(context.Background(), r))
+	require.Equal(t, true, s.HasBlock(t.Context(), r))
+	err = s.blockBeingSynced.set(r)
+	require.NoError(t, err)
+	err = s.blockBeingSynced.set(r)
+	require.ErrorIs(t, err, errBlockBeingSynced)
+	require.Equal(t, false, s.HasBlock(t.Context(), r))
 }

 func TestCheckSaveHotStateDB_Enabling(t *testing.T) {
@@ -305,7 +324,7 @@ func TestCheckSaveHotStateDB_Enabling(t *testing.T) {
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
 	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)

-	require.NoError(t, s.checkSaveHotStateDB(context.Background()))
+	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	assert.LogsContain(t, hook, "Entering mode to save hot states in DB")
 }

@@ -316,19 +335,19 @@ func TestCheckSaveHotStateDB_Disabling(t *testing.T) {

 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
 	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
-	require.NoError(t, s.checkSaveHotStateDB(context.Background()))
+	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	s.genesisTime = time.Now()

-	require.NoError(t, s.checkSaveHotStateDB(context.Background()))
+	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	assert.LogsContain(t, hook, "Exiting mode to save hot states in DB")
 }

 func TestCheckSaveHotStateDB_Overflow(t *testing.T) {
 	hook := logTest.NewGlobal()
 	s, _ := minimalTestService(t)
-	s.genesisTime = time.Now()
+	s.SetGenesisTime(time.Now())

-	require.NoError(t, s.checkSaveHotStateDB(context.Background()))
+	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	assert.LogsDoNotContain(t, hook, "Entering mode to save hot states in DB")
 }

@@ -336,8 +355,9 @@ func TestHandleCaches_EnablingLargeSize(t *testing.T) {
 	hook := logTest.NewGlobal()
 	s, _ := minimalTestService(t)
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	s.SetGenesisTime(time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second))

+	helpers.ClearCache()
 	require.NoError(t, s.handleCaches())
 	assert.LogsContain(t, hook, "Expanding committee cache size")
 }
@@ -443,7 +463,7 @@ func Test_executePostFinalizationTasks(t *testing.T) {

 	headState, err := util.NewBeaconStateElectra()
 	require.NoError(t, err)
-	finalizedStRoot, err := headState.HashTreeRoot(context.Background())
+	finalizedStRoot, err := headState.HashTreeRoot(t.Context())
 	require.NoError(t, err)

 	genesis := util.NewBeaconBlock()
@@ -550,3 +570,48 @@ func Test_executePostFinalizationTasks(t *testing.T) {
 	})

 }
+
+func TestProcessLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+	defer reset()
+
+	s, tr := minimalTestService(t, WithLCStore())
+	ctx := tr.ctx
+
+	for testVersion := version.Altair; testVersion <= version.Electra; testVersion++ {
+		t.Run(version.String(testVersion), func(t *testing.T) {
+			l := util.NewTestLightClient(t, testVersion)
+
+			require.NoError(t, s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock))
+			finalizedBlockRoot, err := l.FinalizedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			require.NoError(t, s.cfg.BeaconDB.SaveState(ctx, l.FinalizedState, finalizedBlockRoot))
+
+			cp := l.AttestedState.FinalizedCheckpoint()
+			require.DeepSSZEqual(t, finalizedBlockRoot, [32]byte(cp.Root))
+
+			require.NoError(t, s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: cp.Epoch, Root: [32]byte(cp.Root)}))
+
+			sss, err := s.cfg.BeaconDB.State(ctx, finalizedBlockRoot)
+			require.NoError(t, err)
+			require.NotNil(t, sss)
+
+			s.executePostFinalizationTasks(s.ctx, l.FinalizedState)
+
+			// wait for the goroutine to finish processing
+			time.Sleep(1 * time.Second)
+
+			// Check that the light client bootstrap is saved
+			b, err := s.lcStore.LightClientBootstrap(ctx, [32]byte(cp.Root))
+			require.NoError(t, err)
+			require.NotNil(t, b)
+
+			btst, err := lightClient.NewLightClientBootstrapFromBeaconState(ctx, l.FinalizedState.Slot(), l.FinalizedState, l.FinalizedBlock)
+			require.NoError(t, err)
+			require.DeepEqual(t, btst, b)
+			require.Equal(t, b.Version(), testVersion)
+		})
+	}
+}
--- a/beacon-chain/blockchain/receive_data_column.go
+++ b/beacon-chain/blockchain/receive_data_column.go
@@ -0,0 +1,24 @@
+package blockchain
+
+import (
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/pkg/errors"
+)
+
+// ReceiveDataColumns receives a batch of data columns.
+func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataColumn) error {
+	if err := s.dataColumnStorage.Save(dataColumnSidecars); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}
+
+// ReceiveDataColumn receives a single data column.
+func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
+	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
+		return errors.Wrap(err, "save data column sidecar")
+	}
+
+	return nil
+}
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -12,7 +12,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
@@ -30,6 +29,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -46,26 +46,29 @@ import (
 // Service represents a service that handles the internal
 // logic of managing the full PoS beacon chain.
 type Service struct {
-	cfg                  *config
-	ctx                  context.Context
-	cancel               context.CancelFunc
-	genesisTime          time.Time
-	head                 *head
-	headLock             sync.RWMutex
-	originBlockRoot      [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
-	boundaryRoots        [][32]byte
-	checkpointStateCache *cache.CheckpointStateCache
-	initSyncBlocks       map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
-	initSyncBlocksLock   sync.RWMutex
-	wsVerifier           *WeakSubjectivityVerifier
-	clockSetter          startup.ClockSetter
-	clockWaiter          startup.ClockWaiter
-	syncComplete         chan struct{}
-	blobNotifiers        *blobNotifierMap
-	blockBeingSynced     *currentlySyncingBlock
-	blobStorage          *filesystem.BlobStorage
-	slasherEnabled       bool
-	lcStore              *lightClient.Store
+	cfg                            *config
+	ctx                            context.Context
+	cancel                         context.CancelFunc
+	genesisTime                    time.Time
+	head                           *head
+	headLock                       sync.RWMutex
+	originBlockRoot                [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
+	boundaryRoots                  [][32]byte
+	checkpointStateCache           *cache.CheckpointStateCache
+	initSyncBlocks                 map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
+	initSyncBlocksLock             sync.RWMutex
+	wsVerifier                     *WeakSubjectivityVerifier
+	clockSetter                    startup.ClockSetter
+	clockWaiter                    startup.ClockWaiter
+	syncComplete                   chan struct{}
+	blobNotifiers                  *blobNotifierMap
+	blockBeingSynced               *currentlySyncingBlock
+	blobStorage                    *filesystem.BlobStorage
+	dataColumnStorage              *filesystem.DataColumnStorage
+	slasherEnabled                 bool
+	lcStore                        *lightClient.Store
+	startWaitingDataColumnSidecars chan bool // for testing purposes only
+	syncCommitteeHeadState         *cache.SyncCommitteeHeadStateCache
 }

