Debug data columns API endpoint (#15701)

* initial * fixing from self review * changelog * fixing endpoints and adding test * removed unneeded test * self review * fixing mock columns * fixing tests * gofmt * fixing endpoint * gaz * gofmt * fixing tests * gofmt * gaz * radek comments * gaz * fixing formatting * deduplicating and fixing an old bug, will break into separate PR * better way for version * optimizing post merge and fixing tests * Update beacon-chain/rpc/eth/debug/handlers.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * Update beacon-chain/rpc/eth/debug/handlers.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * Update beacon-chain/rpc/lookup/blocker.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * Update beacon-chain/rpc/lookup/blocker.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * Update beacon-chain/rpc/lookup/blocker.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * adding some of radek's feedback * reverting and gaz --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>
2026-01-09 13:28:01 -05:00 · 2025-09-19 10:20:43 -05:00
parent 9f9401e615
commit d67ee62efa
12 changed files with 945 additions and 22 deletions
--- a/api/server/structs/endpoints_debug.go
+++ b/api/server/structs/endpoints_debug.go
@@ -56,3 +56,19 @@ type ForkChoiceNodeExtraData struct {
 	TimeStamp                string `json:"timestamp"`
 	Target                   string `json:"target"`
 }
+
+type GetDebugDataColumnSidecarsResponse struct {
+	Version             string               `json:"version"`
+	ExecutionOptimistic bool                 `json:"execution_optimistic"`
+	Finalized           bool                 `json:"finalized"`
+	Data                []*DataColumnSidecar `json:"data"`
+}
+
+type DataColumnSidecar struct {
+	Index                        string                   `json:"index"`
+	Column                       []string                 `json:"column"`
+	KzgCommitments               []string                 `json:"kzg_commitments"`
+	KzgProofs                    []string                 `json:"kzg_proofs"`
+	SignedBeaconBlockHeader      *SignedBeaconBlockHeader `json:"signed_block_header"`
+	KzgCommitmentsInclusionProof []string                 `json:"kzg_commitments_inclusion_proof"`
+}
--- a/beacon-chain/rpc/endpoints.go
+++ b/beacon-chain/rpc/endpoints.go
@@ -106,7 +106,7 @@ func (s *Service) endpoints(
 	}

 	if enableDebug {
-		endpoints = append(endpoints, s.debugEndpoints(stater)...)
+		endpoints = append(endpoints, s.debugEndpoints(stater, blocker)...)
 	}

 	return endpoints
@@ -1097,7 +1097,7 @@ func (s *Service) lightClientEndpoints() []endpoint {
 	}
 }

-func (s *Service) debugEndpoints(stater lookup.Stater) []endpoint {
+func (s *Service) debugEndpoints(stater lookup.Stater, blocker lookup.Blocker) []endpoint {
 	server := &debug.Server{
 		BeaconDB:              s.cfg.BeaconDB,
 		HeadFetcher:           s.cfg.HeadFetcher,
@@ -1107,6 +1107,8 @@ func (s *Service) debugEndpoints(stater lookup.Stater) []endpoint {
 		ForkchoiceFetcher:     s.cfg.ForkchoiceFetcher,
 		FinalizationFetcher:   s.cfg.FinalizationFetcher,
 		ChainInfoFetcher:      s.cfg.ChainInfoFetcher,
+		GenesisTimeFetcher:    s.cfg.GenesisTimeFetcher,
+		Blocker:               blocker,
 	}

 	const namespace = "debug"
@@ -1141,6 +1143,16 @@ func (s *Service) debugEndpoints(stater lookup.Stater) []endpoint {
 			handler: server.GetForkChoice,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/eth/v1/debug/beacon/data_column_sidecars/{block_id}",
+			name:     namespace + ".GetDataColumnSidecars",
+			middleware: []middleware.Middleware{
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType, api.OctetStreamMediaType}),
+				middleware.AcceptEncodingHeaderHandler(),
+			},
+			handler: server.DataColumnSidecars,
+			methods: []string{http.MethodGet},
+		},
 	}
 }

--- a/beacon-chain/rpc/endpoints_test.go
+++ b/beacon-chain/rpc/endpoints_test.go
@@ -83,6 +83,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v2/debug/beacon/states/{state_id}":               {http.MethodGet},
 		"/eth/v2/debug/beacon/heads":                           {http.MethodGet},
 		"/eth/v1/debug/fork_choice":                            {http.MethodGet},
+		"/eth/v1/debug/beacon/data_column_sidecars/{block_id}": {http.MethodGet},
 	}

 	eventsRoutes := map[string][]string{
--- a/beacon-chain/rpc/eth/debug/BUILD.bazel
+++ b/beacon-chain/rpc/eth/debug/BUILD.bazel
@@ -13,13 +13,19 @@ go_library(
        "//api/server/structs:go_default_library",
        "//beacon-chain/blockchain:go_default_library",
        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/rpc/core:go_default_library",
        "//beacon-chain/rpc/eth/helpers:go_default_library",
        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//beacon-chain/rpc/lookup:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/primitives:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
        "//network/httputil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
    ],
 )

