diff --git a/epoch.go b/epoch.go
index 78eb1249..f7f15ac8 100644
--- a/epoch.go
+++ b/epoch.go
@@ -785,11 +785,11 @@ func (ser *Epoch) FindOffsetAndSizeFromCid(ctx context.Context, cid cid.Cid) (os
 	return found, nil
 }
 
-func (ser *Epoch) GetBlock(ctx context.Context, slot uint64) (*ipldbindcode.Block, error) {
+func (ser *Epoch) GetBlock(ctx context.Context, slot uint64) (*ipldbindcode.Block, cid.Cid, error) {
 	// get the slot by slot number
 	wantedCid, err := ser.FindCidFromSlot(ctx, slot)
 	if err != nil {
-		return nil, fmt.Errorf("failed to find CID for slot %d: %w", slot, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to find CID for slot %d: %w", slot, err)
 	}
 	{
 		doPrefetch := getValueFromContext(ctx, "prefetch")
@@ -801,14 +801,14 @@ func (ser *Epoch) GetBlock(ctx context.Context, slot uint64) (*ipldbindcode.Bloc
 	// get the block by CID
 	data, err := ser.GetNodeByCid(ctx, wantedCid)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get node by cid %s: %w", wantedCid, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to get node by cid %s: %w", wantedCid, err)
 	}
 	// try parsing the data as a Block node.
 	decoded, err := iplddecoders.DecodeBlock(data)
 	if err != nil {
-		return nil, fmt.Errorf("failed to decode block with CID %s: %w", wantedCid, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to decode block with CID %s: %w", wantedCid, err)
 	}
-	return decoded, nil
+	return decoded, wantedCid, nil
 }
 
 func (ser *Epoch) GetEntryByCid(ctx context.Context, wantedCid cid.Cid) (*ipldbindcode.Entry, error) {
@@ -863,11 +863,11 @@ func (ser *Epoch) GetRewardsByCid(ctx context.Context, wantedCid cid.Cid) (*ipld
 	return decoded, nil
 }
 
-func (ser *Epoch) GetTransaction(ctx context.Context, sig solana.Signature) (*ipldbindcode.Transaction, error) {
+func (ser *Epoch) GetTransaction(ctx context.Context, sig solana.Signature) (*ipldbindcode.Transaction, cid.Cid, error) {
 	// get the CID by signature
 	wantedCid, err := ser.FindCidFromSignature(ctx, sig)
 	if err != nil {
-		return nil, fmt.Errorf("failed to find CID for signature %s: %w", sig, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to find CID for signature %s: %w", sig, err)
 	}
 	{
 		doPrefetch := getValueFromContext(ctx, "prefetch")
@@ -879,12 +879,12 @@ func (ser *Epoch) GetTransaction(ctx context.Context, sig solana.Signature) (*ip
 	// get the transaction by CID
 	data, err := ser.GetNodeByCid(ctx, wantedCid)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get node by cid %s: %w", wantedCid, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to get node by cid %s: %w", wantedCid, err)
 	}
 	// try parsing the data as a Transaction node.
 	decoded, err := iplddecoders.DecodeTransaction(data)
 	if err != nil {
-		return nil, fmt.Errorf("failed to decode transaction with CID %s: %w", wantedCid, err)
+		return nil, cid.Cid{}, fmt.Errorf("failed to decode transaction with CID %s: %w", wantedCid, err)
 	}
-	return decoded, nil
+	return decoded, wantedCid, nil
 }
diff --git a/multiepoch-getBlock.go b/multiepoch-getBlock.go
index 4c91cc70..ac7bc3b7 100644
--- a/multiepoch-getBlock.go
+++ b/multiepoch-getBlock.go
@@ -70,7 +70,7 @@ func (multi *MultiEpoch) handleGetBlock(ctx context.Context, conn *requestContex
 		}, fmt.Errorf("failed to get epoch %d: %w", epochNumber, err)
 	}
 
