GraphQL master FF for review (#18445)

* Initial work on a graphql API

* Added receipts, and more transaction fields.

* Finish receipts, add logs

* Add transactionCount to block

* Add types  and .

* Update Block type to be compatible with ethql

* Rename nonce to transactionCount in Account, to be compatible with ethql

* Update transaction, receipt and log to match ethql

* Add  query operator, for a range of blocks

* Added ommerCount to Block

* Add transactionAt and ommerAt to Block

* Added sendRawTransaction mutation

* Add Call and EstimateGas to graphQL API

* Refactored to use hexutil.Bytes instead of HexBytes

* Replace BigNum with hexutil.Big

* Refactor call and estimateGas to use ethapi struct type

* Replace ethgraphql.Address with common.Address

* Replace ethgraphql.Hash with common.Hash

* Converted most quantities to Long instead of Int

* Add support for logs

* Fix bug in runFilter

* Restructured Transaction to work primarily with headers, so uncle data is reported properly

* Add gasPrice API

* Add protocolVersion API

* Add syncing API

* Moved schema into its own source file

* Move some single use args types into anonymous structs

* Add doc-comments

* Fixed backend fetching to use context

* Added (very) basic tests

* Add documentation to the graphql schema

* Fix reversion for formatting of big numbers

* Correct spelling error

* s/BigInt/Long/

* Update common/types.go

* Fixes in response to review

* Fix lint error

* Updated calls on private functions

* Fix typo in graphql.go

* Rollback ethapi breaking changes for graphql support
Co-Authored-By: Arachnid <arachnid@notdot.net>