 // config options for the service.
@@ -81,7 +84,7 @@ type config struct {
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
 	BLSToExecPool           blstoexec.PoolManager
-	P2p                     p2p.Broadcaster
+	P2P                     p2p.Accessor
 	MaxRoutines             int
 	StateNotifier           statefeed.Notifier
 	ForkChoiceStore         f.ForkChoicer
@@ -176,14 +179,15 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 		seenIndex: make(map[[32]byte][]bool),
 	}
 	srv := &Service{
-		ctx:                  ctx,
-		cancel:               cancel,
-		boundaryRoots:        [][32]byte{},
-		checkpointStateCache: cache.NewCheckpointStateCache(),
-		initSyncBlocks:       make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock),
-		blobNotifiers:        bn,
-		cfg:                  &config{},
-		blockBeingSynced:     &currentlySyncingBlock{roots: make(map[[32]byte]struct{})},
+		ctx:                    ctx,
+		cancel:                 cancel,
+		boundaryRoots:          [][32]byte{},
+		checkpointStateCache:   cache.NewCheckpointStateCache(),
+		initSyncBlocks:         make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock),
+		blobNotifiers:          bn,
+		cfg:                    &config{},
+		blockBeingSynced:       &currentlySyncingBlock{roots: make(map[[32]byte]struct{})},
+		syncCommitteeHeadState: cache.NewSyncCommitteeHeadState(),
 	}
 	for _, opt := range opts {
 		if err := opt(srv); err != nil {
@@ -202,17 +206,9 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {

 // Start a blockchain service's main event loop.
 func (s *Service) Start() {
-	saved := s.cfg.FinalizedStateAtStartUp
 	defer s.removeStartupState()
-
-	if saved != nil && !saved.IsNil() {
-		if err := s.StartFromSavedState(saved); err != nil {
-			log.Fatal(err)
-		}
-	} else {
-		if err := s.startFromExecutionChain(); err != nil {
-			log.Fatal(err)
-		}
+	if err := s.StartFromSavedState(s.cfg.FinalizedStateAtStartUp); err != nil {
+		log.Fatal(err)
 	}
 	s.spawnProcessAttestationsRoutine()
 	go s.runLateBlockTasks()
@@ -261,8 +257,11 @@ func (s *Service) Status() error {

 // StartFromSavedState initializes the blockchain using a previously saved finalized checkpoint.
 func (s *Service) StartFromSavedState(saved state.BeaconState) error {
+	if state.IsNil(saved) {
+		return errors.New("Last finalized state at startup is nil")
+	}
 	log.Info("Blockchain data already exists in DB, initializing...")
-	s.genesisTime = time.Unix(int64(saved.GenesisTime()), 0) // lint:ignore uintcast -- Genesis time will not exceed int64 in your lifetime.
+	s.genesisTime = saved.GenesisTime()
 	s.cfg.AttService.SetGenesisTime(saved.GenesisTime())

 	originRoot, err := s.originRootFromSavedState(s.ctx)
@@ -290,6 +289,20 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err := s.clockSetter.SetClock(startup.NewClock(s.genesisTime, vr)); err != nil {
 		return errors.Wrap(err, "failed to initialize blockchain service")
 	}
+
+	if !params.FuluEnabled() {
+		return nil
+	}
+
+	earliestAvailableSlot, custodySubnetCount, err := s.updateCustodyInfoInDB(saved.Slot())
+	if err != nil {
+		return errors.Wrap(err, "could not get and save custody group count")
+	}
+
+	if _, _, err := s.cfg.P2P.UpdateCustodyInfo(earliestAvailableSlot, custodySubnetCount); err != nil {
+		return errors.Wrap(err, "update custody info")
+	}
+
 	return nil
 }

@@ -352,62 +365,6 @@ func (s *Service) initializeHead(ctx context.Context, st state.BeaconState) erro
 	return nil
 }

-func (s *Service) startFromExecutionChain() error {
-	log.Info("Waiting to reach the validator deposit threshold to start the beacon chain...")
-	if s.cfg.ChainStartFetcher == nil {
-		return errors.New("not configured execution chain")
-	}
-	go func() {
-		stateChannel := make(chan *feed.Event, 1)
-		stateSub := s.cfg.StateNotifier.StateFeed().Subscribe(stateChannel)
-		defer stateSub.Unsubscribe()
-		for {
-			select {
-			case e := <-stateChannel:
-				if e.Type == statefeed.ChainStarted {
-					data, ok := e.Data.(*statefeed.ChainStartedData)
-					if !ok {
-						log.Error("event data is not type *statefeed.ChainStartedData")
-						return
-					}
-					log.WithField("startTime", data.StartTime).Debug("Received chain start event")
-					s.onExecutionChainStart(s.ctx, data.StartTime)
-					return
-				}
-			case <-s.ctx.Done():
-				log.Debug("Context closed, exiting goroutine")
-				return
-			case err := <-stateSub.Err():
-				log.WithError(err).Error("Subscription to state forRoot failed")
-				return
-			}
-		}
-	}()
-
-	return nil
-}
-
-// onExecutionChainStart initializes a series of deposits from the ChainStart deposits in the eth1
-// deposit contract, initializes the beacon chain's state, and kicks off the beacon chain.
-func (s *Service) onExecutionChainStart(ctx context.Context, genesisTime time.Time) {
-	preGenesisState := s.cfg.ChainStartFetcher.PreGenesisState()
-	initializedState, err := s.initializeBeaconChain(ctx, genesisTime, preGenesisState, s.cfg.ChainStartFetcher.ChainStartEth1Data())
-	if err != nil {
-		log.WithError(err).Fatal("Could not initialize beacon chain")
-	}
-	// We start a counter to genesis, if needed.
-	gRoot, err := initializedState.HashTreeRoot(s.ctx)
-	if err != nil {
-		log.WithError(err).Fatal("Could not hash tree root genesis state")
-	}
-	go slots.CountdownToGenesis(ctx, genesisTime, uint64(initializedState.NumValidators()), gRoot)
-
-	vr := bytesutil.ToBytes32(initializedState.GenesisValidatorsRoot())
-	if err := s.clockSetter.SetClock(startup.NewClock(genesisTime, vr)); err != nil {
-		log.WithError(err).Fatal("failed to initialize blockchain service from execution start event")
-	}
-}
-
 // initializes the state and genesis block of the beacon chain to persistent storage
 // based on a genesis timestamp value obtained from the ChainStart event emitted
 // by the ETH1.0 Deposit Contract and the POWChain service of the node.
@@ -418,7 +375,7 @@ func (s *Service) initializeBeaconChain(
 	eth1data *ethpb.Eth1Data) (state.BeaconState, error) {
 	ctx, span := trace.StartSpan(ctx, "beacon-chain.Service.initializeBeaconChain")
 	defer span.End()
-	s.genesisTime = genesisTime
+	s.genesisTime = genesisTime.Truncate(time.Second) // Genesis time has a precision of 1 second.
 	unixTime := uint64(genesisTime.Unix())

 	genesisState, err := transition.OptimizedGenesisBeaconState(unixTime, preGenesisState, eth1data)
@@ -479,7 +436,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 	if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, genesisBlkRoot); err != nil {
 		return errors.Wrap(err, "Could not set optimistic status of genesis block to false")
 	}
-	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))
+	s.cfg.ForkChoiceStore.SetGenesisTime(s.genesisTime)

 	if err := s.setHead(&head{
 		genesisBlkRoot,
@@ -510,6 +467,57 @@ func (s *Service) removeStartupState() {
 	s.cfg.FinalizedStateAtStartUp = nil
 }