@@ -34,9 +40,13 @@ go_test(
        "//beacon-chain/db/testing:go_default_library",
        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/rpc/core:go_default_library",
        "//beacon-chain/rpc/testutil:go_default_library",
        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
--- a/beacon-chain/rpc/eth/debug/handlers.go
+++ b/beacon-chain/rpc/eth/debug/handlers.go
@@ -4,19 +4,31 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math"
 	"net/http"
+	"net/url"
+	"strconv"
+	"strings"

 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/core"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
 )

-const errMsgStateFromConsensus = "Could not convert consensus state to response"
+const (
+	errMsgStateFromConsensus = "Could not convert consensus state to response"
+)

 // GetBeaconStateV2 returns the full beacon state for a given state ID.
 func (s *Server) GetBeaconStateV2(w http.ResponseWriter, r *http.Request) {
@@ -208,3 +220,181 @@ func (s *Server) GetForkChoice(w http.ResponseWriter, r *http.Request) {
 	}
 	httputil.WriteJson(w, resp)
 }
+
+// DataColumnSidecars retrieves data column sidecars for a given block id.
+func (s *Server) DataColumnSidecars(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "debug.DataColumnSidecars")
+	defer span.End()
+
+	// Check if we're before Fulu fork - data columns are only available from Fulu onwards
+	fuluForkEpoch := params.BeaconConfig().FuluForkEpoch
+	if fuluForkEpoch == math.MaxUint64 {
+		httputil.HandleError(w, "Data columns are not supported - Fulu fork not configured", http.StatusBadRequest)
+		return
+	}
+
+	// Check if we're before Fulu fork based on current slot
+	currentSlot := s.GenesisTimeFetcher.CurrentSlot()
+	currentEpoch := primitives.Epoch(currentSlot / params.BeaconConfig().SlotsPerEpoch)
+	if currentEpoch < fuluForkEpoch {
+		httputil.HandleError(w, "Data columns are not supported - before Fulu fork", http.StatusBadRequest)
+		return
+	}
+
+	indices, err := parseDataColumnIndices(r.URL)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	segments := strings.Split(r.URL.Path, "/")
+	blockId := segments[len(segments)-1]
+
+	verifiedDataColumns, rpcErr := s.Blocker.DataColumns(ctx, blockId, indices)
+	if rpcErr != nil {
+		code := core.ErrorReasonToHTTP(rpcErr.Reason)
+		switch code {
+		case http.StatusBadRequest:
+			httputil.HandleError(w, "Bad request: "+rpcErr.Err.Error(), code)
+			return
+		case http.StatusNotFound:
+			httputil.HandleError(w, "Not found: "+rpcErr.Err.Error(), code)
+			return
+		case http.StatusInternalServerError:
+			httputil.HandleError(w, "Internal server error: "+rpcErr.Err.Error(), code)
+			return
+		default:
+			httputil.HandleError(w, rpcErr.Err.Error(), code)
+			return
+		}
+	}
+
+	blk, err := s.Blocker.Block(ctx, []byte(blockId))
+	if err != nil {
+		httputil.HandleError(w, "Could not fetch block: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if blk == nil {
+		httputil.HandleError(w, "Block not found", http.StatusNotFound)
+		return
+	}
+
+	if httputil.RespondWithSsz(r) {
+		sszResp, err := buildDataColumnSidecarsSSZResponse(verifiedDataColumns)
+		if err != nil {
+			httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set(api.VersionHeader, version.String(blk.Version()))
+		httputil.WriteSsz(w, sszResp)
+		return
+	}
+
+	blkRoot, err := blk.Block().HashTreeRoot()
+	if err != nil {
+		httputil.HandleError(w, "Could not hash block: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	isOptimistic, err := s.OptimisticModeFetcher.IsOptimisticForRoot(ctx, blkRoot)
+	if err != nil {
