Add EIP-7691 blob throughput increase

Implement consensus spec v1.5.0-alpha.10 (#14733 )
* Use 16 bit random value * enforce 0x02 credentials for consolidations * Limit consolidating balance by validator effective balance * Update max blob commitment size * Fix next sync committee indices * Bytes to little endian * Handle proposer computations in between forks * Fix config and tests Fix tests Fix tests * Fix test stream events by properly set effective balance Fix test stream events by properly set effective balance * Preallocate buffers to avoid repeated allocations * Potuz's feedback * Use 16 bit random value * enforce 0x02 credentials for consolidations * Limit consolidating balance by validator effective balance * Update max blob commitment size * Fix next sync committee indices * Bytes to little endian * Handle proposer computations in between forks * Fix config and tests Fix tests Fix tests * Fix test stream events by properly set effective balance Fix test stream events by properly set effective balance * Preallocate buffers to avoid repeated allocations * Potuz's feedback * Fix change log
2026-01-10 05:47:59 -05:00 · 2024-12-23 15:54:39 -08:00 · 2024-12-23 17:32:41 +00:00 · 2024-12-23 10:18:38 +00:00 · 2024-12-23 09:59:32 +00:00 · 2024-12-20 11:14:14 +00:00
263 changed files with 9934 additions and 6379 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,62 @@ 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.

-## [Unreleased](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...HEAD)
+## [Unreleased](https://github.com/prysmaticlabs/prysm/compare/v5.2.0...HEAD)
+
+### Added
+
+- Added proper gas limit check for header from the builder.
+- Added an error field to log `Finished building block`.
+- Implemented a new `EmptyExecutionPayloadHeader` function.
+- `Finished building block`: Display error only if not nil.
+- Added support to update target and max blob count to different values per hard fork config.
+- Log before blob filesystem cache warm-up.
+- New design for the attestation pool. [PR](https://github.com/prysmaticlabs/prysm/pull/14324)
+- Add field param placeholder for Electra blob target and max to pass spec tests.
+- Add EIP-7691: Blob throughput increase.
+
+### Changed
+
+- Process light client finality updates only for new finalized epochs instead of doing it for every block.
+- Refactor subnets subscriptions.
+- Refactor RPC handlers subscriptions.
+- Go deps upgrade, from `ioutil` to `io`
+- Move successfully registered validator(s) on builder log to debug.
+- Update some test files to use `crypto/rand` instead of `math/rand`
+- Enforce Compound prefix (0x02) for target when processing pending consolidation request.
+- Limit consolidating by validator's effective balance.
+- Use 16-bit random value for proposer and sync committee selection filter.
+
+### Deprecated
+
+
+### Removed
+
+
+### Fixed
+
+- Added check to prevent nil pointer deference or out of bounds array access when validating the BLSToExecutionChange on an impossibly nil validator.
+
+### Security
+
+
+## [v5.2.0](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...v5.2.0)
+
+Updating to this release is highly recommended, especially for users running v5.1.1 or v5.1.2.
+This release is **mandatory** for all validator clients using mev-boost with a gas limit increase.
+Without upgrading to this release, validator clients will default to using local execution blocks
+when the gas limit starts to increase.
+
+This release has several fixes and new features. In this release, we have enabled QUIC protocol by
+default, which uses port 13000 for `--p2p-quic-port`. This may be a [breaking change](https://github.com/prysmaticlabs/prysm/pull/14688#issuecomment-2516713826)
+if you're using port 13000 already. This release has some improvements for raising the gas limit,
+but there are [known issues](https://hackmd.io/@ttsao/prysm-gas-limit) with the proposer settings
+file provided gas limit not being respected for mev-boost outsourced blocks. Signalling an increase
+for the gas limit works perfectly for local block production as of this release. See [pumpthegas.org](https://pumpthegas.org) for more info on raising the gas limit on L1.
+
+Notable features:
+- Prysm can reuse blobs from the EL via engine_getBlobsV1, [potentially saving bandwidth](https://hackmd.io/@ttsao/get-blobs-early-results).
+- QUIC is enabled by default. This is a UDP based networking protocol with default port 13000.

 ### Added

@@ -29,6 +84,11 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - PeerDAS: Added proto for `DataColumnIdentifier`, `DataColumnSidecar`, `DataColumnSidecarsByRangeRequest` and `MetadataV2`.
 - Better attestation packing for Electra. [PR](https://github.com/prysmaticlabs/prysm/pull/14534)
 - P2P: Add logs when a peer is (dis)connected. Add the reason of the disconnection when we initiate it.
+- Added a Prometheus error counter metric for HTTP requests to track beacon node requests.
+- Added a Prometheus error counter metric for SSE requests.
+- Save light client updates and bootstraps in DB.
+- Added more comprehensive tests for `BlockToLightClientHeader`. [PR](https://github.com/prysmaticlabs/prysm/pull/14699)
+- Added light client feature flag check to RPC handlers. [PR](https://github.com/prysmaticlabs/prysm/pull/14736)

 ### Changed

@@ -63,18 +123,28 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Updated light client protobufs. [PR](https://github.com/prysmaticlabs/prysm/pull/14650)
 - Added `Eth-Consensus-Version` header to `ListAttestationsV2` and `GetAggregateAttestationV2` endpoints.
 - Updated light client consensus types. [PR](https://github.com/prysmaticlabs/prysm/pull/14652)
+- Update earliest exit epoch for upgrade to electra
+- Add missed exit checks to consolidation processing
 - Fixed pending deposits processing on Electra.
 - Modified `ListAttestationsV2`, `GetAttesterSlashingsV2` and `GetAggregateAttestationV2` endpoints to use slot to determine fork version.
+- Improvements to HTTP response handling. [pr](https://github.com/prysmaticlabs/prysm/pull/14673)
+- Updated `Blobs` endpoint to return additional metadata fields.
+- Made QUIC the default method to connect with peers.
+- Check kzg commitments align with blobs and proofs for beacon api end point.
+- Revert "Proposer checks gas limit before accepting builder's bid".
+- Updated quic-go to v0.48.2 .

 ### Deprecated

 - `/eth/v1alpha1/validator/activation/stream` grpc wait for activation stream is deprecated. [pr](https://github.com/prysmaticlabs/prysm/pull/14514)
+- `--interop-genesis-time` and `--interop-num-validators` have been deprecated in the beacon node as the functionality has been removed. These flags have no effect.

 ### Removed

 - Removed finalized validator index cache, no longer needed.
 - Removed validator queue position log on key reload and wait for activation.
 - Removed outdated spectest exclusions for EIP-6110.
+- Removed support for starting a beacon node with a deterministic interop genesis state via interop flags. Alteratively, create a genesis state with prysmctl and use `--genesis-state`. This removes about 9Mb (~11%) of unnecessary code and dependencies from the final production binary.
 - Removed kzg proof check from blob reconstructor.

 ### Fixed
@@ -96,7 +166,14 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - corrects nil check on some interface attestation types
 - temporary solution to handling electra attesation and attester_slashing events. [pr](14655)
 - Diverse log improvements and comment additions.
-
+- Validate that each committee bitfield in an aggregate contains at least one non-zero bit
+- P2P: Avoid infinite loop when looking for peers in small networks.
+- Fixed another rollback bug due to a context deadline.
+- Fix checkpoint sync bug on holesky. [pr](https://github.com/prysmaticlabs/prysm/pull/14689)
+- Fix proposer boost spec tests being flakey by adjusting start time from 3 to 2s into slot.
+- Fix segmentation fault in E2E when light-client feature flag is enabled. [PR](https://github.com/prysmaticlabs/prysm/pull/14699)
+- Fix `searchForPeers` infinite loop in small networks.
+- Fix slashing pool behavior to enforce MaxAttesterSlashings limit in Electra version.

 ### Security

@@ -421,6 +498,7 @@ block profit. If you want to preserve the existing behavior, set --local-block-v
 - Set default LocalBlockValueBoost to 10
 - Add bid value metrics
 - REST VC metrics
+- `startDB`: Add log when checkpoint sync.

 ### Changed

--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -129,7 +129,7 @@ If your change is user facing, you must include a CHANGELOG.md entry. See the [M

 **17. Create a pull request.**

-Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base master”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base develop”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.

 **18. Respond to comments by Core Contributors.**

--- a/INTEROP.md
+++ b/INTEROP.md
@@ -2,18 +2,21 @@

 This README details how to setup Prysm for interop testing for usage with other Ethereum consensus clients.

+> [!IMPORTANT]  
+> This guide is likely to be outdated. The Prysm team does not have capacity to troubleshoot
+> outdated interop guides or instructions. If you experience issues with this guide, please file and
+> issue for visibility and propose fixes, if possible.
+
 ## Installation & Setup

 1. Install [Bazel](https://docs.bazel.build/versions/master/install.html) **(Recommended)**
 2. `git clone https://github.com/prysmaticlabs/prysm && cd prysm`
-3. `bazel build //...`
+3. `bazel build //cmd/...`

 ## Starting from Genesis

-Prysm supports a few ways to quickly launch a beacon node from basic configurations:
-
- `NumValidators + GenesisTime`: Launches a beacon node by deterministically generating a state from a num-validators flag along with a genesis time **(Recommended)**
- `SSZ Genesis`: Launches a beacon node  from a .ssz file containing a SSZ-encoded, genesis beacon state
+Prysm can be started from a built-in mainnet genesis state, or started with a provided genesis state by
+using the `--genesis-state` flag and providing a path to the genesis.ssz file.

 ## Generating a Genesis State

@@ -21,21 +24,34 @@ To setup the necessary files for these quick starts, Prysm provides a tool to ge
 a deterministically generated set of validator private keys following the official interop YAML format 
 [here](https://github.com/ethereum/eth2.0-pm/blob/master/interop/mocked_start).

-You can use `bazel run //tools/genesis-state-gen` to create a deterministic genesis state for interop.
+You can use `prysmctl` to create a deterministic genesis state for interop.

-### Usage
-
- **--genesis-time** uint: Unix timestamp used as the genesis time in the generated genesis state (defaults to now)
- **--num-validators** int: Number of validators to deterministically include in the generated genesis state
- **--output-ssz** string: Output filename of the SSZ marshaling of the generated genesis state
- **--config-name=interop** string: name of the beacon chain config to use when generating the state. ex mainnet|minimal|interop
-
-The example below creates 64 validator keys, instantiates a genesis state with those 64 validators and with genesis unix timestamp 1567542540,
-and finally writes a ssz encoded output to ~/Desktop/genesis.ssz. This file can be used to kickstart the beacon chain in the next section. When using the `--interop-*` flags, the beacon node will assume the `interop` config should be used, unless a different config is specified on the command line.
+```sh
+# Download (or create) a chain config file.
+curl https://raw.githubusercontent.com/ethereum/consensus-specs/refs/heads/dev/configs/minimal.yaml -o /tmp/minimal.yaml

+# Run prysmctl to generate genesis with a 2 minute genesis delay and 256 validators. 
+bazel run //cmd/prysmctl --config=minimal -- \
+  testnet generate-genesis \
+  --genesis-time-delay=120 \
+  --num-validators=256 \
+  --output-ssz=/tmp/genesis.ssz \
+  --chain-config-file=/tmp/minimal.yaml
 ```
-bazel run //tools/genesis-state-gen -- --config-name interop --output-ssz ~/Desktop/genesis.ssz --num-validators 64 --genesis-time 1567542540
-```
+
+The flags are explained below:
+- `bazel run //cmd/prysmctl` is the bazel command to compile and run prysmctl.
+- `--config=minimal` is a bazel build time configuration flag to compile Prysm with minimal state constants.
+- `--` is an argument divider to tell bazel that everything after this divider should be passed as arguments to prysmctl. Without this divider, it isn't clear to bazel if the arguments are meant to be build time arguments or runtime arguments so the operation complains and fails to build without this divider.
+- `testnet` is the primary command argument for prysmctl.
+- `generate-genesis` is the subcommand to `testnet` in prysmctl.
+- `--genesis-time-delay` uint: The number of seconds in the future to define genesis. Example: a value of 60 will set the genesis time to 1 minute in the future. This should be sufficiently large enough to allow for you to start the beacon node before the genesis time. 
+- `--num-validators` int: Number of validators to deterministically include in the generated genesis state
+- `--output-ssz` string: Output filename of the SSZ marshaling of the generated genesis state
+- `--chain-config-file` string: Filepath to a chain config yaml file.
+
+Note: This guide saves items to the `/tmp/` directory which will not persist if your machine is
+restarted. Consider tweaking the arguments if persistence is needed.

 ## Launching a Beacon Node + Validator Client

@@ -44,45 +60,33 @@ bazel run //tools/genesis-state-gen -- --config-name interop --output-ssz ~/Desk
 Open up two terminal windows, run:

 ```
-bazel run //beacon-chain -- \
--bootstrap-node= \
--deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
--datadir=/tmp/beacon-chain-interop \
--force-clear-db \
--min-sync-peers=0 \
--interop-num-validators 64 \
--interop-eth1data-votes
+bazel run //cmd/beacon-chain --config=minimal -- \
+  --minimal-config \
+  --bootstrap-node= \
+  --deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
+  --datadir=/tmp/beacon-chain-minimal-devnet \
+  --force-clear-db \
+  --min-sync-peers=0 \
+  --genesis-state=/tmp/genesis.ssz \
+  --chain-config-file=/tmp/minimal.yaml
 ```

-This will deterministically generate a beacon genesis state and start
-the system with 64 validators and the genesis time set to the current unix timestamp.
-Wait a bit until your beacon chain starts, and in the other window:
+This will start the system with 256 validators. The flags used can be explained as such:
+
+- `bazel run //cmd/beacon-chain --config=minimal` builds and runs the beacon node in minimal build configuration.
+- `--` is a flag divider to distingish between bazel flags and flags that should be passed to the application. All flags and arguments after this divider are passed to the beacon chain.
+- `--minimal-config` tells the beacon node to use minimal network configuration. This is different from the compile time state configuration flag `--config=minimal` and both are required.
+- `--bootstrap-node=` disables the default bootstrap nodes. This prevents the client from attempting to peer with mainnet nodes.
+- `--datadir=/tmp/beacon-chain-minimal-devnet` sets the data directory in a temporary location. Change this to your preferred destination.
+- `--force-clear-db` will delete the beaconchain.db file without confirming with the user. This is helpful for iteratively running local devnets without changing the datadir, but less helpful for one off runs where there was no database in the data directory.
+- `--min-sync-peers=0` allows the beacon node to skip initial sync without peers. This is essential because Prysm expects at least a few peers to start start the blockchain.
+- `--genesis-state=/tmp/genesis.ssz` defines the path to the generated genesis ssz file. The beacon node will use this as the initial genesis state.
+- `--chain-config-file=/tmp/minimal.yaml` defines the path to the yaml file with the chain configuration.
+
+As soon as the beacon node has started, start the validator in the other terminal window. 