4 files changed, 1533 insertions, 0 deletions

diff --git a/graphql/grahpql.go b/graphql/grahpql.go
new file mode 100644
index 000000000..1eca78956
--- /dev/null
+++ b/graphql/grahpql.go
@@ -0,0 +1,1104 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package graphql provides a GraphQL interface to Ethereum node data.
+package graphql
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/filters"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/rpc"
+	graphqlgo "github.com/graph-gophers/graphql-go"
+	"github.com/graph-gophers/graphql-go/relay"
+)
+
+// Account represents an Ethereum account at a particular block.
+type Account struct {
+	backend     *eth.EthAPIBackend
+	address     common.Address
+	blockNumber rpc.BlockNumber
+}
+
+// getState fetches the StateDB object for an account.
+func (a *Account) getState(ctx context.Context) (*state.StateDB, error) {
+	state, _, err := a.backend.StateAndHeaderByNumber(ctx, a.blockNumber)
+	return state, err
+}
+
+func (a *Account) Address(ctx context.Context) (common.Address, error) {
+	return a.address, nil
+}
+
+func (a *Account) Balance(ctx context.Context) (hexutil.Big, error) {
+	state, err := a.getState(ctx)
+	if err != nil {
+		return hexutil.Big{}, err
+	}
+
+	return hexutil.Big(*state.GetBalance(a.address)), nil
+}
+
+func (a *Account) TransactionCount(ctx context.Context) (hexutil.Uint64, error) {
+	state, err := a.getState(ctx)
+	if err != nil {
+		return 0, err
+	}
+
+	return hexutil.Uint64(state.GetNonce(a.address)), nil
+}
+
+func (a *Account) Code(ctx context.Context) (hexutil.Bytes, error) {
+	state, err := a.getState(ctx)
+	if err != nil {
+		return hexutil.Bytes{}, err
+	}
+
+	return hexutil.Bytes(state.GetCode(a.address)), nil
+}
+
+func (a *Account) Storage(ctx context.Context, args struct{ Slot common.Hash }) (common.Hash, error) {
+	state, err := a.getState(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	return state.GetState(a.address, args.Slot), nil
+}
+
+// Log represents an individual log message. All arguments are mandatory.
+type Log struct {
+	backend     *eth.EthAPIBackend
+	transaction *Transaction
+	log         *types.Log
+}
+
+func (l *Log) Transaction(ctx context.Context) *Transaction {
+	return l.transaction
+}
+
+func (l *Log) Account(ctx context.Context, args BlockNumberArgs) *Account {
+	return &Account{
+		backend:     l.backend,
+		address:     l.log.Address,
+		blockNumber: args.Number(),
+	}
+}
+
+func (l *Log) Index(ctx context.Context) int32 {
+	return int32(l.log.Index)
+}
+
+func (l *Log) Topics(ctx context.Context) []common.Hash {
+	return l.log.Topics
+}
+
+func (l *Log) Data(ctx context.Context) hexutil.Bytes {
+	return hexutil.Bytes(l.log.Data)
+}
+
+// Transactionn represents an Ethereum transaction.
+// backend and hash are mandatory; all others will be fetched when required.
+type Transaction struct {
+	backend *eth.EthAPIBackend
+	hash    common.Hash
+	tx      *types.Transaction
+	block   *Block
+	index   uint64
+}
+
+// resolve returns the internal transaction object, fetching it if needed.
+func (t *Transaction) resolve(ctx context.Context) (*types.Transaction, error) {
+	if t.tx == nil {
+		tx, blockHash, _, index := rawdb.ReadTransaction(t.backend.ChainDb(), t.hash)
+		if tx != nil {
+			t.tx = tx
+			t.block = &Block{
+				backend: t.backend,
+				hash:    blockHash,
+			}
+			t.index = index
+		} else {
+			t.tx = t.backend.GetPoolTransaction(t.hash)
+		}
+	}
+	return t.tx, nil
+}
+
+func (tx *Transaction) Hash(ctx context.Context) common.Hash {
+	return tx.hash
+}
+
+func (t *Transaction) InputData(ctx context.Context) (hexutil.Bytes, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return hexutil.Bytes{}, err
+	}
+	return hexutil.Bytes(tx.Data()), nil
+}
+
+func (t *Transaction) Gas(ctx context.Context) (hexutil.Uint64, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return 0, err
+	}
+	return hexutil.Uint64(tx.Gas()), nil
+}
+
+func (t *Transaction) GasPrice(ctx context.Context) (hexutil.Big, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return hexutil.Big{}, err
+	}
+	return hexutil.Big(*tx.GasPrice()), nil
+}
+
+func (t *Transaction) Value(ctx context.Context) (hexutil.Big, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return hexutil.Big{}, err
+	}
+	return hexutil.Big(*tx.Value()), nil
+}
+
+func (t *Transaction) Nonce(ctx context.Context) (hexutil.Uint64, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return 0, err
+	}
+	return hexutil.Uint64(tx.Nonce()), nil
+}
+
+func (t *Transaction) To(ctx context.Context, args BlockNumberArgs) (*Account, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return nil, err
+	}
+
+	to := tx.To()
+	if to == nil {
+		return nil, nil
+	}
+
+	return &Account{
+		backend:     t.backend,
+		address:     *to,
+		blockNumber: args.Number(),
+	}, nil
+}
+
+func (t *Transaction) From(ctx context.Context, args BlockNumberArgs) (*Account, error) {
+	tx, err := t.resolve(ctx)
+	if err != nil || tx == nil {
+		return nil, err
+	}
+
+	var signer types.Signer = types.FrontierSigner{}
+	if tx.Protected() {
+		signer = types.NewEIP155Signer(tx.ChainId())
+	}
+	from, _ := types.Sender(signer, tx)
+
+	return &Account{
+		backend:     t.backend,
+		address:     from,
+		blockNumber: args.Number(),
+	}, nil
+}
+
+func (t *Transaction) Block(ctx context.Context) (*Block, error) {
+	if _, err := t.resolve(ctx); err != nil {
+		return nil, err
+	}
+	return t.block, nil
+}
+
+func (t *Transaction) Index(ctx context.Context) (*int32, error) {
+	if _, err := t.resolve(ctx); err != nil {
+		return nil, err
+	}
+	if t.block == nil {
+		return nil, nil
+	}
+	index := int32(t.index)
+	return &index, nil
+}
+
+// getReceipt returns the receipt associated with this transaction, if any.
+func (t *Transaction) getReceipt(ctx context.Context) (*types.Receipt, error) {
+	if _, err := t.resolve(ctx); err != nil {
+		return nil, err
+	}
+
+	if t.block == nil {
+		return nil, nil
+	}
+
+	receipts, err := t.block.resolveReceipts(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	return receipts[t.index], nil
+}
+
+func (t *Transaction) Status(ctx context.Context) (*hexutil.Uint64, error) {
+	receipt, err := t.getReceipt(ctx)
+	if err != nil || receipt == nil {
+		return nil, err
+	}
+
+	ret := hexutil.Uint64(receipt.Status)
+	return &ret, nil
+}
+
+func (t *Transaction) GasUsed(ctx context.Context) (*hexutil.Uint64, error) {
+	receipt, err := t.getReceipt(ctx)
+	if err != nil || receipt == nil {
+		return nil, err
+	}
+
+	ret := hexutil.Uint64(receipt.GasUsed)
+	return &ret, nil
+}
+
