diff --git a/cmd/hmyclient/main.go b/cmd/hmyclient/main.go
new file mode 100644
index 000000000..c5fdfe350
--- /dev/null
+++ b/cmd/hmyclient/main.go
@@ -0,0 +1,57 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"math/big"
+	"time"
+
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/harmony-one/harmony/hmyclient"
+)
+
+// newRPCClient creates a rpc client with specified node URL.
+func newRPCClient(url string) *rpc.Client {
+	client, err := rpc.Dial(url)
+	if err != nil {
+		fmt.Errorf("Failed to connect to Ethereum node: %v", err)
+	}
+	return client
+}
+
+func main() {
+	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancelFn()
+	rpcClient := newRPCClient("http://localhost:9500")
+	if rpcClient == nil {
+		fmt.Errorf("Failed to create rpc client")
+	}
+	client := hmyclient.NewClient(rpcClient)
+	if client == nil {
+		fmt.Errorf("Failed to create client")
+	}
+
+	networkID, err := client.NetworkID(ctx)
+	if err != nil {
+		fmt.Errorf("Failed to get net_version: %v", err)
+	}
+	fmt.Printf("net_version: %v\n", networkID)
+
+	blockNumber, err := client.BlockNumber(ctx)
+	if err != nil {
+		fmt.Errorf("Failed to get hmy_blockNumber: %v", err)
+	}
+	fmt.Printf("hmy_blockNumber: %v\n", blockNumber)
+
+	block, err := client.BlockByNumber(ctx, new(big.Int).SetUint64(uint64(blockNumber)))
+	if err != nil {
+		fmt.Errorf("Failed to get hmy_getBlockByNumber %v: %v", blockNumber, err)
+	}
+	fmt.Printf("hmy_getBlockByNumber(%v): %v\n", blockNumber, block)
+
+	block, err = client.BlockByNumber(ctx, nil)
+	if err != nil {
+		fmt.Errorf("Failed to get block: %v", err)
+	}
+	fmt.Printf("hmy_getBlockByNumber(latest): %v", block)
+}
diff --git a/core/types/block.go b/core/types/block.go
index 581519799..3026b1c5d 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -69,7 +69,7 @@ func (n *BlockNonce) UnmarshalText(input []byte) error {
 	return hexutil.UnmarshalFixedText("BlockNonce", input, n[:])
 }
 
-// Header represents a block header in the Ethereum blockchain.
+// Header represents a block header in the Harmony blockchain.
 type Header struct {
 	ParentHash  common.Hash    `json:"parentHash"       gencodec:"required"`
 	Coinbase    common.Address `json:"miner"            gencodec:"required"`
diff --git a/hmyclient/hmyclient.go b/hmyclient/hmyclient.go
new file mode 100644
index 000000000..4f54f437c
--- /dev/null
+++ b/hmyclient/hmyclient.go
@@ -0,0 +1,157 @@
+package hmyclient
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/harmony-one/harmony/core/types"
+)
+
+// NotFound is returned by API methods if the requested item does not exist.
+var NotFound = errors.New("not found")
+
+// Client defines typed wrappers for the Ethereum RPC API.
+type Client struct {
+	c *rpc.Client
+}
+
+// Dial connects a client to the given URL.
+func Dial(rawurl string) (*Client, error) {
+	return dialContext(context.Background(), rawurl)
+}
+
+func dialContext(ctx context.Context, rawurl string) (*Client, error) {
+	c, err := rpc.DialContext(ctx, rawurl)
+	if err != nil {
+		return nil, err
+	}
+	return NewClient(c), nil
+}
+
+// NewClient creates a client that uses the given RPC client.
+func NewClient(c *rpc.Client) *Client {
+	return &Client{c}
+}
+
+// Close closes the client
+func (c *Client) Close() {
+	c.c.Close()
+}
+
+// BlockNumber returns the block height.
+func (c *Client) BlockNumber(ctx context.Context) (hexutil.Uint64, error) {
+	var raw json.RawMessage
+	err := c.c.CallContext(ctx, &raw, "hmy_blockNumber")
+	if err != nil {
+		return 0, err
+	} else if len(raw) == 0 {
+		return 0, NotFound
+	}
+	var blockNumber hexutil.Uint64
+	if err := json.Unmarshal(raw, &blockNumber); err != nil {
+		return 0, err
+	}
+	return blockNumber, nil
+}
+
+// BlockByHash returns the given full block.
+//
+// Note that loading full blocks requires two requests. Use HeaderByHash
+// if you don't need all transactions or uncle headers.
+func (c *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
+	return c.getBlock(ctx, "hmy_getBlockByHash", hash, true)
+}
+
+// BlockByNumber returns a block from the current canonical chain. If number is nil, the
+// latest known block is returned.
+//
+// Note that loading full blocks requires two requests. Use HeaderByNumber
+// if you don't need all transactions or uncle headers.
+func (c *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error) {
+	return c.getBlock(ctx, "hmy_getBlockByNumber", toBlockNumArg(number), true)
+}
+
+// NetworkID returns the network ID (also known as the chain ID) for this chain.