+// UpdateCustodyInfoInDB updates the custody information in the database.
+// It returns the (potentially updated) custody group count and the earliest available slot.
+func (s *Service) updateCustodyInfoInDB(slot primitives.Slot) (primitives.Slot, uint64, error) {
+	isSubscribedToAllDataSubnets := flags.Get().SubscribeAllDataSubnets
+
+	beaconConfig := params.BeaconConfig()
+	custodyRequirement := beaconConfig.CustodyRequirement
+
+	// Check if the node was previously subscribed to all data subnets, and if so,
+	// store the new status accordingly.
+	wasSubscribedToAllDataSubnets, err := s.cfg.BeaconDB.UpdateSubscribedToAllDataSubnets(s.ctx, isSubscribedToAllDataSubnets)
+	if err != nil {
+		log.WithError(err).Error("Could not update subscription status to all data subnets")
+	}
+
+	// Warn the user if the node was previously subscribed to all data subnets and is not any more.
+	if wasSubscribedToAllDataSubnets && !isSubscribedToAllDataSubnets {
+		log.Warnf(
+			"Because the flag `--%s` was previously used, the node will still subscribe to all data subnets.",
+			flags.SubscribeAllDataSubnets.Name,
+		)
+	}
+
+	// Compute the custody group count.
+	custodyGroupCount := custodyRequirement
+	if isSubscribedToAllDataSubnets {
+		custodyGroupCount = beaconConfig.NumberOfColumns
+	}
+
+	// Safely compute the fulu fork slot.
+	fuluForkSlot, err := fuluForkSlot()
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "fulu fork slot")
+	}
+
+	// If slot is before the fulu fork slot, then use the earliest stored slot as the reference slot.
+	if slot < fuluForkSlot {
+		slot, err = s.cfg.BeaconDB.EarliestSlot(s.ctx)
+		if err != nil {
+			return 0, 0, errors.Wrap(err, "earliest slot")
+		}
+	}
+
+	earliestAvailableSlot, custodyGroupCount, err := s.cfg.BeaconDB.UpdateCustodyInfo(s.ctx, slot, custodyGroupCount)
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "update custody info")
+	}
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
 func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db db.HeadAccessDatabase) {
 	currentTime := prysmTime.Now()
 	if currentTime.After(genesisTime) {
@@ -526,3 +534,19 @@ func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db d
 	}
 	go slots.CountdownToGenesis(ctx, genesisTime, uint64(gState.NumValidators()), gRoot)
 }
+
+func fuluForkSlot() (primitives.Slot, error) {
+	beaconConfig := params.BeaconConfig()
+
+	fuluForkEpoch := beaconConfig.FuluForkEpoch
+	if fuluForkEpoch == beaconConfig.FarFutureEpoch {
+		return beaconConfig.FarFutureSlot, nil
+	}
+
+	forkFuluSlot, err := slots.EpochStart(fuluForkEpoch)
+	if err != nil {
+		return 0, errors.Wrap(err, "epoch start")
+	}
+
+	return forkFuluSlot, nil
+}
--- a/beacon-chain/blockchain/service_norace_test.go
+++ b/beacon-chain/blockchain/service_norace_test.go
@@ -1,11 +1,9 @@
 package blockchain

 import (
-	"context"
 	"io"
 	"testing"

-	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -18,15 +16,12 @@ func init() {
 }

 func TestChainService_SaveHead_DataRace(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg: &config{BeaconDB: beaconDB},
-	}
+	s := testServiceWithDB(t)
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	st, _ := util.DeterministicGenesisState(t, 1)
 	require.NoError(t, err)
 	go func() {
-		require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+		require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))
 	}()
-	require.NoError(t, s.saveHead(context.Background(), [32]byte{}, b, st))
+	require.NoError(t, s.saveHead(t.Context(), [32]byte{}, b, st))
 }
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -31,6 +31,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/trie"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -42,7 +43,7 @@ import (
 )

 func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
-	ctx := context.Background()
+	ctx := t.Context()
 	var web3Service *execution.Service
 	var err error
 	srv, endpoint, err := mockExecution.SetupRPCServer()
@@ -51,6 +52,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		srv.Stop()
 	})
 	bState, _ := util.DeterministicGenesisState(t, 10)
+	genesis.StoreStateDuringTest(t, bState)
 	pbState, err := state_native.ProtobufBeaconStatePhase0(bState.ToProtoUnsafe())
 	require.NoError(t, err)
 	mockTrie, err := trie.NewTrie(0)
@@ -71,20 +73,22 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		DepositContainers: []*ethpb.DepositContainer{},
 	})
 	require.NoError(t, err)
+
+	depositCache, err := depositsnapshot.New()
+	require.NoError(t, err)
+
 	web3Service, err = execution.NewService(
 		ctx,
 		execution.WithDatabase(beaconDB),
 		execution.WithHttpEndpoint(endpoint),
 		execution.WithDepositContractAddress(common.Address{}),
+		execution.WithDepositCache(depositCache),
 	)
 	require.NoError(t, err, "Unable to set up web3 service")

 	attService, err := attestations.NewService(ctx, &attestations.Config{Pool: attestations.NewPool()})
 	require.NoError(t, err)

-	depositCache, err := depositsnapshot.New()
-	require.NoError(t, err)
-
 	fc := doublylinkedtree.New()
 	stateGen := stategen.New(beaconDB, fc)
 	// Safe a state in stategen to purposes of testing a service stop / shutdown.
@@ -97,7 +101,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithAttestationPool(attestations.NewPool()),
 		WithSlashingPool(slashings.NewPool()),
 		WithExitPool(voluntaryexits.NewPool()),
-		WithP2PBroadcaster(&mockBroadcaster{}),
+		WithP2PBroadcaster(&mockAccessor{}),
 		WithStateNotifier(&mockBeaconNode{}),
 		WithForkChoiceStore(fc),
 		WithAttestationService(attService),
@@ -115,7 +119,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {

 func TestChainStartStop_Initialized(t *testing.T) {
 	hook := logTest.NewGlobal()
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)