 ```
-bazel run //validator -- --keymanager=interop --keymanageropts='{"keys":64}'
+bazel run //cmd/validator --config=minimal -- --datadir=/tmp/validator --interopt-num-validators=256 --minimal-config --suggested-fee-recipient=0x8A04d14125D0FDCDc742F4A05C051De07232EDa4
 ```

-This will launch and kickstart the system with your 64 validators performing their duties accordingly.
-
-### Launching from `genesis.ssz`
-
-Assuming you generated a `genesis.ssz` file with 64 validators, open up two terminal windows, run:
-
-```
- bazel run //beacon-chain -- \
--bootstrap-node= \
--deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
--datadir=/tmp/beacon-chain-interop \
--force-clear-db \
--min-sync-peers=0 \
--interop-genesis-state /path/to/genesis.ssz \
--interop-eth1data-votes
-```
-
-Wait a bit until your beacon chain starts, and in the other window:
-
-```
-bazel run //validator -- --keymanager=interop --keymanageropts='{"keys":64}'
-```
-
-This will launch and kickstart the system with your 64 validators performing their duties accordingly.
+This will launch and kickstart the system with your 256 validators performing their duties accordingly.
--- a/10
+++ b/10
@@ -227,7 +227,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.5.0-alpha.8"
+consensus_spec_version = "v1.5.0-alpha.10"

 bls_test_version = "v0.1.1"

@@ -243,7 +243,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-BsGIbEyJuYrzhShGl0tHhR4lP5Qwno8R3k8a6YBR/DA=",
+    integrity = "sha256-NtWIhbO/mVMb1edq5jqABL0o8R1tNFiuG8PCMAsUHcs=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -259,7 +259,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-DkdvhPP2KiqUOpwFXQIFDCWCwsUDIC/xhTBD+TZevm0=",
+    integrity = "sha256-DFlFlnzls1bBrDm+/xD8NK2ivvkhxR+rSNVLLqScVKc=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -275,7 +275,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-vkZqV0HB8A2Uc56C1Us/p5G57iaHL+zw2No93Xt6M/4=",
+    integrity = "sha256-G9ENPF8udZL/BqRHbi60GhFPnZDPZAH6UjcjRiOlvbk=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -290,7 +290,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-D/HPAW61lKqjoWwl7N0XvhdX+67dCEFAy8JxVzqBGtU=",
+    integrity = "sha256-ClOLKkmAcEi8/uKi6LDeqthask5+E3sgxVoA0bqmQ0c=",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -12,8 +12,10 @@ go_library(
    visibility = ["//visibility:public"],
    deps = [
        "//api:go_default_library",
+        "//api/client:go_default_library",
        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -14,6 +14,7 @@ import (

 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/api"
+	"github.com/prysmaticlabs/prysm/v5/api/client"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
@@ -176,7 +177,7 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 		err = non200Err(r)
 		return
 	}
-	res, err = io.ReadAll(r.Body)
+	res, err = io.ReadAll(io.LimitReader(r.Body, client.MaxBodySize))
 	if err != nil {
 		err = errors.Wrap(err, "error reading http response body from builder server")
 		return
@@ -281,7 +282,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 	if err != nil {
 		return err
 	}
-	log.WithField("num_registrations", len(svr)).Info("successfully registered validator(s) on builder")
+	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
 	return nil
 }

@@ -358,7 +359,7 @@ func (c *Client) Status(ctx context.Context) error {
 }

 func non200Err(response *http.Response) error {
-	bodyBytes, err := io.ReadAll(response.Body)
+	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, client.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
 	if err != nil {
--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
@@ -9,6 +9,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -1013,7 +1014,7 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 	if err != nil {
 		return nil, err
 	}
-	if len(bb.BlobKzgCommitments) > fieldparams.MaxBlobsPerBlock {
+	if len(bb.BlobKzgCommitments) > params.BeaconConfig().DeprecatedMaxBlobsPerBlock {
 		return nil, fmt.Errorf("too many blob commitments: %d", len(bb.BlobKzgCommitments))
 	}
 	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
--- a/api/client/client.go
+++ b/api/client/client.go
@@ -10,11 +10,18 @@ import (
 	"github.com/pkg/errors"
 )

+const (
+	MaxBodySize      int64 = 1 << 23 // 8MB default, WithMaxBodySize can override
+	MaxBodySizeState int64 = 1 << 29 // 512MB
+	MaxErrBodySize   int64 = 1 << 17 // 128KB
+)
+
 // Client is a wrapper object around the HTTP client.
 type Client struct {
-	hc      *http.Client
-	baseURL *url.URL
-	token   string
+	hc          *http.Client
+	baseURL     *url.URL
+	token       string
+	maxBodySize int64
 }

 // NewClient constructs a new client with the provided options (ex WithTimeout).
@@ -26,8 +33,9 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {
 		return nil, err
 	}
 	c := &Client{
-		hc:      &http.Client{},
-		baseURL: u,
+		hc:          &http.Client{},
+		baseURL:     u,
+		maxBodySize: MaxBodySize,
 	}
 	for _, o := range opts {
 		o(c)
@@ -72,7 +80,7 @@ func (c *Client) NodeURL() string {
 // Get is a generic, opinionated GET function to reduce boilerplate amongst the getters in this package.
 func (c *Client) Get(ctx context.Context, path string, opts ...ReqOption) ([]byte, error) {
 	u := c.baseURL.ResolveReference(&url.URL{Path: path})
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), http.NoBody)
 	if err != nil {
 		return nil, err
 	}
@@ -89,7 +97,7 @@ func (c *Client) Get(ctx context.Context, path string, opts ...ReqOption) ([]byt
 	if r.StatusCode != http.StatusOK {
 		return nil, Non200Err(r)
 	}
-	b, err := io.ReadAll(r.Body)
+	b, err := io.ReadAll(io.LimitReader(r.Body, c.maxBodySize))
 	if err != nil {
 		return nil, errors.Wrap(err, "error reading http response body")
 	}
--- a/api/client/errors.go
+++ b/api/client/errors.go
@@ -25,16 +25,16 @@ var ErrInvalidNodeVersion = errors.New("invalid node version response")
 var ErrConnectionIssue = errors.New("could not connect")

 // Non200Err is a function that parses an HTTP response to handle responses that are not 200 with a formatted error.
-func Non200Err(response *http.Response) error {
-	bodyBytes, err := io.ReadAll(response.Body)
+func Non200Err(r *http.Response) error {
+	b, err := io.ReadAll(io.LimitReader(r.Body, MaxErrBodySize))
 	var body string
 	if err != nil {
 		body = "(Unable to read response body.)"
 	} else {
-		body = "response body:\n" + string(bodyBytes)
+		body = "response body:\n" + string(b)
 	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
-	switch response.StatusCode {
+	msg := fmt.Sprintf("code=%d, url=%s, body=%s", r.StatusCode, r.Request.URL, body)
+	switch r.StatusCode {
 	case http.StatusNotFound:
 		return errors.Wrap(ErrNotFound, msg)
 	default:
--- a/api/client/options.go
+++ b/api/client/options.go
@@ -46,3 +46,10 @@ func WithAuthenticationToken(token string) ClientOpt {
 		c.token = token
 	}
 }
+
+// WithMaxBodySize overrides the default max body size of 8MB.
+func WithMaxBodySize(size int64) ClientOpt {
+	return func(c *Client) {
+		c.maxBodySize = size
+	}
+}
--- a/api/server/structs/BUILD.bazel
+++ b/api/server/structs/BUILD.bazel
@@ -36,9 +36,8 @@ go_library(
        "//math:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
-        "//proto/migration: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",
--- a/api/server/structs/conversions.go
+++ b/api/server/structs/conversions.go
@@ -1546,3 +1546,10 @@ func EventChainReorgFromV1(event *ethv1.EventChainReorg) *ChainReorgEvent {
 		ExecutionOptimistic: event.ExecutionOptimistic,
 	}
 }
+
+func SyncAggregateFromConsensus(sa *eth.SyncAggregate) *SyncAggregate {
+	return &SyncAggregate{
+		SyncCommitteeBits:      hexutil.Encode(sa.SyncCommitteeBits),
+		SyncCommitteeSignature: hexutil.Encode(sa.SyncCommitteeSignature),
+	}
+}
--- a/api/server/structs/conversions_lightclient.go
+++ b/api/server/structs/conversions_lightclient.go
@@ -3,125 +3,227 @@ package structs
 import (
 	"encoding/json"
 	"fmt"
-	"strconv"

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	v2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	"github.com/prysmaticlabs/prysm/v5/proto/migration"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )

-func LightClientUpdateFromConsensus(update *v2.LightClientUpdate) (*LightClientUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientUpdateFromConsensus(update interfaces.LightClientUpdate) (*LightClientUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}
-	finalizedHeader, err := lightClientHeaderContainerToJSON(update.FinalizedHeader)
+	finalizedHeader, err := lightClientHeaderToJSON(update.FinalizedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal finalized light client header")
 	}

+	var scBranch [][32]byte
+	var finalityBranch [][32]byte
+	if update.Version() >= version.Electra {
+		scb, err := update.NextSyncCommitteeBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = scb[:]
+		fb, err := update.FinalityBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = fb[:]
+	} else {
+		scb, err := update.NextSyncCommitteeBranch()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = scb[:]
+		fb, err := update.FinalityBranch()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = fb[:]
+	}
+
 	return &LightClientUpdate{
 		AttestedHeader:          attestedHeader,
-		NextSyncCommittee:       SyncCommitteeFromConsensus(migration.V2SyncCommitteeToV1Alpha1(update.NextSyncCommittee)),
-		NextSyncCommitteeBranch: branchToJSON(update.NextSyncCommitteeBranch),
+		NextSyncCommittee:       SyncCommitteeFromConsensus(update.NextSyncCommittee()),
+		NextSyncCommitteeBranch: branchToJSON(scBranch),
 		FinalizedHeader:         finalizedHeader,
-		FinalityBranch:          branchToJSON(update.FinalityBranch),
-		SyncAggregate:           syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:           strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		FinalityBranch:          branchToJSON(finalityBranch),
+		SyncAggregate:           SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:           fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }

-func LightClientFinalityUpdateFromConsensus(update *v2.LightClientFinalityUpdate) (*LightClientFinalityUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientFinalityUpdateFromConsensus(update interfaces.LightClientFinalityUpdate) (*LightClientFinalityUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}
-	finalizedHeader, err := lightClientHeaderContainerToJSON(update.FinalizedHeader)
+	finalizedHeader, err := lightClientHeaderToJSON(update.FinalizedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal finalized light client header")
 	}

+	var finalityBranch [][32]byte
+	if update.Version() >= version.Electra {
+		b, err := update.FinalityBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = b[:]
+	} else {
+		b, err := update.FinalityBranch()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = b[:]
+	}
+
 	return &LightClientFinalityUpdate{
 		AttestedHeader:  attestedHeader,
 		FinalizedHeader: finalizedHeader,
-		FinalityBranch:  branchToJSON(update.FinalityBranch),
-		SyncAggregate:   syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:   strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		FinalityBranch:  branchToJSON(finalityBranch),
+		SyncAggregate:   SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:   fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }

-func LightClientOptimisticUpdateFromConsensus(update *v2.LightClientOptimisticUpdate) (*LightClientOptimisticUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientOptimisticUpdateFromConsensus(update interfaces.LightClientOptimisticUpdate) (*LightClientOptimisticUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}

 	return &LightClientOptimisticUpdate{
 		AttestedHeader: attestedHeader,
-		SyncAggregate:  syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:  strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		SyncAggregate:  SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:  fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }

-func branchToJSON(branchBytes [][]byte) []string {
+func branchToJSON[S [][32]byte](branchBytes S) []string {
 	if branchBytes == nil {
 		return nil
 	}
 	branch := make([]string, len(branchBytes))
 	for i, root := range branchBytes {
-		branch[i] = hexutil.Encode(root)
+		branch[i] = hexutil.Encode(root[:])
 	}
 	return branch
 }

-func syncAggregateToJSON(input *v1.SyncAggregate) *SyncAggregate {
-	return &SyncAggregate{
-		SyncCommitteeBits:      hexutil.Encode(input.SyncCommitteeBits),
-		SyncCommitteeSignature: hexutil.Encode(input.SyncCommitteeSignature),
-	}
-}
-
-func lightClientHeaderContainerToJSON(container *v2.LightClientHeaderContainer) (json.RawMessage, error) {
+func lightClientHeaderToJSON(header interfaces.LightClientHeader) (json.RawMessage, error) {
 	// In the case that a finalizedHeader is nil.
-	if container == nil {
+	if header == nil {
 		return nil, nil
 	}

-	beacon, err := container.GetBeacon()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get beacon block header")
-	}
+	var result any

-	var header any
-
-	switch t := (container.Header).(type) {
-	case *v2.LightClientHeaderContainer_HeaderAltair:
-		header = &LightClientHeader{Beacon: BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon))}
-	case *v2.LightClientHeaderContainer_HeaderCapella:
-		execution, err := ExecutionPayloadHeaderCapellaFromConsensus(t.HeaderCapella.Execution)
+	switch v := header.Version(); v {
+	case version.Altair:
+		result = &LightClientHeader{Beacon: BeaconBlockHeaderFromConsensus(header.Beacon())}
+	case version.Capella:
+		exInterface, err := header.Execution()
 		if err != nil {
 			return nil, err
 		}
-		header = &LightClientHeaderCapella{
-			Beacon:          BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon)),
-			Execution:       execution,
-			ExecutionBranch: branchToJSON(t.HeaderCapella.ExecutionBranch),
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderCapella)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderCapella{})
 		}
-	case *v2.LightClientHeaderContainer_HeaderDeneb:
-		execution, err := ExecutionPayloadHeaderDenebFromConsensus(t.HeaderDeneb.Execution)
+		execution, err := ExecutionPayloadHeaderCapellaFromConsensus(ex)
 		if err != nil {
 			return nil, err
 		}
-		header = &LightClientHeaderDeneb{
-			Beacon:          BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon)),
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderCapella{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
 			Execution:       execution,
-			ExecutionBranch: branchToJSON(t.HeaderDeneb.ExecutionBranch),
+			ExecutionBranch: branchToJSON(executionBranch[:]),
+		}
+	case version.Deneb:
+		exInterface, err := header.Execution()
+		if err != nil {
+			return nil, err
+		}
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderDeneb{})
+		}
+		execution, err := ExecutionPayloadHeaderDenebFromConsensus(ex)
+		if err != nil {
+			return nil, err
+		}
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderDeneb{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
+			Execution:       execution,
+			ExecutionBranch: branchToJSON(executionBranch[:]),
+		}
+	case version.Electra:
+		exInterface, err := header.Execution()
+		if err != nil {
+			return nil, err
+		}
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderElectra)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderElectra{})
+		}
+		execution, err := ExecutionPayloadHeaderElectraFromConsensus(ex)
+		if err != nil {
+			return nil, err
+		}
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderDeneb{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
+			Execution:       execution,
+			ExecutionBranch: branchToJSON(executionBranch[:]),
 		}
 	default:
-		return nil, fmt.Errorf("unsupported header type %T", t)
+		return nil, fmt.Errorf("unsupported header version %s", version.String(v))
 	}

-	return json.Marshal(header)
+	return json.Marshal(result)
+}
+
+func LightClientBootstrapFromConsensus(bootstrap interfaces.LightClientBootstrap) (*LightClientBootstrap, error) {
+	header, err := lightClientHeaderToJSON(bootstrap.Header())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal light client header")
+	}
+
+	var scBranch [][32]byte
+	if bootstrap.Version() >= version.Electra {
+		b, err := bootstrap.CurrentSyncCommitteeBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = b[:]
+	} else {
+		b, err := bootstrap.CurrentSyncCommitteeBranch()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = b[:]
+	}
+
+	return &LightClientBootstrap{
+		Header:                     header,
+		CurrentSyncCommittee:       SyncCommitteeFromConsensus(bootstrap.CurrentSyncCommittee()),
+		CurrentSyncCommitteeBranch: branchToJSON(scBranch),
+	}, nil
 }
--- a/api/server/structs/endpoints_blob.go
+++ b/api/server/structs/endpoints_blob.go
@@ -1,7 +1,10 @@
 package structs

 type SidecarsResponse struct {
-	Data []*Sidecar `json:"data"`
+	Version             string     `json:"version"`
+	Data                []*Sidecar `json:"data"`
+	ExecutionOptimistic bool       `json:"execution_optimistic"`
+	Finalized           bool       `json:"finalized"`
 }

 type Sidecar struct {
--- a/api/server/structs/endpoints_events.go
+++ b/api/server/structs/endpoints_events.go
@@ -83,6 +83,16 @@ type PayloadAttributesV3 struct {
 	ParentBeaconBlockRoot string        `json:"parent_beacon_block_root"`
 }

+type PayloadAttributesV4 struct {
+	Timestamp             string        `json:"timestamp"`
+	PrevRandao            string        `json:"prev_randao"`
+	SuggestedFeeRecipient string        `json:"suggested_fee_recipient"`
+	Withdrawals           []*Withdrawal `json:"withdrawals"`
+	ParentBeaconBlockRoot string        `json:"parent_beacon_block_root"`
+	TargetBlobsPerBlock   string        `json:"target_blobs_per_block"`
+	MaxBlobsPerBlock      string        `json:"max_blobs_per_block"`
+}
+
 type BlobSidecarEvent struct {
 	BlockRoot     string `json:"block_root"`
 	Index         string `json:"index"`
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -84,7 +84,6 @@ go_library(
        "//monitoring/tracing/trace:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//runtime/version:go_default_library",
@@ -141,6 +140,7 @@ go_test(
        "//beacon-chain/core/blocks:go_default_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/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
        "//beacon-chain/das:go_default_library",
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -13,7 +13,6 @@ import (
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
@@ -39,7 +38,7 @@ func prepareForkchoiceState(
 	payloadHash [32]byte,
 	justified *ethpb.Checkpoint,
 	finalized *ethpb.Checkpoint,
-) (state.BeaconState, consensus_blocks.ROBlock, error) {
+) (state.BeaconState, blocks.ROBlock, error) {
 	blockHeader := &ethpb.BeaconBlockHeader{
 		ParentRoot: parentRoot[:],
 	}
@@ -61,7 +60,7 @@ func prepareForkchoiceState(
 	base.BlockRoots[0] = append(base.BlockRoots[0], blockRoot[:]...)
 	st, err := state_native.InitializeFromProtoBellatrix(base)
 	if err != nil {
-		return nil, consensus_blocks.ROBlock{}, err
+		return nil, blocks.ROBlock{}, err
 	}
 	blk := &ethpb.SignedBeaconBlockBellatrix{
 		Block: &ethpb.BeaconBlockBellatrix{
@@ -76,9 +75,9 @@ func prepareForkchoiceState(
 	}
 	signed, err := blocks.NewSignedBeaconBlock(blk)
 	if err != nil {
-		return nil, consensus_blocks.ROBlock{}, err
+		return nil, blocks.ROBlock{}, err
 	}
-	roblock, err := consensus_blocks.NewROBlockWithRoot(signed, blockRoot)
+	roblock, err := blocks.NewROBlockWithRoot(signed, blockRoot)
 	return st, roblock, err
 }

--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -364,7 +364,26 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,

 	var attr payloadattribute.Attributer
 	switch st.Version() {
-	case version.Deneb, version.Electra:
+	case version.Electra:
+		withdrawals, _, err := st.ExpectedWithdrawals()
+		if err != nil {
+			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
+			return emptyAttri
+		}
+		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV4{
+			Timestamp:             uint64(t.Unix()),
+			PrevRandao:            prevRando,
+			SuggestedFeeRecipient: val.FeeRecipient[:],
+			Withdrawals:           withdrawals,
+			ParentBeaconBlockRoot: headRoot,
+			TargetBlobsPerBlock:   uint64(params.BeaconConfig().TargetBlobsPerBlockBySlot(slot)),
+			MaxBlobsPerBlock:      uint64(params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)),
+		})
+		if err != nil {
+			log.WithError(err).Error("Could not get payload attribute")
+			return emptyAttri
+		}
+	case version.Deneb:
 		withdrawals, _, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -23,6 +23,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
@@ -867,8 +868,53 @@ func Test_GetPayloadAttributeV3(t *testing.T) {
 				return st
 			}(),
 		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+			ctx := tr.ctx
+
+			attr := service.getPayloadAttribute(ctx, test.st, 0, []byte{})
+			require.Equal(t, true, attr.IsEmpty())
+
+			// Cache hit, advance state, no fee recipient
+			slot := primitives.Slot(1)
+			service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
+			service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
+			attr = service.getPayloadAttribute(ctx, test.st, slot, params.BeaconConfig().ZeroHash[:])
+			require.Equal(t, false, attr.IsEmpty())
+			require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+			a, err := attr.Withdrawals()
+			require.NoError(t, err)
+			require.Equal(t, 0, len(a))
+
+			// Cache hit, advance state, has fee recipient
+			suggestedAddr := common.HexToAddress("123")
+			service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
+			service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
+			attr = service.getPayloadAttribute(ctx, test.st, slot, params.BeaconConfig().ZeroHash[:])
+			require.Equal(t, false, attr.IsEmpty())
+			require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
+			a, err = attr.Withdrawals()
+			require.NoError(t, err)
+			require.Equal(t, 0, len(a))
+
+			attrV3, err := attr.PbV3()
+			require.NoError(t, err)
+			hr := service.headRoot()
+			require.Equal(t, hr, [32]byte(attrV3.ParentBeaconBlockRoot))
+		})
+	}
+}
+
+func Test_GetPayloadAttributeV4(t *testing.T) {
+	var testCases = []struct {
+		name string
+		st   bstate.BeaconState
+	}{
 		{
-			name: "electra",
+			name: "deneb",
 			st: func() bstate.BeaconState {
 				st, _ := util.DeterministicGenesisStateElectra(t, 1)
 				return st
@@ -906,10 +952,13 @@ func Test_GetPayloadAttributeV3(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, 0, len(a))

-			attrV3, err := attr.PbV3()
+			attrV4, err := attr.PbV4()
 			require.NoError(t, err)
 			hr := service.headRoot()
-			require.Equal(t, hr, [32]byte(attrV3.ParentBeaconBlockRoot))
+			require.Equal(t, hr, [32]byte(attrV4.ParentBeaconBlockRoot))
+
+			require.Equal(t, int(attrV4.MaxBlobsPerBlock), params.BeaconConfig().MaxBlobsPerBlockByVersion(version.Electra))
+			require.Equal(t, int(attrV4.TargetBlobsPerBlock), params.BeaconConfig().TargetBlobsPerBlockByVersion(version.Electra))
 		})
 	}
 }
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -11,6 +11,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -404,13 +405,19 @@ func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]b
 			if a.GetData().Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
 				continue
 			}
-			if helpers.IsAggregated(a) {
-				if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+			if features.Get().EnableExperimentalAttestationPool {
+				if err = s.cfg.AttestationCache.Add(a); err != nil {
 					return err
 				}
 			} else {
-				if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
-					return err
+				if a.IsAggregated() {
+					if err = s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+						return err
+					}
+				} else {
+					if err = s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
+						return err
+					}
 				}
 			}
 			saveOrphanedAttCount.Inc()
--- a/beacon-chain/blockchain/kzg/BUILD.bazel
+++ b/beacon-chain/blockchain/kzg/BUILD.bazel
@@ -26,8 +26,7 @@ go_test(
    deps = [
        "//consensus-types/blocks:go_default_library",
        "//testing/require:go_default_library",
-        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "//testing/util:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -1,51 +1,14 @@
 package kzg

 import (
-	"bytes"
-	"crypto/sha256"
-	"encoding/binary"
 	"testing"

-	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/sirupsen/logrus"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
 )

-func deterministicRandomness(seed int64) [32]byte {
-	// Converts an int64 to a byte slice
-	buf := new(bytes.Buffer)
-	err := binary.Write(buf, binary.BigEndian, seed)
-	if err != nil {
-		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
-		return [32]byte{}
-	}
-	bytes := buf.Bytes()
-
-	return sha256.Sum256(bytes)
-}
-
-// Returns a serialized random field element in big-endian
-func GetRandFieldElement(seed int64) [32]byte {
-	bytes := deterministicRandomness(seed)
-	var r fr.Element
-	r.SetBytes(bytes[:])
-
-	return GoKZG.SerializeScalar(r)
-}
-
-// Returns a random blob using the passed seed as entropy
-func GetRandBlob(seed int64) GoKZG.Blob {
-	var blob GoKZG.Blob
-	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
-	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
-		fieldElementBytes := GetRandFieldElement(seed + int64(i))
-		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
-	}
-	return blob
-}
-
 func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
 	commitment, err := kzgContext.BlobToKZGCommitment(blob, 0)
 	if err != nil {
@@ -74,7 +37,7 @@ func TestBytesToAny(t *testing.T) {
 }

 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := GetRandBlob(123)
+	blob := util.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}
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -85,6 +85,14 @@ func WithTrackedValidatorsCache(c *cache.TrackedValidatorsCache) Option {
 	}
 }

+// WithAttestationCache for attestation lifecycle after chain inclusion.
+func WithAttestationCache(c *cache.AttestationCache) Option {
+	return func(s *Service) error {
+		s.cfg.AttestationCache = c
+		return nil
+	}
+}
+
 // WithAttestationPool for attestation lifecycle after chain inclusion.
 func WithAttestationPool(p attestations.Pool) Option {
 	return func(s *Service) error {
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -15,7 +15,6 @@ import (
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
@@ -67,7 +66,10 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	if s.inRegularSync() {
 		defer s.handleSecondFCUCall(cfg, fcuArgs)
 	}
-	defer s.sendLightClientFeeds(cfg)
+	if features.Get().EnableLightClient && slots.ToEpoch(s.CurrentSlot()) >= params.BeaconConfig().AltairForkEpoch {
+		defer s.processLightClientUpdates(cfg)
