diff --git a/api/indexer/client.go b/api/indexer/client.go
index c8ca2b9347..3cc139659d 100644
--- a/api/indexer/client.go
+++ b/api/indexer/client.go
@@ -32,7 +32,7 @@ type Client struct {
 // Use a separate type that only decodes the block bytes because we cannot decode block JSON
 // due to Actions/Auth interfaces included in the block's transactions.
 type GetBlockClientResponse struct {
-	BlockBytes codec.Bytes `json:"blockBytes"`
+	BlockBytes codec.Bytes `json:"block"`
 }
 
 func (c *Client) GetBlock(ctx context.Context, blkID ids.ID, parser chain.Parser) (*chain.ExecutedBlock, error) {
@@ -40,7 +40,7 @@ func (c *Client) GetBlock(ctx context.Context, blkID ids.ID, parser chain.Parser
 	err := c.requester.SendRequest(
 		ctx,
 		"getBlock",
-		&GetBlockRequest{BlockID: blkID},
+		&GetBlockRequest{BlockID: blkID, Encoding: Hex},
 		&resp,
 	)
 	if err != nil {
@@ -54,7 +54,7 @@ func (c *Client) GetBlockByHeight(ctx context.Context, height uint64, parser cha
 	err := c.requester.SendRequest(
 		ctx,
 		"getBlockByHeight",
-		&GetBlockByHeightRequest{Height: height},
+		&GetBlockByHeightRequest{Height: height, Encoding: Hex},
 		&resp,
 	)
 	if err != nil {
@@ -68,7 +68,7 @@ func (c *Client) GetLatestBlock(ctx context.Context, parser chain.Parser) (*chai
 	err := c.requester.SendRequest(
 		ctx,
 		"getLatestBlock",
-		nil,
+		&GetLatestBlockRequest{Encoding: Hex},
 		&resp,
 	)
 	if err != nil {
diff --git a/api/indexer/server.go b/api/indexer/server.go
index e8cec42f03..2d1f9e2d7f 100644
--- a/api/indexer/server.go
+++ b/api/indexer/server.go
@@ -19,7 +19,9 @@ import (
 const Endpoint = "/indexer"
 
 var (
-	ErrTxNotFound = errors.New("tx not found")
+	ErrTxNotFound               = errors.New("tx not found")
+	ErrInvalidEncodingParameter = errors.New("invalid encoding parameter")
+	ErrUnsupportedEncoding      = errors.New("unsupported encoding")
 
 	_ api.HandlerFactory[api.VM] = (*apiFactory)(nil)
 )
@@ -46,25 +48,36 @@ func (f *apiFactory) New(vm api.VM) (api.Handler, error) {
 }
 
 type GetBlockRequest struct {
-	BlockID ids.ID `json:"blockID"`
+	BlockID  ids.ID   `json:"blockID"`
+	Encoding Encoding `json:"encoding"`
 }
 
 type GetBlockByHeightRequest struct {
-	Height uint64 `json:"height"`
+	Height   uint64   `json:"height"`
+	Encoding Encoding `json:"encoding"`
+}
+
+type GetLatestBlockRequest struct {
+	Encoding Encoding `json:"encoding"`
 }
 
 type GetBlockResponse struct {
-	Block      *chain.ExecutedBlock `json:"block"`
-	BlockBytes codec.Bytes          `json:"blockBytes"`
+	Block any `json:"block"`
 }
 
-func (g *GetBlockResponse) setResponse(block *chain.ExecutedBlock) error {
-	g.Block = block
-	blockBytes, err := block.Marshal()
-	if err != nil {
-		return err
+func (g *GetBlockResponse) setResponse(block *chain.ExecutedBlock, encoding Encoding) error {
+	switch encoding {
+	case JSON:
+		g.Block = block
+	case Hex:
+		blockBytes, err := block.Marshal()
+		if err != nil {
+			return err
+		}
+		g.Block = codec.Bytes(blockBytes)
+	default:
+		return ErrUnsupportedEncoding
 	}
-	g.BlockBytes = blockBytes
 	return nil
 }
 
@@ -72,33 +85,46 @@ func (s *Server) GetBlock(req *http.Request, args *GetBlockRequest, reply *GetBl
 	_, span := s.tracer.Start(req.Context(), "Indexer.GetBlock")
 	defer span.End()
 
+	if err := args.Encoding.Validate(); err != nil {
+		return err
+	}
+
 	block, err := s.indexer.GetBlock(args.BlockID)
 	if err != nil {
 		return err
 	}
-	return reply.setResponse(block)
+
+	return reply.setResponse(block, args.Encoding)
 }
 
 func (s *Server) GetBlockByHeight(req *http.Request, args *GetBlockByHeightRequest, reply *GetBlockResponse) error {
 	_, span := s.tracer.Start(req.Context(), "Indexer.GetBlockByHeight")
 	defer span.End()
 
+	if err := args.Encoding.Validate(); err != nil {
+		return err
+	}
+
 	block, err := s.indexer.GetBlockByHeight(args.Height)
 	if err != nil {
 		return err
 	}
-	return reply.setResponse(block)
+	return reply.setResponse(block, args.Encoding)
 }
 
-func (s *Server) GetLatestBlock(req *http.Request, _ *struct{}, reply *GetBlockResponse) error {
+func (s *Server) GetLatestBlock(req *http.Request, args *GetLatestBlockRequest, reply *GetBlockResponse) error {
 	_, span := s.tracer.Start(req.Context(), "Indexer.GetLatestBlock")
 	defer span.End()
 