 	chainService := setupBeaconChain(t, beaconDB)
@@ -127,7 +131,7 @@ func TestChainStartStop_Initialized(t *testing.T) {
 	util.SaveBlock(t, ctx, beaconDB, genesisBlk)
 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
-	require.NoError(t, s.SetGenesisTime(uint64(gt.Unix())))
+	require.NoError(t, s.SetGenesisTime(gt))
 	require.NoError(t, s.SetSlot(1))
 	require.NoError(t, beaconDB.SaveState(ctx, s, blkRoot))
 	require.NoError(t, beaconDB.SaveHeadBlockRoot(ctx, blkRoot))
@@ -152,7 +156,7 @@ func TestChainStartStop_Initialized(t *testing.T) {

 func TestChainStartStop_GenesisZeroHashes(t *testing.T) {
 	hook := logTest.NewGlobal()
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)

 	chainService := setupBeaconChain(t, beaconDB)
@@ -164,7 +168,7 @@ func TestChainStartStop_GenesisZeroHashes(t *testing.T) {
 	wsb := util.SaveBlock(t, ctx, beaconDB, genesisBlk)
 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
-	require.NoError(t, s.SetGenesisTime(uint64(gt.Unix())))
+	require.NoError(t, s.SetGenesisTime(gt))
 	require.NoError(t, beaconDB.SaveState(ctx, s, blkRoot))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, blkRoot))
 	require.NoError(t, beaconDB.SaveBlock(ctx, wsb))
@@ -184,7 +188,7 @@ func TestChainStartStop_GenesisZeroHashes(t *testing.T) {
 func TestChainService_InitializeBeaconChain(t *testing.T) {
 	helpers.ClearCache()
 	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
+	ctx := t.Context()

 	bc := setupBeaconChain(t, beaconDB)
 	var err error
@@ -226,7 +230,7 @@ func TestChainService_InitializeBeaconChain(t *testing.T) {
 }

 func TestChainService_CorrectGenesisRoots(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)

 	chainService := setupBeaconChain(t, beaconDB)
@@ -238,7 +242,7 @@ func TestChainService_CorrectGenesisRoots(t *testing.T) {
 	util.SaveBlock(t, ctx, beaconDB, genesisBlk)
 	s, err := util.NewBeaconState()
 	require.NoError(t, err)
-	require.NoError(t, s.SetGenesisTime(uint64(gt.Unix())))
+	require.NoError(t, s.SetGenesisTime(gt))
 	require.NoError(t, s.SetSlot(0))
 	require.NoError(t, beaconDB.SaveState(ctx, s, blkRoot))
 	require.NoError(t, beaconDB.SaveHeadBlockRoot(ctx, blkRoot))
@@ -295,7 +299,7 @@ func TestChainService_InitializeChainInfo(t *testing.T) {
 	require.NoError(t, err)
 	assert.DeepSSZEqual(t, headState.ToProtoUnsafe(), s.ToProtoUnsafe(), "Head state incorrect")
 	assert.Equal(t, c.HeadSlot(), headBlock.Block.Slot, "Head slot incorrect")
-	r, err := c.HeadRoot(context.Background())
+	r, err := c.HeadRoot(t.Context())
 	require.NoError(t, err)
 	if !bytes.Equal(headRoot[:], r) {
 		t.Error("head slot incorrect")
@@ -345,12 +349,8 @@ func TestChainService_InitializeChainInfo_SetHeadAtGenesis(t *testing.T) {
 }

 func TestChainService_SaveHeadNoDB(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-	fc := doublylinkedtree.New()
-	s := &Service{
-		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, fc), ForkChoiceStore: fc},
-	}
+	ctx := t.Context()
+	s := testServiceWithDB(t)
 	blk := util.NewBeaconBlock()
 	blk.Block.Slot = 1
 	r, err := blk.HashTreeRoot()
@@ -370,11 +370,8 @@ func TestChainService_SaveHeadNoDB(t *testing.T) {
 }

 func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
-	ctx := context.Background()
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg: &config{ForkChoiceStore: doublylinkedtree.New(), BeaconDB: beaconDB},
-	}
+	ctx := t.Context()
+	s := testServiceWithDB(t)
 	b := util.NewBeaconBlock()
 	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
@@ -391,48 +388,21 @@ func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 }

 func TestServiceStop_SaveCachedBlocks(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	beaconDB := testDB.SetupDB(t)
-	s := &Service{
-		cfg:            &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
-		ctx:            ctx,
-		cancel:         cancel,
-		initSyncBlocks: make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock),
-	}
+	s := testServiceWithDB(t)
+	s.initSyncBlocks = make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock)
 	bb := util.NewBeaconBlock()
 	r, err := bb.Block.HashTreeRoot()
 	require.NoError(t, err)
 	wsb, err := consensusblocks.NewSignedBeaconBlock(bb)
 	require.NoError(t, err)
-	require.NoError(t, s.saveInitSyncBlock(ctx, r, wsb))
+	require.NoError(t, s.saveInitSyncBlock(s.ctx, r, wsb))
 	require.NoError(t, s.Stop())
-	require.Equal(t, true, s.cfg.BeaconDB.HasBlock(ctx, r))
-}
-
-func TestProcessChainStartTime_ReceivedFeed(t *testing.T) {
-	ctx := context.Background()
-	beaconDB := testDB.SetupDB(t)
-	service := setupBeaconChain(t, beaconDB)
-	mgs := &MockClockSetter{}
-	service.clockSetter = mgs
-	gt := time.Now()
-	service.onExecutionChainStart(context.Background(), gt)
-	gs, err := beaconDB.GenesisState(ctx)
-	require.NoError(t, err)
-	require.NotEqual(t, nil, gs)
-	require.Equal(t, 32, len(gs.GenesisValidatorsRoot()))
-	var zero [32]byte
-	require.DeepNotEqual(t, gs.GenesisValidatorsRoot(), zero[:])
-	require.Equal(t, gt, mgs.G.GenesisTime())
-	require.Equal(t, bytesutil.ToBytes32(gs.GenesisValidatorsRoot()), mgs.G.GenesisValidatorsRoot())
+	require.Equal(t, true, s.cfg.BeaconDB.HasBlock(s.ctx, r))
 }

 func BenchmarkHasBlockDB(b *testing.B) {
-	beaconDB := testDB.SetupDB(b)
-	ctx := context.Background()
-	s := &Service{
-		cfg: &config{BeaconDB: beaconDB},
-	}
+	ctx := b.Context()
+	s := testServiceWithDB(b)
 	blk := util.NewBeaconBlock()
 	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
 	require.NoError(b, err)
@@ -447,11 +417,8 @@ func BenchmarkHasBlockDB(b *testing.B) {
 }