+		defer s.saveLightClientUpdate(cfg)
+	}
 	defer s.sendStateFeedOnBlock(cfg)
 	defer reportProcessingTime(startTime)
 	defer reportAttestationInclusion(cfg.roblock.Block())
@@ -376,7 +378,11 @@ func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.Re
 		r := bytesutil.ToBytes32(a.GetData().BeaconBlockRoot)
 		if s.cfg.ForkChoiceStore.HasNode(r) {
 			s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, r, a.GetData().Target.Epoch)
-		} else if err := s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
+		} else if features.Get().EnableExperimentalAttestationPool {
+			if err = s.cfg.AttestationCache.Add(a); err != nil {
+				return err
+			}
+		} else if err = s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
 			return err
 		}
 	}
@@ -404,10 +410,9 @@ func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interface
 		return errors.Wrapf(err, "could not save block from slot %d", b.Block().Slot())
 	}
 	if err := s.cfg.StateGen.SaveState(ctx, r, st); err != nil {
-		log.Warnf("Rolling back insertion of block with root %#x", r)
-		if err := s.cfg.BeaconDB.DeleteBlock(ctx, r); err != nil {
-			log.WithError(err).Errorf("Could not delete block with block root %#x", r)
-		}
+		// Do not use parent context in the event it deadlined
+		ctx = trace.NewContext(context.Background(), span)
+		s.rollbackBlock(ctx, r)
 		return errors.Wrap(err, "could not save state")
 	}
 	return nil
@@ -417,7 +422,11 @@ func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interface
 func (s *Service) pruneAttsFromPool(headBlock interfaces.ReadOnlySignedBeaconBlock) error {
 	atts := headBlock.Block().Body().Attestations()
 	for _, att := range atts {
-		if helpers.IsAggregated(att) {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := s.cfg.AttestationCache.DeleteCovered(att); err != nil {
+				return errors.Wrap(err, "could not delete attestation")
+			}
+		} else if att.IsAggregated() {
 			if err := s.cfg.AttPool.DeleteAggregatedAttestation(att); err != nil {
 				return err
 			}
@@ -494,14 +503,15 @@ func (s *Service) runLateBlockTasks() {
 // 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) (map[uint64]struct{}, error) {
+func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte, slot primitives.Slot) (map[uint64]struct{}, error) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)
 	if len(expected) == 0 {
 		return nil, nil
 	}
-	if len(expected) > fieldparams.MaxBlobsPerBlock {
+	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices, err := bs.Indices(root)
+	indices, err := bs.Indices(root, slot)
 	if err != nil {
 		return nil, err
 	}
@@ -550,7 +560,7 @@ 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)
+	missing, err := missingIndices(s.blobStorage, root, kzgCommitments, block.Slot())
 	if err != nil {
 		return err
 	}
@@ -561,7 +571,7 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int

 	// The gossip handler for blobs writes the index of each verified blob referencing the given
 	// root to the channel returned by blobNotifiers.forRoot.
-	nc := s.blobNotifiers.forRoot(root)
+	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)
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -1,6 +1,7 @@
 package blockchain

 import (
+	"bytes"
 	"context"
 	"fmt"
 	"time"
@@ -15,7 +16,6 @@ import (
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
 	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -24,7 +24,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v5/math"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
@@ -115,64 +114,123 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 	})
 }

-// sendLightClientFeeds sends the light client feeds when feature flag is enabled.
-func (s *Service) sendLightClientFeeds(cfg *postBlockProcessConfig) {
-	if features.Get().EnableLightClient {
-		if _, err := s.sendLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
-			log.WithError(err).Error("Failed to send light client optimistic update")
-		}
-
-		// Get the finalized checkpoint
-		finalized := s.ForkChoicer().FinalizedCheckpoint()
-
-		// LightClientFinalityUpdate needs super majority
-		s.tryPublishLightClientFinalityUpdate(cfg.ctx, cfg.roblock, finalized, cfg.postState)
+func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
+	if err := s.processLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
+		log.WithError(err).Error("Failed to process light client optimistic update")
+	}
+	if err := s.processLightClientFinalityUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
+		log.WithError(err).Error("Failed to process light client finality update")
 	}
 }

-func (s *Service) tryPublishLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, finalized *forkchoicetypes.Checkpoint, postState state.BeaconState) {
-	if finalized.Epoch <= s.lastPublishedLightClientEpoch {
-		return
-	}
-
-	config := params.BeaconConfig()
-	if finalized.Epoch < config.AltairForkEpoch {
-		return
-	}
-
-	syncAggregate, err := signed.Block().Body().SyncAggregate()
-	if err != nil || syncAggregate == nil {
-		return
-	}
-
-	// LightClientFinalityUpdate needs super majority
-	if syncAggregate.SyncCommitteeBits.Count()*3 < config.SyncCommitteeSize*2 {
-		return
-	}
-
-	_, err = s.sendLightClientFinalityUpdate(ctx, signed, postState)
+// saveLightClientUpdate 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) {
+	attestedRoot := cfg.roblock.Block().ParentRoot()
+	attestedBlock, err := s.getBlock(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Error("Failed to send light client finality update")
+		log.WithError(err).Error("Saving light client update failed: Could not get attested block")
+		return
+	}
+	if attestedBlock == nil || attestedBlock.IsNil() {
+		log.Error("Saving light client update failed: Attested block is nil")
+		return
+	}
+	attestedState, err := s.cfg.StateGen.StateByRoot(cfg.ctx, attestedRoot)
+	if err != nil {
+		log.WithError(err).Error("Saving light client update failed: Could not get attested state")
+		return
+	}
+	if attestedState == nil || attestedState.IsNil() {
+		log.Error("Saving light client update failed: Attested state is nil")
+		return
+	}
+
+	finalizedRoot := attestedState.FinalizedCheckpoint().Root
+	finalizedBlock, err := s.getBlock(cfg.ctx, [32]byte(finalizedRoot))
+	if err != nil {
+		log.WithError(err).Error("Saving light client update failed: Could not get finalized block")
+		return
+	}
+
+	update, err := lightclient.NewLightClientUpdateFromBeaconState(
+		cfg.ctx,
+		s.CurrentSlot(),
+		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
+	}
+
+	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 {
-		s.lastPublishedLightClientEpoch = finalized.Epoch
+		log.WithField("period", period).Debug("Saving light client update: New update is not better than the current one. Skipping save.")
 	}
 }

-// sendLightClientFinalityUpdate sends a light client finality update notification to the state feed.
-func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState) (int, error) {
-	// Get attested state
+// 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")
+	}
+}
+
+func (s *Service) processLightClientFinalityUpdate(
+	ctx context.Context,
+	signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState,
+) error {
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
+		return errors.Wrap(err, "could not get attested block")
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested state")
+		return errors.Wrap(err, "could not get attested state")
 	}

-	// Get finalized block
 	var finalizedBlock interfaces.ReadOnlySignedBeaconBlock
 	finalizedCheckPoint := attestedState.FinalizedCheckpoint()
 	if finalizedCheckPoint != nil {
@@ -183,8 +241,14 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 		}
 	}

+	// Check if the finalized checkpoint has changed
+	if finalizedCheckPoint == nil || bytes.Equal(finalizedCheckPoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+		return nil
+	}
+
 	update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
 		ctx,
+		postState.Slot(),
 		postState,
 		signed,
 		attestedState,
@@ -193,38 +257,31 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 	)

 	if err != nil {
-		return 0, errors.Wrap(err, "could not create light client update")
+		return errors.Wrap(err, "could not create light client finality update")
 	}

-	// Return the result
-	result := &ethpbv2.LightClientFinalityUpdateWithVersion{
-		Version: ethpbv2.Version(signed.Version()),
-		Data:    update,
-	}
-
-	// Send event
-	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientFinalityUpdate,
-		Data: result,
-	}), nil
+		Data: update,
+	})
+	return nil
 }

-// sendLightClientOptimisticUpdate sends a light client optimistic update notification to the state feed.
-func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState) (int, error) {
-	// Get attested state
+func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) error {
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
+		return errors.Wrap(err, "could not get attested block")
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested state")
+		return errors.Wrap(err, "could not get attested state")
 	}

 	update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
 		ctx,
+		postState.Slot(),
 		postState,
 		signed,
 		attestedState,
@@ -232,19 +289,15 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 	)

 	if err != nil {
-		return 0, errors.Wrap(err, "could not create light client update")
+		return errors.Wrap(err, "could not create light client optimistic update")
 	}

-	// Return the result
-	result := &ethpbv2.LightClientOptimisticUpdateWithVersion{
-		Version: ethpbv2.Version(signed.Version()),
-		Data:    update,
-	}
-
-	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientOptimisticUpdate,
-		Data: result,
-	}), nil
+		Data: update,
+	})
+
+	return nil
 }

 // updateCachesPostBlockProcessing updates the next slot cache and handles the epoch
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
+	lightClient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
@@ -40,6 +41,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
 	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -2204,23 +2206,23 @@ func TestMissingIndices(t *testing.T) {
 		},
 		{
 			name:     "expected exceeds max",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock + 1),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlockBySlot(0) + 1),
 			err:      errMaxBlobsExceeded,
 		},
 		{
 			name:     "first missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlockBySlot(0)),
 			present:  []uint64{1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{0}),
 		},
 		{
 			name:     "all missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlockBySlot(0)),
 			result:   fakeResult([]uint64{0, 1, 2, 3, 4, 5}),
 		},
 		{
 			name:     "none missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlockBySlot(0)),
 			present:  []uint64{0, 1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{}),
 		},
@@ -2254,7 +2256,7 @@ func TestMissingIndices(t *testing.T) {
 		bm, bs := filesystem.NewEphemeralBlobStorageWithMocker(t)
 		t.Run(c.name, func(t *testing.T) {
 			require.NoError(t, bm.CreateFakeIndices(c.root, c.present...))
-			missing, err := missingIndices(bs, c.root, c.expected)
+			missing, err := missingIndices(bs, c.root, c.expected, 0)
 			if c.err != nil {
 				require.ErrorIs(t, err, c.err)
 				return
@@ -2352,6 +2354,62 @@ func TestRollbackBlock(t *testing.T) {
 	require.Equal(t, false, hasState)
 }

+func TestRollbackBlock_SavePostStateInfo_ContextDeadline(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	st, keys := util.DeterministicGenesisState(t, 64)
+	stateRoot, err := st.HashTreeRoot(ctx)
+	require.NoError(t, err, "Could not hash genesis state")
+
+	require.NoError(t, service.saveGenesisData(ctx, st))
+
+	genesis := blocks.NewGenesisBlock(stateRoot[:])
+	wsb, err := consensusblocks.NewSignedBeaconBlock(genesis)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb), "Could not save genesis block")
+	parentRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root")
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveJustifiedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+
+	st, err = service.HeadState(ctx)
+	require.NoError(t, err)
+	b, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 128)
+	require.NoError(t, err)
+	wsb, err = consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	root, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	preState, err := service.getBlockPreState(ctx, wsb.Block())
+	require.NoError(t, err)
+	postState, err := service.validateStateTransition(ctx, preState, wsb)
+	require.NoError(t, err)
+
+	// Save state summaries so that the cache is flushed and saved to disk
+	// later.
+	for i := 1; i <= 127; i++ {
+		require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{
+			Slot: primitives.Slot(i),
+			Root: bytesutil.Bytes32(uint64(i)),
+		}))
+	}
+
+	// Set deadlined context when saving block and state
+	cancCtx, canc := context.WithCancel(ctx)
+	canc()
+
+	require.ErrorContains(t, context.Canceled.Error(), service.savePostStateInfo(cancCtx, root, wsb, postState))
+
+	// The block should no longer exist.
+	require.Equal(t, false, service.cfg.BeaconDB.HasBlock(ctx, root))
+	hasState, err := service.cfg.StateGen.HasState(ctx, root)
+	require.NoError(t, err)
+	require.Equal(t, false, hasState)
+}
+
 func TestRollbackBlock_ContextDeadline(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx
@@ -2446,3 +2504,605 @@ func fakeResult(missing []uint64) map[uint64]struct{} {
 	}
 	return r
 }
+
+func TestSaveLightClientUpdate(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
+	s, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	t.Run("Altair", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Altair)
+		})
+	})
+
+	t.Run("Capella", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Capella)
+		})
+	})
+
+	t.Run("Deneb", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+	})
+
+	reset()
+}
+
+func TestSaveLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
+	s, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	t.Run("Altair", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestAltair()
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Altair)
+	})
+
+	t.Run("Capella", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Capella)
+	})
+
+	t.Run("Deneb", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Deneb)
+	})
+
+	reset()
+}
--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -166,7 +167,13 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)

 // This processes fork choice attestations from the pool to account for validator votes and fork choice.
 func (s *Service) processAttestations(ctx context.Context, disparity time.Duration) {
-	atts := s.cfg.AttPool.ForkchoiceAttestations()
+	var atts []ethpb.Att
+	if features.Get().EnableExperimentalAttestationPool {
+		atts = s.cfg.AttestationCache.ForkchoiceAttestations()
+	} else {
+		atts = s.cfg.AttPool.ForkchoiceAttestations()
+	}
+
 	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.
@@ -182,7 +189,11 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 			continue
 		}

-		if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := s.cfg.AttestationCache.DeleteForkchoiceAttestation(a); err != nil {
+				log.WithError(err).Error("Could not delete fork choice attestation in pool")
+			}
+		} else if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
 			log.WithError(err).Error("Could not delete fork choice attestation in pool")
 		}

--- a/beacon-chain/blockchain/receive_attestation_test.go
+++ b/beacon-chain/blockchain/receive_attestation_test.go
@@ -10,7 +10,6 @@ import (
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -87,9 +86,7 @@ func TestProcessAttestations_Ok(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	attsToSave := make([]ethpb.Att, len(atts))
-	for i, a := range atts {
-		attsToSave[i] = a
-	}
+	copy(attsToSave, atts)
 	require.NoError(t, service.cfg.AttPool.SaveForkchoiceAttestations(attsToSave))
 	service.processAttestations(ctx, 0)
 	require.Equal(t, 0, len(service.cfg.AttPool.ForkchoiceAttestations()))
@@ -119,7 +116,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	roblock, err := consensus_blocks.NewROBlockWithRoot(wsb, tRoot)
+	roblock, err := blocks.NewROBlockWithRoot(wsb, tRoot)
 	require.NoError(t, err)
 	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, roblock, [32]byte{}, postState, false}))
 	copied, err = service.cfg.StateGen.StateByRoot(ctx, tRoot)
@@ -131,9 +128,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	atts, err := util.GenerateAttestations(copied, pks, 1, 1, false)
 	require.NoError(t, err)
 	attsToSave := make([]ethpb.Att, len(atts))
-	for i, a := range atts {
-		attsToSave[i] = a
-	}
+	copy(attsToSave, atts)
 	require.NoError(t, service.cfg.AttPool.SaveForkchoiceAttestations(attsToSave))
 	// Verify the target is in forkchoice
 	require.Equal(t, true, fcs.HasNode(bytesutil.ToBytes32(atts[0].GetData().BeaconBlockRoot)))
@@ -181,7 +176,7 @@ func TestService_UpdateHead_NoAtts(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	roblock, err := consensus_blocks.NewROBlockWithRoot(wsb, tRoot)
+	roblock, err := blocks.NewROBlockWithRoot(wsb, tRoot)
 	require.NoError(t, err)
 	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, roblock, [32]byte{}, postState, false}))
 	require.Equal(t, 2, fcs.NodeCount())
--- a/beacon-chain/blockchain/receive_blob.go
+++ b/beacon-chain/blockchain/receive_blob.go
@@ -4,12 +4,13 @@ import (
 	"context"

 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )

 // SendNewBlobEvent sends a message to the BlobNotifier channel that the blob
 // for the block root `root` is ready in the database
-func (s *Service) sendNewBlobEvent(root [32]byte, index uint64) {
-	s.blobNotifiers.notifyIndex(root, index)
+func (s *Service) sendNewBlobEvent(root [32]byte, index uint64, slot primitives.Slot) {
+	s.blobNotifiers.notifyIndex(root, index, slot)
 }

 // ReceiveBlob saves the blob to database and sends the new event
@@ -18,6 +19,6 @@ func (s *Service) ReceiveBlob(ctx context.Context, b blocks.VerifiedROBlob) erro
 		return err
 	}

-	s.sendNewBlobEvent(b.BlockRoot(), b.Index)
+	s.sendNewBlobEvent(b.BlockRoot(), b.Index, b.Slot())
 	return nil
 }
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -17,8 +17,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -85,7 +83,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	}

 	currentCheckpoints := s.saveCurrentCheckpoints(preState)
-	roblock, err := consensus_blocks.NewROBlockWithRoot(blockCopy, blockRoot)
+	roblock, err := blocks.NewROBlockWithRoot(blockCopy, blockRoot)
 	if err != nil {
 		return err
 	}
@@ -190,7 +188,7 @@ func (s *Service) updateCheckpoints(
 func (s *Service) validateExecutionAndConsensus(
 	ctx context.Context,
 	preState state.BeaconState,
-	block consensusblocks.ROBlock,
+	block blocks.ROBlock,
 ) (state.BeaconState, bool, error) {
 	preStateVersion, preStateHeader, err := getStateVersionAndPayload(preState)
 	if err != nil {
@@ -560,7 +558,7 @@ func (s *Service) sendBlockAttestationsToSlasher(signed interfaces.ReadOnlySigne
 }

 // validateExecutionOnBlock notifies the engine of the incoming block execution payload and returns true if the payload is valid
-func (s *Service) validateExecutionOnBlock(ctx context.Context, ver int, header interfaces.ExecutionData, block consensusblocks.ROBlock) (bool, error) {
+func (s *Service) validateExecutionOnBlock(ctx context.Context, ver int, header interfaces.ExecutionData, block blocks.ROBlock) (bool, error) {
 	isValidPayload, err := s.notifyNewPayload(ctx, ver, header, block)
 	if err != nil {
 		s.cfg.ForkChoiceStore.Lock()
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -33,10 +33,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -49,25 +47,24 @@ 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
-	lastPublishedLightClientEpoch primitives.Epoch
+	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
 }

 // config options for the service.
@@ -78,6 +75,7 @@ type config struct {
 	DepositCache            cache.DepositCache
 	PayloadIDCache          *cache.PayloadIDCache
 	TrackedValidatorsCache  *cache.TrackedValidatorsCache
+	AttestationCache        *cache.AttestationCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
@@ -107,18 +105,22 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][fieldparams.MaxBlobsPerBlock]bool
+	seenIndex map[[32]byte][]bool
 }

 // notifyIndex notifies a blob by its index for a given root.
 // It uses internal maps to keep track of seen indices and notifier channels.
-func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
-	if idx >= fieldparams.MaxBlobsPerBlock {
+func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitives.Slot) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)
+	if idx >= uint64(maxBlobsPerBlock) {
 		return
 	}

 	bn.Lock()
 	seen := bn.seenIndex[root]
+	if seen == nil {
+		seen = make([]bool, maxBlobsPerBlock)
+	}
 	if seen[idx] {
 		bn.Unlock()
 		return
@@ -129,7 +131,7 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, maxBlobsPerBlock)
 		bn.notifiers[root] = c
 	}

@@ -138,12 +140,13 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	c <- idx
 }

-func (bn *blobNotifierMap) forRoot(root [32]byte) chan uint64 {
+func (bn *blobNotifierMap) forRoot(root [32]byte, slot primitives.Slot) chan uint64 {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)
 	bn.Lock()
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, maxBlobsPerBlock)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -169,7 +172,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	bn := &blobNotifierMap{
 		notifiers: make(map[[32]byte]chan uint64),
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		seenIndex: make(map[[32]byte][]bool),
 	}
 	srv := &Service{
 		ctx:                  ctx,
@@ -308,7 +311,7 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized checkpoint block")
 	}
-	roblock, err := consensus_blocks.NewROBlockWithRoot(finalizedBlock, fRoot)
+	roblock, err := blocks.NewROBlockWithRoot(finalizedBlock, fRoot)
 	if err != nil {
 		return err
 	}
@@ -524,7 +527,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon

 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
-	gb, err := consensus_blocks.NewROBlockWithRoot(genesisBlk, genesisBlkRoot)
+	gb, err := blocks.NewROBlockWithRoot(genesisBlk, genesisBlkRoot)
 	if err != nil {
 		return err
 	}
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -587,7 +587,7 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		seenIndex: make(map[[32]byte][]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}

@@ -596,7 +596,7 @@ func TestNotifyIndex(t *testing.T) {
 	copy(root[:], "exampleRoot")

 	// Test notifying a new index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if !bn.seenIndex[root][1] {
 		t.Errorf("Index was not marked as seen")
 	}
@@ -607,13 +607,13 @@ func TestNotifyIndex(t *testing.T) {
 	}

 	// Test notifying an already seen index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if len(bn.notifiers[root]) > 1 {
 		t.Errorf("Notifier channel should not receive multiple messages for the same index")
 	}

 	// Test notifying a new index again
-	bn.notifyIndex(root, 2)
+	bn.notifyIndex(root, 2, 1)
 	if !bn.seenIndex[root][2] {
 		t.Errorf("Index was not marked as seen")
 	}
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -5,6 +5,7 @@ go_library(
    srcs = [
        "active_balance.go",
        "active_balance_disabled.go",  # keep
+        "attestation.go",
        "attestation_data.go",
        "balance_cache_key.go",
        "checkpoint_state.go",
@@ -36,18 +37,21 @@ go_library(
    ],
    deps = [
        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/operations/attestations/attmap:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//cache/lru:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
        "//crypto/hash:go_default_library",
        "//crypto/rand:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//runtime/version:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_hashicorp_golang_lru//:go_default_library",
@@ -66,6 +70,7 @@ go_test(
    srcs = [
        "active_balance_test.go",
        "attestation_data_test.go",
+        "attestation_test.go",
        "cache_test.go",
        "checkpoint_state_test.go",
        "committee_fuzz_test.go",
@@ -88,14 +93,17 @@ go_test(
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
+        "//crypto/bls/blst:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_google_gofuzz//:go_default_library",
        "@com_github_hashicorp_golang_lru//:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
        "@com_github_stretchr_testify//require:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
    ],
--- a/beacon-chain/cache/attestation.go
+++ b/beacon-chain/cache/attestation.go
@@ -0,0 +1,275 @@
+package cache
+
+import (
+	"sync"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations/attmap"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+	log "github.com/sirupsen/logrus"
+)
+
+type attGroup struct {
+	slot primitives.Slot
+	atts []ethpb.Att
+}
+
+// AttestationCache holds a map of attGroup items that group together all attestations for a single slot.
+// When we add an attestation to the cache by calling Add, we either create a new group with this attestation
+// (if this is the first attestation for some slot) or two things can happen:
+//
+//   - If the attestation is unaggregated, we add its attestation bit to attestation bits of the first
+//     attestation in the group.
+//   - If the attestation is aggregated, we append it to the group. There should be no redundancy
+//     in the list because we ignore redundant aggregates in gossip.
+//
+// The first bullet point above means that we keep one aggregate attestation to which we keep appending bits
+// as new single-bit attestations arrive. This means that at any point during seconds 0-4 of a slot
+// we will have only one attestation for this slot in the cache.
+//
+// NOTE: This design in principle can result in worse aggregates since we lose the ability to aggregate some
+// single bit attestations in case of overlaps with incoming aggregates.
+//
+// The cache also keeps forkchoice attestations in a separate struct. These attestations are used for
+// forkchoice-related operations.
+type AttestationCache struct {
+	atts map[attestation.Id]*attGroup
+	sync.RWMutex
+	forkchoiceAtts *attmap.Attestations
+}
+
+// NewAttestationCache creates a new cache instance.
+func NewAttestationCache() *AttestationCache {
+	return &AttestationCache{
+		atts:           make(map[attestation.Id]*attGroup),
+		forkchoiceAtts: attmap.New(),
+	}
+}
+
+// Add does one of two things:
+//
+//   - For unaggregated attestations, it adds the attestation bit to attestation bits of the running aggregate,
+//     which is the first aggregate for the slot.