+func (c *Client) NetworkID(ctx context.Context) (*big.Int, error) {
+	version := new(big.Int)
+	var ver string
+	if err := c.c.CallContext(ctx, &ver, "net_version"); err != nil {
+		return nil, err
+	}
+	if _, ok := version.SetString(ver, 10); !ok {
+		return nil, fmt.Errorf("invalid net_version result %q", ver)
+	}
+	return version, nil
+}
+
+func (c *Client) getBlock(ctx context.Context, method string, args ...interface{}) (*types.Block, error) {
+	var raw json.RawMessage
+	err := c.c.CallContext(ctx, &raw, method, args...)
+	if err != nil {
+		return nil, err
+	} else if len(raw) == 0 {
+		return nil, NotFound
+	}
+	// Decode header and transactions.
+	var head *types.Header
+	var body rpcBlock
+	if err := json.Unmarshal(raw, &head); err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(raw, &body); err != nil {
+		return nil, err
+	}
+	// Quick-verify transaction. This mostly helps with debugging the server.
+	if head.TxHash == types.EmptyRootHash && len(body.Transactions) > 0 {
+		return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions")
+	}
+	if head.TxHash != types.EmptyRootHash && len(body.Transactions) == 0 {
+		return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions")
+	}
+	// Load uncles because they are not included in the block response.
+	var uncles []*types.Header
+	if len(body.UncleHashes) > 0 {
+		uncles = make([]*types.Header, len(body.UncleHashes))
+		reqs := make([]rpc.BatchElem, len(body.UncleHashes))
+		for i := range reqs {
+			reqs[i] = rpc.BatchElem{
+				Method: "eth_getUncleByBlockHashAndIndex",
+				Args:   []interface{}{body.Hash, hexutil.EncodeUint64(uint64(i))},
+				Result: &uncles[i],
+			}
+		}
+		if err := c.c.BatchCallContext(ctx, reqs); err != nil {
+			return nil, err
+		}
+		for i := range reqs {
+			if reqs[i].Error != nil {
+				return nil, reqs[i].Error
+			}
+			if uncles[i] == nil {
+				return nil, fmt.Errorf("got null header for uncle %d of block %x", i, body.Hash[:])
+			}
+		}
+	}
+	// Fill the sender cache of transactions in the block.
+	txs := make([]*types.Transaction, len(body.Transactions))
+	for i, tx := range body.Transactions {
+		if tx.From != nil {
+			setSenderFromServer(tx.tx, *tx.From, body.Hash)
+		}
+		txs[i] = tx.tx
+	}
+	return types.NewBlockWithHeader(head).WithBody(txs, uncles), nil
+}
+
+func toBlockNumArg(number *big.Int) string {
+	if number == nil {
+		return "latest"
+	}
+	return hexutil.EncodeBig(number)
+}
diff --git a/hmyclient/signer.go b/hmyclient/signer.go
new file mode 100644
index 000000000..3ab6070e8
--- /dev/null
+++ b/hmyclient/signer.go
@@ -0,0 +1,42 @@
+package hmyclient
+
+import (
+	"errors"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/harmony-one/harmony/core/types"
+)
+
+var errNotCached = errors.New("sender not cached")
+
+// senderFromServer is a types.Signer that remembers the sender address returned by the RPC
+// server. It is stored in the transaction's sender address cache to avoid an additional
+// request in TransactionSender.
+type senderFromServer struct {
+	addr      common.Address
+	blockhash common.Hash
+}
+
+func setSenderFromServer(tx *types.Transaction, addr common.Address, block common.Hash) {
+	// Use types.Sender for side-effect to store our signer into the cache.
+	types.Sender(&senderFromServer{addr, block}, tx)
+}
+func (s *senderFromServer) Equal(other types.Signer) bool {
+	os, ok := other.(*senderFromServer)
+	return ok && os.blockhash == s.blockhash
+}
+
+func (s *senderFromServer) Sender(tx *types.Transaction) (common.Address, error) {
+	if s.blockhash == (common.Hash{}) {
+		return common.Address{}, errNotCached
+	}
+	return s.addr, nil
+}
+
+func (s *senderFromServer) Hash(tx *types.Transaction) common.Hash {
+	panic("can't sign with senderFromServer")
+}
+func (s *senderFromServer) SignatureValues(tx *types.Transaction, sig []byte) (R, S, V *big.Int, err error) {
+	panic("can't sign with senderFromServer")
+}
diff --git a/hmyclient/type.go b/hmyclient/type.go
new file mode 100644
index 000000000..dffa64bcf
--- /dev/null
+++ b/hmyclient/type.go
@@ -0,0 +1,23 @@
+package hmyclient
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/harmony-one/harmony/core/types"
+)
+
+type rpcBlock struct {
+	Hash         common.Hash      `json:"hash"`
+	Transactions []rpcTransaction `json:"transactions"`
+	UncleHashes  []common.Hash    `json:"uncles"`
+}
+
+type rpcTransaction struct {
+	tx *types.Transaction
+	txExtraInfo
+}
+
+type txExtraInfo struct {
+	BlockNumber *string         `json:"blockNumber,omitempty"`
+	BlockHash   *common.Hash    `json:"blockHash,omitempty"`
+	From        *common.Address `json:"from,omitempty"`
+}