+func (t *Transaction) CumulativeGasUsed(ctx context.Context) (*hexutil.Uint64, error) {
+	receipt, err := t.getReceipt(ctx)
+	if err != nil || receipt == nil {
+		return nil, err
+	}
+
+	ret := hexutil.Uint64(receipt.CumulativeGasUsed)
+	return &ret, nil
+}
+
+func (t *Transaction) CreatedContract(ctx context.Context, args BlockNumberArgs) (*Account, error) {
+	receipt, err := t.getReceipt(ctx)
+	if err != nil || receipt == nil || receipt.ContractAddress == (common.Address{}) {
+		return nil, err
+	}
+
+	return &Account{
+		backend:     t.backend,
+		address:     receipt.ContractAddress,
+		blockNumber: args.Number(),
+	}, nil
+}
+
+func (t *Transaction) Logs(ctx context.Context) (*[]*Log, error) {
+	receipt, err := t.getReceipt(ctx)
+	if err != nil || receipt == nil {
+		return nil, err
+	}
+
+	ret := make([]*Log, 0, len(receipt.Logs))
+	for _, log := range receipt.Logs {
+		ret = append(ret, &Log{
+			backend:     t.backend,
+			transaction: t,
+			log:         log,
+		})
+	}
+	return &ret, nil
+}
+
+// Block represennts an Ethereum block.
+// backend, and either num or hash are mandatory. All other fields are lazily fetched
+// when required.
+type Block struct {
+	backend  *eth.EthAPIBackend
+	num      *rpc.BlockNumber
+	hash     common.Hash
+	header   *types.Header
+	block    *types.Block
+	receipts []*types.Receipt
+}
+
+// resolve returns the internal Block object representing this block, fetching
+// it if necessary.
+func (b *Block) resolve(ctx context.Context) (*types.Block, error) {
+	if b.block != nil {
+		return b.block, nil
+	}
+
+	var err error
+	if b.hash != (common.Hash{}) {
+		b.block, err = b.backend.GetBlock(ctx, b.hash)
+	} else {
+		b.block, err = b.backend.BlockByNumber(ctx, *b.num)
+	}
+	if b.block != nil {
+		b.header = b.block.Header()
+	}
+	return b.block, err
+}
+
+// resolveHeader returns the internal Header object for this block, fetching it
+// if necessary. Call this function instead of `resolve` unless you need the
+// additional data (transactions and uncles).
+func (b *Block) resolveHeader(ctx context.Context) (*types.Header, error) {
+	if b.header == nil {
+		if _, err := b.resolve(ctx); err != nil {
+			return nil, err
+		}
+	}
+	return b.header, nil
+}
+
+// resolveReceipts returns the list of receipts for this block, fetching them
+// if necessary.
+func (b *Block) resolveReceipts(ctx context.Context) ([]*types.Receipt, error) {
+	if b.receipts == nil {
+		hash := b.hash
+		if hash == (common.Hash{}) {
+			header, err := b.resolveHeader(ctx)
+			if err != nil {
+				return nil, err
+			}
+			hash = header.Hash()
+		}
+
+		receipts, err := b.backend.GetReceipts(ctx, hash)
+		if err != nil {
+			return nil, err
+		}
+		b.receipts = []*types.Receipt(receipts)
+	}
+	return b.receipts, nil
+}
+
+func (b *Block) Number(ctx context.Context) (hexutil.Uint64, error) {
+	if b.num == nil || *b.num == rpc.LatestBlockNumber {
+		header, err := b.resolveHeader(ctx)
+		if err != nil {
+			return 0, err
+		}
+		num := rpc.BlockNumber(header.Number.Uint64())
+		b.num = &num
+	}
+	return hexutil.Uint64(*b.num), nil
+}
+
+func (b *Block) Hash(ctx context.Context) (common.Hash, error) {
+	if b.hash == (common.Hash{}) {
+		header, err := b.resolveHeader(ctx)
+		if err != nil {
+			return common.Hash{}, err
+		}
+		b.hash = header.Hash()
+	}
+	return b.hash, nil
+}
+
+func (b *Block) GasLimit(ctx context.Context) (hexutil.Uint64, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return hexutil.Uint64(header.GasLimit), nil
+}
+
+func (b *Block) GasUsed(ctx context.Context) (hexutil.Uint64, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return hexutil.Uint64(header.GasUsed), nil
+}
+
+func (b *Block) Parent(ctx context.Context) (*Block, error) {
+	// If the block hasn't been fetched, and we'll need it, fetch it.
+	if b.num == nil && b.hash != (common.Hash{}) && b.header == nil {
+		if _, err := b.resolve(ctx); err != nil {
+			return nil, err
+		}
+	}
+
+	if b.header != nil && b.block.NumberU64() > 0 {
+		num := rpc.BlockNumber(b.header.Number.Uint64() - 1)
+		return &Block{
+			backend: b.backend,
+			num:     &num,
+			hash:    b.header.ParentHash,
+		}, nil
+	} else if b.num != nil && *b.num != 0 {
+		num := *b.num - 1
+		return &Block{
+			backend: b.backend,
+			num:     &num,
+		}, nil
+	}
+	return nil, nil
+}
+
+func (b *Block) Difficulty(ctx context.Context) (hexutil.Big, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return hexutil.Big{}, err
+	}
+	return hexutil.Big(*header.Difficulty), nil
+}
+
+func (b *Block) Timestamp(ctx context.Context) (hexutil.Big, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return hexutil.Big{}, err
+	}
+	return hexutil.Big(*header.Time), nil
+}
+
+func (b *Block) Nonce(ctx context.Context) (hexutil.Bytes, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return hexutil.Bytes{}, err
+	}
+	return hexutil.Bytes(header.Nonce[:]), nil
+}
+
+func (b *Block) MixHash(ctx context.Context) (common.Hash, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	return header.MixDigest, nil
+}
+
+func (b *Block) TransactionsRoot(ctx context.Context) (common.Hash, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	return header.TxHash, nil
+}
+
+func (b *Block) StateRoot(ctx context.Context) (common.Hash, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	return header.Root, nil
+}
+
+func (b *Block) ReceiptsRoot(ctx context.Context) (common.Hash, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	return header.ReceiptHash, nil
+}
+
+func (b *Block) OmmerHash(ctx context.Context) (common.Hash, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	return header.UncleHash, nil
+}
+
+func (b *Block) OmmerCount(ctx context.Context) (*int32, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+	count := int32(len(block.Uncles()))
+	return &count, err
+}
+
+func (b *Block) Ommers(ctx context.Context) (*[]*Block, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+
+	ret := make([]*Block, 0, len(block.Uncles()))
+	for _, uncle := range block.Uncles() {
+		blockNumber := rpc.BlockNumber(uncle.Number.Uint64())
+		ret = append(ret, &Block{
+			backend: b.backend,
+			num:     &blockNumber,
+			hash:    uncle.Hash(),
+			header:  uncle,
+		})
+	}
+	return &ret, nil
+}
+
+func (b *Block) ExtraData(ctx context.Context) (hexutil.Bytes, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return hexutil.Bytes{}, err
+	}
+	return hexutil.Bytes(header.Extra), nil
+}
+
+func (b *Block) LogsBloom(ctx context.Context) (hexutil.Bytes, error) {
+	header, err := b.resolveHeader(ctx)
+	if err != nil {
+		return hexutil.Bytes{}, err