+//   - For aggregated attestations, it appends the attestation to the existng list of attestations for the slot.
+func (c *AttestationCache) Add(att ethpb.Att) error {
+	if att.IsNil() {
+		log.Debug("Attempted to add a nil attestation to the attestation cache")
+		return nil
+	}
+	if len(att.GetAggregationBits().BitIndices()) == 0 {
+		log.Debug("Attempted to add an attestation with 0 bits set to the attestation cache")
+		return nil
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		group = &attGroup{
+			slot: att.GetData().Slot,
+			atts: []ethpb.Att{att},
+		}
+		c.atts[id] = group
+		return nil
+	}
+
+	if att.IsAggregated() {
+		group.atts = append(group.atts, att.Clone())
+		return nil
+	}
+
+	// This should never happen because we return early for a new group.
+	if len(group.atts) == 0 {
+		log.Error("Attestation group contains no attestations, skipping insertion")
+		return nil
+	}
+
+	a := group.atts[0]
+
+	// Indexing is safe because we have guarded against 0 bits set.
+	bit := att.GetAggregationBits().BitIndices()[0]
+	if a.GetAggregationBits().BitAt(uint64(bit)) {
+		return nil
+	}
+	sig, err := aggregateSig(a, att)
+	if err != nil {
+		return errors.Wrapf(err, "could not aggregate signatures")
+	}
+
+	a.GetAggregationBits().SetBitAt(uint64(bit), true)
+	a.SetSignature(sig)
+
+	return nil
+}
+
+// GetAll returns all attestations in the cache, excluding forkchoice attestations.
+func (c *AttestationCache) GetAll() []ethpb.Att {
+	c.RLock()
+	defer c.RUnlock()
+
+	var result []ethpb.Att
+	for _, group := range c.atts {
+		result = append(result, group.atts...)
+	}
+	return result
+}
+
+// Count returns the number of all attestations in the cache, excluding forkchoice attestations.
+func (c *AttestationCache) Count() int {
+	c.RLock()
+	defer c.RUnlock()
+
+	count := 0
+	for _, group := range c.atts {
+		count += len(group.atts)
+	}
+	return count
+}
+
+// DeleteCovered removes all attestations whose attestation bits are a proper subset of the passed-in attestation.
+func (c *AttestationCache) DeleteCovered(att ethpb.Att) error {
+	if att.IsNil() {
+		return nil
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		return nil
+	}
+
+	idx := 0
+	for _, a := range group.atts {
+		if covered, err := att.GetAggregationBits().Contains(a.GetAggregationBits()); err != nil {
+			return err
+		} else if !covered {
+			group.atts[idx] = a
+			idx++
+		}
+	}
+	group.atts = group.atts[:idx]
+
+	if len(group.atts) == 0 {
+		delete(c.atts, id)
+	}
+
+	return nil
+}
+
+// PruneBefore removes all attestations whose slot is earlier than the passed-in slot.
+func (c *AttestationCache) PruneBefore(slot primitives.Slot) uint64 {
+	c.Lock()
+	defer c.Unlock()
+
+	var pruneCount int
+	for id, group := range c.atts {
+		if group.slot < slot {
+			pruneCount += len(group.atts)
+			delete(c.atts, id)
+		}
+	}
+	return uint64(pruneCount)
+}
+
+// AggregateIsRedundant checks whether all attestation bits of the passed-in aggregate
+// are already included by any aggregate in the cache.
+func (c *AttestationCache) AggregateIsRedundant(att ethpb.Att) (bool, error) {
+	if att.IsNil() {
+		return true, nil
+	}
+
+	c.RLock()
+	defer c.RUnlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return true, errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		return false, nil
+	}
+
+	for _, a := range group.atts {
+		if redundant, err := a.GetAggregationBits().Contains(att.GetAggregationBits()); err != nil {
+			return true, err
+		} else if redundant {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+// SaveForkchoiceAttestations saves forkchoice attestations.
+func (c *AttestationCache) SaveForkchoiceAttestations(att []ethpb.Att) error {
+	return c.forkchoiceAtts.SaveMany(att)
+}
+
+// ForkchoiceAttestations returns all forkchoice attestations.
+func (c *AttestationCache) ForkchoiceAttestations() []ethpb.Att {
+	return c.forkchoiceAtts.GetAll()
+}
+
+// DeleteForkchoiceAttestation deletes a forkchoice attestation.
+func (c *AttestationCache) DeleteForkchoiceAttestation(att ethpb.Att) error {
+	return c.forkchoiceAtts.Delete(att)
+}
+
+// GetBySlotAndCommitteeIndex returns all attestations in the cache that match the provided slot
+// and committee index. Forkchoice attestations are not returned.
+//
+// NOTE: This function cannot be declared as a method on the AttestationCache because it is a generic function.
+func GetBySlotAndCommitteeIndex[T ethpb.Att](c *AttestationCache, slot primitives.Slot, committeeIndex primitives.CommitteeIndex) []T {
+	c.RLock()
+	defer c.RUnlock()
+
+	var result []T
+
+	for _, group := range c.atts {
+		if len(group.atts) > 0 {
+			// We can safely compare the first attestation because all attestations in a group
+			// must have the same slot and committee index, since they are under the same key.
+			a, ok := group.atts[0].(T)
+			if ok && a.GetData().Slot == slot && a.CommitteeBitsVal().BitAt(uint64(committeeIndex)) {
+				for _, a := range group.atts {
+					a, ok := a.(T)
+					if ok {
+						result = append(result, a)
+					}
+				}
+			}
+		}
+	}
+
+	return result
+}
+
+func aggregateSig(agg ethpb.Att, att ethpb.Att) ([]byte, error) {
+	aggSig, err := bls.SignatureFromBytesNoValidation(agg.GetSignature())
+	if err != nil {
+		return nil, err
+	}
+	attSig, err := bls.SignatureFromBytesNoValidation(att.GetSignature())
+	if err != nil {
+		return nil, err
+	}
+	return bls.AggregateSignatures([]bls.Signature{aggSig, attSig}).Marshal(), nil
+}
--- a/beacon-chain/cache/attestation_data.go
+++ b/beacon-chain/cache/attestation_data.go
@@ -15,24 +15,24 @@ type AttestationConsensusData struct {
 	Source   forkchoicetypes.Checkpoint
 }

-// AttestationCache stores cached results of AttestationData requests.
-type AttestationCache struct {
+// AttestationDataCache stores cached results of AttestationData requests.
+type AttestationDataCache struct {
 	a *AttestationConsensusData
 	sync.RWMutex
 }

-// NewAttestationCache creates a new instance of AttestationCache.
-func NewAttestationCache() *AttestationCache {
-	return &AttestationCache{}
+// NewAttestationDataCache creates a new instance of AttestationDataCache.
+func NewAttestationDataCache() *AttestationDataCache {
+	return &AttestationDataCache{}
 }

 // Get retrieves cached attestation data, recording a cache hit or miss. This method is lock free.
-func (c *AttestationCache) Get() *AttestationConsensusData {
+func (c *AttestationDataCache) Get() *AttestationConsensusData {
 	return c.a
 }

 // Put adds a response to the cache. This method is lock free.
-func (c *AttestationCache) Put(a *AttestationConsensusData) error {
+func (c *AttestationDataCache) Put(a *AttestationConsensusData) error {
 	if a == nil {
 		return errors.New("attestation cannot be nil")
 	}
--- a/beacon-chain/cache/attestation_data_test.go
+++ b/beacon-chain/cache/attestation_data_test.go
@@ -9,7 +9,7 @@ import (
 )

 func TestAttestationCache_RoundTrip(t *testing.T) {
-	c := cache.NewAttestationCache()
+	c := cache.NewAttestationDataCache()

 	a := c.Get()
 	require.Nil(t, a)
--- a/beacon-chain/cache/attestation_test.go
+++ b/beacon-chain/cache/attestation_test.go
@@ -0,0 +1,353 @@
+package cache
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls/blst"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestAdd(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	t.Run("new ID", func(t *testing.T) {
+		t.Run("first ID ever", func(t *testing.T) {
+			c := NewAttestationCache()
+			ab := bitfield.NewBitlist(8)
+			ab.SetBitAt(0, true)
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			id, err := attestation.NewId(att, attestation.Data)
+			require.NoError(t, err)
+			require.NoError(t, c.Add(att))
+
+			require.Equal(t, 1, len(c.atts))
+			group, ok := c.atts[id]
+			require.Equal(t, true, ok)
+			assert.Equal(t, primitives.Slot(123), group.slot)
+			require.Equal(t, 1, len(group.atts))
+			assert.DeepEqual(t, group.atts[0], att)
+		})
+		t.Run("other ID exists", func(t *testing.T) {
+			c := NewAttestationCache()
+			ab := bitfield.NewBitlist(8)
+			ab.SetBitAt(0, true)
+			existingAtt := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			existingId, err := attestation.NewId(existingAtt, attestation.Data)
+			require.NoError(t, err)
+			c.atts[existingId] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			id, err := attestation.NewId(att, attestation.Data)
+			require.NoError(t, err)
+			require.NoError(t, c.Add(att))
+
+			require.Equal(t, 2, len(c.atts))
+			group, ok := c.atts[id]
+			require.Equal(t, true, ok)
+			assert.Equal(t, primitives.Slot(123), group.slot)
+			require.Equal(t, 1, len(group.atts))
+			assert.DeepEqual(t, group.atts[0], att)
+		})
+	})
+	t.Run("aggregated", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 2, len(group.atts))
+		assert.DeepEqual(t, group.atts[0], existingAtt)
+		assert.DeepEqual(t, group.atts[1], att)
+	})
+	t.Run("unaggregated - existing bit", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		existingAtt.AggregationBits.SetBitAt(0, true)
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 1, len(group.atts))
+		assert.DeepEqual(t, []int{0}, group.atts[0].GetAggregationBits().BitIndices())
+	})
+	t.Run("unaggregated - new bit", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		existingAtt.AggregationBits.SetBitAt(0, true)
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(1, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 1, len(group.atts))
+		assert.DeepEqual(t, []int{0, 1}, group.atts[0].GetAggregationBits().BitIndices())
+	})
+}
+
+func TestGetAll(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	assert.Equal(t, 3, len(c.GetAll()))
+}
+
+func TestCount(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	assert.Equal(t, 3, c.Count())
+}
+
+func TestDeleteCovered(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	att1 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att1.AggregationBits.SetBitAt(0, true)
+
+	att2 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att2.AggregationBits.SetBitAt(1, true)
+	att2.AggregationBits.SetBitAt(2, true)
+
+	att3 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att3.AggregationBits.SetBitAt(1, true)
+	att3.AggregationBits.SetBitAt(3, true)
+	att3.AggregationBits.SetBitAt(4, true)
+
+	c := NewAttestationCache()
+	id, err := attestation.NewId(att1, attestation.Data)
+	require.NoError(t, err)
+	c.atts[id] = &attGroup{slot: att1.Data.Slot, atts: []ethpb.Att{att1, att2, att3}}
+
+	t.Run("no matching group", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 456, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(2, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		assert.Equal(t, 3, len(c.atts[id].atts))
+	})
+	t.Run("covered atts deleted", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		atts := c.atts[id].atts
+		require.Equal(t, 1, len(atts))
+		assert.DeepEqual(t, att2, atts[0])
+	})
+	t.Run("last att in group deleted", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(2, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		assert.Equal(t, 0, len(c.atts))
+	})
+}
+
+func TestPruneBefore(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{slot: 3, atts: []ethpb.Att{&ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id3"))] = &attGroup{slot: 2, atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	count := c.PruneBefore(3)
+
+	require.Equal(t, 1, len(c.atts))
+	_, ok := c.atts[bytesutil.ToBytes32([]byte("id2"))]
+	assert.Equal(t, true, ok)
+	assert.Equal(t, uint64(3), count)
+}
+
+func TestAggregateIsRedundant(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	c := NewAttestationCache()
+	existingAtt := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	existingAtt.AggregationBits.SetBitAt(0, true)
+	existingAtt.AggregationBits.SetBitAt(1, true)
+	id, err := attestation.NewId(existingAtt, attestation.Data)
+	require.NoError(t, err)
+	c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+	t.Run("no matching group", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 456, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+
+		redundant, err := c.AggregateIsRedundant(att)
+		require.NoError(t, err)
+		assert.Equal(t, false, redundant)
+	})
+	t.Run("redundant", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+
+		redundant, err := c.AggregateIsRedundant(att)
+		require.NoError(t, err)
+		assert.Equal(t, true, redundant)
+	})
+	t.Run("not redundant", func(t *testing.T) {
+		t.Run("strictly better", func(t *testing.T) {
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: bitfield.NewBitlist(8),
+				Signature:       sig.Marshal(),
+			}
+			att.AggregationBits.SetBitAt(0, true)
+			att.AggregationBits.SetBitAt(1, true)
+			att.AggregationBits.SetBitAt(2, true)
+
+			redundant, err := c.AggregateIsRedundant(att)
+			require.NoError(t, err)
+			assert.Equal(t, false, redundant)
+		})
+		t.Run("overlapping and new bits", func(t *testing.T) {
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: bitfield.NewBitlist(8),
+				Signature:       sig.Marshal(),
+			}
+			att.AggregationBits.SetBitAt(0, true)
+			att.AggregationBits.SetBitAt(2, true)
+
+			redundant, err := c.AggregateIsRedundant(att)
+			require.NoError(t, err)
+			assert.Equal(t, false, redundant)
+		})
+	})
+}
+
+func TestGetBySlotAndCommitteeIndex(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 1, CommitteeIndex: 1}}, &ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 1, CommitteeIndex: 1}}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{slot: 2, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 2}}}}
+	c.atts[bytesutil.ToBytes32([]byte("id3"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 2}}}}
+
+	// committeeIndex has to be small enough to fit in the bitvector
+	atts := GetBySlotAndCommitteeIndex[*ethpb.Attestation](c, 1, 1)
+	require.Equal(t, 2, len(atts))
+	assert.Equal(t, primitives.Slot(1), atts[0].Data.Slot)
+	assert.Equal(t, primitives.Slot(1), atts[1].Data.Slot)
+	assert.Equal(t, primitives.CommitteeIndex(1), atts[0].Data.CommitteeIndex)
+	assert.Equal(t, primitives.CommitteeIndex(1), atts[1].Data.CommitteeIndex)
+}
--- a/beacon-chain/core/altair/sync_committee.go
+++ b/beacon-chain/core/altair/sync_committee.go
@@ -2,6 +2,7 @@ package altair

 import (
 	"context"
+	"encoding/binary"
 	goErrors "errors"
 	"fmt"
 	"time"
@@ -22,8 +23,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )

-const maxRandomByte = uint64(1<<8 - 1)
-
 var (
 	ErrTooLate = errors.New("sync message is too late")
 )
@@ -91,19 +90,22 @@ func NextSyncCommittee(ctx context.Context, s state.BeaconState) (*ethpb.SyncCom
 //	"""
 //	epoch = Epoch(get_current_epoch(state) + 1)
 //
-//	MAX_RANDOM_BYTE = 2**8 - 1
+//	MAX_RANDOM_VALUE = 2**16 - 1  # [Modified in Electra]
 //	active_validator_indices = get_active_validator_indices(state, epoch)
 //	active_validator_count = uint64(len(active_validator_indices))
 //	seed = get_seed(state, epoch, DOMAIN_SYNC_COMMITTEE)
-//	i = 0
+//	i = uint64(0)
 //	sync_committee_indices: List[ValidatorIndex] = []
 //	while len(sync_committee_indices) < SYNC_COMMITTEE_SIZE:
 //	    shuffled_index = compute_shuffled_index(uint64(i % active_validator_count), active_validator_count, seed)
 //	    candidate_index = active_validator_indices[shuffled_index]
-//	    random_byte = hash(seed + uint_to_bytes(uint64(i // 32)))[i % 32]
+//	    # [Modified in Electra]
+//	    random_bytes = hash(seed + uint_to_bytes(i // 16))
+//	    offset = i % 16 * 2
+//	    random_value = bytes_to_uint64(random_bytes[offset:offset + 2])
 //	    effective_balance = state.validators[candidate_index].effective_balance
 //	    # [Modified in Electra:EIP7251]
-//	    if effective_balance * MAX_RANDOM_BYTE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_byte:
+//	    if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value:
 //	        sync_committee_indices.append(candidate_index)
 //	    i += 1
 //	return sync_committee_indices
@@ -123,12 +125,11 @@ func NextSyncCommitteeIndices(ctx context.Context, s state.BeaconState) ([]primi
 	cIndices := make([]primitives.ValidatorIndex, 0, syncCommitteeSize)
 	hashFunc := hash.CustomSHA256Hasher()

-	maxEB := cfg.MaxEffectiveBalanceElectra
-	if s.Version() < version.Electra {
-		maxEB = cfg.MaxEffectiveBalance
-	}
+	// Preallocate buffers to avoid repeated allocations
+	seedBuffer := make([]byte, len(seed)+8)
+	copy(seedBuffer, seed[:])

-	for i := primitives.ValidatorIndex(0); uint64(len(cIndices)) < params.BeaconConfig().SyncCommitteeSize; i++ {
+	for i := primitives.ValidatorIndex(0); uint64(len(cIndices)) < syncCommitteeSize; i++ {
 		if ctx.Err() != nil {
 			return nil, ctx.Err()
 		}
@@ -137,18 +138,30 @@ func NextSyncCommitteeIndices(ctx context.Context, s state.BeaconState) ([]primi
 		if err != nil {
 			return nil, err
 		}
-
-		b := append(seed[:], bytesutil.Bytes8(uint64(i.Div(32)))...)
-		randomByte := hashFunc(b)[i%32]
 		cIndex := indices[sIndex]
 		v, err := s.ValidatorAtIndexReadOnly(cIndex)
 		if err != nil {
 			return nil, err
 		}
-
 		effectiveBal := v.EffectiveBalance()
-		if effectiveBal*maxRandomByte >= maxEB*uint64(randomByte) {
-			cIndices = append(cIndices, cIndex)
+
+		if s.Version() >= version.Electra {
+			// Use the preallocated seed buffer
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], uint64(i/16))
+			randomByte := hashFunc(seedBuffer)
+			offset := (i % 16) * 2
+			randomValue := uint64(randomByte[offset]) | uint64(randomByte[offset+1])<<8
+
+			if effectiveBal*fieldparams.MaxRandomValueElectra >= cfg.MaxEffectiveBalanceElectra*randomValue {
+				cIndices = append(cIndices, cIndex)
+			}
+		} else {
+			// Use the preallocated seed buffer
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], uint64(i/32))
+			randomByte := hashFunc(seedBuffer)[i%32]
+			if effectiveBal*fieldparams.MaxRandomByte >= cfg.MaxEffectiveBalance*uint64(randomByte) {
+				cIndices = append(cIndices, cIndex)
+			}
 		}
 	}

--- a/beacon-chain/core/blocks/exports_test.go
+++ b/beacon-chain/core/blocks/exports_test.go
@@ -1,5 +1,5 @@
 package blocks

 var ProcessBLSToExecutionChange = processBLSToExecutionChange
-
+var ErrInvalidBLSPrefix = errInvalidBLSPrefix
 var VerifyBlobCommitmentCount = verifyBlobCommitmentCount
--- a/beacon-chain/core/blocks/payload.go
+++ b/beacon-chain/core/blocks/payload.go
@@ -8,10 +8,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
@@ -210,7 +211,7 @@ func ProcessPayload(st state.BeaconState, body interfaces.ReadOnlyBeaconBlockBod
 	if err != nil {
 		return err
 	}
-	if err := verifyBlobCommitmentCount(body); err != nil {
+	if err := verifyBlobCommitmentCount(st.Slot(), body); err != nil {
 		return err
 	}
 	if err := ValidatePayloadWhenMergeCompletes(st, payload); err != nil {
@@ -225,7 +226,7 @@ func ProcessPayload(st state.BeaconState, body interfaces.ReadOnlyBeaconBlockBod
 	return nil
 }

-func verifyBlobCommitmentCount(body interfaces.ReadOnlyBeaconBlockBody) error {
+func verifyBlobCommitmentCount(slot primitives.Slot, body interfaces.ReadOnlyBeaconBlockBody) error {
 	if body.Version() < version.Deneb {
 		return nil
 	}
@@ -233,7 +234,8 @@ func verifyBlobCommitmentCount(body interfaces.ReadOnlyBeaconBlockBody) error {
 	if err != nil {
 		return err
 	}
-	if len(kzgs) > field_params.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)
+	if len(kzgs) > maxBlobsPerBlock {
 		return fmt.Errorf("too many kzg commitments in block: %d", len(kzgs))
 	}
 	return nil
--- a/beacon-chain/core/blocks/payload_test.go
+++ b/beacon-chain/core/blocks/payload_test.go
@@ -9,6 +9,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -923,10 +924,10 @@ func TestVerifyBlobCommitmentCount(t *testing.T) {
 	b := &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{}}
 	rb, err := consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Body()))
+	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))

-	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, fieldparams.MaxBlobsPerBlock+1)}}
+	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, params.BeaconConfig().MaxBlobsPerBlockBySlot(rb.Slot())+1)}}
 	rb, err = consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", fieldparams.MaxBlobsPerBlock+1), blocks.VerifyBlobCommitmentCount(rb.Body()))
+	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", params.BeaconConfig().MaxBlobsPerBlockBySlot(rb.Slot())+1), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 }
--- a/beacon-chain/core/blocks/withdrawals.go
+++ b/beacon-chain/core/blocks/withdrawals.go
@@ -100,8 +100,11 @@ func ValidateBLSToExecutionChange(st state.ReadOnlyBeaconState, signed *ethpb.Si
 	if err != nil {
 		return nil, err
 	}
+	if val == nil {
+		return nil, errors.Wrap(errInvalidWithdrawalCredentials, "validator is nil") // This should not be possible.
+	}
 	cred := val.WithdrawalCredentials
-	if cred[0] != params.BeaconConfig().BLSWithdrawalPrefixByte {
+	if len(cred) < 2 || cred[0] != params.BeaconConfig().BLSWithdrawalPrefixByte {
 		return nil, errInvalidBLSPrefix
 	}

--- a/beacon-chain/core/blocks/withdrawals_test.go
+++ b/beacon-chain/core/blocks/withdrawals_test.go
@@ -113,7 +113,42 @@ func TestProcessBLSToExecutionChange(t *testing.T) {
 		require.NoError(t, err)
 		require.DeepEqual(t, digest[:], val.WithdrawalCredentials)
 	})
+	t.Run("nil validator does not panic", func(t *testing.T) {
+		priv, err := bls.RandKey()
+		require.NoError(t, err)
+		pubkey := priv.PublicKey().Marshal()

+		message := &ethpb.BLSToExecutionChange{
+			ToExecutionAddress: []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13},
+			ValidatorIndex:     0,
+			FromBlsPubkey:      pubkey,
+		}
+
+		registry := []*ethpb.Validator{
+			nil,
+		}
+		st, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
+			Validators: registry,
+			Fork: &ethpb.Fork{
+				CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
+				PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+			},
+			Slot: params.BeaconConfig().SlotsPerEpoch * 5,
+		})
+		require.NoError(t, err)
+
+		signature, err := signing.ComputeDomainAndSign(st, time.CurrentEpoch(st), message, params.BeaconConfig().DomainBLSToExecutionChange, priv)
+		require.NoError(t, err)
+
+		signed := &ethpb.SignedBLSToExecutionChange{
+			Message:   message,
+			Signature: signature,
+		}
+		_, err = blocks.ValidateBLSToExecutionChange(st, signed)
+		// The state should return an empty validator, even when the validator object in the registry is
+		// nil. This error should return when the withdrawal credentials are invalid or too short.
+		require.ErrorIs(t, err, blocks.ErrInvalidBLSPrefix)
+	})
 	t.Run("non-existent validator", func(t *testing.T) {
 		priv, err := bls.RandKey()
 		require.NoError(t, err)
--- a/beacon-chain/core/electra/BUILD.bazel
+++ b/beacon-chain/core/electra/BUILD.bazel
@@ -41,6 +41,7 @@ go_library(
        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/math:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
    ],
--- a/beacon-chain/core/electra/churn_test.go
+++ b/beacon-chain/core/electra/churn_test.go
@@ -20,7 +20,7 @@ func createValidatorsWithTotalActiveBalance(totalBal primitives.Gwei) []*eth.Val
 	vals := make([]*eth.Validator, num)
 	for i := range vals {
 		wd := make([]byte, 32)
-		wd[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+		wd[0] = params.BeaconConfig().CompoundingWithdrawalPrefixByte
 		wd[31] = byte(i)

 		vals[i] = &eth.Validator{
--- a/beacon-chain/core/electra/consolidations.go
+++ b/beacon-chain/core/electra/consolidations.go
@@ -5,6 +5,7 @@ import (
 	"context"
 	"fmt"

+	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
@@ -36,8 +37,7 @@ import (
 //	        break
 //
 //	    # Calculate the consolidated balance
-//	    max_effective_balance = get_max_effective_balance(source_validator)
-//	    source_effective_balance = min(state.balances[pending_consolidation.source_index], max_effective_balance)
+//	    source_effective_balance = min(state.balances[pending_consolidation.source_index], source_validator.effective_balance)
 //
 //	    # Move active balance to target. Excess balance is withdrawable.
 //	    decrease_balance(state, pending_consolidation.source_index, source_effective_balance)
@@ -77,7 +77,7 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 		if err != nil {
 			return err
 		}
-		b := min(validatorBalance, helpers.ValidatorMaxEffectiveBalance(sourceValidator))
+		b := min(validatorBalance, sourceValidator.EffectiveBalance())

 		if err := helpers.DecreaseBalance(st, pc.SourceIndex, b); err != nil {
 			return err
@@ -140,8 +140,8 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 //	    if not (has_correct_credential and is_correct_source_address):
 //	        return
 //
-//	    # Verify that target has execution withdrawal credentials
-//	    if not has_execution_withdrawal_credential(target_validator):
+//	    # Verify that target has compounding withdrawal credentials
+//	    if not has_compounding_withdrawal_credential(target_validator):
 //	        return
 //
 //	    # Verify the source and the target are active
@@ -156,6 +156,13 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 //	    if target_validator.exit_epoch != FAR_FUTURE_EPOCH:
 //	        return
 //
+//	    # Verify the source has been active long enough
+//	    if current_epoch < source_validator.activation_epoch + SHARD_COMMITTEE_PERIOD:
+//	        return
+//
+//	    # Verify the source has no pending withdrawals in the queue
+//	    if get_pending_balance_to_withdraw(state, source_index) > 0:
+//	        return
 //	    # Initiate source validator exit and append pending consolidation
 //	    source_validator.exit_epoch = compute_consolidation_epoch_and_update_churn(
 //	        state, source_validator.effective_balance
@@ -167,10 +174,6 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 //	        source_index=source_index,
 //	        target_index=target_index
 //	    ))
-//
-//	    # Churn any target excess active balance of target and raise its max
-//	    if has_eth1_withdrawal_credential(target_validator):
-//	        switch_to_compounding_validator(state, target_index)
 func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, reqs []*enginev1.ConsolidationRequest) error {
 	if len(reqs) == 0 || st == nil {
 		return nil
@@ -245,7 +248,7 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		}

 		// Target validator must have their withdrawal credentials set appropriately.
-		if !helpers.HasExecutionWithdrawalCredentials(tgtV) {
+		if !helpers.HasCompoundingWithdrawalCredential(tgtV) {
 			continue
 		}

@@ -258,6 +261,23 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 			continue
 		}

+		e, overflow := math.SafeAdd(uint64(srcV.ActivationEpoch), uint64(params.BeaconConfig().ShardCommitteePeriod))
+		if overflow {
+			log.Error("Overflow when adding activation epoch and shard committee period")
+			continue
+		}
+		if uint64(curEpoch) < e {
+			continue
+		}
+		bal, err := st.PendingBalanceToWithdraw(srcIdx)
+		if err != nil {