 func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
-	ctx := context.Background()
-	beaconDB := testDB.SetupDB(b)
-	s := &Service{
-		cfg: &config{ForkChoiceStore: doublylinkedtree.New(), BeaconDB: beaconDB},
-	}
+	ctx := b.Context()
+	s := testServiceWithDB(b)
 	blk := util.NewBeaconBlock()
 	r, err := blk.Block.HashTreeRoot()
 	require.NoError(b, err)
--- a/beacon-chain/blockchain/setup_forkchoice.go
+++ b/beacon-chain/blockchain/setup_forkchoice.go
@@ -20,7 +20,7 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {
 		return errors.Wrap(err, "could not set up forkchoice checkpoints")
 	}
 	if err := s.setupForkchoiceTree(st); err != nil {
-		return errors.Wrap(err, "could not set up forkchoice root")
+		return errors.Wrap(err, "could not set up forkchoice tree")
 	}
 	if err := s.initializeHead(s.ctx, st); err != nil {
 		return errors.Wrap(err, "could not initialize head from db")
@@ -30,24 +30,24 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {

 func (s *Service) startupHeadRoot() [32]byte {
 	headStr := features.Get().ForceHead
-	cp := s.FinalizedCheckpt()
-	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	jp := s.CurrentJustifiedCheckpt()
+	jRoot := s.ensureRootNotZeros([32]byte(jp.Root))
 	if headStr == "" {
-		return fRoot
+		return jRoot
 	}
 	if headStr == "head" {
 		root, err := s.cfg.BeaconDB.HeadBlockRoot()
 		if err != nil {
-			log.WithError(err).Error("could not get head block root, starting with finalized block as head")
-			return fRoot
+			log.WithError(err).Error("Could not get head block root, starting with justified block as head")
+			return jRoot
 		}
 		log.Infof("Using Head root of %#x", root)
 		return root
 	}
 	root, err := bytesutil.DecodeHexWithLength(headStr, 32)
 	if err != nil {
-		log.WithError(err).Error("could not parse head root, starting with finalized block as head")
-		return fRoot
+		log.WithError(err).Error("Could not parse head root, starting with justified block as head")
+		return jRoot
 	}
 	return [32]byte(root)
 }
@@ -64,21 +64,24 @@ func (s *Service) setupForkchoiceTree(st state.BeaconState) error {
 	}
 	blk, err := s.cfg.BeaconDB.Block(s.ctx, headRoot)
 	if err != nil {
-		log.WithError(err).Error("could not get head block, starting with finalized block as head")
+		log.WithError(err).Error("Could not get head block, starting with finalized block as head")
 		return nil
 	}
 	if slots.ToEpoch(blk.Block().Slot()) < cp.Epoch {
-		log.WithField("headRoot", fmt.Sprintf("%#x", headRoot)).Error("head block is older than finalized block, starting with finalized block as head")
+		log.WithField("headRoot", fmt.Sprintf("%#x", headRoot)).Error("Head block is older than finalized block, starting with finalized block as head")
 		return nil
 	}
 	chain, err := s.buildForkchoiceChain(s.ctx, blk)
 	if err != nil {
-		log.WithError(err).Error("could not build forkchoice chain, starting with finalized block as head")
+		log.WithError(err).Error("Could not build forkchoice chain, starting with finalized block as head")
 		return nil
 	}
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
-	return s.cfg.ForkChoiceStore.InsertChain(s.ctx, chain)
+	if err := s.cfg.ForkChoiceStore.InsertChain(s.ctx, chain); err != nil {
+		return errors.Wrap(err, "could not insert forkchoice chain")
+	}
+	return s.cfg.ForkChoiceStore.InsertNode(s.ctx, st, chain[0].Block)
 }

 func (s *Service) buildForkchoiceChain(ctx context.Context, head interfaces.ReadOnlySignedBeaconBlock) ([]*forkchoicetypes.BlockAndCheckpoints, error) {
@@ -170,6 +173,6 @@ func (s *Service) setupForkchoiceCheckpoints() error {
 		Root: fRoot}); err != nil {
 		return errors.Wrap(err, "could not update forkchoice's finalized checkpoint")
 	}
-	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))
+	s.cfg.ForkChoiceStore.SetGenesisTime(s.genesisTime)
 	return nil
 }
--- a/beacon-chain/blockchain/setup_forkchoice_test.go
+++ b/beacon-chain/blockchain/setup_forkchoice_test.go
@@ -32,7 +32,7 @@ func Test_startupHeadRoot(t *testing.T) {
 		})
 		defer resetCfg()
 		require.Equal(t, service.startupHeadRoot(), gr)
-		require.LogsContain(t, hook, "could not get head block root, starting with finalized block as head")
+		require.LogsContain(t, hook, "Could not get head block root, starting with justified block as head")
 	})

 	st, _ := util.DeterministicGenesisState(t, 64)
@@ -124,5 +124,5 @@ func Test_setupForkchoiceTree_Head(t *testing.T) {
 	require.NotEqual(t, fRoot, root)
 	require.Equal(t, root, service.startupHeadRoot())
 	require.NoError(t, service.setupForkchoiceTree(st))
-	require.Equal(t, 2, service.cfg.ForkChoiceStore.NodeCount())
+	require.Equal(t, 3, service.cfg.ForkChoiceStore.NodeCount())
 }
--- a/beacon-chain/blockchain/setup_test.go
+++ b/beacon-chain/blockchain/setup_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"sync"
 	"testing"
+	"time"

 	"github.com/OffchainLabs/prysm/v6/async/event"
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
@@ -20,10 +21,16 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"google.golang.org/protobuf/proto"
 )

@@ -46,6 +53,12 @@ type mockBroadcaster struct {
 	broadcastCalled bool
 }

+type mockAccessor struct {
+	mockBroadcaster
+	mockCustodyManager
+	p2pTesting.MockPeerManager
+}
+
 func (mb *mockBroadcaster) Broadcast(_ context.Context, _ proto.Message) error {
 	mb.broadcastCalled = true
 	return nil
@@ -66,11 +79,63 @@ func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.B
 	return nil
 }

+func (mb *mockBroadcaster) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
+func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
+func (mb *mockBroadcaster) BroadcastDataColumnSidecar(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }

 var _ p2p.Broadcaster = (*mockBroadcaster)(nil)

+// mockCustodyManager is a mock implementation of p2p.CustodyManager
+type mockCustodyManager struct {
+	mut                   sync.RWMutex
+	earliestAvailableSlot primitives.Slot
+	custodyGroupCount     uint64
+}
+
+func (dch *mockCustodyManager) EarliestAvailableSlot() (primitives.Slot, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.earliestAvailableSlot, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCount() (uint64, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	dch.mut.Lock()
+	defer dch.mut.Unlock()
+
+	dch.earliestAvailableSlot = earliestAvailableSlot
+	dch.custodyGroupCount = custodyGroupCount
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCountFromPeer(peer.ID) uint64 {
+	return 0
+}
+
+var _ p2p.CustodyManager = (*mockCustodyManager)(nil)
+
 type testServiceRequirements struct {
 	ctx     context.Context
 	db      db.Database
@@ -85,9 +150,11 @@ type testServiceRequirements struct {
 }