+	}
+	return hexutil.Bytes(header.Bloom.Bytes()), nil
+}
+
+func (b *Block) TotalDifficulty(ctx context.Context) (hexutil.Big, error) {
+	h := b.hash
+	if h == (common.Hash{}) {
+		header, err := b.resolveHeader(ctx)
+		if err != nil {
+			return hexutil.Big{}, err
+		}
+		h = header.Hash()
+	}
+
+	return hexutil.Big(*b.backend.GetTd(h)), nil
+}
+
+// BlockNumberArgs encapsulates arguments to accessors that specify a block number.
+type BlockNumberArgs struct {
+	Block *hexutil.Uint64
+}
+
+// Number returns the provided block number, or rpc.LatestBlockNumber if none
+// was provided.
+func (a BlockNumberArgs) Number() rpc.BlockNumber {
+	if a.Block != nil {
+		return rpc.BlockNumber(*a.Block)
+	}
+	return rpc.LatestBlockNumber
+}
+
+func (b *Block) Miner(ctx context.Context, args BlockNumberArgs) (*Account, error) {
+	block, err := b.resolve(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Account{
+		backend:     b.backend,
+		address:     block.Coinbase(),
+		blockNumber: args.Number(),
+	}, nil
+}
+
+func (b *Block) TransactionCount(ctx context.Context) (*int32, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+	count := int32(len(block.Transactions()))
+	return &count, err
+}
+
+func (b *Block) Transactions(ctx context.Context) (*[]*Transaction, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+
+	ret := make([]*Transaction, 0, len(block.Transactions()))
+	for i, tx := range block.Transactions() {
+		ret = append(ret, &Transaction{
+			backend: b.backend,
+			hash:    tx.Hash(),
+			tx:      tx,
+			block:   b,
+			index:   uint64(i),
+		})
+	}
+	return &ret, nil
+}
+
+func (b *Block) TransactionAt(ctx context.Context, args struct{ Index int32 }) (*Transaction, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+
+	txes := block.Transactions()
+	if args.Index < 0 || int(args.Index) >= len(txes) {
+		return nil, nil
+	}
+
+	tx := txes[args.Index]
+	return &Transaction{
+		backend: b.backend,
+		hash:    tx.Hash(),
+		tx:      tx,
+		block:   b,
+		index:   uint64(args.Index),
+	}, nil
+}
+
+func (b *Block) OmmerAt(ctx context.Context, args struct{ Index int32 }) (*Block, error) {
+	block, err := b.resolve(ctx)
+	if err != nil || block == nil {
+		return nil, err
+	}
+
+	uncles := block.Uncles()
+	if args.Index < 0 || int(args.Index) >= len(uncles) {
+		return nil, nil
+	}
+
+	uncle := uncles[args.Index]
+	blockNumber := rpc.BlockNumber(uncle.Number.Uint64())
+	return &Block{
+		backend: b.backend,
+		num:     &blockNumber,
+		hash:    uncle.Hash(),
+		header:  uncle,
+	}, nil
+}
+
+// BlockFilterCriteria encapsulates criteria passed to a `logs` accessor inside
+// a block.
+type BlockFilterCriteria struct {
+	Addresses *[]common.Address // restricts matches to events created by specific contracts
+
+	// The Topic list restricts matches to particular event topics. Each event has a list
+	// of topics. Topics matches a prefix of that list. An empty element slice matches any
+	// topic. Non-empty elements represent an alternative that matches any of the
+	// contained topics.
+	//
+	// Examples:
+	// {} or nil          matches any topic list
+	// {{A}}              matches topic A in first position
+	// {{}, {B}}          matches any topic in first position, B in second position
+	// {{A}, {B}}         matches topic A in first position, B in second position
+	// {{A, B}}, {C, D}}  matches topic (A OR B) in first position, (C OR D) in second position
+	Topics *[][]common.Hash
+}
+
+// runFilter accepts a filter and executes it, returning all its results as
+// `Log` objects.
+func runFilter(ctx context.Context, be *eth.EthAPIBackend, filter *filters.Filter) ([]*Log, error) {
+	logs, err := filter.Logs(ctx)
+	if err != nil || logs == nil {
+		return nil, err
+	}
+
+	ret := make([]*Log, 0, len(logs))
+	for _, log := range logs {
+		ret = append(ret, &Log{
+			backend:     be,
+			transaction: &Transaction{backend: be, hash: log.TxHash},
+			log:         log,
+		})
+	}
+	return ret, nil
+}
+
+func (b *Block) Logs(ctx context.Context, args struct{ Filter BlockFilterCriteria }) ([]*Log, error) {
+	var addresses []common.Address
+	if args.Filter.Addresses != nil {
+		addresses = *args.Filter.Addresses
+	}
+
+	var topics [][]common.Hash
+	if args.Filter.Topics != nil {
+		topics = *args.Filter.Topics
+	}
+
+	hash := b.hash
+	if hash == (common.Hash{}) {
+		block, err := b.resolve(ctx)
+		if err != nil {
+			return nil, err
+		}
+		hash = block.Hash()
+	}
+
+	// Construct the range filter
+	filter := filters.NewBlockFilter(b.backend, hash, addresses, topics)
+
+	// Run the filter and return all the logs
+	return runFilter(ctx, b.backend, filter)
+}
+
+// Resolver is the top-level object in the GraphQL hierarchy.
+type Resolver struct {
+	backend *eth.EthAPIBackend
+}
+
+func (r *Resolver) Block(ctx context.Context, args struct {
+	Number *hexutil.Uint64
+	Hash   *common.Hash
+}) (*Block, error) {
+	var block *Block
+	if args.Number != nil {
+		num := rpc.BlockNumber(uint64(*args.Number))
+		block = &Block{
+			backend: r.backend,
+			num:     &num,
+		}
+	} else if args.Hash != nil {
+		block = &Block{
+			backend: r.backend,
+			hash:    *args.Hash,
+		}
+	} else {
+		num := rpc.LatestBlockNumber
+		block = &Block{
+			backend: r.backend,
+			num:     &num,
+		}
+	}
+
+	// Resolve the block; if it doesn't exist, return nil.
+	b, err := block.resolve(ctx)
+	if err != nil {
+		return nil, err
+	} else if b == nil {
+		return nil, nil
+	}
+	return block, nil
+}
+
+func (r *Resolver) Blocks(ctx context.Context, args struct {
+	From hexutil.Uint64
+	To   *hexutil.Uint64
+}) ([]*Block, error) {
+	from := rpc.BlockNumber(args.From)
+
+	var to rpc.BlockNumber
+	if args.To != nil {
+		to = rpc.BlockNumber(*args.To)
+	} else {
+		to = rpc.BlockNumber(r.backend.CurrentBlock().Number().Int64())
+	}
+
+	if to < from {
+		return []*Block{}, nil
+	}
+
+	ret := make([]*Block, 0, to-from+1)
+	for i := from; i <= to; i++ {
+		num := i
+		ret = append(ret, &Block{
+			backend: r.backend,
+			num:     &num,
+		})
+	}
+	return ret, nil
+}
+
+func (r *Resolver) Account(ctx context.Context, args struct {
+	Address     common.Address
+	BlockNumber *hexutil.Uint64
+}) *Account {
+	blockNumber := rpc.LatestBlockNumber
+	if args.BlockNumber != nil {
+		blockNumber = rpc.BlockNumber(*args.BlockNumber)
+	}
+
+	return &Account{
+		backend:     r.backend,
+		address:     args.Address,
+		blockNumber: blockNumber,
+	}
+}
+
+func (r *Resolver) Transaction(ctx context.Context, args struct{ Hash common.Hash }) (*Transaction, error) {
+	tx := &Transaction{
+		backend: r.backend,