+			log.WithError(err).Error("failed to fetch pending balance to withdraw")
+			continue
+		}
+		if bal > 0 {
+			continue
+		}
+
 		// Initiate the exit of the source validator.
 		exitEpoch, err := ComputeConsolidationEpochAndUpdateChurn(ctx, st, primitives.Gwei(srcV.EffectiveBalance))
 		if err != nil {
@@ -273,13 +293,6 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		if err := st.AppendPendingConsolidation(&eth.PendingConsolidation{SourceIndex: srcIdx, TargetIndex: tgtIdx}); err != nil {
 			return fmt.Errorf("failed to append pending consolidation: %w", err) // This should never happen.
 		}
-
-		if helpers.HasETH1WithdrawalCredential(tgtV) {
-			if err := SwitchToCompoundingValidator(st, tgtIdx); err != nil {
-				log.WithError(err).Error("failed to switch to compounding validator")
-				continue
-			}
-		}
 	}

 	return nil
--- a/beacon-chain/core/electra/consolidations_test.go
+++ b/beacon-chain/core/electra/consolidations_test.go
@@ -46,6 +46,7 @@ func TestProcessPendingConsolidations(t *testing.T) {
 					Validators: []*eth.Validator{
 						{
 							WithdrawalCredentials: []byte{0x01, 0xFF},
+							EffectiveBalance:      params.BeaconConfig().MinActivationBalance,
 						},
 						{
 							WithdrawalCredentials: []byte{0x01, 0xAB},
@@ -213,15 +214,22 @@ func TestProcessConsolidationRequests(t *testing.T) {
 			name: "one valid request",
 			state: func() state.BeaconState {
 				st := &eth.BeaconStateElectra{
+					Slot:       params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().ShardCommitteePeriod)),
 					Validators: createValidatorsWithTotalActiveBalance(32000000000000000), // 32M ETH
 				}
 				// Validator scenario setup. See comments in reqs section.
 				st.Validators[3].WithdrawalCredentials = bytesutil.Bytes32(0)
-				st.Validators[8].WithdrawalCredentials = bytesutil.Bytes32(0)
+				st.Validators[8].WithdrawalCredentials = bytesutil.Bytes32(1)
 				st.Validators[9].ActivationEpoch = params.BeaconConfig().FarFutureEpoch
 				st.Validators[12].ActivationEpoch = params.BeaconConfig().FarFutureEpoch
 				st.Validators[13].ExitEpoch = 10
 				st.Validators[16].ExitEpoch = 10
+				st.PendingPartialWithdrawals = []*eth.PendingPartialWithdrawal{
+					{
+						Index:  17,
+						Amount: 100,
+					},
+				}
 				s, err := state_native.InitializeFromProtoElectra(st)
 				require.NoError(t, err)
 				return s
@@ -239,7 +247,7 @@ func TestProcessConsolidationRequests(t *testing.T) {
 					SourcePubkey:  []byte("val_5"),
 					TargetPubkey:  []byte("val_6"),
 				},
-				// Target does not have their withdrawal credentials set appropriately.
+				// Target does not have their withdrawal credentials set appropriately. (Using eth1 address prefix)
 				{
 					SourceAddress: append(bytesutil.PadTo(nil, 19), byte(7)),
 					SourcePubkey:  []byte("val_7"),
@@ -287,6 +295,12 @@ func TestProcessConsolidationRequests(t *testing.T) {
 					SourcePubkey:  []byte("val_0"),
 					TargetPubkey:  []byte("val_0"),
 				},
+				// Has pending partial withdrawal
+				{
+					SourceAddress: append(bytesutil.PadTo(nil, 19), byte(0)),
+					SourcePubkey:  []byte("val_17"),
+					TargetPubkey:  []byte("val_1"),
+				},
 				// Valid consolidation request. This should be last to ensure invalid requests do
 				// not end the processing early.
 				{
@@ -347,6 +361,7 @@ func TestProcessConsolidationRequests(t *testing.T) {
 			name: "pending consolidations limit reached during processing",
 			state: func() state.BeaconState {
 				st := &eth.BeaconStateElectra{
+					Slot:                  params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().ShardCommitteePeriod)),
 					Validators:            createValidatorsWithTotalActiveBalance(32000000000000000), // 32M ETH
 					PendingConsolidations: make([]*eth.PendingConsolidation, params.BeaconConfig().PendingConsolidationsLimit-1),
 				}
--- a/beacon-chain/core/electra/upgrade.go
+++ b/beacon-chain/core/electra/upgrade.go
@@ -16,36 +16,20 @@ import (
 )

 // UpgradeToElectra updates inputs a generic state to return the version Electra state.
+//
+// nolint:dupword
+// Spec code:
 // def upgrade_to_electra(pre: deneb.BeaconState) -> BeaconState:
 //
 //	epoch = deneb.get_current_epoch(pre)
-//	latest_execution_payload_header = ExecutionPayloadHeader(
-//	    parent_hash=pre.latest_execution_payload_header.parent_hash,
-//	    fee_recipient=pre.latest_execution_payload_header.fee_recipient,
-//	    state_root=pre.latest_execution_payload_header.state_root,
-//	    receipts_root=pre.latest_execution_payload_header.receipts_root,
-//	    logs_bloom=pre.latest_execution_payload_header.logs_bloom,
-//	    prev_randao=pre.latest_execution_payload_header.prev_randao,
-//	    block_number=pre.latest_execution_payload_header.block_number,
-//	    gas_limit=pre.latest_execution_payload_header.gas_limit,
-//	    gas_used=pre.latest_execution_payload_header.gas_used,
-//	    timestamp=pre.latest_execution_payload_header.timestamp,
-//	    extra_data=pre.latest_execution_payload_header.extra_data,
-//	    base_fee_per_gas=pre.latest_execution_payload_header.base_fee_per_gas,
-//	    block_hash=pre.latest_execution_payload_header.block_hash,
-//	    transactions_root=pre.latest_execution_payload_header.transactions_root,
-//	    withdrawals_root=pre.latest_execution_payload_header.withdrawals_root,
-//	    blob_gas_used=pre.latest_execution_payload_header.blob_gas_used,
-//	    excess_blob_gas=pre.latest_execution_payload_header.excess_blob_gas,
-//	    deposit_requests_root=Root(),  # [New in Electra:EIP6110]
-//	    withdrawal_requests_root=Root(),  # [New in Electra:EIP7002],
-//	    consolidation_requests_root=Root(),  # [New in Electra:EIP7251]
-//	)
+//	latest_execution_payload_header = pre.latest_execution_payload_header
 //
-//	exit_epochs = [v.exit_epoch for v in pre.validators if v.exit_epoch != FAR_FUTURE_EPOCH]
-//	if not exit_epochs:
-//	    exit_epochs = [get_current_epoch(pre)]
-//	earliest_exit_epoch = max(exit_epochs) + 1
+//	earliest_exit_epoch = compute_activation_exit_epoch(get_current_epoch(pre))
+//	for validator in pre.validators:
+//	    if validator.exit_epoch != FAR_FUTURE_EPOCH:
+//	        if validator.exit_epoch > earliest_exit_epoch:
+//	            earliest_exit_epoch = validator.exit_epoch
+//	earliest_exit_epoch += Epoch(1)
 //
 //	post = BeaconState(
 //	    # Versioning
@@ -120,7 +104,20 @@ import (
 //	))
 //
 //	for index in pre_activation:
-//	    queue_entire_balance_and_reset_validator(post, ValidatorIndex(index))
+//	    balance = post.balances[index]
+//	    post.balances[index] = 0
+//	    validator = post.validators[index]
+//	    validator.effective_balance = 0
+//	    validator.activation_eligibility_epoch = FAR_FUTURE_EPOCH
+//	    # Use bls.G2_POINT_AT_INFINITY as a signature field placeholder
+//	    # and GENESIS_SLOT to distinguish from a pending deposit request
+//	    post.pending_deposits.append(PendingDeposit(
+//	        pubkey=validator.pubkey,
+//	        withdrawal_credentials=validator.withdrawal_credentials,
+//	        amount=balance,
+//	        signature=bls.G2_POINT_AT_INFINITY,
+//	        slot=GENESIS_SLOT,
+//	    ))
 //
 //	# Ensure early adopters of compounding credentials go through the activation churn
 //	for index, validator in enumerate(post.validators):
@@ -187,7 +184,7 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 	}

 	// [New in Electra:EIP7251]
-	earliestExitEpoch := time.CurrentEpoch(beaconState)
+	earliestExitEpoch := helpers.ActivationExitEpoch(time.CurrentEpoch(beaconState))
 	preActivationIndices := make([]primitives.ValidatorIndex, 0)
 	compoundWithdrawalIndices := make([]primitives.ValidatorIndex, 0)
 	if err = beaconState.ReadFromEveryValidator(func(index int, val state.ReadOnlyValidator) error {
--- a/beacon-chain/core/electra/upgrade_test.go
+++ b/beacon-chain/core/electra/upgrade_test.go
@@ -159,7 +159,7 @@ func TestUpgradeToElectra(t *testing.T) {

 	eee, err := mSt.EarliestExitEpoch()
 	require.NoError(t, err)
-	require.Equal(t, primitives.Epoch(1), eee)
+	require.Equal(t, helpers.ActivationExitEpoch(primitives.Epoch(1)), eee)

 	cbtc, err := mSt.ConsolidationBalanceToConsume()
 	require.NoError(t, err)
--- a/beacon-chain/core/helpers/attestation.go
+++ b/beacon-chain/core/helpers/attestation.go
@@ -67,12 +67,6 @@ func IsAggregator(committeeCount uint64, slotSig []byte) (bool, error) {
 	return binary.LittleEndian.Uint64(b[:8])%modulo == 0, nil
 }

-// IsAggregated returns true if the attestation is an aggregated attestation,
-// false otherwise.
-func IsAggregated(attestation ethpb.Att) bool {
-	return attestation.GetAggregationBits().Count() > 1
-}
-
 // ComputeSubnetForAttestation returns the subnet for which the provided attestation will be broadcasted to.
 // This differs from the spec definition by instead passing in the active validators indices in the attestation's
 // given epoch.
--- a/beacon-chain/core/helpers/validators.go
+++ b/beacon-chain/core/helpers/validators.go
@@ -3,6 +3,7 @@ package helpers
 import (
 	"bytes"
 	"context"
+	"encoding/binary"

 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
@@ -11,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -347,27 +349,33 @@ func BeaconProposerIndexAtSlot(ctx context.Context, state state.ReadOnlyBeaconSt
 // Spec pseudocode definition:
 //
 //	def compute_proposer_index(state: BeaconState, indices: Sequence[ValidatorIndex], seed: Bytes32) -> ValidatorIndex:
-//	  """
-//	  Return from ``indices`` a random index sampled by effective balance.
-//	  """
-//	  assert len(indices) > 0
-//	  MAX_RANDOM_BYTE = 2**8 - 1
-//	  i = uint64(0)
-//	  total = uint64(len(indices))
-//	  while True:
-//	      candidate_index = indices[compute_shuffled_index(i % total, total, seed)]
-//	      random_byte = hash(seed + uint_to_bytes(uint64(i // 32)))[i % 32]
-//	      effective_balance = state.validators[candidate_index].effective_balance
-//	      if effective_balance * MAX_RANDOM_BYTE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_byte: #[Modified in Electra:EIP7251]
-//	          return candidate_index
-//	      i += 1
+//	   """
+//	   Return from ``indices`` a random index sampled by effective balance.
+//	   """
+//	   assert len(indices) > 0
+//	   MAX_RANDOM_VALUE = 2**16 - 1  # [Modified in Electra]
+//	   i = uint64(0)
+//	   total = uint64(len(indices))
+//	   while True:
+//	       candidate_index = indices[compute_shuffled_index(i % total, total, seed)]
+//	       # [Modified in Electra]
+//	       random_bytes = hash(seed + uint_to_bytes(i // 16))
+//	       offset = i % 16 * 2
+//	       random_value = bytes_to_uint64(random_bytes[offset:offset + 2])
+//	       effective_balance = state.validators[candidate_index].effective_balance
+//	       # [Modified in Electra:EIP7251]
+//	       if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value:
+//	           return candidate_index
+//	       i += 1
 func ComputeProposerIndex(bState state.ReadOnlyBeaconState, activeIndices []primitives.ValidatorIndex, seed [32]byte) (primitives.ValidatorIndex, error) {
 	length := uint64(len(activeIndices))
 	if length == 0 {
 		return 0, errors.New("empty active indices list")
 	}
-	maxRandomByte := uint64(1<<8 - 1)
 	hashFunc := hash.CustomSHA256Hasher()
+	beaconConfig := params.BeaconConfig()
+	seedBuffer := make([]byte, len(seed)+8)
+	copy(seedBuffer, seed[:])

 	for i := uint64(0); ; i++ {
 		candidateIndex, err := ComputeShuffledIndex(primitives.ValidatorIndex(i%length), length, seed, true /* shuffle */)
@@ -378,21 +386,28 @@ func ComputeProposerIndex(bState state.ReadOnlyBeaconState, activeIndices []prim
 		if uint64(candidateIndex) >= uint64(bState.NumValidators()) {
 			return 0, errors.New("active index out of range")
 		}
-		b := append(seed[:], bytesutil.Bytes8(i/32)...)
-		randomByte := hashFunc(b)[i%32]
+
 		v, err := bState.ValidatorAtIndexReadOnly(candidateIndex)
 		if err != nil {
 			return 0, err
 		}
 		effectiveBal := v.EffectiveBalance()
-
-		maxEB := params.BeaconConfig().MaxEffectiveBalance
 		if bState.Version() >= version.Electra {
-			maxEB = params.BeaconConfig().MaxEffectiveBalanceElectra
-		}
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], i/16)
+			randomByte := hashFunc(seedBuffer)
+			offset := (i % 16) * 2
+			randomValue := uint64(randomByte[offset]) | uint64(randomByte[offset+1])<<8

-		if effectiveBal*maxRandomByte >= maxEB*uint64(randomByte) {
-			return candidateIndex, nil
+			if effectiveBal*fieldparams.MaxRandomValueElectra >= beaconConfig.MaxEffectiveBalanceElectra*randomValue {
+				return candidateIndex, nil
+			}
+		} else {
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], i/32)
+			randomByte := hashFunc(seedBuffer)[i%32]
+
+			if effectiveBal*fieldparams.MaxRandomByte >= beaconConfig.MaxEffectiveBalance*uint64(randomByte) {
+				return candidateIndex, nil
+			}
 		}
 	}
 }
--- a/beacon-chain/core/helpers/validators_test.go
+++ b/beacon-chain/core/helpers/validators_test.go
@@ -841,7 +841,6 @@ func computeProposerIndexWithValidators(validators []*ethpb.Validator, activeInd
 	if length == 0 {
 		return 0, errors.New("empty active indices list")
 	}
-	maxRandomByte := uint64(1<<8 - 1)
 	hashFunc := hash.CustomSHA256Hasher()

 	for i := uint64(0); ; i++ {
@@ -860,7 +859,7 @@ func computeProposerIndexWithValidators(validators []*ethpb.Validator, activeInd
 		if v != nil {
 			effectiveBal = v.EffectiveBalance
 		}
-		if effectiveBal*maxRandomByte >= params.BeaconConfig().MaxEffectiveBalance*uint64(randomByte) {
+		if effectiveBal*fieldparams.MaxRandomByte >= params.BeaconConfig().MaxEffectiveBalance*uint64(randomByte) {
 			return candidateIndex, nil
 		}
 	}
--- a/beacon-chain/core/light-client/BUILD.bazel
+++ b/beacon-chain/core/light-client/BUILD.bazel
@@ -6,19 +6,22 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client",
    visibility = ["//visibility:public"],
    deps = [
+        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/light-client:go_default_library",
+        "//consensus-types/primitives:go_default_library",
        "//encoding/ssz:go_default_library",
        "//proto/engine/v1:go_default_library",
-        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
    ],
 )

@@ -28,10 +31,14 @@ go_test(
    deps = [
        ":go_default_library",
        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/light-client:go_default_library",
+        "//consensus-types/primitives:go_default_library",
        "//encoding/ssz:go_default_library",
        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
--- a/beacon-chain/core/light-client/lightclient.go
+++ b/beacon-chain/core/light-client/lightclient.go
--- a/beacon-chain/core/light-client/lightclient_test.go
+++ b/beacon-chain/core/light-client/lightclient_test.go
--- a/beacon-chain/core/validators/validator_test.go
+++ b/beacon-chain/core/validators/validator_test.go
@@ -217,6 +217,7 @@ func TestSlashValidator_OK(t *testing.T) {
 }

 func TestSlashValidator_Electra(t *testing.T) {
+	helpers.ClearCache()
 	validatorCount := 100
 	registry := make([]*ethpb.Validator, 0, validatorCount)
 	balances := make([]uint64, 0, validatorCount)
--- a/beacon-chain/das/BUILD.bazel
+++ b/beacon-chain/das/BUILD.bazel
@@ -13,7 +13,6 @@ go_library(
    deps = [
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/verification:go_default_library",
-        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -35,7 +34,6 @@ go_test(
    deps = [
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/verification:go_default_library",
-        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/primitives:go_default_library",
--- a/beacon-chain/das/availability.go
+++ b/beacon-chain/das/availability.go
@@ -83,10 +83,10 @@ func (s *LazilyPersistentStore) Persist(current primitives.Slot, sc ...blocks.RO
 func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error {
 	blockCommitments, err := commitmentsToCheck(b, current)
 	if err != nil {
-		return errors.Wrapf(err, "could check data availability for block %#x", b.Root())
+		return errors.Wrapf(err, "could not check data availability for block %#x", b.Root())
 	}
 	// Return early for blocks that are pre-deneb or which do not have any commitments.
-	if blockCommitments.count() == 0 {
+	if len(blockCommitments) == 0 {
 		return nil
 	}

@@ -106,7 +106,7 @@ func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current pri
 	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
 	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
 	// ignore their response and decrease their peer score.
-	sidecars, err := entry.filter(root, blockCommitments)
+	sidecars, err := entry.filter(root, blockCommitments, b.Block().Slot())
 	if err != nil {
 		return errors.Wrap(err, "incomplete BlobSidecar batch")
 	}
@@ -137,22 +137,28 @@ func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current pri
 	return nil
 }

-func commitmentsToCheck(b blocks.ROBlock, current primitives.Slot) (safeCommitmentArray, error) {
-	var ar safeCommitmentArray
+func commitmentsToCheck(b blocks.ROBlock, current primitives.Slot) ([][]byte, error) {
 	if b.Version() < version.Deneb {
-		return ar, nil
+		return nil, nil
 	}
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUEST
 	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
-		return ar, nil
+		return nil, nil
 	}
-	kc, err := b.Block().Body().BlobKzgCommitments()
+
+	kzgCommitments, err := b.Block().Body().BlobKzgCommitments()
 	if err != nil {
-		return ar, err
+		return nil, err
 	}
-	if len(kc) > len(ar) {
-		return ar, errIndexOutOfBounds
+
+	maxBlobCount := params.BeaconConfig().MaxBlobsPerBlockBySlot(b.Block().Slot())
+	if len(kzgCommitments) > maxBlobCount {
+		return nil, errIndexOutOfBounds
 	}
-	copy(ar[:], kc)
-	return ar, nil
+
+	result := make([][]byte, len(kzgCommitments))
+	copy(result, kzgCommitments)
+
+	return result, nil
 }
--- a/beacon-chain/das/availability_test.go
+++ b/beacon-chain/das/availability_test.go
@@ -8,7 +8,6 @@ import (
 	errors "github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -89,7 +88,7 @@ func Test_commitmentsToCheck(t *testing.T) {
 				require.NoError(t, err)
 				c, err := rb.Block().Body().BlobKzgCommitments()
 				require.NoError(t, err)
-				require.Equal(t, true, len(c) > fieldparams.MaxBlobsPerBlock)
+				require.Equal(t, true, len(c) > params.BeaconConfig().MaxBlobsPerBlockBySlot(sb.Block().Slot()))
 				return rb
 			},
 			slot: windowSlots + 1,
@@ -105,7 +104,7 @@ func Test_commitmentsToCheck(t *testing.T) {
 			} else {
 				require.NoError(t, err)
 			}
-			require.Equal(t, len(c.commits), co.count())
+			require.Equal(t, len(c.commits), len(co))
 			for i := 0; i < len(c.commits); i++ {
 				require.Equal(t, true, bytes.Equal(c.commits[i], co[i]))
 			}
--- a/beacon-chain/das/cache.go
+++ b/beacon-chain/das/cache.go
@@ -5,7 +5,7 @@ import (

 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )
@@ -60,7 +60,7 @@ func (c *cache) delete(key cacheKey) {

 // cacheEntry holds a fixed-length cache of BlobSidecars.
 type cacheEntry struct {
-	scs         [fieldparams.MaxBlobsPerBlock]*blocks.ROBlob
+	scs         []*blocks.ROBlob
 	diskSummary filesystem.BlobStorageSummary
 }

@@ -72,9 +72,13 @@ func (e *cacheEntry) setDiskSummary(sum filesystem.BlobStorageSummary) {
 // Only the first BlobSidecar of a given Index will be kept in the cache.
 // stash will return an error if the given blob is already in the cache, or if the Index is out of bounds.
 func (e *cacheEntry) stash(sc *blocks.ROBlob) error {
-	if sc.Index >= fieldparams.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(sc.Slot())
+	if sc.Index >= uint64(maxBlobsPerBlock) {
 		return errors.Wrapf(errIndexOutOfBounds, "index=%d", sc.Index)
 	}
+	if e.scs == nil {
+		e.scs = make([]*blocks.ROBlob, maxBlobsPerBlock)
+	}
 	if e.scs[sc.Index] != nil {
 		return errors.Wrapf(ErrDuplicateSidecar, "root=%#x, index=%d, commitment=%#x", sc.BlockRoot(), sc.Index, sc.KzgCommitment)
 	}
@@ -88,12 +92,13 @@ func (e *cacheEntry) stash(sc *blocks.ROBlob) error {
 // commitments were found in the cache and the sidecar slice return value can be used
 // to perform a DA check against the cached sidecars.
 // filter only returns blobs that need to be checked. Blobs already available on disk will be excluded.
-func (e *cacheEntry) filter(root [32]byte, kc safeCommitmentArray) ([]blocks.ROBlob, error) {
-	if e.diskSummary.AllAvailable(kc.count()) {
+func (e *cacheEntry) filter(root [32]byte, kc [][]byte, slot primitives.Slot) ([]blocks.ROBlob, error) {
+	count := len(kc)
+	if e.diskSummary.AllAvailable(count) {
 		return nil, nil
 	}
-	scs := make([]blocks.ROBlob, 0, kc.count())
-	for i := uint64(0); i < fieldparams.MaxBlobsPerBlock; i++ {
+	scs := make([]blocks.ROBlob, 0, count)
+	for i := uint64(0); i < uint64(count); i++ {
 		// We already have this blob, we don't need to write it or validate it.
 		if e.diskSummary.HasIndex(i) {
 			continue
@@ -116,16 +121,3 @@ func (e *cacheEntry) filter(root [32]byte, kc safeCommitmentArray) ([]blocks.ROB

 	return scs, nil
 }
-
-// safeCommitmentArray is a fixed size array of commitment byte slices. This is helpful for avoiding
-// gratuitous bounds checks.
-type safeCommitmentArray [fieldparams.MaxBlobsPerBlock][]byte
-
-func (s safeCommitmentArray) count() int {
-	for i := range s {
-		if s[i] == nil {
-			return i
-		}
-	}
-	return fieldparams.MaxBlobsPerBlock
-}
--- a/beacon-chain/das/cache_test.go
+++ b/beacon-chain/das/cache_test.go
@@ -29,10 +29,10 @@ func TestCacheEnsureDelete(t *testing.T) {
 	require.Equal(t, nilEntry, c.entries[k])
 }

-type filterTestCaseSetupFunc func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob)
+type filterTestCaseSetupFunc func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob)

 func filterTestCaseSetup(slot primitives.Slot, nBlobs int, onDisk []int, numExpected int) filterTestCaseSetupFunc {
-	return func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob) {
+	return func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob) {
 		blk, blobs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, slot, nBlobs)
 		commits, err := commitmentsToCheck(blk, blk.Block().Slot())
 		require.NoError(t, err)
@@ -44,7 +44,7 @@ func filterTestCaseSetup(slot primitives.Slot, nBlobs int, onDisk []int, numExpe
 			entry.setDiskSummary(sum)
 		}
 		expected := make([]blocks.ROBlob, 0, nBlobs)
-		for i := 0; i < commits.count(); i++ {
+		for i := 0; i < len(commits); i++ {
 			if entry.diskSummary.HasIndex(uint64(i)) {
 				continue
 			}
@@ -113,7 +113,7 @@ func TestFilterDiskSummary(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			entry, commits, expected := c.setup(t)
 			// first (root) argument doesn't matter, it is just for logs
-			got, err := entry.filter([32]byte{}, commits)
+			got, err := entry.filter([32]byte{}, commits, 100)
 			require.NoError(t, err)
 			require.Equal(t, len(expected), len(got))
 		})
@@ -125,12 +125,12 @@ func TestFilter(t *testing.T) {
 	require.NoError(t, err)
 	cases := []struct {
 		name  string
-		setup func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob)
+		setup func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob)
 		err   error
 	}{
 		{
 			name: "commitments mismatch - extra sidecar",
-			setup: func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob) {
+			setup: func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob) {
 				entry, commits, expected := filterTestCaseSetup(denebSlot, 6, []int{0, 1}, 4)(t)
 				commits[5] = nil
 				return entry, commits, expected
@@ -139,7 +139,7 @@ func TestFilter(t *testing.T) {
 		},
 		{
 			name: "sidecar missing",
-			setup: func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob) {
+			setup: func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob) {
 				entry, commits, expected := filterTestCaseSetup(denebSlot, 6, []int{0, 1}, 4)(t)
 				entry.scs[5] = nil
 				return entry, commits, expected
@@ -148,7 +148,7 @@ func TestFilter(t *testing.T) {
 		},
 		{
 			name: "commitments mismatch - different bytes",
-			setup: func(t *testing.T) (*cacheEntry, safeCommitmentArray, []blocks.ROBlob) {
+			setup: func(t *testing.T) (*cacheEntry, [][]byte, []blocks.ROBlob) {
 				entry, commits, expected := filterTestCaseSetup(denebSlot, 6, []int{0, 1}, 4)(t)
 				entry.scs[5].KzgCommitment = []byte("nope")
 				return entry, commits, expected
@@ -160,7 +160,7 @@ func TestFilter(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			entry, commits, expected := c.setup(t)
 			// first (root) argument doesn't matter, it is just for logs
-			got, err := entry.filter([32]byte{}, commits)
+			got, err := entry.filter([32]byte{}, commits, 100)
 			if c.err != nil {
 				require.ErrorIs(t, err, c.err)
 				return
--- a/beacon-chain/db/filesystem/BUILD.bazel
+++ b/beacon-chain/db/filesystem/BUILD.bazel
@@ -42,7 +42,7 @@ go_test(
    embed = [":go_default_library"],
    deps = [
        "//beacon-chain/verification:go_default_library",
-        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
--- a/beacon-chain/db/filesystem/blob.go
+++ b/beacon-chain/db/filesystem/blob.go
@@ -13,7 +13,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -25,7 +25,7 @@ import (
 )

 var (
-	errIndexOutOfBounds    = errors.New("blob index in file name >= MaxBlobsPerBlock")
+	errIndexOutOfBounds    = errors.New("blob index in file name >= DeprecatedMaxBlobsPerBlock")
 	errEmptyBlobWritten    = errors.New("zero bytes written to disk when saving blob sidecar")
 	errSidecarEmptySSZData = errors.New("sidecar marshalled to an empty ssz byte slice")
 	errNoBasePath          = errors.New("BlobStorage base path not specified in init")
@@ -109,10 +109,11 @@ func (bs *BlobStorage) WarmCache() {
 	}
 	go func() {
 		start := time.Now()
+		log.Info("Blob filesystem cache warm-up started. This may take a few minutes.")
 		if err := bs.pruner.warmCache(); err != nil {
 			log.WithError(err).Error("Error encountered while warming up blob pruner cache")
 		}
-		log.WithField("elapsed", time.Since(start)).Info("Blob filesystem cache warm-up complete.")
+		log.WithField("elapsed", time.Since(start)).Info("Blob filesystem cache warm-up complete")
 	}()
 }

@@ -218,6 +219,7 @@ func (bs *BlobStorage) Save(sidecar blocks.VerifiedROBlob) error {
 	partialMoved = true
 	blobsWrittenCounter.Inc()
 	blobSaveLatency.Observe(float64(time.Since(startTime).Milliseconds()))
+
 	return nil
 }

@@ -255,8 +257,10 @@ func (bs *BlobStorage) Remove(root [32]byte) error {
 // Indices generates a bitmap representing which BlobSidecar.Index values are present on disk for a given root.
 // This value can be compared to the commitments observed in a block to determine which indices need to be found
 // on the network to confirm data availability.
-func (bs *BlobStorage) Indices(root [32]byte) ([fieldparams.MaxBlobsPerBlock]bool, error) {
-	var mask [fieldparams.MaxBlobsPerBlock]bool
+func (bs *BlobStorage) Indices(root [32]byte, s primitives.Slot) ([]bool, error) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(s)