+		httputil.HandleError(w, "Could not check if block is optimistic: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	data := buildDataColumnSidecarsJsonResponse(verifiedDataColumns)
+	resp := &structs.GetDebugDataColumnSidecarsResponse{
+		Version:             version.String(blk.Version()),
+		Data:                data,
+		ExecutionOptimistic: isOptimistic,
+		Finalized:           s.FinalizationFetcher.IsFinalized(ctx, blkRoot),
+	}
+	w.Header().Set(api.VersionHeader, version.String(blk.Version()))
+	httputil.WriteJson(w, resp)
+}
+
+// parseDataColumnIndices filters out invalid and duplicate data column indices
+func parseDataColumnIndices(url *url.URL) ([]int, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	rawIndices := url.Query()["indices"]
+	indices := make([]int, 0, numberOfColumns)
+	invalidIndices := make([]string, 0)
+loop:
+	for _, raw := range rawIndices {
+		ix, err := strconv.Atoi(raw)
+		if err != nil {
+			invalidIndices = append(invalidIndices, raw)
+			continue
+		}
+		if !(0 <= ix && uint64(ix) < numberOfColumns) {
+			invalidIndices = append(invalidIndices, raw)
+			continue
+		}
+		for i := range indices {
+			if ix == indices[i] {
+				continue loop
+			}
+		}
+		indices = append(indices, ix)
+	}
+
+	if len(invalidIndices) > 0 {
+		return nil, fmt.Errorf("requested data column indices %v are invalid", invalidIndices)
+	}
+	return indices, nil
+}
+
+func buildDataColumnSidecarsJsonResponse(verifiedDataColumns []blocks.VerifiedRODataColumn) []*structs.DataColumnSidecar {
+	sidecars := make([]*structs.DataColumnSidecar, len(verifiedDataColumns))
+	for i, dc := range verifiedDataColumns {
+		column := make([]string, len(dc.Column))
+		for j, cell := range dc.Column {
+			column[j] = hexutil.Encode(cell)
+		}
+
+		kzgCommitments := make([]string, len(dc.KzgCommitments))
+		for j, commitment := range dc.KzgCommitments {
+			kzgCommitments[j] = hexutil.Encode(commitment)
+		}
+
+		kzgProofs := make([]string, len(dc.KzgProofs))
+		for j, proof := range dc.KzgProofs {
+			kzgProofs[j] = hexutil.Encode(proof)
+		}
+
+		kzgCommitmentsInclusionProof := make([]string, len(dc.KzgCommitmentsInclusionProof))
+		for j, proof := range dc.KzgCommitmentsInclusionProof {
+			kzgCommitmentsInclusionProof[j] = hexutil.Encode(proof)
+		}
+
+		sidecars[i] = &structs.DataColumnSidecar{
+			Index:                        strconv.FormatUint(dc.Index, 10),
+			Column:                       column,
+			KzgCommitments:               kzgCommitments,
+			KzgProofs:                    kzgProofs,
+			SignedBeaconBlockHeader:      structs.SignedBeaconBlockHeaderFromConsensus(dc.SignedBlockHeader),
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+	}
+	return sidecars
+}
+
+// buildDataColumnSidecarsSSZResponse builds SSZ response for data column sidecars
+func buildDataColumnSidecarsSSZResponse(verifiedDataColumns []blocks.VerifiedRODataColumn) ([]byte, error) {
+	if len(verifiedDataColumns) == 0 {
+		return []byte{}, nil
+	}
+
+	// Pre-allocate buffer for all sidecars using the known SSZ size
+	sizePerSidecar := (&ethpb.DataColumnSidecar{}).SizeSSZ()
+	ssz := make([]byte, 0, sizePerSidecar*len(verifiedDataColumns))
+
+	// Marshal and append each sidecar
+	for i, sidecar := range verifiedDataColumns {
+		sszrep, err := sidecar.MarshalSSZ()
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to marshal data column sidecar at index %d", i)
+		}
+		ssz = append(ssz, sszrep...)
+	}
+
+	return ssz, nil
+}
--- a/beacon-chain/rpc/eth/debug/handlers_test.go
+++ b/beacon-chain/rpc/eth/debug/handlers_test.go
@@ -2,9 +2,13 @@ package debug