+		hash:    args.Hash,
+	}
+
+	// Resolve the transaction; if it doesn't exist, return nil.
+	t, err := tx.resolve(ctx)
+	if err != nil {
+		return nil, err
+	} else if t == nil {
+		return nil, nil
+	}
+	return tx, nil
+}
+
+func (r *Resolver) SendRawTransaction(ctx context.Context, args struct{ Data hexutil.Bytes }) (common.Hash, error) {
+	tx := new(types.Transaction)
+	if err := rlp.DecodeBytes(args.Data, tx); err != nil {
+		return common.Hash{}, err
+	}
+	hash, err := ethapi.SubmitTransaction(ctx, r.backend, tx)
+	return hash, err
+}
+
+// CallData encapsulates arguments to `call` or `estimateGas`.
+// All arguments are optional.
+type CallData struct {
+	From     *common.Address // The Ethereum address the call is from.
+	To       *common.Address // The Ethereum address the call is to.
+	Gas      *hexutil.Uint64 // The amount of gas provided for the call.
+	GasPrice *hexutil.Big    // The price of each unit of gas, in wei.
+	Value    *hexutil.Big    // The value sent along with the call.
+	Data     *hexutil.Bytes  // Any data sent with the call.
+}
+
+// CallResult encapsulates the result of an invocation of the `call` accessor.
+type CallResult struct {
+	data    hexutil.Bytes  // The return data from the call
+	gasUsed hexutil.Uint64 // The amount of gas used
+	status  hexutil.Uint64 // The return status of the call - 0 for failure or 1 for success.
+}
+
+func (c *CallResult) Data() hexutil.Bytes {
+	return c.data
+}
+
+func (c *CallResult) GasUsed() hexutil.Uint64 {
+	return c.gasUsed
+}
+
+func (c *CallResult) Status() hexutil.Uint64 {
+	return c.status
+}
+
+func (r *Resolver) Call(ctx context.Context, args struct {
+	Data        ethapi.CallArgs
+	BlockNumber *hexutil.Uint64
+}) (*CallResult, error) {
+	blockNumber := rpc.LatestBlockNumber
+	if args.BlockNumber != nil {
+		blockNumber = rpc.BlockNumber(*args.BlockNumber)
+	}
+
+	result, gas, failed, err := ethapi.DoCall(ctx, r.backend, args.Data, blockNumber, vm.Config{}, 5*time.Second)
+	status := hexutil.Uint64(1)
+	if failed {
+		status = 0
+	}
+	return &CallResult{
+		data:    hexutil.Bytes(result),
+		gasUsed: hexutil.Uint64(gas),
+		status:  status,
+	}, err
+}
+
+func (r *Resolver) EstimateGas(ctx context.Context, args struct {
+	Data        ethapi.CallArgs
+	BlockNumber *hexutil.Uint64
+}) (hexutil.Uint64, error) {
+	blockNumber := rpc.LatestBlockNumber
+	if args.BlockNumber != nil {
+		blockNumber = rpc.BlockNumber(*args.BlockNumber)
+	}
+
+	gas, err := ethapi.DoEstimateGas(ctx, r.backend, args.Data, blockNumber)
+	return gas, err
+}
+
+// FilterCritera encapsulates the arguments to `logs` on the root resolver object.
+type FilterCriteria struct {
+	FromBlock *hexutil.Uint64   // beginning of the queried range, nil means genesis block
+	ToBlock   *hexutil.Uint64   // end of the range, nil means latest block
+	Addresses *[]common.Address // restricts matches to events created by specific contracts
+
+	// The Topic list restricts matches to particular event topics. Each event has a list
+	// of topics. Topics matches a prefix of that list. An empty element slice matches any
+	// topic. Non-empty elements represent an alternative that matches any of the
+	// contained topics.
+	//
+	// Examples:
+	// {} or nil          matches any topic list
+	// {{A}}              matches topic A in first position
+	// {{}, {B}}          matches any topic in first position, B in second position
+	// {{A}, {B}}         matches topic A in first position, B in second position
+	// {{A, B}}, {C, D}}  matches topic (A OR B) in first position, (C OR D) in second position
+	Topics *[][]common.Hash
+}
+
+func (r *Resolver) Logs(ctx context.Context, args struct{ Filter FilterCriteria }) ([]*Log, error) {
+	// Convert the RPC block numbers into internal representations
+	begin := rpc.LatestBlockNumber.Int64()
+	if args.Filter.FromBlock != nil {
+		begin = int64(*args.Filter.FromBlock)
+	}
+	end := rpc.LatestBlockNumber.Int64()
+	if args.Filter.ToBlock != nil {
+		end = int64(*args.Filter.ToBlock)
+	}
+
+	var addresses []common.Address
+	if args.Filter.Addresses != nil {
+		addresses = *args.Filter.Addresses
+	}
+
+	var topics [][]common.Hash
+	if args.Filter.Topics != nil {
+		topics = *args.Filter.Topics
+	}
+
+	// Construct the range filter
+	filter := filters.NewRangeFilter(filters.Backend(r.backend), begin, end, addresses, topics)
+
+	return runFilter(ctx, r.backend, filter)
+}
+
+func (r *Resolver) GasPrice(ctx context.Context) (hexutil.Big, error) {
+	price, err := r.backend.SuggestPrice(ctx)
+	return hexutil.Big(*price), err
+}
+
+func (r *Resolver) ProtocolVersion(ctx context.Context) (int32, error) {
+	return int32(r.backend.ProtocolVersion()), nil
+}
+
+// SyncState represents the synchronisation status returned from the `syncing` accessor.
+type SyncState struct {
+	progress ethereum.SyncProgress
+}
+
+func (s *SyncState) StartingBlock() hexutil.Uint64 {
+	return hexutil.Uint64(s.progress.StartingBlock)
+}
+
+func (s *SyncState) CurrentBlock() hexutil.Uint64 {
+	return hexutil.Uint64(s.progress.CurrentBlock)
+}
+
+func (s *SyncState) HighestBlock() hexutil.Uint64 {
+	return hexutil.Uint64(s.progress.HighestBlock)
+}
+
+func (s *SyncState) PulledStates() *hexutil.Uint64 {
+	ret := hexutil.Uint64(s.progress.PulledStates)
+	return &ret
+}
+
+func (s *SyncState) KnownStates() *hexutil.Uint64 {
+	ret := hexutil.Uint64(s.progress.KnownStates)
+	return &ret
+}
+
+// Syncing returns false in case the node is currently not syncing with the network. It can be up to date or has not
+// yet received the latest block headers from its pears. In case it is synchronizing:
+// - startingBlock: block number this node started to synchronise from
+// - currentBlock:  block number this node is currently importing
+// - highestBlock:  block number of the highest block header this node has received from peers
+// - pulledStates:  number of state entries processed until now
+// - knownStates:   number of known state entries that still need to be pulled
+func (r *Resolver) Syncing() (*SyncState, error) {
+	progress := r.backend.Downloader().Progress()
+
+	// Return not syncing if the synchronisation already completed
+	if progress.CurrentBlock >= progress.HighestBlock {
+		return nil, nil
+	}
+	// Otherwise gather the block sync stats
+	return &SyncState{progress}, nil
+}
+
+// NewHandler returns a new `http.Handler` that will answer GraphQL queries.
+// It additionally exports an interactive query browser on the / endpoint.
+func NewHandler(be *eth.EthAPIBackend) (http.Handler, error) {
+	q := Resolver{be}
+