+	mask := make([]bool, maxBlobsPerBlock)
+
 	rootDir := blobNamer{root: root}.dir()
 	entries, err := afero.ReadDir(bs.fs, rootDir)
 	if err != nil {
@@ -265,6 +269,7 @@ func (bs *BlobStorage) Indices(root [32]byte) ([fieldparams.MaxBlobsPerBlock]boo
 		}
 		return mask, err
 	}
+
 	for i := range entries {
 		if entries[i].IsDir() {
 			continue
@@ -281,7 +286,7 @@ func (bs *BlobStorage) Indices(root [32]byte) ([fieldparams.MaxBlobsPerBlock]boo
 		if err != nil {
 			return mask, errors.Wrapf(err, "unexpected directory entry breaks listing, %s", parts[0])
 		}
-		if u >= fieldparams.MaxBlobsPerBlock {
+		if u >= uint64(maxBlobsPerBlock) {
 			return mask, errIndexOutOfBounds
 		}
 		mask[u] = true
--- a/beacon-chain/db/filesystem/blob_test.go
+++ b/beacon-chain/db/filesystem/blob_test.go
@@ -10,7 +10,7 @@ import (

 	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -20,7 +20,7 @@ import (
 )

 func TestBlobStorage_SaveBlobData(t *testing.T) {
-	_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, fieldparams.MaxBlobsPerBlock)
+	_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, params.BeaconConfig().MaxBlobsPerBlockBySlot(1))
 	testSidecars, err := verification.BlobSidecarSliceNoop(sidecars)
 	require.NoError(t, err)

@@ -56,10 +56,10 @@ func TestBlobStorage_SaveBlobData(t *testing.T) {
 		require.NoError(t, bs.Save(sc))
 		actualSc, err := bs.Get(sc.BlockRoot(), sc.Index)
 		require.NoError(t, err)
-		expectedIdx := [fieldparams.MaxBlobsPerBlock]bool{false, false, true}
-		actualIdx, err := bs.Indices(actualSc.BlockRoot())
+		expectedIdx := []bool{false, false, true, false, false, false}
+		actualIdx, err := bs.Indices(actualSc.BlockRoot(), 100)
 		require.NoError(t, err)
-		require.Equal(t, expectedIdx, actualIdx)
+		require.DeepEqual(t, expectedIdx, actualIdx)
 	})

 	t.Run("round trip write then read", func(t *testing.T) {
@@ -132,19 +132,19 @@ func TestBlobIndicesBounds(t *testing.T) {
 	fs, bs := NewEphemeralBlobStorageWithFs(t)
 	root := [32]byte{}

-	okIdx := uint64(fieldparams.MaxBlobsPerBlock - 1)
+	okIdx := uint64(params.BeaconConfig().MaxBlobsPerBlockBySlot(0)) - 1
 	writeFakeSSZ(t, fs, root, okIdx)
-	indices, err := bs.Indices(root)
+	indices, err := bs.Indices(root, 100)
 	require.NoError(t, err)
-	var expected [fieldparams.MaxBlobsPerBlock]bool
+	expected := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 	expected[okIdx] = true
 	for i := range expected {
 		require.Equal(t, expected[i], indices[i])
 	}

-	oobIdx := uint64(fieldparams.MaxBlobsPerBlock)
+	oobIdx := uint64(params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 	writeFakeSSZ(t, fs, root, oobIdx)
-	_, err = bs.Indices(root)
+	_, err = bs.Indices(root, 100)
 	require.ErrorIs(t, err, errIndexOutOfBounds)
 }

@@ -163,7 +163,7 @@ func TestBlobStoragePrune(t *testing.T) {
 	fs, bs := NewEphemeralBlobStorageWithFs(t)

 	t.Run("PruneOne", func(t *testing.T) {
-		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 300, fieldparams.MaxBlobsPerBlock)
+		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 300, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 		testSidecars, err := verification.BlobSidecarSliceNoop(sidecars)
 		require.NoError(t, err)

@@ -178,7 +178,7 @@ func TestBlobStoragePrune(t *testing.T) {
 		require.Equal(t, 0, len(remainingFolders))
 	})
 	t.Run("Prune dangling blob", func(t *testing.T) {
-		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 299, fieldparams.MaxBlobsPerBlock)
+		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 299, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 		testSidecars, err := verification.BlobSidecarSliceNoop(sidecars)
 		require.NoError(t, err)

@@ -198,7 +198,7 @@ func TestBlobStoragePrune(t *testing.T) {

 		for j := 0; j <= blockQty; j++ {
 			root := bytesutil.ToBytes32(bytesutil.ToBytes(uint64(slot), 32))
-			_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, root, slot, fieldparams.MaxBlobsPerBlock)
+			_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, root, slot, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 			testSidecars, err := verification.BlobSidecarSliceNoop(sidecars)
 			require.NoError(t, err)
 			require.NoError(t, bs.Save(testSidecars[0]))
@@ -224,7 +224,7 @@ func BenchmarkPruning(b *testing.B) {

 	for j := 0; j <= blockQty; j++ {
 		root := bytesutil.ToBytes32(bytesutil.ToBytes(uint64(slot), 32))
-		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, root, slot, fieldparams.MaxBlobsPerBlock)
+		_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, root, slot, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 		testSidecars, err := verification.BlobSidecarSliceNoop(sidecars)
 		require.NoError(t, err)
 		require.NoError(t, bs.Save(testSidecars[0]))
--- a/beacon-chain/db/filesystem/cache.go
+++ b/beacon-chain/db/filesystem/cache.go
@@ -9,7 +9,7 @@ import (
 )

 // blobIndexMask is a bitmask representing the set of blob indices that are currently set.
-type blobIndexMask [fieldparams.MaxBlobsPerBlock]bool
+type blobIndexMask []bool

 // BlobStorageSummary represents cached information about the BlobSidecars on disk for each root the cache knows about.
 type BlobStorageSummary struct {
@@ -20,7 +20,11 @@ type BlobStorageSummary struct {
 // HasIndex returns true if the BlobSidecar at the given index is available in the filesystem.
 func (s BlobStorageSummary) HasIndex(idx uint64) bool {
 	// Protect from panic, but assume callers are sophisticated enough to not need an error telling them they have an invalid idx.
-	if idx >= fieldparams.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(s.slot)
+	if idx >= uint64(maxBlobsPerBlock) {
+		return false
+	}
+	if idx >= uint64(len(s.mask)) {
 		return false
 	}
 	return s.mask[idx]
@@ -28,7 +32,11 @@ func (s BlobStorageSummary) HasIndex(idx uint64) bool {

 // AllAvailable returns true if we have all blobs for all indices from 0 to count-1.
 func (s BlobStorageSummary) AllAvailable(count int) bool {
-	if count > fieldparams.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(s.slot)
+	if count > maxBlobsPerBlock {
+		return false
+	}
+	if count > len(s.mask) {
 		return false
 	}
 	for i := 0; i < count; i++ {
@@ -68,13 +76,17 @@ func (s *blobStorageCache) Summary(root [32]byte) BlobStorageSummary {
 }

 func (s *blobStorageCache) ensure(key [32]byte, slot primitives.Slot, idx uint64) error {
-	if idx >= fieldparams.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlockBySlot(slot)
+	if idx >= uint64(maxBlobsPerBlock) {
 		return errIndexOutOfBounds
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	v := s.cache[key]
 	v.slot = slot
+	if v.mask == nil {
+		v.mask = make(blobIndexMask, maxBlobsPerBlock)
+	}
 	if !v.mask[idx] {
 		s.updateMetrics(1)
 	}
--- a/beacon-chain/db/filesystem/cache_test.go
+++ b/beacon-chain/db/filesystem/cache_test.go
@@ -3,13 +3,17 @@ package filesystem
 import (
 	"testing"

-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )

 func TestSlotByRoot_Summary(t *testing.T) {
-	var noneSet, allSet, firstSet, lastSet, oneSet blobIndexMask
+	noneSet := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
+	allSet := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
+	firstSet := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
+	lastSet := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
+	oneSet := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 	firstSet[0] = true
 	lastSet[len(lastSet)-1] = true
 	oneSet[1] = true
@@ -19,49 +23,49 @@ func TestSlotByRoot_Summary(t *testing.T) {
 	cases := []struct {
 		name     string
 		root     [32]byte
-		expected *blobIndexMask
+		expected blobIndexMask
 	}{
 		{
 			name: "not found",
 		},
 		{
 			name:     "none set",
-			expected: &noneSet,
+			expected: noneSet,
 		},
 		{
 			name:     "index 1 set",
-			expected: &oneSet,
+			expected: oneSet,
 		},
 		{
 			name:     "all set",
-			expected: &allSet,
+			expected: allSet,
 		},
 		{
 			name:     "first set",
-			expected: &firstSet,
+			expected: firstSet,
 		},
 		{
 			name:     "last set",
-			expected: &lastSet,
+			expected: lastSet,
 		},
 	}
 	sc := newBlobStorageCache()
 	for _, c := range cases {
 		if c.expected != nil {
 			key := bytesutil.ToBytes32([]byte(c.name))
-			sc.cache[key] = BlobStorageSummary{slot: 0, mask: *c.expected}
+			sc.cache[key] = BlobStorageSummary{slot: 0, mask: c.expected}
 		}
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
 			key := bytesutil.ToBytes32([]byte(c.name))
 			sum := sc.Summary(key)
-			for i := range c.expected {
+			for i, has := range c.expected {
 				ui := uint64(i)
 				if c.expected == nil {
 					require.Equal(t, false, sum.HasIndex(ui))
 				} else {
-					require.Equal(t, c.expected[i], sum.HasIndex(ui))
+					require.Equal(t, has, sum.HasIndex(ui))
 				}
 			}
 		})
@@ -121,13 +125,13 @@ func TestAllAvailable(t *testing.T) {
 		},
 		{
 			name:  "out of bound is safe",
-			count: fieldparams.MaxBlobsPerBlock + 1,
+			count: params.BeaconConfig().MaxBlobsPerBlockBySlot(0) + 1,
 			aa:    false,
 		},
 		{
 			name:   "max present",
-			count:  fieldparams.MaxBlobsPerBlock,
-			idxSet: idxUpTo(fieldparams.MaxBlobsPerBlock),
+			count:  params.BeaconConfig().MaxBlobsPerBlockBySlot(0),
+			idxSet: idxUpTo(params.BeaconConfig().MaxBlobsPerBlockBySlot(0)),
 			aa:     true,
 		},
 		{
@@ -139,7 +143,7 @@ func TestAllAvailable(t *testing.T) {
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
-			var mask blobIndexMask
+			mask := make([]bool, params.BeaconConfig().MaxBlobsPerBlockBySlot(0))
 			for _, idx := range c.idxSet {
 				mask[idx] = true
 			}
--- a/beacon-chain/db/filesystem/pruner_test.go
+++ b/beacon-chain/db/filesystem/pruner_test.go
@@ -12,7 +12,7 @@ import (
 	"time"

 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
@@ -25,7 +25,7 @@ func TestTryPruneDir_CachedNotExpired(t *testing.T) {
 	pr, err := newBlobPruner(fs, 0)
 	require.NoError(t, err)
 	slot := pr.windowSize
-	_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, slot, fieldparams.MaxBlobsPerBlock)
+	_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, slot, params.BeaconConfig().MaxBlobsPerBlockBySlot(slot))
 	sc, err := verification.BlobSidecarNoop(sidecars[0])
 	require.NoError(t, err)
 	rootStr := rootString(sc.BlockRoot())
--- a/beacon-chain/db/iface/BUILD.bazel
+++ b/beacon-chain/db/iface/BUILD.bazel
@@ -18,7 +18,6 @@ go_library(
        "//consensus-types/primitives:go_default_library",
        "//monitoring/backup:go_default_library",
        "//proto/dbval:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
    ],
--- a/beacon-chain/db/iface/interface.go
+++ b/beacon-chain/db/iface/interface.go
@@ -7,8 +7,6 @@ import (
 	"context"
 	"io"

-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filters"
 	slashertypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/slasher/types"
@@ -59,8 +57,9 @@ type ReadOnlyDatabase interface {
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
 	// light client operations
-	LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]*ethpbv2.LightClientUpdateWithVersion, error)
-	LightClientUpdate(ctx context.Context, period uint64) (*ethpbv2.LightClientUpdateWithVersion, error)
+	LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]interfaces.LightClientUpdate, error)
+	LightClientUpdate(ctx context.Context, period uint64) (interfaces.LightClientUpdate, error)
+	LightClientBootstrap(ctx context.Context, blockRoot []byte) (interfaces.LightClientBootstrap, error)

 	// origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
@@ -98,7 +97,8 @@ type NoHeadAccessDatabase interface {
 	SaveFeeRecipientsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, addrs []common.Address) error
 	SaveRegistrationsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, regs []*ethpb.ValidatorRegistrationV1) error
 	// light client operations
-	SaveLightClientUpdate(ctx context.Context, period uint64, update *ethpbv2.LightClientUpdateWithVersion) error
+	SaveLightClientUpdate(ctx context.Context, period uint64, update interfaces.LightClientUpdate) error
+	SaveLightClientBootstrap(ctx context.Context, blockRoot []byte, bootstrap interfaces.LightClientBootstrap) error

 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 }
--- a/beacon-chain/db/kv/BUILD.bazel
+++ b/beacon-chain/db/kv/BUILD.bazel
@@ -44,6 +44,7 @@ go_library(
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/light-client:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//container/slice:go_default_library",
        "//encoding/bytesutil:go_default_library",
@@ -53,7 +54,6 @@ go_library(
        "//monitoring/tracing:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
        "//proto/dbval:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
        "//time:go_default_library",
@@ -112,18 +112,18 @@ go_test(
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/light-client:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/dbval:go_default_library",
        "//proto/engine/v1:go_default_library",
-        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//proto/testing:go_default_library",
        "//runtime/version:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
+        "//time/slots:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_golang_snappy//:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
--- a/beacon-chain/db/kv/kv.go
+++ b/beacon-chain/db/kv/kv.go
@@ -108,6 +108,7 @@ var Buckets = [][]byte{
 	stateSummaryBucket,
 	stateValidatorsBucket,
 	lightClientUpdatesBucket,
+	lightClientBootstrapBucket,
 	// Indices buckets.
 	blockSlotIndicesBucket,
 	stateSlotIndicesBucket,
--- a/beacon-chain/db/kv/lightclient.go
+++ b/beacon-chain/db/kv/lightclient.go
@@ -5,35 +5,126 @@ import (
 	"encoding/binary"
 	"fmt"

+	"github.com/golang/snappy"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	light_client "github.com/prysmaticlabs/prysm/v5/consensus-types/light-client"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	bolt "go.etcd.io/bbolt"
+	"google.golang.org/protobuf/proto"
 )

-func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update *ethpbv2.LightClientUpdateWithVersion) error {
-	ctx, span := trace.StartSpan(ctx, "BeaconDB.saveLightClientUpdate")
+func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update interfaces.LightClientUpdate) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.SaveLightClientUpdate")
 	defer span.End()

 	return s.db.Update(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(lightClientUpdatesBucket)
-		updateMarshalled, err := encode(ctx, update)
+		enc, err := encodeLightClientUpdate(update)
 		if err != nil {
 			return err
 		}
-		return bkt.Put(bytesutil.Uint64ToBytesBigEndian(period), updateMarshalled)
+		return bkt.Put(bytesutil.Uint64ToBytesBigEndian(period), enc)
 	})
 }

-func (s *Store) LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]*ethpbv2.LightClientUpdateWithVersion, error) {
-	ctx, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdates")
+func (s *Store) SaveLightClientBootstrap(ctx context.Context, blockRoot []byte, bootstrap interfaces.LightClientBootstrap) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.SaveLightClientBootstrap")
+	defer span.End()
+
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(lightClientBootstrapBucket)
+		enc, err := encodeLightClientBootstrap(bootstrap)
+		if err != nil {
+			return err
+		}
+		return bkt.Put(blockRoot, enc)
+	})
+}
+
+func (s *Store) LightClientBootstrap(ctx context.Context, blockRoot []byte) (interfaces.LightClientBootstrap, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.LightClientBootstrap")
+	defer span.End()
+
+	var bootstrap interfaces.LightClientBootstrap
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(lightClientBootstrapBucket)
+		enc := bkt.Get(blockRoot)
+		if enc == nil {
+			return nil
+		}
+		var err error
+		bootstrap, err = decodeLightClientBootstrap(enc)
+		return err
+	})
+	return bootstrap, err
+}
+
+func encodeLightClientBootstrap(bootstrap interfaces.LightClientBootstrap) ([]byte, error) {
+	key, err := keyForLightClientUpdate(bootstrap.Version())
+	if err != nil {
+		return nil, err
+	}
+	enc, err := bootstrap.MarshalSSZ()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal light client bootstrap")
+	}
+	fullEnc := make([]byte, len(key)+len(enc))
+	copy(fullEnc, key)
+	copy(fullEnc[len(key):], enc)
+	return snappy.Encode(nil, fullEnc), nil
+}
+
+func decodeLightClientBootstrap(enc []byte) (interfaces.LightClientBootstrap, error) {
+	var err error
+	enc, err = snappy.Decode(nil, enc)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not snappy decode light client bootstrap")
+	}
+	var m proto.Message
+	switch {
+	case hasAltairKey(enc):
+		bootstrap := &ethpb.LightClientBootstrapAltair{}
+		if err := bootstrap.UnmarshalSSZ(enc[len(altairKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Altair light client bootstrap")
+		}
+		m = bootstrap
+	case hasCapellaKey(enc):
+		bootstrap := &ethpb.LightClientBootstrapCapella{}
+		if err := bootstrap.UnmarshalSSZ(enc[len(capellaKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Capella light client bootstrap")
+		}
+		m = bootstrap
+	case hasDenebKey(enc):
+		bootstrap := &ethpb.LightClientBootstrapDeneb{}
+		if err := bootstrap.UnmarshalSSZ(enc[len(denebKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Deneb light client bootstrap")
+		}
+		m = bootstrap
+	case hasElectraKey(enc):
+		bootstrap := &ethpb.LightClientBootstrapElectra{}
+		if err := bootstrap.UnmarshalSSZ(enc[len(electraKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Electra light client bootstrap")
+		}
+		m = bootstrap
+	default:
+		return nil, errors.New("decoding of saved light client bootstrap is unsupported")
+	}
+	return light_client.NewWrappedBootstrap(m)
+}
+
+func (s *Store) LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]interfaces.LightClientUpdate, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdates")
 	defer span.End()

 	if startPeriod > endPeriod {
 		return nil, fmt.Errorf("start period %d is greater than end period %d", startPeriod, endPeriod)
 	}

-	updates := make(map[uint64]*ethpbv2.LightClientUpdateWithVersion)
+	updates := make(map[uint64]interfaces.LightClientUpdate)
 	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(lightClientUpdatesBucket)
 		c := bkt.Cursor()
@@ -46,11 +137,11 @@ func (s *Store) LightClientUpdates(ctx context.Context, startPeriod, endPeriod u
 		for k, v := c.Seek(bytesutil.Uint64ToBytesBigEndian(startPeriod)); k != nil && binary.BigEndian.Uint64(k) <= endPeriod; k, v = c.Next() {
 			currentPeriod := binary.BigEndian.Uint64(k)

-			var update ethpbv2.LightClientUpdateWithVersion
-			if err := decode(ctx, v, &update); err != nil {
+			update, err := decodeLightClientUpdate(v)
+			if err != nil {
 				return err
 			}
-			updates[currentPeriod] = &update
+			updates[currentPeriod] = update
 		}

 		return nil
@@ -62,18 +153,88 @@ func (s *Store) LightClientUpdates(ctx context.Context, startPeriod, endPeriod u
 	return updates, err
 }

-func (s *Store) LightClientUpdate(ctx context.Context, period uint64) (*ethpbv2.LightClientUpdateWithVersion, error) {
-	ctx, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdate")
+func (s *Store) LightClientUpdate(ctx context.Context, period uint64) (interfaces.LightClientUpdate, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdate")
 	defer span.End()

-	var update ethpbv2.LightClientUpdateWithVersion
+	var update interfaces.LightClientUpdate
 	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(lightClientUpdatesBucket)
 		updateBytes := bkt.Get(bytesutil.Uint64ToBytesBigEndian(period))
 		if updateBytes == nil {
 			return nil
 		}
-		return decode(ctx, updateBytes, &update)
+		var err error
+		update, err = decodeLightClientUpdate(updateBytes)
+		return err
 	})
-	return &update, err
+	return update, err
+}
+
+func encodeLightClientUpdate(update interfaces.LightClientUpdate) ([]byte, error) {
+	key, err := keyForLightClientUpdate(update.Version())
+	if err != nil {
+		return nil, err
+	}
+	enc, err := update.MarshalSSZ()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal light client update")
+	}
+	fullEnc := make([]byte, len(key)+len(enc))
+	copy(fullEnc, key)
+	copy(fullEnc[len(key):], enc)
+	return snappy.Encode(nil, fullEnc), nil
+}
+
+func decodeLightClientUpdate(enc []byte) (interfaces.LightClientUpdate, error) {
+	var err error
+	enc, err = snappy.Decode(nil, enc)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not snappy decode light client update")
+	}
+	var m proto.Message
+	switch {
+	case hasAltairKey(enc):
+		update := &ethpb.LightClientUpdateAltair{}
+		if err := update.UnmarshalSSZ(enc[len(altairKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Altair light client update")
+		}
+		m = update
+	case hasCapellaKey(enc):
+		update := &ethpb.LightClientUpdateCapella{}
+		if err := update.UnmarshalSSZ(enc[len(capellaKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Capella light client update")
+		}
+		m = update
+	case hasDenebKey(enc):
+		update := &ethpb.LightClientUpdateDeneb{}
+		if err := update.UnmarshalSSZ(enc[len(denebKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Deneb light client update")
+		}
+		m = update
+	case hasElectraKey(enc):
+		update := &ethpb.LightClientUpdateElectra{}
+		if err := update.UnmarshalSSZ(enc[len(electraKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Electra light client update")
+		}
+		m = update
+	default:
+		return nil, errors.New("decoding of saved light client update is unsupported")
+	}
+	return light_client.NewWrappedUpdate(m)
+}
+
+func keyForLightClientUpdate(v int) ([]byte, error) {
+	switch v {
+	case version.Electra:
+		return electraKey, nil
+	case version.Deneb:
+		return denebKey, nil
+	case version.Capella:
+		return capellaKey, nil
+	case version.Altair:
+		return altairKey, nil
+	default:
+		return nil, fmt.Errorf("unsupported light client update version %s", version.String(v))
+	}
 }
--- a/beacon-chain/db/kv/lightclient_test.go
+++ b/beacon-chain/db/kv/lightclient_test.go
--- a/beacon-chain/db/kv/schema.go
+++ b/beacon-chain/db/kv/schema.go
@@ -18,7 +18,8 @@ var (
 	registrationBucket    = []byte("registration")

 	// Light Client Updates Bucket
-	lightClientUpdatesBucket = []byte("light-client-updates")
+	lightClientUpdatesBucket   = []byte("light-client-updates")
+	lightClientBootstrapBucket = []byte("light-client-bootstrap")

 	// Deprecated: This bucket was migrated in PR 6461. Do not use, except for migrations.
 	slotsHasObjectBucket = []byte("slots-has-objects")
--- a/beacon-chain/db/kv/state_test.go
+++ b/beacon-chain/db/kv/state_test.go
@@ -2,8 +2,10 @@ package kv

 import (
 	"context"
+	"crypto/rand"
 	"encoding/binary"
-	"math/rand"
+	mathRand "math/rand"
+
 	"strconv"
 	"testing"
 	"time"
@@ -878,16 +880,16 @@ func validators(limit int) []*ethpb.Validator {
 	var vals []*ethpb.Validator
 	for i := 0; i < limit; i++ {
 		pubKey := make([]byte, params.BeaconConfig().BLSPubkeyLength)
-		binary.LittleEndian.PutUint64(pubKey, rand.Uint64())
+		binary.LittleEndian.PutUint64(pubKey, mathRand.Uint64())
 		val := &ethpb.Validator{
 			PublicKey:                  pubKey,
-			WithdrawalCredentials:      bytesutil.ToBytes(rand.Uint64(), 32),
-			EffectiveBalance:           rand.Uint64(),
+			WithdrawalCredentials:      bytesutil.ToBytes(mathRand.Uint64(), 32),
+			EffectiveBalance:           mathRand.Uint64(),
 			Slashed:                    i%2 != 0,
-			ActivationEligibilityEpoch: primitives.Epoch(rand.Uint64()),
-			ActivationEpoch:            primitives.Epoch(rand.Uint64()),
-			ExitEpoch:                  primitives.Epoch(rand.Uint64()),
-			WithdrawableEpoch:          primitives.Epoch(rand.Uint64()),
+			ActivationEligibilityEpoch: primitives.Epoch(mathRand.Uint64()),
+			ActivationEpoch:            primitives.Epoch(mathRand.Uint64()),
+			ExitEpoch:                  primitives.Epoch(mathRand.Uint64()),
+			WithdrawableEpoch:          primitives.Epoch(mathRand.Uint64()),
 		}
 		vals = append(vals, val)
 	}
@@ -913,8 +915,8 @@ func checkStateSaveTime(b *testing.B, saveCount int) {
 		allValidators := append(initialSetOfValidators, validatosToAddInTest...)

 		// shuffle validators.
-		rand.Seed(time.Now().UnixNano())
-		rand.Shuffle(len(allValidators), func(i, j int) { allValidators[i], allValidators[j] = allValidators[j], allValidators[i] })
+		mathRand.New(mathRand.NewSource(time.Now().UnixNano()))
+		mathRand.Shuffle(len(allValidators), func(i, j int) { allValidators[i], allValidators[j] = allValidators[j], allValidators[i] })

 		require.NoError(b, st.SetValidators(allValidators))
 		require.NoError(b, db.SaveState(context.Background(), st, bytesutil.ToBytes32(key)))
@@ -959,8 +961,8 @@ func checkStateReadTime(b *testing.B, saveCount int) {
 		allValidators := append(initialSetOfValidators, validatosToAddInTest...)

 		// shuffle validators.
-		rand.Seed(time.Now().UnixNano())
-		rand.Shuffle(len(allValidators), func(i, j int) { allValidators[i], allValidators[j] = allValidators[j], allValidators[i] })
+		mathRand.New(mathRand.NewSource(time.Now().UnixNano()))
+		mathRand.Shuffle(len(allValidators), func(i, j int) { allValidators[i], allValidators[j] = allValidators[j], allValidators[i] })

 		require.NoError(b, st.SetValidators(allValidators))
 		require.NoError(b, db.SaveState(context.Background(), st, bytesutil.ToBytes32(key)))
--- a/beacon-chain/deterministic-genesis/BUILD.bazel
+++ b/beacon-chain/deterministic-genesis/BUILD.bazel
@@ -1,24 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = [
-        "log.go",
-        "service.go",
-    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/deterministic-genesis",
-    visibility = ["//beacon-chain:__subpackages__"],
-    deps = [
-        "//beacon-chain/cache:go_default_library",
-        "//beacon-chain/db:go_default_library",
-        "//beacon-chain/execution:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//beacon-chain/state/state-native:go_default_library",
-        "//consensus-types/primitives:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime:go_default_library",
-        "//runtime/interop:go_default_library",
-        "//time/slots:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
-    ],
-)
--- a/beacon-chain/deterministic-genesis/log.go
+++ b/beacon-chain/deterministic-genesis/log.go
@@ -1,7 +0,0 @@
-package interopcoldstart
-
-import (
-	"github.com/sirupsen/logrus"
-)
-
-var log = logrus.WithField("prefix", "deterministic-genesis")
--- a/beacon-chain/deterministic-genesis/service.go
+++ b/beacon-chain/deterministic-genesis/service.go
@@ -1,206 +0,0 @@
-// Package interopcoldstart allows for spinning up a deterministic-genesis
-// local chain without the need for eth1 deposits useful for
-// local client development and interoperability testing.
-package interopcoldstart
-
-import (
-	"context"
-	"math/big"
-	"os"
-	"time"