 import (
 	"bytes"
+	"context"
 	"encoding/json"
+	"errors"
+	"math"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"testing"

 	"github.com/OffchainLabs/prysm/v6/api"
@@ -13,9 +17,13 @@ import (
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/core"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -515,3 +523,285 @@ func TestGetForkChoice(t *testing.T) {
 	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
 	require.Equal(t, "2", resp.FinalizedCheckpoint.Epoch)
 }
+
+func TestDataColumnSidecars(t *testing.T) {
+	t.Run("Fulu fork not configured", func(t *testing.T) {
+		// Save the original config
+		originalConfig := params.BeaconConfig()
+		defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+		// Set Fulu fork epoch to MaxUint64 (unconfigured)
+		config := params.BeaconConfig().Copy()
+		config.FuluForkEpoch = math.MaxUint64
+		params.OverrideBeaconConfig(config)
+
+		chainService := &blockchainmock.ChainService{}
+
+		// Create a mock blocker to avoid nil pointer
+		mockBlocker := &testutil.MockBlocker{}
+
+		s := &Server{
+			GenesisTimeFetcher: chainService,
+			Blocker:            mockBlocker,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/beacon/data_column_sidecars/head", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.DataColumnSidecars(writer, request)
+		require.Equal(t, http.StatusBadRequest, writer.Code)
+		assert.StringContains(t, "Data columns are not supported - Fulu fork not configured", writer.Body.String())
+	})
+
+	t.Run("Before Fulu fork", func(t *testing.T) {
+		// Save the original config
+		originalConfig := params.BeaconConfig()
+		defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+		// Set Fulu fork epoch to 100
+		config := params.BeaconConfig().Copy()
+		config.FuluForkEpoch = 100
+		params.OverrideBeaconConfig(config)
+
+		chainService := &blockchainmock.ChainService{}
+		currentSlot := primitives.Slot(0) // Current slot 0 (epoch 0, before epoch 100)
+		chainService.Slot = &currentSlot
+
+		// Create a mock blocker to avoid nil pointer
+		mockBlocker := &testutil.MockBlocker{
+			DataColumnsFunc: func(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+				return nil, &core.RpcError{Err: errors.New("before Fulu fork"), Reason: core.BadRequest}
+			},
+		}
+
+		s := &Server{
+			GenesisTimeFetcher: chainService,
+			Blocker:            mockBlocker,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/beacon/data_column_sidecars/head", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.DataColumnSidecars(writer, request)
+		require.Equal(t, http.StatusBadRequest, writer.Code)
+		assert.StringContains(t, "Data columns are not supported - before Fulu fork", writer.Body.String())
+	})
+
+	t.Run("Invalid indices", func(t *testing.T) {
+		// Save the original config
+		originalConfig := params.BeaconConfig()
+		defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+		// Set Fulu fork epoch to 0 (already activated)
+		config := params.BeaconConfig().Copy()
+		config.FuluForkEpoch = 0
+		params.OverrideBeaconConfig(config)
+
+		chainService := &blockchainmock.ChainService{}
+		currentSlot := primitives.Slot(0) // Current slot 0 (epoch 0, at fork)
+		chainService.Slot = &currentSlot
+
+		// Create a mock blocker to avoid nil pointer
+		mockBlocker := &testutil.MockBlocker{
+			DataColumnsFunc: func(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+				return nil, &core.RpcError{Err: errors.New("invalid index"), Reason: core.BadRequest}
+			},
+		}
+
+		s := &Server{
+			GenesisTimeFetcher: chainService,
+			Blocker:            mockBlocker,
+		}
+
+		// Test with invalid index (out of range)
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/beacon/data_column_sidecars/head?indices=9999", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.DataColumnSidecars(writer, request)
+		require.Equal(t, http.StatusBadRequest, writer.Code)
+		assert.StringContains(t, "requested data column indices [9999] are invalid", writer.Body.String())
+	})
+
+	t.Run("Block not found", func(t *testing.T) {
+		// Save the original config
+		originalConfig := params.BeaconConfig()
+		defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+		// Set Fulu fork epoch to 0 (already activated)
+		config := params.BeaconConfig().Copy()
+		config.FuluForkEpoch = 0
+		params.OverrideBeaconConfig(config)
+
+		chainService := &blockchainmock.ChainService{}
+		currentSlot := primitives.Slot(0) // Current slot 0
+		chainService.Slot = &currentSlot
+
+		// Create a mock blocker that returns block not found
+		mockBlocker := &testutil.MockBlocker{
+			DataColumnsFunc: func(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+				return nil, &core.RpcError{Err: errors.New("block not found"), Reason: core.NotFound}
+			},
+			BlockToReturn: nil, // Block not found
+		}
+
+		s := &Server{
+			GenesisTimeFetcher: chainService,
+			Blocker:            mockBlocker,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/beacon/data_column_sidecars/head", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.DataColumnSidecars(writer, request)
+		require.Equal(t, http.StatusNotFound, writer.Code)
+	})
+