+	if err := args.Encoding.Validate(); err != nil {
+		return err
+	}
+
 	block, err := s.indexer.GetLatestBlock()
 	if err != nil {
 		return err
 	}
-	return reply.setResponse(block)
+	return reply.setResponse(block, args.Encoding)
 }
 
 type GetTxRequest struct {
@@ -116,7 +142,7 @@ type GetTxResponse struct {
 
 type Server struct {
 	tracer  trace.Tracer
-	indexer *Indexer
+	indexer AbstractIndexer
 }
 
 func (s *Server) GetTx(req *http.Request, args *GetTxRequest, reply *GetTxResponse) error {
@@ -143,3 +169,27 @@ func (s *Server) GetTx(req *http.Request, args *GetTxRequest, reply *GetTxRespon
 	reply.ErrorStr = errorStr
 	return nil
 }
+
+type Encoding string
+
+var (
+	JSON Encoding = "json"
+	Hex  Encoding = "hex"
+)
+
+func (e *Encoding) Validate() error {
+	if *e == "" {
+		*e = JSON
+	}
+	if *e != JSON && *e != Hex {
+		return ErrInvalidEncodingParameter
+	}
+	return nil
+}
+
+type AbstractIndexer interface {
+	GetBlock(blkID ids.ID) (*chain.ExecutedBlock, error)
+	GetBlockByHeight(height uint64) (*chain.ExecutedBlock, error)
+	GetLatestBlock() (*chain.ExecutedBlock, error)
+	GetTransaction(txID ids.ID) (bool, int64, bool, fees.Dimensions, uint64, [][]byte, string, error)
+}
diff --git a/api/indexer/server_test.go b/api/indexer/server_test.go
new file mode 100644
index 0000000000..ef7890ef20
--- /dev/null
+++ b/api/indexer/server_test.go
@@ -0,0 +1,116 @@
+// Copyright (C) 2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package indexer
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/ava-labs/avalanchego/ids"
+	"github.com/ava-labs/avalanchego/trace"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ava-labs/hypersdk/api"
+	"github.com/ava-labs/hypersdk/chain"
+	"github.com/ava-labs/hypersdk/chain/chaintest"
+	"github.com/ava-labs/hypersdk/fees"
+)
+
+func TestEncodingValidate(t *testing.T) {
+	tests := []struct {
+		input  Encoding
+		exp    Encoding
+		expErr error
+	}{
+		{
+			input: JSON,
+			exp:   JSON,
+		},
+		{
+			input: Hex,
+			exp:   Hex,
+		},
+		{
+			input: Encoding(""),
+			exp:   JSON,
+		},
+		{
+			input:  Encoding("another"),
+			expErr: ErrInvalidEncodingParameter,
+		},
+	}
+
+	for _, test := range tests {
+		err := test.input.Validate()
+		if test.expErr != nil {
+			require.EqualError(t, ErrInvalidEncodingParameter, err.Error())
+		} else {
+			require.Equal(t, test.exp, test.input)
+		}
+	}
+}
+
+func TestBlockRequests(t *testing.T) {
+	require := require.New(t)
+	blocks := chaintest.GenerateEmptyExecutedBlocks(require, ids.GenerateTestID(), 0, 0, 0, 1)
+	server, client := newIndexerHTTPServerAndClient(require, blocks[0])
+	defer server.Close()
+
+	res, err := client.GetBlock(context.Background(), blocks[0].BlockID, chaintest.NewEmptyParser())
+	require.NoError(err)
+	require.Equal(blocks[0].BlockID, res.BlockID)
+
+	res, err = client.GetBlockByHeight(context.Background(), blocks[0].Block.Hght, chaintest.NewEmptyParser())
+	require.NoError(err)
+	require.Equal(blocks[0].BlockID, res.BlockID)
+
+	res, err = client.GetLatestBlock(context.Background(), chaintest.NewEmptyParser())
+	require.NoError(err)
+	require.Equal(blocks[0].BlockID, res.BlockID)
+}
+
+func newIndexerHTTPServerAndClient(require *require.Assertions, block *chain.ExecutedBlock) (*httptest.Server, *Client) {
+	rpcServer := &Server{
+		tracer: trace.Noop,
+		indexer: &mockIndexer{
+			execuredBlock: block,
+		},
+	}
+	handler, err := api.NewJSONRPCHandler(Name, rpcServer)
+	require.NoError(err)
+	mux := http.NewServeMux()
+	mux.Handle(Endpoint, handler)
+	testServer := httptest.NewServer(mux)
+	client := NewClient(testServer.URL)
+	return testServer, client
+}
+
+type mockIndexer struct {
+	execuredBlock *chain.ExecutedBlock
+}
+
+func (m *mockIndexer) GetBlock(blockID ids.ID) (*chain.ExecutedBlock, error) {
+	if blockID == m.execuredBlock.BlockID {
+		return m.execuredBlock, nil
+	}
+	return nil, errors.New("not found")
+}
+
+func (m *mockIndexer) GetBlockByHeight(height uint64) (*chain.ExecutedBlock, error) {
+	if height == m.execuredBlock.Block.Hght {
+		return m.execuredBlock, nil
+	}
+	return nil, errors.New("not found")
+}
+
+func (m *mockIndexer) GetLatestBlock() (*chain.ExecutedBlock, error) {
+	return m.execuredBlock, nil
+}
+
+func (*mockIndexer) GetTransaction(_ ids.ID) (bool, int64, bool, fees.Dimensions, uint64, [][]byte, string, error) {
+	panic("unimplemented")
+}