+	s, err := graphqlgo.ParseSchema(schema, &q)
+	if err != nil {
+		return nil, err
+	}
+	h := &relay.Handler{Schema: s}
+
+	mux := http.NewServeMux()
+	mux.Handle("/", GraphiQL{})
+	mux.Handle("/graphql", h)
+	mux.Handle("/graphql/", h)
+	return mux, nil
+}
+
+// Service encapsulates a GraphQL service.
+type Service struct {
+	endpoint string             // The host:port endpoint for this service.
+	cors     []string           // Allowed CORS domains
+	vhosts   []string           // Recognised vhosts
+	timeouts rpc.HTTPTimeouts   // Timeout settings for HTTP requests.
+	backend  *eth.EthAPIBackend // The backend that queries will operate onn.
+	handler  http.Handler       // The `http.Handler` used to answer queries.
+	listener net.Listener       // The listening socket.
+}
+
+// Protocols returns the list of protocols exported by this service.
+func (s *Service) Protocols() []p2p.Protocol { return nil }
+
+// APIs returns the list of APIs exported by this service.
+func (s *Service) APIs() []rpc.API { return nil }
+
+// Start is called after all services have been constructed and the networking
+// layer was also initialized to spawn any goroutines required by the service.
+func (s *Service) Start(server *p2p.Server) error {
+	var err error
+	s.handler, err = NewHandler(s.backend)
+	if err != nil {
+		return err
+	}
+
+	if s.listener, err = net.Listen("tcp", s.endpoint); err != nil {
+		return err
+	}
+
+	go rpc.NewHTTPServer(s.cors, s.vhosts, s.timeouts, s.handler).Serve(s.listener)
+	log.Info("GraphQL endpoint opened", "url", fmt.Sprintf("http://%s", s.endpoint))
+	return nil
+}
+
+// Stop terminates all goroutines belonging to the service, blocking until they
+// are all terminated.
+func (s *Service) Stop() error {
+	if s.listener != nil {
+		s.listener.Close()
+		s.listener = nil
+		log.Info("GraphQL endpoint closed", "url", fmt.Sprintf("http://%s", s.endpoint))
+	}
+	return nil
+}
+
+// NewService constructs a new service instance.
+func NewService(backend *eth.EthAPIBackend, endpoint string, cors, vhosts []string, timeouts rpc.HTTPTimeouts) (*Service, error) {
+	return &Service{
+		endpoint: endpoint,
+		cors:     cors,
+		vhosts:   vhosts,
+		timeouts: timeouts,
+		backend:  backend,
+	}, nil
+}
+
+// RegisterGraphQLService is a utility function to construct a new service and register it against a node.
+func RegisterGraphQLService(stack *node.Node, endpoint string, cors, vhosts []string, timeouts rpc.HTTPTimeouts) error {
+	return stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+		var ethereum *eth.Ethereum
+		if err := ctx.Service(&ethereum); err != nil {
+			return nil, err
+		}
+		return NewService(ethereum.APIBackend, endpoint, cors, vhosts, timeouts)
+	})
+}
diff --git a/graphql/graphiql.go b/graphql/graphiql.go
new file mode 100644
index 000000000..6d9dda3e8
--- /dev/null
+++ b/graphql/graphiql.go
@@ -0,0 +1,95 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2016 Muhammed Thanish
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package graphql
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+)
+
+// GraphiQL is an in-browser IDE for exploring GraphiQL APIs.
+// This handler returns GraphiQL when requested.
+//
+// For more information, see https://github.com/graphql/graphiql.
+type GraphiQL struct{}
+
+func respond(w http.ResponseWriter, body []byte, code int) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.WriteHeader(code)
+	_, _ = w.Write(body)
+}
+
+func errorJSON(msg string) []byte {
+	buf := bytes.Buffer{}
+	fmt.Fprintf(&buf, `{"error": "%s"}`, msg)
+	return buf.Bytes()
+}
+
+func (h GraphiQL) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" {
+		respond(w, errorJSON("only GET requests are supported"), http.StatusMethodNotAllowed)
+		return
+	}
+
+	w.Write(graphiql)
+}
+
+var graphiql = []byte(`
+<!DOCTYPE html>
+<html>
+	<head>
+		<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/graphiql/0.11.11/graphiql.css"/>
+		<script src="https://cdnjs.cloudflare.com/ajax/libs/fetch/2.0.3/fetch.min.js"></script>
+		<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.2.0/umd/react.production.min.js"></script>
+		<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.2.0/umd/react-dom.production.min.js"></script>
+		<script src="https://cdnjs.cloudflare.com/ajax/libs/graphiql/0.11.11/graphiql.min.js"></script>
+	</head>
+	<body style="width: 100%; height: 100%; margin: 0; overflow: hidden;">
+		<div id="graphiql" style="height: 100vh;">Loading...</div>
+		<script>
+			function fetchGQL(params) {
+				return fetch("/graphql", {
+					method: "post",
+					body: JSON.stringify(params),
+					credentials: "include",
+				}).then(function (resp) {
+					return resp.text();
+				}).then(function (body) {
+					try {
+						return JSON.parse(body);
+					} catch (error) {
+						return body;
+					}
+				});
+			}
+
+			ReactDOM.render(
+				React.createElement(GraphiQL, {fetcher: fetchGQL}),
+				document.getElementById("graphiql")
+			)
+		</script>
+	</body>
+</html>
+`)
diff --git a/graphql/graphql_test.go b/graphql/graphql_test.go
new file mode 100644
index 000000000..d63418398
--- /dev/null
+++ b/graphql/graphql_test.go
@@ -0,0 +1,29 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package graphql
+
+import (
+	"testing"
+)
+
+func TestBuildSchema(t *testing.T) {
+	// Make sure the schema can be parsed and matched up to the object model.
+	_, err := NewHandler(nil)
+	if err != nil {
+		t.Errorf("Could not construct GraphQL handler: %v", err)
+	}
+}
diff --git a/graphql/schema.go b/graphql/schema.go
new file mode 100644
index 000000000..c1ba87d2d
--- /dev/null
+++ b/graphql/schema.go
@@ -0,0 +1,305 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package graphql
+
+const schema string = `
+    # Bytes32 is a 32 byte binary string, represented as 0x-prefixed hexadecimal.
+    scalar Bytes32
+    # Address is a 20 byte Ethereum address, represented as 0x-prefixed hexadecimal.
+    scalar Address
+    # Bytes is an arbitrary length binary string, represented as 0x-prefixed hexadecimal.
+    scalar Bytes
+    # BigInt is a large integer. Input is accepted as either a JSON number or as a string.
+    # Strings may be either decimal or 0x-prefixed hexadecimal. Output values are all
+    # 0x-prefixed hexadecimal.
+    scalar BigInt
+    # Long is a 64 bit unsigned integer.
+    scalar Long
+
+    schema {
+        query: Query
+        mutation: Mutation
+    }
+
+    # Account is an Ethereum account at a particular block.
+    type Account {
+        # Address is the address owning the account.