+	t.Run("Empty data columns", func(t *testing.T) {
+		// Save the original config
+		originalConfig := params.BeaconConfig()
+		defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+		// Set Fulu fork epoch to 0
+		config := params.BeaconConfig().Copy()
+		config.FuluForkEpoch = 0
+		params.OverrideBeaconConfig(config)
+
+		// Create a simple test block
+		signedTestBlock := util.NewBeaconBlock()
+		roBlock, err := blocks.NewSignedBeaconBlock(signedTestBlock)
+		require.NoError(t, err)
+
+		chainService := &blockchainmock.ChainService{}
+		currentSlot := primitives.Slot(0) // Current slot 0
+		chainService.Slot = &currentSlot
+		chainService.OptimisticRoots = make(map[[32]byte]bool)
+		chainService.FinalizedRoots = make(map[[32]byte]bool)
+
+		mockBlocker := &testutil.MockBlocker{
+			DataColumnsFunc: func(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+				return []blocks.VerifiedRODataColumn{}, nil // Empty data columns
+			},
+			BlockToReturn: roBlock,
+		}
+
+		s := &Server{
+			GenesisTimeFetcher:    chainService,
+			OptimisticModeFetcher: chainService,
+			FinalizationFetcher:   chainService,
+			Blocker:               mockBlocker,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/beacon/data_column_sidecars/head", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.DataColumnSidecars(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+
+		resp := &structs.GetDebugDataColumnSidecarsResponse{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		require.Equal(t, 0, len(resp.Data))
+	})
+}
+
+func TestParseDataColumnIndices(t *testing.T) {
+	// Save the original config
+	originalConfig := params.BeaconConfig()
+	defer func() { params.OverrideBeaconConfig(originalConfig) }()
+
+	// Set NumberOfColumns to 128 for testing
+	config := params.BeaconConfig().Copy()
+	config.NumberOfColumns = 128
+	params.OverrideBeaconConfig(config)
+
+	tests := []struct {
+		name        string
+		queryParams map[string][]string
+		expected    []int
+		expectError bool
+	}{
+		{
+			name:        "no indices",
+			queryParams: map[string][]string{},
+			expected:    []int{},
+			expectError: false,
+		},
+		{
+			name:        "valid indices",
+			queryParams: map[string][]string{"indices": {"0", "1", "127"}},
+			expected:    []int{0, 1, 127},
+			expectError: false,
+		},
+		{
+			name:        "duplicate indices",
+			queryParams: map[string][]string{"indices": {"0", "1", "0"}},
+			expected:    []int{0, 1},
+			expectError: false,
+		},
+		{
+			name:        "invalid string index",
+			queryParams: map[string][]string{"indices": {"abc"}},
+			expected:    nil,
+			expectError: true,
+		},
+		{
+			name:        "negative index",
+			queryParams: map[string][]string{"indices": {"-1"}},
+			expected:    nil,
+			expectError: true,
+		},
+		{
+			name:        "index too large",
+			queryParams: map[string][]string{"indices": {"128"}}, // 128 >= NumberOfColumns (128)
+			expected:    nil,
+			expectError: true,
+		},
+		{
+			name:        "mixed valid and invalid",
+			queryParams: map[string][]string{"indices": {"0", "abc", "1"}},
+			expected:    nil,
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			u, err := url.Parse("http://example.com/test")
+			require.NoError(t, err)
+
+			q := u.Query()
+			for key, values := range tt.queryParams {
+				for _, value := range values {
+					q.Add(key, value)
+				}
+			}
+			u.RawQuery = q.Encode()
+
+			result, err := parseDataColumnIndices(u)
+
+			if tt.expectError {
+				assert.NotNil(t, err)
+			} else {
+				require.NoError(t, err)
+				assert.DeepEqual(t, tt.expected, result)
+			}
+		})
+	}
+}
+
+func TestBuildDataColumnSidecarsSSZResponse(t *testing.T) {
+	t.Run("empty data columns", func(t *testing.T) {
+		result, err := buildDataColumnSidecarsSSZResponse([]blocks.VerifiedRODataColumn{})
+		require.NoError(t, err)
+		require.DeepEqual(t, []byte{}, result)
+	})
+
+	t.Run("get SSZ size", func(t *testing.T) {
+		size := (&ethpb.DataColumnSidecar{}).SizeSSZ()
+		assert.Equal(t, true, size > 0)
+	})
+}
--- a/beacon-chain/rpc/eth/debug/server.go
+++ b/beacon-chain/rpc/eth/debug/server.go
@@ -20,4 +20,6 @@ type Server struct {
 	ForkchoiceFetcher     blockchain.ForkchoiceFetcher
 	FinalizationFetcher   blockchain.FinalizationFetcher
 	ChainInfoFetcher      blockchain.ChainInfoFetcher
+	GenesisTimeFetcher    blockchain.TimeFetcher
+	Blocker               lookup.Blocker
 }
--- a/beacon-chain/rpc/lookup/BUILD.bazel
+++ b/beacon-chain/rpc/lookup/BUILD.bazel
@@ -25,7 +25,6 @@ go_library(
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
-        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
--- a/beacon-chain/rpc/lookup/blocker.go
+++ b/beacon-chain/rpc/lookup/blocker.go
@@ -19,7 +19,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
@@ -62,6 +61,7 @@ func (e BlockIdParseError) Error() string {
 type Blocker interface {
 	Block(ctx context.Context, id []byte) (interfaces.ReadOnlySignedBeaconBlock, error)
 	Blobs(ctx context.Context, id string, opts ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError)
+	DataColumns(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError)
 }