 func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceRequirements) {
-	ctx := context.Background()
+	ctx := t.Context()
+	genesis := time.Now().Add(-1 * 4 * time.Duration(params.BeaconConfig().SlotsPerEpoch*primitives.Slot(params.BeaconConfig().SecondsPerSlot)) * time.Second) // Genesis was 4 epochs ago.
 	beaconDB := testDB.SetupDB(t)
 	fcs := doublylinkedtree.New()
+	fcs.SetGenesisTime(genesis)
 	sg := stategen.New(beaconDB, fcs)
 	notif := &mockBeaconNode{}
 	fcs.SetBalancesByRooter(sg.ActiveNonSlashedBalancesByRoot)
@@ -121,9 +188,12 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithDepositCache(dc),
 		WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
 		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
+		WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)),
 		WithSyncChecker(mock.MockChecker{}),
 		WithExecutionEngineCaller(&mockExecution.EngineClient{}),
+		WithP2PBroadcaster(&mockAccessor{}),
 		WithLightClientStore(&lightclient.Store{}),
+		WithGenesisTime(genesis),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards
 	opts = append(defOpts, opts...)
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -53,6 +53,7 @@ type ChainService struct {
 	InitSyncBlockRoots          map[[32]byte]bool
 	DB                          db.Database
 	State                       state.BeaconState
+	HeadStateErr                error
 	Block                       interfaces.ReadOnlySignedBeaconBlock
 	VerifyBlkDescendantErr      error
 	stateNotifier               statefeed.Notifier
@@ -74,6 +75,7 @@ type ChainService struct {
 	BlockSlot                   primitives.Slot
 	SyncingRoot                 [32]byte
 	Blobs                       []blocks.VerifiedROBlob
+	DataColumns                 []blocks.VerifiedRODataColumn
 	TargetRoot                  [32]byte
 	MockHeadSlot                *primitives.Slot
 }
@@ -364,6 +366,9 @@ func (s *ChainService) HeadState(context.Context) (state.BeaconState, error) {

 // HeadStateReadOnly mocks HeadStateReadOnly method in chain service.
 func (s *ChainService) HeadStateReadOnly(context.Context) (state.ReadOnlyBeaconState, error) {
+	if s.HeadStateErr != nil {
+		return nil, s.HeadStateErr
+	}
 	return s.State, nil
 }

@@ -550,11 +555,11 @@ func (s *ChainService) UpdateHead(ctx context.Context, slot primitives.Slot) {
 	ojc := &ethpb.Checkpoint{}
 	st, root, err := prepareForkchoiceState(ctx, slot, bytesutil.ToBytes32(s.Root), [32]byte{}, [32]byte{}, ojc, ojc)
 	if err != nil {
-		logrus.WithError(err).Error("could not update head")
+		logrus.WithError(err).Error("Could not update head")
 	}
 	err = s.ForkChoiceStore.InsertNode(ctx, st, root)
 	if err != nil {
-		logrus.WithError(err).Error("could not insert node to forkchoice")
+		logrus.WithError(err).Error("Could not insert node to forkchoice")
 	}
 }

@@ -636,7 +641,7 @@ func (s *ChainService) GetProposerHead() [32]byte {
 }

 // SetForkChoiceGenesisTime mocks the same method in the chain service
-func (s *ChainService) SetForkChoiceGenesisTime(timestamp uint64) {
+func (s *ChainService) SetForkChoiceGenesisTime(timestamp time.Time) {
 	if s.ForkChoiceStore != nil {
 		s.ForkChoiceStore.SetGenesisTime(timestamp)
 	}
@@ -711,7 +716,29 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 	return nil
 }

+// ReceiveDataColumn implements the same method in chain service
+func (c *ChainService) ReceiveDataColumn(dc blocks.VerifiedRODataColumn) error {
+	c.DataColumns = append(c.DataColumns, dc)
+	return nil
+}
+
+// ReceiveDataColumns implements the same method in chain service
+func (*ChainService) ReceiveDataColumns(_ []blocks.VerifiedRODataColumn) error {
+	return nil
+}
+
 // TargetRootForEpoch mocks the same method in the chain service
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil
 }
+
+// MockSyncChecker is a mock implementation of blockchain.Checker.
+// We can't make an assertion here that this is true because that would create a circular dependency.
+type MockSyncChecker struct {
+	synced bool
+}
+
+// Synced satisfies the blockchain.Checker interface.
+func (m *MockSyncChecker) Synced() bool {
+	return m.synced
+}
--- a/beacon-chain/blockchain/weak_subjectivity_checks_test.go
+++ b/beacon-chain/blockchain/weak_subjectivity_checks_test.go
@@ -1,11 +1,8 @@
 package blockchain

 import (
-	"context"
 	"testing"

-	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -18,11 +15,8 @@ import (
 )

 func TestService_VerifyWeakSubjectivityRoot(t *testing.T) {
-	beaconDB := testDB.SetupDB(t)
-
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 1792480
-	util.SaveBlock(t, context.Background(), beaconDB, b)
 	r, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)

@@ -69,17 +63,17 @@ func TestService_VerifyWeakSubjectivityRoot(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			s := testServiceWithDB(t)
+			beaconDB := s.cfg.BeaconDB
+			util.SaveBlock(t, t.Context(), beaconDB, b)
 			wv, err := NewWeakSubjectivityVerifier(tt.checkpt, beaconDB)
-			require.Equal(t, !tt.disabled, wv.enabled)
 			require.NoError(t, err)
-			fcs := doublylinkedtree.New()
-			s := &Service{
-				cfg:        &config{BeaconDB: beaconDB, WeakSubjectivityCheckpt: tt.checkpt, ForkChoiceStore: fcs},
-				wsVerifier: wv,
-			}
-			require.NoError(t, fcs.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: tt.finalizedEpoch}))
+			s.cfg.WeakSubjectivityCheckpt = tt.checkpt
+			s.wsVerifier = wv
+			require.Equal(t, !tt.disabled, wv.enabled)
+			require.NoError(t, s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: tt.finalizedEpoch}))
 			cp := s.cfg.ForkChoiceStore.FinalizedCheckpoint()
-			err = s.wsVerifier.VerifyWeakSubjectivity(context.Background(), cp.Epoch)
+			err = s.wsVerifier.VerifyWeakSubjectivity(t.Context(), cp.Epoch)
 			if tt.wantErr == nil {
 				require.NoError(t, err)
 			} else {
--- a/beacon-chain/builder/service.go
+++ b/beacon-chain/builder/service.go
@@ -24,7 +24,8 @@ var ErrNoBuilder = errors.New("builder endpoint not configured")

 // BlockBuilder defines the interface for interacting with the block builder
 type BlockBuilder interface {
-	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) error
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error)
 	RegisterValidator(ctx context.Context, reg []*ethpb.SignedValidatorRegistrationV1) error
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -68,7 +69,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 			log.WithError(err).Error("Failed to check builder status")
 		} else {
 			log.WithField("endpoint", s.c.NodeURL()).Info("Builder has been configured")
-			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time.  " +
+			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time. " +
 				"Builder-constructed blocks or fallback blocks may get orphaned. Use at your own risk!")
 		}
 	}
@@ -87,7 +88,7 @@ func (s *Service) Stop() error {
 }