+        address: Address!
+        # Balance is the balance of the account, in wei.
+        balance: BigInt!
+        # TransactionCount is the number of transactions sent from this account,
+        # or in the case of a contract, the number of contracts created. Otherwise
+        # known as the nonce.
+        transactionCount: Long!
+        # Code contains the smart contract code for this account, if the account
+        # is a (non-self-destructed) contract.
+        code: Bytes!
+        # Storage provides access to the storage of a contract account, indexed
+        # by its 32 byte slot identifier.
+        storage(slot: Bytes32!): Bytes32!
+    }
+
+    # Log is an Ethereum event log.
+    type Log {
+        # Index is the index of this log in the block.
+        index: Int!
+        # Account is the account which generated this log - this will always
+        # be a contract account.
+        account(block: Long): Account!
+        # Topics is a list of 0-4 indexed topics for the log.
+        topics: [Bytes32!]!
+        # Data is unindexed data for this log.
+        data: Bytes!
+        # Transaction is the transaction that generated this log entry.
+        transaction: Transaction!
+    }
+
+    # Transaction is an Ethereum transaction.
+    type Transaction {
+        # Hash is the hash of this transaction.
+        hash: Bytes32!
+        # Nonce is the nonce of the account this transaction was generated with.
+        nonce: Long!
+        # Index is the index of this transaction in the parent block. This will
+        # be null if the transaction has not yet beenn mined.
+        index: Int
+        # From is the account that sent this transaction - this will always be
+        # an externally owned account.
+        from(block: Long): Account!
+        # To is the account the transaction was sent to. This is null for
+        # contract-creating transactions.
+        to(block: Long): Account
+        # Value is the value, in wei, sent along with this transaction.
+        value: BigInt!
+        # GasPrice is the price offered to miners for gas, in wei per unit.
+        gasPrice: BigInt!
+        # Gas is the maximum amount of gas this transaction can consume.
+        gas: Long!
+        # InputData is the data supplied to the target of the transaction.
+        inputData: Bytes!
+        # Block is the block this transaction was mined in. This will be null if
+        # the transaction has not yet been mined.
+        block: Block
+
+        # Status is the return status of the transaction. This will be 1 if the
+        # transaction succeeded, or 0 if it failed (due to a revert, or due to
+        # running out of gas). If the transaction has not yet been mined, this
+        # field will be null.
+        status: Long
+        # GasUsed is the amount of gas that was used processing this transaction.
+        # If the transaction has not yet been mined, this field will be null.
+        gasUsed: Long
+        # CumulativeGasUsed is the total gas used in the block up to and including
+        # this transaction. If the transaction has not yet been mined, this field
+        # will be null.
+        cumulativeGasUsed: Long
+        # CreatedContract is the account that was created by a contract creation
+        # transaction. If the transaction was not a contract creation transaction,
+        # or it has not yet been mined, this field will be null.
+        createdContract(block: Long): Account
+        # Logs is a list of log entries emitted by this transaction. If the
+        # transaction has not yet been mined, this field will be null.
+        logs: [Log!]
+    }
+
+    # BlockFilterCriteria encapsulates log filter criteria for a filter applied
+    # to a single block.
+    input BlockFilterCriteria {
+        # Addresses is list of addresses that are of interest. If this list is
+        # empty, results will not be filtered by address.
+        addresses: [Address!]
+        # Topics list restricts matches to particular event topics. Each event has a list
+    	# of topics. Topics matches a prefix of that list. An empty element array matches any
+    	# topic. Non-empty elements represent an alternative that matches any of the
+    	# contained topics.
+    	#
+    	# Examples:
+    	#  - [] or nil          matches any topic list
+    	#  - [[A]]              matches topic A in first position
+    	#  - [[], [B]]          matches any topic in first position, B in second position
+    	#  - [[A], [B]]         matches topic A in first position, B in second position
+    	#  - [[A, B]], [C, D]]  matches topic (A OR B) in first position, (C OR D) in second position
+        topics: [[Bytes32!]!]
+    }
+
+    # Block is an Ethereum block.
+    type Block {
+        # Number is the number of this block, starting at 0 for the genesis block.
+        number: Long!
+        # Hash is the block hash of this block.
+        hash: Bytes32!
+        # Parent is the parent block of this block.
+        parent: Block
+        # Nonce is the block nonce, an 8 byte sequence determined by the miner.
+        nonce: Bytes!
+        # TransactionsRoot is the keccak256 hash of the root of the trie of transactions in this block.
+        transactionsRoot: Bytes32!
+        # TransactionCount is the number of transactions in this block. if
+        # transactions are not available for this block, this field will be null.
+        transactionCount: Int
+        # StateRoot is the keccak256 hash of the state trie after this block was processed.
+        stateRoot: Bytes32!
+        # ReceiptsRoot is the keccak256 hash of the trie of transaction receipts in this block.
+        receiptsRoot: Bytes32!
+        # Miner is the account that mined this block.
+        miner(block: Long): Account!
+        # ExtraData is an arbitrary data field supplied by the miner.
+        extraData: Bytes!
+        # GasLimit is the maximum amount of gas that was available to transactions in this block.
+        gasLimit: Long!
+        # GasUsed is the amount of gas that was used executing transactions in this block.
+        gasUsed: Long!
+        # Timestamp is the unix timestamp at which this block was mined.
+        timestamp: BigInt!
+        # LogsBloom is a bloom filter that can be used to check if a block may
+        # contain log entries matching a filter.
+        logsBloom: Bytes!
+        # MixHash is the hash that was used as an input to the PoW process.
+        mixHash: Bytes32!
+        # Difficulty is a measure of the difficulty of mining this block.