 // BeaconDbBlocker is an implementation of Blocker. It retrieves blocks from the beacon chain database.
@@ -267,13 +267,9 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, opts ...options.
 		return nil, &core.RpcError{Err: err, Reason: core.ErrorReason(reason)}
 	}

-	// Validate fork epoch for Deneb (blobs)
-	if roSignedBlock != nil {
 	slot := roSignedBlock.Block().Slot()
 	if slots.ToEpoch(slot) < params.BeaconConfig().DenebForkEpoch {
-			forkName := version.String(slots.ToForkVersion(slot))
-			return nil, &core.RpcError{Err: fmt.Errorf("not supported before %s fork", forkName), Reason: core.BadRequest}
-		}
+		return nil, &core.RpcError{Err: errors.New("blobs are not supported before Deneb fork"), Reason: core.BadRequest}
 	}

 	roBlock := roSignedBlock.Block()
@@ -489,3 +485,93 @@ func (p *BeaconDbBlocker) neededDataColumnSidecars(root [fieldparams.RootLength]

 	return verifiedRoSidecars, nil
 }
+
+// DataColumns returns the data column sidecars for a given block id identifier and column indices. The identifier can be one of:
+//   - "head" (canonical head in node's view)
+//   - "genesis"
+//   - "finalized"
+//   - "justified"
+//   - <slot>
+//   - <hex encoded block root with '0x' prefix>
+//   - <block root>
+//
+// cases:
+//   - no block, 404
+//   - block exists, before Fulu fork, 400 (data columns are not supported before Fulu fork)
+func (p *BeaconDbBlocker) DataColumns(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+	// Check for genesis block first (not supported for data columns)
+	if id == "genesis" {
+		return nil, &core.RpcError{Err: errors.New("data columns are not supported for Phase 0 fork"), Reason: core.BadRequest}
+	}
+
+	// Resolve block ID to root and block
+	root, roSignedBlock, err := p.resolveBlockID(ctx, id)
+	if err != nil {
+		var blockNotFound *BlockNotFoundError
+		var blockIdParseErr *BlockIdParseError
+
+		reason := core.Internal // Default to Internal for unexpected errors
+		if errors.As(err, &blockNotFound) {
+			reason = core.NotFound
+		} else if errors.As(err, &blockIdParseErr) {
+			reason = core.BadRequest
+		}
+		return nil, &core.RpcError{Err: err, Reason: core.ErrorReason(reason)}
+	}
+
+	slot := roSignedBlock.Block().Slot()
+	fuluForkEpoch := params.BeaconConfig().FuluForkEpoch
+	fuluForkSlot, err := slots.EpochStart(fuluForkEpoch)
+	if err != nil {
+		return nil, &core.RpcError{Err: errors.Wrap(err, "could not calculate Fulu start slot"), Reason: core.Internal}
+	}
+	if slot < fuluForkSlot {
+		return nil, &core.RpcError{Err: errors.New("data columns are not supported before Fulu fork"), Reason: core.BadRequest}
+	}
+
+	roBlock := roSignedBlock.Block()
+
+	commitments, err := roBlock.Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to retrieve kzg commitments from block %#x", root), Reason: core.Internal}
+	}
+
+	// If there are no commitments return 200 w/ empty list
+	if len(commitments) == 0 {
+		return make([]blocks.VerifiedRODataColumn, 0), nil
+	}
+
+	// Get column indices to retrieve
+	columnIndices := make([]uint64, 0)
+	if len(indices) == 0 {
+		// If no indices specified, return all columns this node is custodying
+		summary := p.DataColumnStorage.Summary(root)
+		stored := summary.Stored()
+		for index := range stored {
+			columnIndices = append(columnIndices, index)
+		}
+	} else {
+		// Validate and convert indices
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		for _, index := range indices {
+			if index < 0 || uint64(index) >= numberOfColumns {
+				return nil, &core.RpcError{
+					Err:    fmt.Errorf("requested index %d is outside valid range [0, %d)", index, numberOfColumns),
+					Reason: core.BadRequest,
+				}
+			}
+			columnIndices = append(columnIndices, uint64(index))
+		}
+	}
+
+	// Retrieve data column sidecars from storage
+	verifiedRoDataColumns, err := p.DataColumnStorage.Get(root, columnIndices)
+	if err != nil {
+		return nil, &core.RpcError{
+			Err:    errors.Wrapf(err, "could not retrieve data columns for block root %#x", root),
+			Reason: core.Internal,
+		}
+	}
+
+	return verifiedRoDataColumns, nil
+}
--- a/beacon-chain/rpc/lookup/blocker_test.go
+++ b/beacon-chain/rpc/lookup/blocker_test.go
@@ -329,9 +329,9 @@ func TestGetBlob(t *testing.T) {
 	for _, blob := range fuluBlobSidecars {
 		var kzgBlob kzg.Blob
 		copy(kzgBlob[:], blob.Blob)
-		cellsAndProogs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+		cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 		require.NoError(t, err)
-		cellsAndProofsList = append(cellsAndProofsList, cellsAndProogs)
+		cellsAndProofsList = append(cellsAndProofsList, cellsAndProofs)
 	}