 // SubmitBlindedBlock submits a blinded block to the builder relay network.
-func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlock")
 	defer span.End()
 	start := time.Now()
@@ -101,6 +102,22 @@ func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlyS
 	return s.c.SubmitBlindedBlock(ctx, b)
 }

+// SubmitBlindedBlockPostFulu submits a blinded block to the builder relay network post-Fulu.
+// After Fulu, relays only return status codes (no payload).
+func (s *Service) SubmitBlindedBlockPostFulu(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) error {
+	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlockPostFulu")
+	defer span.End()
+	start := time.Now()
+	defer func() {
+		submitBlindedBlockLatency.Observe(float64(time.Since(start).Milliseconds()))
+	}()
+	if s.c == nil {
+		return ErrNoBuilder
+	}
+
+	return s.c.SubmitBlindedBlockPostFulu(ctx, b)
+}
+
 // GetHeader retrieves the header for a given slot and parent hash from the builder relay network.
 func (s *Service) GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.GetHeader")
--- a/beacon-chain/builder/service_test.go
+++ b/beacon-chain/builder/service_test.go
@@ -1,7 +1,6 @@
 package builder

 import (
-	"context"
 	"testing"
 	"time"

@@ -15,19 +14,19 @@ import (
 )

 func Test_NewServiceWithBuilder(t *testing.T) {
-	s, err := NewService(context.Background(), WithBuilderClient(&buildertesting.MockClient{}))
+	s, err := NewService(t.Context(), WithBuilderClient(&buildertesting.MockClient{}))
 	require.NoError(t, err)
 	assert.Equal(t, true, s.Configured())
 }

 func Test_NewServiceWithoutBuilder(t *testing.T) {
-	s, err := NewService(context.Background())
+	s, err := NewService(t.Context())
 	require.NoError(t, err)
 	assert.Equal(t, false, s.Configured())
 }

 func Test_RegisterValidator(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	db := dbtesting.SetupDB(t)
 	headFetcher := &blockchainTesting.ChainService{}
 	builder := buildertesting.NewClient()
@@ -40,7 +39,7 @@ func Test_RegisterValidator(t *testing.T) {
 }

 func Test_RegisterValidator_WithCache(t *testing.T) {
-	ctx := context.Background()
+	ctx := t.Context()
 	headFetcher := &blockchainTesting.ChainService{}
 	builder := buildertesting.NewClient()
 	s, err := NewService(ctx, WithRegistrationCache(), WithHeadFetcher(headFetcher), WithBuilderClient(&builder))
@@ -55,16 +54,16 @@ func Test_RegisterValidator_WithCache(t *testing.T) {
 }

 func Test_BuilderMethodsWithouClient(t *testing.T) {
-	s, err := NewService(context.Background())
+	s, err := NewService(t.Context())
 	require.NoError(t, err)
 	assert.Equal(t, false, s.Configured())

-	_, err = s.GetHeader(context.Background(), 0, [32]byte{}, [48]byte{})
+	_, err = s.GetHeader(t.Context(), 0, [32]byte{}, [48]byte{})
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)

-	_, _, err = s.SubmitBlindedBlock(context.Background(), nil)
+	_, _, err = s.SubmitBlindedBlock(t.Context(), nil)
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)

-	err = s.RegisterValidator(context.Background(), nil)
+	err = s.RegisterValidator(t.Context(), nil)
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)
 }
--- a/beacon-chain/builder/testing/mock.go
+++ b/beacon-chain/builder/testing/mock.go
@@ -24,20 +24,22 @@ type Config struct {

 // MockBuilderService to mock builder.
 type MockBuilderService struct {
-	HasConfigured         bool
-	Payload               *v1.ExecutionPayload
-	PayloadCapella        *v1.ExecutionPayloadCapella
-	PayloadDeneb          *v1.ExecutionPayloadDeneb
-	BlobBundle            *v1.BlobsBundle
-	ErrSubmitBlindedBlock error
-	Bid                   *ethpb.SignedBuilderBid
-	BidCapella            *ethpb.SignedBuilderBidCapella
-	BidDeneb              *ethpb.SignedBuilderBidDeneb
-	BidElectra            *ethpb.SignedBuilderBidElectra
-	RegistrationCache     *cache.RegistrationCache
-	ErrGetHeader          error
-	ErrRegisterValidator  error
-	Cfg                   *Config
+	HasConfigured                 bool
+	Payload                       *v1.ExecutionPayload
+	PayloadCapella                *v1.ExecutionPayloadCapella
+	PayloadDeneb                  *v1.ExecutionPayloadDeneb
+	BlobBundle                    *v1.BlobsBundle
+	BlobBundleV2                  *v1.BlobsBundleV2
+	ErrSubmitBlindedBlock         error
+	ErrSubmitBlindedBlockPostFulu error
+	Bid                           *ethpb.SignedBuilderBid
+	BidCapella                    *ethpb.SignedBuilderBidCapella
+	BidDeneb                      *ethpb.SignedBuilderBidDeneb
+	BidElectra                    *ethpb.SignedBuilderBidElectra
+	RegistrationCache             *cache.RegistrationCache
+	ErrGetHeader                  error
+	ErrRegisterValidator          error
+	Cfg                           *Config
 }

 // Configured for mocking.
@@ -46,7 +48,7 @@ func (s *MockBuilderService) Configured() bool {
 }

 // SubmitBlindedBlock for mocking.
-func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	switch b.Version() {
 	case version.Bellatrix:
 		w, err := blocks.WrappedExecutionPayload(s.Payload)
@@ -66,6 +68,16 @@ func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.
 			return nil, nil, errors.Wrap(err, "could not wrap deneb payload")
 		}
 		return w, s.BlobBundle, s.ErrSubmitBlindedBlock
+	case version.Fulu:
+		w, err := blocks.WrappedExecutionPayloadDeneb(s.PayloadDeneb)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not wrap deneb payload for fulu")
+		}
+		// For Fulu, return BlobsBundleV2 if available, otherwise regular BlobsBundle
+		if s.BlobBundleV2 != nil {
+			return w, s.BlobBundleV2, s.ErrSubmitBlindedBlock
+		}
+		return w, s.BlobBundle, s.ErrSubmitBlindedBlock
 	default:
 		return nil, nil, errors.New("unknown block version for mocking")
 	}
@@ -104,3 +116,8 @@ func (s *MockBuilderService) RegistrationByValidatorID(ctx context.Context, id p
 func (s *MockBuilderService) RegisterValidator(context.Context, []*ethpb.SignedValidatorRegistrationV1) error {
 	return s.ErrRegisterValidator
 }
+
+// SubmitBlindedBlockPostFulu for mocking.
+func (s *MockBuilderService) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return s.ErrSubmitBlindedBlockPostFulu
+}
--- a/beacon-chain/cache/committee.go
+++ b/beacon-chain/cache/committee.go
@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
 	mathutil "github.com/OffchainLabs/prysm/v6/math"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -104,11 +105,16 @@ func (c *CommitteeCache) CompressCommitteeCache() {
 // Committee fetches the shuffled indices by slot and committee index. Every list of indices
 // represent one committee. Returns true if the list exists with slot and committee index. Otherwise returns false, nil.
 func (c *CommitteeCache) Committee(ctx context.Context, slot primitives.Slot, seed [32]byte, index primitives.CommitteeIndex) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.Committee")
+	defer span.End()
+	span.SetAttributes(trace.Int64Attribute("slot", int64(slot)), trace.Int64Attribute("index", int64(index))) // lint:ignore uintcast -- OK for tracing.
+
 	if err := c.checkInProgress(ctx, seed); err != nil {
 		return nil, err
 	}