-
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime"
-	"github.com/prysmaticlabs/prysm/v5/runtime/interop"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
-)
-
-var _ runtime.Service = (*Service)(nil)
-var _ cache.FinalizedFetcher = (*Service)(nil)
-var _ execution.ChainStartFetcher = (*Service)(nil)
-
-// Service spins up an client interoperability service that handles responsibilities such
-// as kickstarting a genesis state for the beacon node from cli flags or a genesis.ssz file.
-type Service struct {
-	cfg                *Config
-	ctx                context.Context
-	cancel             context.CancelFunc
-	chainStartDeposits []*ethpb.Deposit
-}
-
-// All of these methods are stubs as they are not used by a node running with deterministic-genesis.
-
-func (s *Service) AllDepositContainers(ctx context.Context) []*ethpb.DepositContainer {
-	log.Errorf("AllDepositContainers should not be called")
-	return nil
-}
-
-func (s *Service) InsertPendingDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) {
-	log.Errorf("InsertPendingDeposit should not be called")
-}
-
-func (s *Service) PendingDeposits(ctx context.Context, untilBlk *big.Int) []*ethpb.Deposit {
-	log.Errorf("PendingDeposits should not be called")
-	return nil
-}
-
-func (s *Service) PendingContainers(ctx context.Context, untilBlk *big.Int) []*ethpb.DepositContainer {
-	log.Errorf("PendingContainers should not be called")
-	return nil
-}
-
-func (s *Service) PrunePendingDeposits(ctx context.Context, merkleTreeIndex int64) {
-	log.Errorf("PrunePendingDeposits should not be called")
-}
-
-func (s *Service) PruneProofs(ctx context.Context, untilDepositIndex int64) error {
-	log.Errorf("PruneProofs should not be called")
-	return nil
-}
-
-// Config options for the interop service.
-type Config struct {
-	GenesisTime   uint64
-	NumValidators uint64
-	BeaconDB      db.HeadAccessDatabase
-	DepositCache  cache.DepositCache
-	GenesisPath   string
-}
-
-// NewService is an interoperability testing service to inject a deterministically generated genesis state
-// into the beacon chain database and running services at start up. This service should not be used in production
-// as it does not have any value other than ease of use for testing purposes.
-func NewService(ctx context.Context, cfg *Config) *Service {
-	ctx, cancel := context.WithCancel(ctx)
-
-	return &Service{
-		cfg:    cfg,
-		ctx:    ctx,
-		cancel: cancel,
-	}
-}
-
-// Start initializes the genesis state from configured flags.
-func (s *Service) Start() {
-	log.Warn("Saving generated genesis state in database for interop testing")
-
-	if s.cfg.GenesisPath != "" {
-		data, err := os.ReadFile(s.cfg.GenesisPath)
-		if err != nil {
-			log.WithError(err).Fatal("Could not read pre-loaded state")
-		}
-		genesisState := &ethpb.BeaconState{}
-		if err := genesisState.UnmarshalSSZ(data); err != nil {
-			log.WithError(err).Fatal("Could not unmarshal pre-loaded state")
-		}
-		genesisTrie, err := state_native.InitializeFromProtoPhase0(genesisState)
-		if err != nil {
-			log.WithError(err).Fatal("Could not get state trie")
-		}
-		if err := s.saveGenesisState(s.ctx, genesisTrie); err != nil {
-			log.WithError(err).Fatal("Could not save interop genesis state")
-		}
-		return
-	}
-
-	// Save genesis state in db
-	genesisState, _, err := interop.GenerateGenesisState(s.ctx, s.cfg.GenesisTime, s.cfg.NumValidators)
-	if err != nil {
-		log.WithError(err).Fatal("Could not generate interop genesis state")
-	}
-	genesisTrie, err := state_native.InitializeFromProtoPhase0(genesisState)
-	if err != nil {
-		log.WithError(err).Fatal("Could not get state trie")
-	}
-	if s.cfg.GenesisTime == 0 {
-		// Generated genesis time; fetch it
-		s.cfg.GenesisTime = genesisTrie.GenesisTime()
-	}
-	gRoot, err := genesisTrie.HashTreeRoot(s.ctx)
-	if err != nil {
-		log.WithError(err).Fatal("Could not hash tree root genesis state")
-	}
-	go slots.CountdownToGenesis(s.ctx, time.Unix(int64(s.cfg.GenesisTime), 0), s.cfg.NumValidators, gRoot)
-
-	if err := s.saveGenesisState(s.ctx, genesisTrie); err != nil {
-		log.WithError(err).Fatal("Could not save interop genesis state")
-	}
-}
-
-// Stop does nothing.
-func (_ *Service) Stop() error {
-	return nil
-}
-
-// Status always returns nil.
-func (_ *Service) Status() error {
-	return nil
-}
-
-// AllDeposits mocks out the deposit cache functionality for interop.
-func (_ *Service) AllDeposits(_ context.Context, _ *big.Int) []*ethpb.Deposit {
-	return []*ethpb.Deposit{}
-}
-
-// ChainStartEth1Data mocks out the powchain functionality for interop.
-func (_ *Service) ChainStartEth1Data() *ethpb.Eth1Data {
-	return &ethpb.Eth1Data{}
-}
-
-// PreGenesisState returns an empty beacon state.
-func (_ *Service) PreGenesisState() state.BeaconState {
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
-	if err != nil {
-		panic("could not initialize state")
-	}
-	return s
-}
-
-// ClearPreGenesisData --
-func (_ *Service) ClearPreGenesisData() {
-	// no-op
-}
-
-// DepositByPubkey mocks out the deposit cache functionality for interop.
-func (_ *Service) DepositByPubkey(_ context.Context, _ []byte) (*ethpb.Deposit, *big.Int) {
-	return &ethpb.Deposit{}, nil
-}
-
-// DepositsNumberAndRootAtHeight mocks out the deposit cache functionality for interop.
-func (_ *Service) DepositsNumberAndRootAtHeight(_ context.Context, _ *big.Int) (uint64, [32]byte) {
-	return 0, [32]byte{}
-}
-
-// FinalizedDeposits mocks out the deposit cache functionality for interop.
-func (_ *Service) FinalizedDeposits(ctx context.Context) (cache.FinalizedDeposits, error) {
-	return nil, nil
-}
-
-// NonFinalizedDeposits mocks out the deposit cache functionality for interop.
-func (_ *Service) NonFinalizedDeposits(_ context.Context, _ int64, _ *big.Int) []*ethpb.Deposit {
-	return []*ethpb.Deposit{}
-}
-
-func (s *Service) saveGenesisState(ctx context.Context, genesisState state.BeaconState) error {
-	if err := s.cfg.BeaconDB.SaveGenesisData(ctx, genesisState); err != nil {
-		return err
-	}
-
-	s.chainStartDeposits = make([]*ethpb.Deposit, genesisState.NumValidators())
-
-	for i := primitives.ValidatorIndex(0); uint64(i) < uint64(genesisState.NumValidators()); i++ {
-		pk := genesisState.PubkeyAtIndex(i)
-		s.chainStartDeposits[i] = &ethpb.Deposit{
-			Data: &ethpb.Deposit_Data{
-				PublicKey: pk[:],
-			},
-		}
-	}
-	return nil
-}
--- a/beacon-chain/execution/engine_client.go
+++ b/beacon-chain/execution/engine_client.go
@@ -136,30 +136,18 @@ func (s *Service) NewPayload(ctx context.Context, payload interfaces.ExecutionDa
 	defer cancel()
 	result := &pb.PayloadStatus{}

-	switch payload.Proto().(type) {
+	switch payloadPb := payload.Proto().(type) {
 	case *pb.ExecutionPayload:
-		payloadPb, ok := payload.Proto().(*pb.ExecutionPayload)
-		if !ok {
-			return nil, errors.New("execution data must be a Bellatrix or Capella execution payload")
-		}
 		err := s.rpcClient.CallContext(ctx, result, NewPayloadMethod, payloadPb)
 		if err != nil {
 			return nil, handleRPCError(err)
 		}
 	case *pb.ExecutionPayloadCapella:
-		payloadPb, ok := payload.Proto().(*pb.ExecutionPayloadCapella)
-		if !ok {
-			return nil, errors.New("execution data must be a Capella execution payload")
-		}
 		err := s.rpcClient.CallContext(ctx, result, NewPayloadMethodV2, payloadPb)
 		if err != nil {
 			return nil, handleRPCError(err)
 		}
 	case *pb.ExecutionPayloadDeneb:
-		payloadPb, ok := payload.Proto().(*pb.ExecutionPayloadDeneb)
-		if !ok {
-			return nil, errors.New("execution data must be a Deneb execution payload")
-		}
 		if executionRequests == nil {
 			err := s.rpcClient.CallContext(ctx, result, NewPayloadMethodV3, payloadPb, versionedHashes, parentBlockRoot)
 			if err != nil {
@@ -170,7 +158,7 @@ func (s *Service) NewPayload(ctx context.Context, payload interfaces.ExecutionDa
 			if err != nil {
 				return nil, errors.Wrap(err, "failed to encode execution requests")
 			}
-			err = s.rpcClient.CallContext(ctx, result, NewPayloadMethodV4, payloadPb, versionedHashes, parentBlockRoot, flattenedRequests)
+			err = s.rpcClient.CallContext(ctx, result, NewPayloadMethodV4, payloadPb, versionedHashes, parentBlockRoot, flattenedRequests, params.BeaconConfig().TargetBlobsPerBlockByVersion(version.Electra))
 			if err != nil {
 				return nil, handleRPCError(err)
 			}
@@ -801,7 +789,7 @@ func tDStringToUint256(td string) (*uint256.Int, error) {
 	return i, nil
 }

-func buildEmptyExecutionPayload(v int) (proto.Message, error) {
+func EmptyExecutionPayload(v int) (proto.Message, error) {
 	switch v {
 	case version.Bellatrix:
 		return &pb.ExecutionPayload{
@@ -849,6 +837,53 @@ func buildEmptyExecutionPayload(v int) (proto.Message, error) {
 	}
 }

+func EmptyExecutionPayloadHeader(v int) (proto.Message, error) {
+	switch v {
+	case version.Bellatrix:
+		return &pb.ExecutionPayloadHeader{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			ExtraData:     make([]byte, 0),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+		}, nil
+	case version.Capella:
+		return &pb.ExecutionPayloadHeaderCapella{
+			ParentHash:       make([]byte, fieldparams.RootLength),
+			FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:        make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+			LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:       make([]byte, fieldparams.RootLength),
+			ExtraData:        make([]byte, 0),
+			BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+			BlockHash:        make([]byte, fieldparams.RootLength),
+			TransactionsRoot: make([]byte, fieldparams.RootLength),
+			WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+		}, nil
+	case version.Deneb, version.Electra:
+		return &pb.ExecutionPayloadHeaderDeneb{
+			ParentHash:       make([]byte, fieldparams.RootLength),
+			FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:        make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+			LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:       make([]byte, fieldparams.RootLength),
+			ExtraData:        make([]byte, 0),
+			BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+			BlockHash:        make([]byte, fieldparams.RootLength),
+			TransactionsRoot: make([]byte, fieldparams.RootLength),
+			WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+		}, nil
+	default:
+		return nil, errors.Wrapf(ErrUnsupportedVersion, "version=%s", version.String(v))
+	}
+}
+
 func toBlockNumArg(number *big.Int) string {
 	if number == nil {
 		return "latest"
--- a/beacon-chain/execution/payload_body.go
+++ b/beacon-chain/execution/payload_body.go
@@ -205,7 +205,7 @@ func (r *blindedBlockReconstructor) requestBodiesByHash(ctx context.Context, cli
 func (r *blindedBlockReconstructor) payloadForHeader(header interfaces.ExecutionData, v int) (proto.Message, error) {
 	bodyKey := bytesutil.ToBytes32(header.BlockHash())
 	if bodyKey == params.BeaconConfig().ZeroHash {
-		payload, err := buildEmptyExecutionPayload(v)
+		payload, err := EmptyExecutionPayload(v)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to reconstruct payload for body hash %#x", bodyKey)
 		}
--- a/beacon-chain/node/BUILD.bazel
+++ b/beacon-chain/node/BUILD.bazel
@@ -26,7 +26,6 @@ go_library(
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/kv:go_default_library",
        "//beacon-chain/db/slasherkv:go_default_library",
-        "//beacon-chain/deterministic-genesis:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/forkchoice:go_default_library",
        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
@@ -92,12 +91,9 @@ go_test(
        "//cmd: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",
        "//consensus-types/primitives:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime:go_default_library",
-        "//runtime/interop:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
--- a/beacon-chain/node/config.go
+++ b/beacon-chain/node/config.go
@@ -144,23 +144,6 @@ func configureNetwork(cliCtx *cli.Context) {
 	}
 }

-func configureInteropConfig(cliCtx *cli.Context) error {
-	// an explicit chain config was specified, don't mess with it
-	if cliCtx.IsSet(cmd.ChainConfigFileFlag.Name) {
-		return nil
-	}
-	genTimeIsSet := cliCtx.IsSet(flags.InteropGenesisTimeFlag.Name)
-	numValsIsSet := cliCtx.IsSet(flags.InteropNumValidatorsFlag.Name)
-	votesIsSet := cliCtx.IsSet(flags.InteropMockEth1DataVotesFlag.Name)
-
-	if genTimeIsSet || numValsIsSet || votesIsSet {
-		if err := params.SetActive(params.InteropConfig().Copy()); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 func configureExecutionSetting(cliCtx *cli.Context) error {
 	if cliCtx.IsSet(flags.TerminalTotalDifficultyOverride.Name) {
 		c := params.BeaconConfig()
--- a/beacon-chain/node/config_test.go
+++ b/beacon-chain/node/config_test.go
@@ -169,66 +169,6 @@ func TestConfigureNetwork_ConfigFile(t *testing.T) {
 	require.NoError(t, os.Remove("flags_test.yaml"))
 }

-func TestConfigureInterop(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-
-	tests := []struct {
-		name       string
-		flagSetter func() *cli.Context
-		configName string
-	}{
-		{
-			"nothing set",
-			func() *cli.Context {
-				app := cli.App{}
-				set := flag.NewFlagSet("test", 0)
-				return cli.NewContext(&app, set, nil)
-			},
-			"mainnet",
-		},
-		{
-			"mock votes set",
-			func() *cli.Context {
-				app := cli.App{}
-				set := flag.NewFlagSet("test", 0)
-				set.Bool(flags.InteropMockEth1DataVotesFlag.Name, false, "")
-				assert.NoError(t, set.Set(flags.InteropMockEth1DataVotesFlag.Name, "true"))
-				return cli.NewContext(&app, set, nil)
-			},
-			"interop",
-		},
-		{
-			"validators set",
-			func() *cli.Context {
-				app := cli.App{}
-				set := flag.NewFlagSet("test", 0)
-				set.Uint64(flags.InteropNumValidatorsFlag.Name, 0, "")
-				assert.NoError(t, set.Set(flags.InteropNumValidatorsFlag.Name, "20"))
-				return cli.NewContext(&app, set, nil)
-			},
-			"interop",
-		},
-		{
-			"genesis time set",
-			func() *cli.Context {
-				app := cli.App{}
-				set := flag.NewFlagSet("test", 0)
-				set.Uint64(flags.InteropGenesisTimeFlag.Name, 0, "")
-				assert.NoError(t, set.Set(flags.InteropGenesisTimeFlag.Name, "200"))
-				return cli.NewContext(&app, set, nil)
-			},
-			"interop",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			require.NoError(t, configureInteropConfig(tt.flagSetter()))
-			assert.DeepEqual(t, tt.configName, params.BeaconConfig().ConfigName)
-		})
-	}
-}
-
 func TestAliasFlag(t *testing.T) {
 	// Create a new app with the flag
 	app := &cli.App{
--- a/beacon-chain/node/node.go
+++ b/beacon-chain/node/node.go
@@ -30,7 +30,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/kv"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/slasherkv"
-	interopcoldstart "github.com/prysmaticlabs/prysm/v5/beacon-chain/deterministic-genesis"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
@@ -94,6 +93,7 @@ type BeaconNode struct {
 	stop                    chan struct{} // Channel to wait for termination notifications.
 	db                      db.Database
 	slasherDB               db.SlasherDatabase
+	attestationCache        *cache.AttestationCache
 	attestationPool         attestations.Pool
 	exitPool                voluntaryexits.PoolManager
 	slashingsPool           slashings.PoolManager
@@ -145,6 +145,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		stateFeed:               new(event.Feed),
 		blockFeed:               new(event.Feed),
 		opFeed:                  new(event.Feed),
+		attestationCache:        cache.NewAttestationCache(),
 		attestationPool:         attestations.NewPool(),
 		exitPool:                voluntaryexits.NewPool(),
 		slashingsPool:           slashings.NewPool(),
@@ -261,10 +262,6 @@ func configureBeacon(cliCtx *cli.Context) error {

 	configureNetwork(cliCtx)

-	if err := configureInteropConfig(cliCtx); err != nil {
-		return errors.Wrap(err, "could not configure interop config")
-	}
-
 	if err := configureExecutionSetting(cliCtx); err != nil {
 		return errors.Wrap(err, "could not configure execution setting")
 	}
@@ -324,11 +321,6 @@ func registerServices(cliCtx *cli.Context, beacon *BeaconNode, synchronizer *sta
 		return errors.Wrap(err, "could not register attestation pool service")
 	}

-	log.Debugln("Registering Deterministic Genesis Service")
-	if err := beacon.registerDeterministicGenesisService(); err != nil {
-		return errors.Wrap(err, "could not register deterministic genesis service")
-	}
-
 	log.Debugln("Registering Blockchain Service")
 	if err := beacon.registerBlockchainService(beacon.forkChoicer, synchronizer, beacon.initialSyncComplete); err != nil {
 		return errors.Wrap(err, "could not register blockchain service")
@@ -567,6 +559,7 @@ func (b *BeaconNode) startDB(cliCtx *cli.Context, depositAddress string) error {
 	}

 	if b.CheckpointInitializer != nil {
+		log.Info("Checkpoint sync - Downloading origin state and block")
 		if err := b.CheckpointInitializer.Initialize(b.ctx, d); err != nil {
 			return err
 		}
@@ -713,6 +706,7 @@ func (b *BeaconNode) fetchBuilderService() *builder.Service {

 func (b *BeaconNode) registerAttestationPool() error {
 	s, err := attestations.NewService(b.ctx, &attestations.Config{
+		Cache:               b.attestationCache,
 		Pool:                b.attestationPool,
 		InitialSyncComplete: b.initialSyncComplete,
 	})
@@ -741,6 +735,7 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithDepositCache(b.depositCache),
 		blockchain.WithChainStartFetcher(web3Service),
 		blockchain.WithExecutionEngineCaller(web3Service),
+		blockchain.WithAttestationCache(b.attestationCache),
 		blockchain.WithAttestationPool(b.attestationPool),
 		blockchain.WithExitPool(b.exitPool),
 		blockchain.WithSlashingPool(b.slashingsPool),
@@ -825,6 +820,7 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithBlockNotifier(b),
 		regularsync.WithAttestationNotifier(b),
 		regularsync.WithOperationNotifier(b),
+		regularsync.WithAttestationCache(b.attestationCache),
 		regularsync.WithAttestationPool(b.attestationPool),
 		regularsync.WithExitPool(b.exitPool),
 		regularsync.WithSlashingPool(b.slashingsPool),
@@ -921,20 +917,8 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		}
 	}

-	genesisValidators := b.cliCtx.Uint64(flags.InteropNumValidatorsFlag.Name)
-	var depositFetcher cache.DepositFetcher
-	var chainStartFetcher execution.ChainStartFetcher
-	if genesisValidators > 0 {
-		var interopService *interopcoldstart.Service
-		if err := b.services.FetchService(&interopService); err != nil {
-			return err
-		}
-		depositFetcher = interopService
-		chainStartFetcher = interopService
-	} else {
-		depositFetcher = b.depositCache
-		chainStartFetcher = web3Service
-	}
+	depositFetcher := b.depositCache
+	chainStartFetcher := web3Service

 	host := b.cliCtx.String(flags.RPCHost.Name)
 	port := b.cliCtx.String(flags.RPCPort.Name)
@@ -973,6 +957,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		GenesisTimeFetcher:        chainService,
 		GenesisFetcher:            chainService,
 		OptimisticModeFetcher:     chainService,
+		AttestationCache:          b.attestationCache,
 		AttestationsPool:          b.attestationPool,
 		ExitPool:                  b.exitPool,
 		SlashingsPool:             b.slashingsPool,
@@ -1056,32 +1041,6 @@ func (b *BeaconNode) registerHTTPService(router *http.ServeMux) error {
 	return b.services.RegisterService(g)
 }

-func (b *BeaconNode) registerDeterministicGenesisService() error {
-	genesisTime := b.cliCtx.Uint64(flags.InteropGenesisTimeFlag.Name)
-	genesisValidators := b.cliCtx.Uint64(flags.InteropNumValidatorsFlag.Name)
-
-	if genesisValidators > 0 {
-		svc := interopcoldstart.NewService(b.ctx, &interopcoldstart.Config{
-			GenesisTime:   genesisTime,
-			NumValidators: genesisValidators,
-			BeaconDB:      b.db,
-			DepositCache:  b.depositCache,
-		})
-		svc.Start()
-
-		// Register genesis state as start-up state when interop mode.
-		// The start-up state gets reused across services.
-		st, err := b.db.GenesisState(b.ctx)
-		if err != nil {
-			return err
-		}
-		b.finalizedStateAtStartUp = st
-
-		return b.services.RegisterService(svc)
-	}
-	return nil
-}
-
 func (b *BeaconNode) registerValidatorMonitorService(initialSyncComplete chan struct{}) error {
 	cliSlice := b.cliCtx.IntSlice(cmd.ValidatorMonitorIndicesFlag.Name)
 	if cliSlice == nil {
--- a/beacon-chain/node/node_test.go
+++ b/beacon-chain/node/node_test.go
@@ -6,9 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
-	"os"
 	"path/filepath"
-	"strconv"
 	"testing"
 	"time"

@@ -21,13 +19,8 @@ import (
 	mockExecution "github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/testing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/monitor"
 	"github.com/prysmaticlabs/prysm/v5/cmd"
-	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime"
-	"github.com/prysmaticlabs/prysm/v5/runtime/interop"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
@@ -117,55 +110,6 @@ func TestNodeStart_SyncChecker(t *testing.T) {
 	require.LogsContain(t, hook, "Starting beacon node")
 }

-func TestNodeStart_Ok_registerDeterministicGenesisService(t *testing.T) {
-	numValidators := uint64(1)
-	hook := logTest.NewGlobal()
-	app := cli.App{}
-	tmp := fmt.Sprintf("%s/datadirtest2", t.TempDir())
-	set := flag.NewFlagSet("test", 0)
-	set.String("datadir", tmp, "node data directory")
-	set.Uint64(flags.InteropNumValidatorsFlag.Name, numValidators, "")
-	set.String("suggested-fee-recipient", "0x6e35733c5af9B61374A128e6F85f553aF09ff89A", "fee recipient")
-	require.NoError(t, set.Set("suggested-fee-recipient", "0x6e35733c5af9B61374A128e6F85f553aF09ff89A"))
-	genesisState, _, err := interop.GenerateGenesisState(context.Background(), 0, numValidators)
-	require.NoError(t, err, "Could not generate genesis beacon state")
-	for i := uint64(1); i < 2; i++ {
-		var someRoot [32]byte
-		var someKey [fieldparams.BLSPubkeyLength]byte
-		copy(someRoot[:], strconv.Itoa(int(i)))
-		copy(someKey[:], strconv.Itoa(int(i)))
-		genesisState.Validators = append(genesisState.Validators, &ethpb.Validator{
-			PublicKey:                  someKey[:],
-			WithdrawalCredentials:      someRoot[:],
-			EffectiveBalance:           params.BeaconConfig().MaxEffectiveBalance,
-			Slashed:                    false,
-			ActivationEligibilityEpoch: 1,
-			ActivationEpoch:            1,
-			ExitEpoch:                  1,
-			WithdrawableEpoch:          1,
-		})
-		genesisState.Balances = append(genesisState.Balances, params.BeaconConfig().MaxEffectiveBalance)
-	}
-	genesisBytes, err := genesisState.MarshalSSZ()
-	require.NoError(t, err)
-	require.NoError(t, os.WriteFile("genesis_ssz.json", genesisBytes, 0666))
-	set.String("genesis-state", "genesis_ssz.json", "")
-	ctx, cancel := newCliContextWithCancel(&app, set)
-	node, err := New(ctx, cancel, WithBlockchainFlagOptions([]blockchain.Option{}),
-		WithBuilderFlagOptions([]builder.Option{}),
-		WithExecutionChainOptions([]execution.Option{}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
-	require.NoError(t, err)
-	node.services = &runtime.ServiceRegistry{}
-	go func() {
-		node.Start()
-	}()
-	time.Sleep(3 * time.Second)
-	node.Close()
-	require.LogsContain(t, hook, "Starting beacon node")
-	require.NoError(t, os.Remove("genesis_ssz.json"))
-}
-
 // TestClearDB tests clearing the database
 func TestClearDB(t *testing.T) {
 	hook := logTest.NewGlobal()
--- a/beacon-chain/operations/attestations/BUILD.bazel
+++ b/beacon-chain/operations/attestations/BUILD.bazel
@@ -16,6 +16,7 @@ go_library(
        "//testing/spectest:__subpackages__",
    ],
    deps = [
+        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/operations/attestations/kv:go_default_library",
        "//cache/lru:go_default_library",
        "//config/features:go_default_library",
--- a/beacon-chain/operations/attestations/attmap/BUILD.bazel
+++ b/beacon-chain/operations/attestations/attmap/BUILD.bazel
@@ -0,0 +1,13 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["map.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations/attmap",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
+)
--- a/beacon-chain/operations/attestations/attmap/map.go
+++ b/beacon-chain/operations/attestations/attmap/map.go
@@ -0,0 +1,89 @@
+package attmap
+
+import (
+	"sync"
+
+	"github.com/pkg/errors"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+)
+
+// Attestations --
+type Attestations struct {
+	atts map[attestation.Id]ethpb.Att
+	sync.RWMutex
+}
+
+// New creates a new instance of the map.
+func New() *Attestations {
+	return &Attestations{atts: make(map[attestation.Id]ethpb.Att)}
+}
+
+// Save stores an attestation in the map.
+func (a *Attestations) Save(att ethpb.Att) error {
+	if att == nil || att.IsNil() {
+		return nil
+	}
+
+	id, err := attestation.NewId(att, attestation.Full)
+	if err != nil {
+		return errors.Wrap(err, "could not create attestation ID")
+	}
+
+	a.Lock()
+	defer a.Unlock()
+	a.atts[id] = att
+
+	return nil
+}
+
+// SaveMany stores multiple attestation in the map.
+func (a *Attestations) SaveMany(atts []ethpb.Att) error {
+	for _, att := range atts {
+		if err := a.Save(att); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// GetAll retrieves all attestations that are in the map.
+func (a *Attestations) GetAll() []ethpb.Att {
+	a.RLock()
+	defer a.RUnlock()
+
+	atts := make([]ethpb.Att, len(a.atts))
+	i := 0
+	for _, att := range a.atts {
+		atts[i] = att.Clone()
+		i++
+	}
+
+	return atts
+}
+
+// Delete removes an attestation from the map.
+func (a *Attestations) Delete(att ethpb.Att) error {
+	if att == nil || att.IsNil() {
+		return nil
+	}
+
+	id, err := attestation.NewId(att, attestation.Full)
+	if err != nil {
+		return errors.Wrap(err, "could not create attestation ID")
+	}
+
+	a.Lock()
+	defer a.Unlock()
+	delete(a.atts, id)
+
+	return nil
+}
+
+// Count returns the number of attestations in the map.
+func (a *Attestations) Count() int {
+	a.RLock()
+	defer a.RUnlock()
+	return len(a.atts)
+}
--- a/beacon-chain/operations/attestations/kv/BUILD.bazel
+++ b/beacon-chain/operations/attestations/kv/BUILD.bazel
@@ -5,7 +5,6 @@ go_library(
    srcs = [
        "aggregated.go",
        "block.go",
-        "forkchoice.go",
        "kv.go",
        "seen_bits.go",
        "unaggregated.go",
@@ -14,6 +13,7 @@ go_library(
    visibility = ["//beacon-chain:__subpackages__"],
    deps = [
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/operations/attestations/attmap:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
--- a/beacon-chain/operations/attestations/kv/aggregated.go
+++ b/beacon-chain/operations/attestations/kv/aggregated.go
@@ -88,7 +88,7 @@ func (c *AttCaches) aggregateParallel(atts map[attestation.Id][]ethpb.Att, leftO
 					log.Error("nil aggregated attestation")
 					continue
 				}
-				if helpers.IsAggregated(aggregated) {
+				if aggregated.IsAggregated() {
 					if err := c.SaveAggregatedAttestations([]ethpb.Att{aggregated}); err != nil {
 						log.WithError(err).Error("could not save aggregated attestation")