 	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
@@ -794,3 +794,300 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 		require.StringContains(t, "0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb", rpcErr.Err.Error())
 	})
 }
+
+func TestGetDataColumns(t *testing.T) {
+	const (
+		blobCount     = 4
+		fuluForkEpoch = 2
+	)
+
+	setupFulu := func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.DenebForkEpoch = 1
+		cfg.FuluForkEpoch = fuluForkEpoch
+		params.OverrideBeaconConfig(cfg)
+	}
+
+	setupPreFulu := func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.DenebForkEpoch = 1
+		cfg.FuluForkEpoch = 1000 // Set to a high epoch to ensure we're before Fulu
+		params.OverrideBeaconConfig(cfg)
+	}
+
+	ctx := t.Context()
+	db := testDB.SetupDB(t)
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Create Fulu block and convert blob sidecars to data column sidecars.
+	fuluForkSlot := fuluForkEpoch * params.BeaconConfig().SlotsPerEpoch
+	fuluBlock, fuluBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, fuluForkSlot, blobCount)
+	fuluBlockRoot := fuluBlock.Root()
+
+	cellsAndProofsList := make([]kzg.CellsAndProofs, 0, len(fuluBlobSidecars))
+	for _, blob := range fuluBlobSidecars {
+		var kzgBlob kzg.Blob
+		copy(kzgBlob[:], blob.Blob)
+		cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+		require.NoError(t, err)
+		cellsAndProofsList = append(cellsAndProofsList, cellsAndProofs)
+	}
+
+	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
+	require.NoError(t, err)
+
+	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
+	for _, roDataColumn := range roDataColumnSidecars {
+		verifiedRoDataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRoDataColumnSidecars = append(verifiedRoDataColumnSidecars, verifiedRoDataColumn)
+	}
+
+	err = db.SaveBlock(t.Context(), fuluBlock)
+	require.NoError(t, err)
+
+	_, dataColumnStorage := filesystem.NewEphemeralDataColumnStorageAndFs(t)
+	err = dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+	require.NoError(t, err)
+
+	t.Run("pre-fulu fork", func(t *testing.T) {
+		setupPreFulu(t)
+
+		// Create a block at slot 123 (before Fulu fork since FuluForkEpoch is set to MaxUint64)
+		preFuluBlock := util.NewBeaconBlock()
+		preFuluBlock.Block.Slot = 123
+		util.SaveBlock(t, ctx, db, preFuluBlock)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			ChainInfoFetcher: &mockChain.ChainService{},
+			BeaconDB:         db,
+		}
+
+		_, rpcErr := blocker.DataColumns(ctx, "123", nil)
+		require.NotNil(t, rpcErr)
+		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
+		require.StringContains(t, "not supported before Fulu fork", rpcErr.Err.Error())
+	})
+
+	t.Run("genesis", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			ChainInfoFetcher: &mockChain.ChainService{},
+		}
+
+		_, rpcErr := blocker.DataColumns(ctx, "genesis", nil)
+		require.NotNil(t, rpcErr)
+		require.Equal(t, http.StatusBadRequest, core.ErrorReasonToHTTP(rpcErr.Reason))
+		require.StringContains(t, "not supported for Phase 0 fork", rpcErr.Err.Error())
+	})
+
+	t.Run("head", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			ChainInfoFetcher: &mockChain.ChainService{
+				Root:  fuluBlockRoot[:],
+				Block: fuluBlock,
+			},
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, "head", nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, len(verifiedRoDataColumnSidecars), len(retrievedDataColumns))
+
+		// Create a map of expected indices for easier verification
+		expectedIndices := make(map[uint64]bool)
+		for _, expected := range verifiedRoDataColumnSidecars {
+			expectedIndices[expected.RODataColumn.DataColumnSidecar.Index] = true
+		}
+
+		// Verify we got data columns with the expected indices
+		for _, actual := range retrievedDataColumns {
+			require.Equal(t, true, expectedIndices[actual.RODataColumn.DataColumnSidecar.Index])
+		}
+	})
+
+	t.Run("finalized", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: fuluBlockRoot[:]}},
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, "finalized", nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, len(verifiedRoDataColumnSidecars), len(retrievedDataColumns))
+	})
+
+	t.Run("justified", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			ChainInfoFetcher: &mockChain.ChainService{CurrentJustifiedCheckPoint: &ethpb.Checkpoint{Root: fuluBlockRoot[:]}},
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, "justified", nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, len(verifiedRoDataColumnSidecars), len(retrievedDataColumns))
+	})
+