 	obj, exists := c.CommitteeCache.Get(key(seed))
+	span.SetAttributes(trace.BoolAttribute("cache_hit", exists))
 	if exists {
 		CommitteeCacheHit.Inc()
 	} else {
@@ -157,11 +163,14 @@ func (c *CommitteeCache) AddCommitteeShuffledList(ctx context.Context, committee

 // ActiveIndices returns the active indices of a given seed stored in cache.
 func (c *CommitteeCache) ActiveIndices(ctx context.Context, seed [32]byte) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.ActiveIndices")
+	defer span.End()
+
 	if err := c.checkInProgress(ctx, seed); err != nil {
 		return nil, err
 	}
 	obj, exists := c.CommitteeCache.Get(key(seed))
-
+	span.SetAttributes(trace.BoolAttribute("cache_hit", exists))
 	if exists {
 		CommitteeCacheHit.Inc()
 	} else {
--- a/beacon-chain/cache/committee_fuzz_test.go
+++ b/beacon-chain/cache/committee_fuzz_test.go
@@ -3,7 +3,6 @@
 package cache

 import (
-	"context"
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -30,8 +29,8 @@ func TestCommitteeCache_FuzzCommitteesByEpoch(t *testing.T) {

 	for i := 0; i < 100000; i++ {
 		fuzzer.Fuzz(c)
-		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), c))
-		_, err := cache.Committee(context.Background(), 0, c.Seed, 0)
+		require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), c))
+		_, err := cache.Committee(t.Context(), 0, c.Seed, 0)
 		require.NoError(t, err)
 	}

@@ -45,9 +44,9 @@ func TestCommitteeCache_FuzzActiveIndices(t *testing.T) {

 	for i := 0; i < 100000; i++ {
 		fuzzer.Fuzz(c)
-		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), c))
+		require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), c))

-		indices, err := cache.ActiveIndices(context.Background(), c.Seed)
+		indices, err := cache.ActiveIndices(t.Context(), c.Seed)
 		require.NoError(t, err)
 		assert.DeepEqual(t, c.SortedIndices, indices)
 	}
--- a/beacon-chain/cache/committee_test.go
+++ b/beacon-chain/cache/committee_test.go
@@ -44,15 +44,15 @@ func TestCommitteeCache_CommitteesByEpoch(t *testing.T) {

 	slot := params.BeaconConfig().SlotsPerEpoch
 	committeeIndex := primitives.CommitteeIndex(1)
-	indices, err := cache.Committee(context.Background(), slot, item.Seed, committeeIndex)
+	indices, err := cache.Committee(t.Context(), slot, item.Seed, committeeIndex)
 	require.NoError(t, err)
 	if indices != nil {
 		t.Error("Expected committee not to exist in empty cache")
 	}
-	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
+	require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), item))

 	wantedIndex := primitives.CommitteeIndex(0)
-	indices, err = cache.Committee(context.Background(), slot, item.Seed, wantedIndex)
+	indices, err = cache.Committee(t.Context(), slot, item.Seed, wantedIndex)
 	require.NoError(t, err)

 	start, end := startEndIndices(item, uint64(wantedIndex))
@@ -63,15 +63,15 @@ func TestCommitteeCache_ActiveIndices(t *testing.T) {
 	cache := NewCommitteesCache()

 	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6}}
-	indices, err := cache.ActiveIndices(context.Background(), item.Seed)
+	indices, err := cache.ActiveIndices(t.Context(), item.Seed)
 	require.NoError(t, err)
 	if indices != nil {
 		t.Error("Expected committee not to exist in empty cache")
 	}

-	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
+	require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), item))

-	indices, err = cache.ActiveIndices(context.Background(), item.Seed)
+	indices, err = cache.ActiveIndices(t.Context(), item.Seed)
 	require.NoError(t, err)
 	assert.DeepEqual(t, item.SortedIndices, indices)
 }
@@ -80,13 +80,13 @@ func TestCommitteeCache_ActiveCount(t *testing.T) {
 	cache := NewCommitteesCache()

 	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6}}
-	count, err := cache.ActiveIndicesCount(context.Background(), item.Seed)
+	count, err := cache.ActiveIndicesCount(t.Context(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, 0, count, "Expected active count not to exist in empty cache")

-	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
+	require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), item))

-	count, err = cache.ActiveIndicesCount(context.Background(), item.Seed)
+	count, err = cache.ActiveIndicesCount(t.Context(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, len(item.SortedIndices), count)
 }
@@ -100,7 +100,7 @@ func TestCommitteeCache_CanRotate(t *testing.T) {
 	for i := start; i < end; i++ {
 		s := []byte(strconv.Itoa(i))
 		item := &Committees{Seed: bytesutil.ToBytes32(s)}
-		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
+		require.NoError(t, cache.AddCommitteeShuffledList(t.Context(), item))
 	}

 	k := cache.CommitteeCache.Keys()
@@ -130,7 +130,7 @@ func TestCommitteeCacheOutOfRange(t *testing.T) {
 	assert.NoError(t, err)
 	_ = cache.CommitteeCache.Add(key, comms)

-	_, err = cache.Committee(context.Background(), 0, seed, math.MaxUint64) // Overflow!
+	_, err = cache.Committee(t.Context(), 0, seed, math.MaxUint64) // Overflow!
 	require.NotNil(t, err, "Did not fail as expected")
 }

@@ -138,15 +138,15 @@ func TestCommitteeCache_DoesNothingWhenCancelledContext(t *testing.T) {
 	cache := NewCommitteesCache()

 	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6}}
-	count, err := cache.ActiveIndicesCount(context.Background(), item.Seed)
+	count, err := cache.ActiveIndicesCount(t.Context(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, 0, count, "Expected active count not to exist in empty cache")

-	cancelled, cancel := context.WithCancel(context.Background())
+	cancelled, cancel := context.WithCancel(t.Context())
 	cancel()
 	require.ErrorIs(t, cache.AddCommitteeShuffledList(cancelled, item), context.Canceled)

-	count, err = cache.ActiveIndicesCount(context.Background(), item.Seed)
+	count, err = cache.ActiveIndicesCount(t.Context(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, 0, count)
 }
--- a/Show More
+++ b/Show More