 						continue
@@ -122,7 +122,7 @@ func (c *AttCaches) SaveAggregatedAttestation(att ethpb.Att) error {
 	if err := helpers.ValidateNilAttestation(att); err != nil {
 		return err
 	}
-	if !helpers.IsAggregated(att) {
+	if !att.IsAggregated() {
 		return errors.New("attestation is not aggregated")
 	}
 	has, err := c.HasAggregatedAttestation(att)
@@ -255,7 +255,7 @@ func (c *AttCaches) DeleteAggregatedAttestation(att ethpb.Att) error {
 	if err := helpers.ValidateNilAttestation(att); err != nil {
 		return err
 	}
-	if !helpers.IsAggregated(att) {
+	if !att.IsAggregated() {
 		return errors.New("attestation is not aggregated")
 	}

--- a/beacon-chain/operations/attestations/kv/forkchoice.go
+++ b/beacon-chain/operations/attestations/kv/forkchoice.go
@@ -1,74 +0,0 @@
-package kv
-
-import (
-	"github.com/pkg/errors"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
-)
-
-// SaveForkchoiceAttestation saves an forkchoice attestation in cache.
-func (c *AttCaches) SaveForkchoiceAttestation(att ethpb.Att) error {
-	if att == nil || att.IsNil() {
-		return nil
-	}
-
-	id, err := attestation.NewId(att, attestation.Full)
-	if err != nil {
-		return errors.Wrap(err, "could not create attestation ID")
-	}
-
-	c.forkchoiceAttLock.Lock()
-	defer c.forkchoiceAttLock.Unlock()
-	c.forkchoiceAtt[id] = att
-
-	return nil
-}
-
-// SaveForkchoiceAttestations saves a list of forkchoice attestations in cache.
-func (c *AttCaches) SaveForkchoiceAttestations(atts []ethpb.Att) error {
-	for _, att := range atts {
-		if err := c.SaveForkchoiceAttestation(att); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-// ForkchoiceAttestations returns the forkchoice attestations in cache.
-func (c *AttCaches) ForkchoiceAttestations() []ethpb.Att {
-	c.forkchoiceAttLock.RLock()
-	defer c.forkchoiceAttLock.RUnlock()
-
-	atts := make([]ethpb.Att, 0, len(c.forkchoiceAtt))
-	for _, att := range c.forkchoiceAtt {
-		atts = append(atts, att.Clone())
-	}
-
-	return atts
-}
-
-// DeleteForkchoiceAttestation deletes a forkchoice attestation in cache.
-func (c *AttCaches) DeleteForkchoiceAttestation(att ethpb.Att) error {
-	if att == nil || att.IsNil() {
-		return nil
-	}
-
-	id, err := attestation.NewId(att, attestation.Full)
-	if err != nil {
-		return errors.Wrap(err, "could not create attestation ID")
-	}
-
-	c.forkchoiceAttLock.Lock()
-	defer c.forkchoiceAttLock.Unlock()
-	delete(c.forkchoiceAtt, id)
-
-	return nil
-}
-
-// ForkchoiceAttestationCount returns the number of fork choice attestations key in the pool.
-func (c *AttCaches) ForkchoiceAttestationCount() int {
-	c.forkchoiceAttLock.RLock()
-	defer c.forkchoiceAttLock.RUnlock()
-	return len(c.forkchoiceAtt)
-}
--- a/beacon-chain/operations/attestations/kv/forkchoice_test.go
+++ b/beacon-chain/operations/attestations/kv/forkchoice_test.go
@@ -20,7 +20,7 @@ func TestKV_Forkchoice_CanSaveRetrieve(t *testing.T) {
 	atts := []ethpb.Att{att1, att2, att3}

 	for _, att := range atts {
-		require.NoError(t, cache.SaveForkchoiceAttestation(att))
+		require.NoError(t, cache.saveForkchoiceAttestation(att))
 	}

 	returned := cache.ForkchoiceAttestations()
@@ -41,7 +41,7 @@ func TestKV_Forkchoice_CanDelete(t *testing.T) {
 	atts := []ethpb.Att{att1, att2, att3}

 	for _, att := range atts {
-		require.NoError(t, cache.SaveForkchoiceAttestation(att))
+		require.NoError(t, cache.saveForkchoiceAttestation(att))
 	}

 	require.NoError(t, cache.DeleteForkchoiceAttestation(att1))
@@ -61,7 +61,7 @@ func TestKV_Forkchoice_CanCount(t *testing.T) {
 	atts := []*ethpb.Attestation{att1, att2, att3}

 	for _, att := range atts {
-		require.NoError(t, cache.SaveForkchoiceAttestation(att))
+		require.NoError(t, cache.saveForkchoiceAttestation(att))
 	}

 	require.Equal(t, 3, cache.ForkchoiceAttestationCount())
--- a/beacon-chain/operations/attestations/kv/kv.go
+++ b/beacon-chain/operations/attestations/kv/kv.go
@@ -8,6 +8,7 @@ import (
 	"time"

 	"github.com/patrickmn/go-cache"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations/attmap"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
@@ -21,8 +22,7 @@ type AttCaches struct {
 	aggregatedAtt      map[attestation.Id][]ethpb.Att
 	unAggregateAttLock sync.RWMutex
 	unAggregatedAtt    map[attestation.Id]ethpb.Att
-	forkchoiceAttLock  sync.RWMutex
-	forkchoiceAtt      map[attestation.Id]ethpb.Att
+	forkchoiceAtt      *attmap.Attestations
 	blockAttLock       sync.RWMutex
 	blockAtt           map[attestation.Id][]ethpb.Att
 	seenAtt            *cache.Cache
@@ -36,10 +36,35 @@ func NewAttCaches() *AttCaches {
 	pool := &AttCaches{
 		unAggregatedAtt: make(map[attestation.Id]ethpb.Att),
 		aggregatedAtt:   make(map[attestation.Id][]ethpb.Att),
-		forkchoiceAtt:   make(map[attestation.Id]ethpb.Att),
+		forkchoiceAtt:   attmap.New(),
 		blockAtt:        make(map[attestation.Id][]ethpb.Att),
 		seenAtt:         c,
 	}

 	return pool
 }
+
+// saveForkchoiceAttestation saves a forkchoice attestation.
+func (c *AttCaches) saveForkchoiceAttestation(att ethpb.Att) error {
+	return c.forkchoiceAtt.Save(att)
+}
+
+// SaveForkchoiceAttestations saves forkchoice attestations.
+func (c *AttCaches) SaveForkchoiceAttestations(att []ethpb.Att) error {
+	return c.forkchoiceAtt.SaveMany(att)
+}
+
+// ForkchoiceAttestations returns all forkchoice attestations.
+func (c *AttCaches) ForkchoiceAttestations() []ethpb.Att {
+	return c.forkchoiceAtt.GetAll()
+}
+
+// DeleteForkchoiceAttestation deletes a forkchoice attestation.
+func (c *AttCaches) DeleteForkchoiceAttestation(att ethpb.Att) error {
+	return c.forkchoiceAtt.Delete(att)
+}
+
+// ForkchoiceAttestationCount returns the number of forkchoice attestation keys.
+func (c *AttCaches) ForkchoiceAttestationCount() int {
+	return c.forkchoiceAtt.Count()
+}
--- a/beacon-chain/operations/attestations/kv/unaggregated.go
+++ b/beacon-chain/operations/attestations/kv/unaggregated.go
@@ -4,7 +4,6 @@ import (
 	"context"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -17,7 +16,7 @@ func (c *AttCaches) SaveUnaggregatedAttestation(att ethpb.Att) error {
 	if att == nil || att.IsNil() {
 		return nil
 	}
-	if helpers.IsAggregated(att) {
+	if att.IsAggregated() {
 		return errors.New("attestation is aggregated")
 	}

@@ -133,8 +132,7 @@ func (c *AttCaches) DeleteUnaggregatedAttestation(att ethpb.Att) error {
 	if att == nil || att.IsNil() {
 		return nil
 	}
-
-	if helpers.IsAggregated(att) {
+	if att.IsAggregated() {
 		return errors.New("attestation is aggregated")
 	}

@@ -162,7 +160,7 @@ func (c *AttCaches) DeleteSeenUnaggregatedAttestations() (int, error) {

 	count := 0
 	for r, att := range c.unAggregatedAtt {
-		if att == nil || att.IsNil() || helpers.IsAggregated(att) {
+		if att == nil || att.IsNil() || att.IsAggregated() {
 			continue
 		}
 		if seen, err := c.hasSeenBit(att); err == nil && seen {
--- a/beacon-chain/operations/attestations/metrics.go
+++ b/beacon-chain/operations/attestations/metrics.go
@@ -30,6 +30,16 @@ var (
 		Name: "expired_block_atts_total",
 		Help: "The number of expired and deleted block attestations in the pool.",
 	})
+	attCount = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "attestations_in_pool_total",
+			Help: "The number of attestations in the pool.",
+		},
+	)
+	expiredAtts = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "expired_atts_total",
+		Help: "The number of expired and deleted attestations in the pool.",
+	})
 	batchForkChoiceAttsT1 = promauto.NewHistogram(
 		prometheus.HistogramOpts{
 			Name:    "aggregate_attestations_t1",
@@ -50,3 +60,8 @@ func (s *Service) updateMetrics() {
 	aggregatedAttsCount.Set(float64(s.cfg.Pool.AggregatedAttestationCount()))
 	unaggregatedAttsCount.Set(float64(s.cfg.Pool.UnaggregatedAttestationCount()))
 }
+
+func (s *Service) updateMetricsExperimental(numExpired uint64) {
+	attCount.Set(float64(s.cfg.Cache.Count()))
+	expiredAtts.Add(float64(numExpired))
+}
--- a/beacon-chain/operations/attestations/pool.go
+++ b/beacon-chain/operations/attestations/pool.go
@@ -37,7 +37,6 @@ type Pool interface {
 	BlockAttestations() []ethpb.Att
 	DeleteBlockAttestation(att ethpb.Att) error
 	// For attestations to be passed to fork choice.
-	SaveForkchoiceAttestation(att ethpb.Att) error
 	SaveForkchoiceAttestations(atts []ethpb.Att) error
 	ForkchoiceAttestations() []ethpb.Att
 	DeleteForkchoiceAttestation(att ethpb.Att) error
--- a/beacon-chain/operations/attestations/prepare_forkchoice.go
+++ b/beacon-chain/operations/attestations/prepare_forkchoice.go
@@ -61,11 +61,16 @@ func (s *Service) batchForkChoiceAtts(ctx context.Context) error {
 	ctx, span := trace.StartSpan(ctx, "Operations.attestations.batchForkChoiceAtts")
 	defer span.End()

-	if err := s.cfg.Pool.AggregateUnaggregatedAttestations(ctx); err != nil {
-		return err
+	var atts []ethpb.Att
+	if features.Get().EnableExperimentalAttestationPool {
+		atts = append(s.cfg.Cache.GetAll(), s.cfg.Cache.ForkchoiceAttestations()...)
+	} else {
+		if err := s.cfg.Pool.AggregateUnaggregatedAttestations(ctx); err != nil {
+			return err
+		}
+		atts = append(s.cfg.Pool.AggregatedAttestations(), s.cfg.Pool.BlockAttestations()...)
+		atts = append(atts, s.cfg.Pool.ForkchoiceAttestations()...)
 	}
-	atts := append(s.cfg.Pool.AggregatedAttestations(), s.cfg.Pool.BlockAttestations()...)
-	atts = append(atts, s.cfg.Pool.ForkchoiceAttestations()...)

 	attsById := make(map[attestation.Id][]ethpb.Att, len(atts))

@@ -92,9 +97,11 @@ func (s *Service) batchForkChoiceAtts(ctx context.Context) error {
 		}
 	}

-	for _, a := range s.cfg.Pool.BlockAttestations() {
-		if err := s.cfg.Pool.DeleteBlockAttestation(a); err != nil {
-			return err
+	if !features.Get().EnableExperimentalAttestationPool {
+		for _, a := range s.cfg.Pool.BlockAttestations() {
+			if err := s.cfg.Pool.DeleteBlockAttestation(a); err != nil {
+				return err
+			}
 		}
 	}

--- a/beacon-chain/operations/attestations/prune_expired.go
+++ b/beacon-chain/operations/attestations/prune_expired.go
@@ -9,8 +9,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )

-// pruneAttsPool prunes attestations pool on every slot interval.
-func (s *Service) pruneAttsPool() {
+// pruneExpired prunes attestations pool on every slot interval.
+func (s *Service) pruneExpired() {
 	ticker := time.NewTicker(s.cfg.pruneInterval)
 	defer ticker.Stop()
 	for {
@@ -25,6 +25,27 @@ func (s *Service) pruneAttsPool() {
 	}
 }

+// pruneExpiredExperimental prunes attestations on every prune interval.
+func (s *Service) pruneExpiredExperimental() {
+	ticker := time.NewTicker(s.cfg.pruneInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			expirySlot, err := s.expirySlot()
+			if err != nil {
+				log.WithError(err).Error("Could not get expiry slot")
+				continue
+			}
+			numExpired := s.cfg.Cache.PruneBefore(expirySlot)
+			s.updateMetricsExperimental(numExpired)
+		case <-s.ctx.Done():
+			log.Debug("Context closed, exiting routine")
+			return
+		}
+	}
+}
+
 // This prunes expired attestations from the pool.
 func (s *Service) pruneExpiredAtts() {
 	aggregatedAtts := s.cfg.Pool.AggregatedAttestations()
@@ -84,3 +105,17 @@ func (s *Service) expiredPreDeneb(slot primitives.Slot) bool {
 	currentTime := uint64(prysmTime.Now().Unix())
 	return currentTime >= expirationTime
 }
+
+// Attestations for a slot before the returned slot are considered expired.
+func (s *Service) expirySlot() (primitives.Slot, error) {
+	currSlot := slots.CurrentSlot(s.genesisTime)
+	currEpoch := slots.ToEpoch(currSlot)
+	if currEpoch == 0 {
+		return 0, nil
+	}
+	if currEpoch < params.BeaconConfig().DenebForkEpoch {
+		// Safe to subtract because we exited early for epoch 0.
+		return currSlot - 31, nil
+	}
+	return slots.EpochStart(currEpoch - 1)
+}
--- a/beacon-chain/operations/attestations/prune_expired_test.go
+++ b/beacon-chain/operations/attestations/prune_expired_test.go
@@ -50,7 +50,7 @@ func TestPruneExpired_Ticker(t *testing.T) {
 	// Rewind back one epoch worth of time.
 	s.genesisTime = uint64(prysmTime.Now().Unix()) - uint64(params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().SecondsPerSlot))

-	go s.pruneAttsPool()
+	go s.pruneExpired()

 	done := make(chan struct{}, 1)
 	async.RunEvery(ctx, 500*time.Millisecond, func() {
@@ -145,5 +145,4 @@ func TestPruneExpired_ExpiredDeneb(t *testing.T) {

 	assert.Equal(t, true, s.expired(secondEpochStart), "Should be expired")
 	assert.Equal(t, false, s.expired(thirdEpochStart), "Should not be expired")
-
 }
--- a/beacon-chain/operations/attestations/service.go
+++ b/beacon-chain/operations/attestations/service.go
@@ -9,7 +9,9 @@ import (
 	"time"

 	lru "github.com/hashicorp/golang-lru"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	lruwrpr "github.com/prysmaticlabs/prysm/v5/cache/lru"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 )

@@ -27,12 +29,13 @@ type Service struct {

 // Config options for the service.
 type Config struct {
+	Cache               *cache.AttestationCache
 	Pool                Pool
 	pruneInterval       time.Duration
 	InitialSyncComplete chan struct{}
 }

-// NewService instantiates a new attestation pool service instance that will
+// NewService instantiates a new attestation service instance that will
 // be registered into a running beacon node.
 func NewService(ctx context.Context, cfg *Config) (*Service, error) {
 	cache := lruwrpr.New(forkChoiceProcessedAttsSize)
@@ -58,7 +61,12 @@ func (s *Service) Start() {
 		return
 	}
 	go s.prepareForkChoiceAtts()
-	go s.pruneAttsPool()
+
+	if features.Get().EnableExperimentalAttestationPool {
+		go s.pruneExpiredExperimental()
+	} else {
+		go s.pruneExpired()
+	}
 }

 // waitForSync waits until the beacon node is synced to the latest head.
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
terence tsao	13221bed01	Add EIP-7691 blob throughput increase	2024-12-23 15:54:39 -08:00
terence	6ce6b869e5	Implement consensus spec v1.5.0-alpha.10 (#14733 ) * Use 16 bit random value * enforce 0x02 credentials for consolidations * Limit consolidating balance by validator effective balance * Update max blob commitment size * Fix next sync committee indices * Bytes to little endian * Handle proposer computations in between forks * Fix config and tests Fix tests Fix tests * Fix test stream events by properly set effective balance Fix test stream events by properly set effective balance * Preallocate buffers to avoid repeated allocations * Potuz's feedback * Use 16 bit random value * enforce 0x02 credentials for consolidations * Limit consolidating balance by validator effective balance * Update max blob commitment size * Fix next sync committee indices * Bytes to little endian * Handle proposer computations in between forks * Fix config and tests Fix tests Fix tests * Fix test stream events by properly set effective balance Fix test stream events by properly set effective balance * Preallocate buffers to avoid repeated allocations * Potuz's feedback * Fix change log	2024-12-23 17:32:41 +00:00
Charlton Liv	dbd53bd70d	SA1019 fix: `math/rand` to `crypto/rand` (#14747 ) * math/rand to crypto/rand * Update CHANGELOG.md * Update CHANGELOG.md --------- Co-authored-by: terence <terence@prysmaticlabs.com> Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-23 10:18:38 +00:00
Radosław Kapka	d04b361cc3	Redesign of the attestation pool (#14324 ) * Rename existing AttestationCache * Cache with simple Add * fix import cycle * logic for unaggregated, aggregated and block attestations * some small fixes * remove Seen * finishing touches * feature flag * extract forkchoice atts to separate type * gate new functionality behind feature flag * revert test files * preparing for review * change Id to [32]byte * Potuz's review * Potuz's review pt 2 * Nishant's review * keep flat list of atts * fix ForkchoiceAttestations() function * Tests for Add, GetAll, Count * Tests for remaining functions * use DeepEqual * fix tests * documentation * changelog <3 * v2 handlers * nil check for forkchoice atts * guard against 0 bits set * fix failing test * Preston's review * better godocs	2024-12-23 09:59:32 +00:00
Manu NALEPA	96b31a9f64	Logging improvement. (#14735 ) * Add a log before filesystem cache warm-up. * Log `Successfully registered validator(s) on builder` ==> Debug.	2024-12-20 11:14:14 +00:00
Charlton Liv	a7c3004115	Go deps upgrade, from ioutil to io (#14737 ) * ioutil to io * Update CHANGELOG.md --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-20 09:31:00 +00:00
Charlton Liv	30d5749ef6	Update CONTRIBUTING.md (#14738 ) Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-20 09:12:13 +00:00
terence	bc69ab8a44	Support for different blob target and max values (#14678 ) * Add support for different blob target and max * Fix change log to right section	2024-12-19 14:58:24 +00:00
Radosław Kapka	ed7b511949	Light Client: minor improvements (#14739 )	2024-12-19 14:18:22 +00:00
Rupam Dey	0b7c005d7d	add light client flag check to rpc handlers (#14736 ) * add lc flag check to rpc handlers * deps * changelog * update tests * deps	2024-12-19 08:06:37 +00:00
Manu NALEPA	65e8c37b48	Refactor RPC handlers subscription. (#14732 ) * Refactor RPC handlers subscription. * Fix Sammy's comments. * Update beacon-chain/sync/fork_watcher.go Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com> * Update beacon-chain/sync/fork_watcher.go Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com> * Update beacon-chain/sync/fork_watcher.go Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com> * Update beacon-chain/sync/fork_watcher.go Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com> --------- Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com>	2024-12-18 13:05:20 +00:00
Bastin	689015ff01	Add tests for save and read LC Bootstrap DB functions (#14724 ) * add tests for bootstrapSaveAndRetreive * not available boostrap --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-18 09:17:32 +00:00
Bastin	08c14f02f6	clean up the updates by range handler (#14719 ) * clean up the updates by range handler * remove redundant HandleErrors --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-18 08:08:29 +00:00
Bastin	4bb0b44f16	Add tests for saving light client updates (#14717 ) * move flag settings out of individual tests * add tests with better or worst old update * remove whitespace * add zero fields for default update at deneb block in electra --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-18 08:08:25 +00:00
Manu NALEPA	29237cb0bc	Refactor subnets subscriptions. (#14711 ) * Refactor subnets subscriptions. * Remove totally static/dynamic distinction. * Unsubscribing from topic: Use INFO instead of log. ==> So we have something symmetrical with subscriptions. * Address Nishant's comment.	2024-12-17 12:47:29 +00:00
Preston Van Loon	2b25ede641	Update changelog for v5.2.0 release (#14727 ) * Update CHANGELOG.md for v5.2.0 * update latest develop	2024-12-17 06:12:02 +00:00
Preston Van Loon	b7de64a340	Check non-nil validator before accessing withdrawal credentials (#14705 ) * Check non-nil validator before accessing withdrawal credentials * Updated changelog	2024-12-16 16:34:01 +00:00
Manu NALEPA	11aa51e033	Display error in "Finished building block" only if error. (#14722 )	2024-12-15 20:38:47 +00:00
terence	fa0dc09ce0	Add proper gas limit check through local computation (#14707 ) * Add proper gas limit check through local computation * Potuz's feedback * Fix new line	2024-12-13 16:02:00 +00:00
Rupam Dey	d93a1b671c	process lc finality update only for new finalized checkpoints (#14713 ) * add checks for finalized checkpoint * implement `EmptyExecutionPayloadHeader()` function * changelog * fix error message * revert `process_block.go` * fix error message * testing * Update CHANGELOG.md Co-authored-by: Radosław Kapka <radoslaw.kapka@gmail.com> * revert "testing" --------- Co-authored-by: Radosław Kapka <radoslaw.kapka@gmail.com> Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-12 20:39:49 +00:00
Jun Song	1d8ffadd4f	chore: add an error field to "Finished building block" (#14696 ) * fix: print "Finished building block" only when succeeded * Add failed log * Apply preston's review	2024-12-12 17:07:34 +00:00
Nishant Das	ac1717f1e4	Revert "Change Max Payload Size (#14692 )" (#14716 ) This reverts commit `df81fa3e9a`.	2024-12-12 15:21:47 +00:00
Dan Park	6e6012b12f	Bugfix: Apply eip7549 to slashing pool (#14691 ) * Apply eip7549 to slashing pool * Add CHANGELOG.md * Update bazel --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-11 18:57:21 +00:00
Nishant Das	008f157e17	Update Quic-go to the latest version (#14710 ) * Update to v0.48.2 * Changelog	2024-12-11 09:37:54 +00:00
Bastin	7afb8c3c86	move light client rpc helpers tests to core (#14695 ) * move rpc helpers tests to core * remove helpers tests * fix linter * deleted extra files * fix conflicts --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl> Co-authored-by: Inspector-Butters <mohamadbastin@gmail.com>	2024-12-10 19:51:29 +00:00
terence	e925d35d55	Fix proposer boost test (#14701 )	2024-12-10 18:00:24 +00:00
Manu NALEPA	1f2d8cfae9	`searchForPeers`: Replace `batchSize` by `batchPeriod`. (#14704 ) Rationale: Before this commit, the internal loop exited if: - the expected amount of peers is found, or, - the iterator returns `false` (exhaustion), or - `batchSize` iterations are done. The issue with the iterations count is, in case not enough peer are found AND `iterator.Next` always returns `true`, we don't control WHEN the loop is going to stop. The root cause is we don't control the time needed to run the `iterator.Next` function, which is a function of `devp2P (geth)`. The value of `batchSize (2000)` was chosen arbitrarily. It turns out the time needed to run `iterator.Next` can go from a few micro seconds to a few hundreds of milliseconds. ==> In small networks (example: E2E tests), it was possible for the loop not to exit during several dozen of seconds. With this commit, we replace the `batchSize` by a `batchPeriod`, ensuring the loop will never run longer than `batchPeriod`, even in a small network. Co-authored-by: Nishant Das <nishdas93@gmail.com>	2024-12-10 04:52:02 +00:00
terence	63bc965ddc	Revert "Proposer checks gas limit before accepting builder's bid" (#14706 ) * Revert "Proposer checks gas limit before accepting builder's bid (#14311)" This reverts commit `f43383a3fb`. * Change list	2024-12-10 01:37:19 +00:00
Rupam Dey	a0791d77eb	fix segmentation fault in E2E when light-client feature flag is enabled (#14699 ) * use `blockEpoch` in `BlockToLightClientHeader` * deps * dont use `EmptyExecutionPayload()` * use original logic * changelog * add feature flag check * fix * fix error messages * update `BlockToLightClientHeader` tests * changelog * deps	2024-12-10 01:13:58 +00:00
Manu NALEPA	0d810a1fd6	`startDB`: Add log when checkpoint sync. (#14690 )	2024-12-09 18:46:41 +00:00
terence	92bbf6344c	Check kzg commitment for beacon-api propose block (#14702 ) Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>	2024-12-09 14:38:28 +00:00
Nishant Das	df81fa3e9a	Change Max Payload Size (#14692 ) * Increase Max Payload Size * Changelog * Use MaxGossipSize * Remove change	2024-12-09 13:53:24 +00:00
Rupam Dey	30a136f1fb	save light client updates (diff) (#14683 ) * update diff * deps * add tests for `SaveLightClientUpdate` * cleanup imports * lint * changelog * fix incorrect arithmetic * check for lightclient feature flag * fix tests * fix `saveLightClientBootstrap` and `saveLightClientUpdate` * replace and with or * move feature check to `postBlockProcess` --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-12-04 21:22:43 +00:00
terence	b23c562b67	Pass alpha 9 spec tests (#14667 ) * Add missed exit checks to consolidation processing * Use safe add * gaz * Pass spec tests (except single attestation) Revert params.SetupTestConfigCleanupWithLock(t) * Update earlist exit epoch for upgrade to electra * Validate that each committee bitfield in an aggregate contains at least one non-zero bit * Add single attestation * Add single attestation to ssz static * Fix typo Co-authored-by: Md Amaan <114795592+Redidacove@users.noreply.github.com> * Update UpgradeToElectra comments * Add no lint dupword --------- Co-authored-by: james-prysm <james@prysmaticlabs.com> Co-authored-by: Md Amaan <114795592+Redidacove@users.noreply.github.com>	2024-12-04 16:08:10 +00:00
kasey	ae36630ccd	Raise http body limit for fetching genesis state on Holesky (#14689 ) * use larger limit when fetching genesis * changelog --------- Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>	2024-12-03 21:08:19 +00:00
Preston Van Loon	ac72fe2e0e	Remove interop genesis service from beacon node (#14417 ) * Remove interop dependencies from production binary for beacon-chain. Specifically, remove the interop genesis service. Finding links to pebble: bazel query 'somepath(//cmd/beacon-chain, @com_github_cockroachdb_pebble//...)' --notool_deps * Update INTEROP.md * Remove interop config * Remove ancient interop script * Add electra support for premine genesis * Add example of --chain-config-file, test interop instructions * Fixes * Add binary size reduction * Update binary size reduction * Fix duplicate switch case * Move CHANGELOG entries to unreleased section * gofmt * fix	2024-12-03 19:08:49 +00:00
Nishant Das	d09885b7ce	Make QUIC The Default Transport (#14688 ) * Make it the default * Changelog * Remove outdated flag * Update `go-libp2p` to `v0.36.5` and `webtransport-go` to `master`. --------- Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com>	2024-12-03 17:00:15 +00:00
Nishant Das	dc643c9f32	Fix Deadline Again During Rollback (#14686 ) * fix it again * CHANGELOG	2024-12-02 13:29:36 +00:00
Dhruv Bodani	9fa49e7bc9	Add error counter for SSE endpoint (#14681 ) * add error counter for SSE endpoint * add changelog entry	2024-11-29 12:18:53 +00:00
Sammy Rosso	1139c90ab2	Add metadata fields to getBlobSidecars (#14677 ) * add metadata fields to getBlobSidecars * gaz * changelog * Dhruv + Radek' reviews	2024-11-28 16:42:55 +00:00
Manu NALEPA	79d05a87bb	`listenForNewNodes` and `FindPeersWithSubnet`: Stop using `ReadNodes` and use iterator instead. (#14669 ) * `listenForNewNodes` and `FindPeersWithSubnet`: Stop using `Readnodes` and use iterator instead. It avoids infinite loop in small devnets. * Update beacon-chain/p2p/discovery.go Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com> --------- Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com>	2024-11-28 11:25:28 +00:00
kasey	1707cf3ec7	http response handling improvements (#14673 ) Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>	2024-11-27 22:13:45 +00:00
wangjingcun	bdbb850250	chore: fix 404 status URL (#14675 ) Signed-off-by: wangjingcun <wangjingcun@aliyun.com> Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2024-11-27 15:54:00 +00:00
Dhruv Bodani	b28b1ed6ce	Add error count prom metric (#14670 ) * add error count prom metric * address review comments * add comment for response writer * update changelog	2024-11-27 11:56:07 +00:00