+	t.Run("root", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(fuluBlockRoot[:]), nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, len(verifiedRoDataColumnSidecars), len(retrievedDataColumns))
+	})
+
+	t.Run("slot", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			ChainInfoFetcher:  &mockChain.ChainService{},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		slotStr := fmt.Sprintf("%d", fuluForkSlot)
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, slotStr, nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, len(verifiedRoDataColumnSidecars), len(retrievedDataColumns))
+	})
+
+	t.Run("specific indices", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		// Request specific indices (first 3 data columns)
+		indices := []int{0, 1, 2}
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(fuluBlockRoot[:]), indices)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, 3, len(retrievedDataColumns))
+
+		for i, dataColumn := range retrievedDataColumns {
+			require.Equal(t, uint64(indices[i]), dataColumn.RODataColumn.DataColumnSidecar.Index)
+		}
+	})
+
+	t.Run("no data columns returns empty array", func(t *testing.T) {
+		setupFulu(t)
+
+		_, emptyDataColumnStorage := filesystem.NewEphemeralDataColumnStorageAndFs(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: emptyDataColumnStorage,
+		}
+
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(fuluBlockRoot[:]), nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, 0, len(retrievedDataColumns))
+	})
+
+	t.Run("index too big", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		_, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(fuluBlockRoot[:]), []int{0, math.MaxInt})
+		require.NotNil(t, rpcErr)
+		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
+	})
+
+	t.Run("outside retention period", func(t *testing.T) {
+		setupFulu(t)
+
+		// Create a data column storage with very short retention period
+		shortRetentionStorage, err := filesystem.NewDataColumnStorage(ctx,
+			filesystem.WithDataColumnBasePath(t.TempDir()),
+			filesystem.WithDataColumnRetentionEpochs(1), // Only 1 epoch retention
+		)
+		require.NoError(t, err)
+
+		// Mock genesis time to make current slot much later than the block slot
+		// This simulates being outside retention period
+		genesisTime := time.Now().Add(-time.Duration(fuluForkSlot+1000) * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: genesisTime,
+			},
+			BeaconDB:          db,
+			DataColumnStorage: shortRetentionStorage,
+		}
+
+		// Since the block is outside retention period, should return empty array
+		retrievedDataColumns, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(fuluBlockRoot[:]), nil)
+		require.IsNil(t, rpcErr)
+		require.Equal(t, 0, len(retrievedDataColumns))
+	})
+
+	t.Run("block not found", func(t *testing.T) {
+		setupFulu(t)
+
+		blocker := &BeaconDbBlocker{
+			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
+				Genesis: time.Now(),
+			},
+			BeaconDB:          db,
+			DataColumnStorage: dataColumnStorage,
+		}
+
+		nonExistentRoot := bytesutil.PadTo([]byte("nonexistent"), 32)
+		_, rpcErr := blocker.DataColumns(ctx, hexutil.Encode(nonExistentRoot), nil)
+		require.NotNil(t, rpcErr)
+		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
+	})
+}
--- a/beacon-chain/rpc/testutil/mock_blocker.go
+++ b/beacon-chain/rpc/testutil/mock_blocker.go
@@ -18,6 +18,9 @@ type MockBlocker struct {
 	ErrorToReturn            error
 	SlotBlockMap             map[primitives.Slot]interfaces.ReadOnlySignedBeaconBlock
 	RootBlockMap             map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
+	DataColumnsFunc          func(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError)
+	DataColumnsToReturn      []blocks.VerifiedRODataColumn
+	DataColumnsErrorToReturn *core.RpcError
 }

 // Block --
@@ -40,3 +43,17 @@ func (m *MockBlocker) Block(_ context.Context, b []byte) (interfaces.ReadOnlySig
 func (*MockBlocker) Blobs(_ context.Context, _ string, _ ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError) {
 	return nil, &core.RpcError{}
 }
+
+// DataColumns --
+func (m *MockBlocker) DataColumns(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError) {
+	if m.DataColumnsFunc != nil {
+		return m.DataColumnsFunc(ctx, id, indices)
+	}
+	if m.DataColumnsErrorToReturn != nil {
+		return nil, m.DataColumnsErrorToReturn
+	}
+	if m.DataColumnsToReturn != nil {
+		return m.DataColumnsToReturn, nil
+	}
+	return nil, &core.RpcError{}
+}
--- a/changelog/james-prysm_debug-data-columns.md
+++ b/changelog/james-prysm_debug-data-columns.md
@@ -0,0 +1,3 @@
+### Added
+
+- Adding `/eth/v1/debug/beacon/data_column_sidecars/{block_id}` endpoint.