+        difficulty: BigInt!
+        # TotalDifficulty is the sum of all difficulty values up to and including
+        # this block.
+        totalDifficulty: BigInt!
+        # OmmerCount is the number of ommers (AKA uncles) associated with this
+        # block. If ommers are unavailable, this field will be null.
+        ommerCount: Int
+        # Ommers is a list of ommer (AKA uncle) blocks associated with this block.
+        # If ommers are unavailable, this field will be null. Depending on your
+        # node, the transactions, transactionAt, transactionCount, ommers,
+        # ommerCount and ommerAt fields may not be available on any ommer blocks.
+        ommers: [Block]
+        # OmmerAt returns the ommer (AKA uncle) at the specified index. If ommers
+        # are unavailable, or the index is out of bounds, this field will be null.
+        ommerAt(index: Int!): Block
+        # OmmerHash is the keccak256 hash of all the ommers (AKA uncles)
+        # associated with this block.
+        ommerHash: Bytes32!
+        # Transactions is a list of transactions associated with this block. If
+        # transactions are unavailable for this block, this field will be null.
+        transactions: [Transaction!]
+        # TransactionAt returns the transaction at the specified index. If
+        # transactions are unavailable for this block, or if the index is out of
+        # bounds, this field will be null.
+        transactionAt(index: Int!): Transaction
+        # Logs returns a filtered set of logs from this block.
+        logs(filter: BlockFilterCriteria!): [Log!]!
+    }
+
+    # CallData represents the data associated with a local contract call.
+    # All fields are optional.
+    input CallData {
+        # From is the address making the call.
+        from: Address
+        # To is the address the call is sent to.
+        to: Address
+        # Gas is the amount of gas sent with the call.
+        gas: Long
+        # GasPrice is the price, in wei, offered for each unit of gas.
+        gasPrice: BigInt
+        # Value is the value, in wei, sent along with the call.
+        value: BigInt
+        # Data is the data sent to the callee.
+        data: Bytes
+    }
+
+    # CallResult is the result of a local call operationn.
+    type CallResult {
+        # Data is the return data of the called contract.
+        data: Bytes!
+        # GasUsed is the amount of gas used by the call, after any refunds.
+        gasUsed: Long!
+        # Status is the result of the call - 1 for success or 0 for failure.
+        status: Long!
+    }
+
+    # FilterCriteria encapsulates log filter criteria for searching log entries.
+    input FilterCriteria {
+        # FromBlock is the block at which to start searching, inclusive. Defaults
+        # to the latest block if not supplied.
+        fromBlock: Long
+        # ToBlock is the block at which to stop searching, inclusive. Defaults
+        # to the latest block if not supplied.
+        toBlock: Long
+        # Addresses is a list of addresses that are of interest. If this list is
+        # empty, results will not be filtered by address.
+        addresses: [Address!]
+        # Topics list restricts matches to particular event topics. Each event has a list
+    	# of topics. Topics matches a prefix of that list. An empty element array matches any
+    	# topic. Non-empty elements represent an alternative that matches any of the
+    	# contained topics.
+    	#
+    	# Examples:
+    	#  - [] or nil          matches any topic list
+    	#  - [[A]]              matches topic A in first position
+    	#  - [[], [B]]          matches any topic in first position, B in second position
+    	#  - [[A], [B]]         matches topic A in first position, B in second position
+    	#  - [[A, B]], [C, D]]  matches topic (A OR B) in first position, (C OR D) in second position
+        topics: [[Bytes32!]!]
+    }
+
+    # SyncState contains the current synchronisation state of the client.
+    type SyncState{
+        # StartingBlock is the block number at which synchronisation started.
+        startingBlock: Long!
+        # CurrentBlock is the point at which synchronisation has presently reached.
+        currentBlock: Long!
+        # HighestBlock is the latest known block number.
+        highestBlock: Long!
+        # PulledStates is the number of state entries fetched so far, or null
+        # if this is not known or not relevant.
+        pulledStates: Long
+        # KnownStates is the number of states the node knows of so far, or null
+        # if this is not known or not relevant.
+        knownStates: Long
+    }
+
+    type Query {
+        # Account fetches an Ethereum account at the specified block number.
+        # If blockNumber is not provided, it defaults to the most recent block.
+        account(address: Address!, blockNumber: Long): Account!
+        # Block fetches an Ethereum block by number or by hash. If neither is
+        # supplied, the most recent known block is returned.
+        block(number: Long, hash: Bytes32): Block
+        # Blocks returns all the blocks between two numbers, inclusive. If
+        # to is not supplied, it defaults to the most recent known block.
+        blocks(from: Long!, to: Long): [Block!]!
+        # Transaction returns a transaction specified by its hash.
+        transaction(hash: Bytes32!): Transaction
+        # Call executes a local call operation. If blockNumber is not specified,
+        # it defaults to the most recent known block.
+        call(data: CallData!, blockNumber: Long): CallResult
+        # EstimateGas estimates the amount of gas that will be required for
+        # successful execution of a transaction. If blockNumber is not specified,
+        # it defaults ot the most recent known block.
+        estimateGas(data: CallData!, blockNumber: Long): Long!
+        # Logs returns log entries matching the provided filter.
+        logs(filter: FilterCriteria!): [Log!]!
+        # GasPrice returns the node's estimate of a gas price sufficient to
+        # ensure a transaction is mined in a timely fashion.
+        gasPrice: BigInt!
+        # ProtocolVersion returns the current wire protocol version number.
+        protocolVersion: Int!
+        # Syncing returns information on the current synchronisation state.
+        syncing: SyncState
+    }
+
+    type Mutation {
+        # SendRawTransaction sends an RLP-encoded transaction to the network.
+        sendRawTransaction(data: Bytes!): Bytes32!
+    }
+`