-	block, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, true), slot)
+	block, blockCid, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, true), slot)
 	if err != nil {
 		if errors.Is(err, compactindexsized.ErrNotFound) {
 			return &jsonrpc2.Error{
@@ -84,6 +84,11 @@ func (multi *MultiEpoch) handleGetBlock(ctx context.Context, conn *requestContex
 			}, fmt.Errorf("failed to get block: %w", err)
 		}
 	}
+	// set the headers:
+	{
+		conn.ctx.Response.Header.Set("DAG-Root-CID", blockCid.String())
+	}
+
 	tim.time("GetBlock")
 	{
 		prefetcherFromCar := func() error {
@@ -448,7 +453,7 @@ func (multi *MultiEpoch) handleGetBlock(ctx context.Context, conn *requestContex
 		if (parentSlot != 0 || slot == 1) && CalcEpochForSlot(parentSlot) == epochNumber {
 			// NOTE: if the parent is in the same epoch, we can get it from the same epoch handler as the block;
 			// otherwise, we need to get it from the previous epoch (TODO: implement this)
-			parentBlock, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, false), parentSlot)
+			parentBlock, _, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, false), parentSlot)
 			if err != nil {
 				return &jsonrpc2.Error{
 					Code:    jsonrpc2.CodeInternalError,
diff --git a/multiepoch-getBlockTime.go b/multiepoch-getBlockTime.go
index dbcb047b..c9b87172 100644
--- a/multiepoch-getBlockTime.go
+++ b/multiepoch-getBlockTime.go
@@ -28,7 +28,7 @@ func (multi *MultiEpoch) handleGetBlockTime(ctx context.Context, conn *requestCo
 		}, fmt.Errorf("failed to get epoch %d: %w", epochNumber, err)
 	}
 
-	block, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, false), blockNum)
+	block, _, err := epochHandler.GetBlock(WithSubrapghPrefetch(ctx, false), blockNum)
 	if err != nil {
 		if errors.Is(err, compactindexsized.ErrNotFound) {
 			return &jsonrpc2.Error{
diff --git a/multiepoch-getSignaturesForAddress.go b/multiepoch-getSignaturesForAddress.go
index 3e5d2f54..6aaf85ff 100644
--- a/multiepoch-getSignaturesForAddress.go
+++ b/multiepoch-getSignaturesForAddress.go
@@ -123,7 +123,7 @@ func (multi *MultiEpoch) handleGetSignaturesForAddress(ctx context.Context, conn
 		if blockTime, ok := blockTimeCache.m[slot]; ok {
 			return blockTime
 		}
-		block, err := ser.GetBlock(ctx, slot)
+		block, _, err := ser.GetBlock(ctx, slot)
 		if err != nil {
 			klog.Errorf("failed to get block time for slot %d: %v", slot, err)
 			return 0
@@ -158,7 +158,7 @@ func (multi *MultiEpoch) handleGetSignaturesForAddress(ctx context.Context, conn
 				if signaturesOnly {
 					return nil
 				}
-				transactionNode, err := ser.GetTransaction(ctx, sig)
+				transactionNode, _, err := ser.GetTransaction(ctx, sig)
 				if err != nil {
 					klog.Errorf("failed to get tx %s: %v", sig, err)
 					return nil
diff --git a/multiepoch-getTransaction.go b/multiepoch-getTransaction.go
index e5da594e..0fc1ad8e 100644
--- a/multiepoch-getTransaction.go
+++ b/multiepoch-getTransaction.go
@@ -153,7 +153,7 @@ func (multi *MultiEpoch) handleGetTransaction(ctx context.Context, conn *request
 		}, fmt.Errorf("failed to get handler for epoch %d: %w", epochNumber, err)
 	}
 
-	transactionNode, err := epochHandler.GetTransaction(WithSubrapghPrefetch(ctx, true), sig)
+	transactionNode, transactionCid, err := epochHandler.GetTransaction(WithSubrapghPrefetch(ctx, true), sig)
 	if err != nil {
 		if errors.Is(err, compactindexsized.ErrNotFound) {
 			// NOTE: solana just returns null here in case of transaction not found
@@ -167,12 +167,15 @@ func (multi *MultiEpoch) handleGetTransaction(ctx context.Context, conn *request
 			Message: "Internal error",
 		}, fmt.Errorf("failed to get Transaction: %v", err)
 	}
+	{
+		conn.ctx.Response.Header.Set("DAG-Root-CID", transactionCid.String())
+	}
 
 	var response GetTransactionResponse
 
 	response.Slot = ptrToUint64(uint64(transactionNode.Slot))
 	{
-		block, err := epochHandler.GetBlock(ctx, uint64(transactionNode.Slot))
+		block, _, err := epochHandler.GetBlock(ctx, uint64(transactionNode.Slot))
 		if err != nil {
 			return &jsonrpc2.Error{
 				Code:    jsonrpc2.CodeInternalError,