JSON RPC API

JSON is a lightweight data-interchange format. It can represent numbers, strings, ordered sequences of values, and collections of name/value pairs.

JSON-RPC is a stateless, light-weight remote procedure call (RPC) protocol. Primarily this specification defines several data structures and the rules around their processing. It is transport agnostic in that the concepts can be used within the same process, over sockets, over HTTP, or in many various message passing environments. It uses JSON (RFC 4627) as data format.

JavaScript API

To talk to a MOAC node from inside a JavaScript application use the chain3.js library, which gives a convenient interface for the RPC methods. See the JavaScript API for more.

JSON-RPC Endpoint

Default JSON-RPC endpoints:

Client URL
Go http://localhost:8545

Go

You can start the HTTP JSON-RPC with the --rpc flag

moac --rpc

change the default port (8545) and listing address (localhost) with:

moac --rpc --rpcaddr <ip> --rpcport <portnumber>

If accessing the RPC from a browser, CORS will need to be enabled with the appropriate domain set. Otherwise, JavaScript calls are limit by the same-origin policy and requests will fail:

moac --rpc --rpccorsdomain "http://localhost:3000"

The JSON RPC can also be started from the moac console using the admin.startRPC(addr, port) command.

HEX value encoding

At present there are two key datatypes that are passed over JSON: unformatted byte arrays and quantities. Both are passed with a hex encoding, however with different requirements to formatting:

When encoding QUANTITIES (integers, numbers): encode as hex, prefix with “0x”, the most compact representation (slight exception: zero should be represented as “0x0”). Examples: - 0x41 (65 in decimal) - 0x400 (1024 in decimal) - WRONG: 0x (should always have at least one digit - zero is “0x0”) - WRONG: 0x0400 (no leading zeroes allowed) - WRONG: ff (must be prefixed 0x)

When encoding UNFORMATTED DATA (byte arrays, account addresses, hashes, bytecode arrays): encode as hex, prefix with “0x”, two hex digits per byte. Examples: - 0x41 (size 1, “A”) - 0x004200 (size 3, “:raw-latex:`\0`B:raw-latex:`0`”) - 0x (size 0, “”) - WRONG: 0xf0f0f (must be even number of digits) - WRONG: 004200 (must be prefixed 0x)

Currently MOAC provides JSON-RPC communication over http and IPC (unix socket Linux and OSX/named pipes on Windows).

The default block parameter

The following methods have an extra default block parameter:

When requests are made that act on the state of ethereum, the last default block parameter determines the height of the block.

The following options are possible for the defaultBlock parameter:

  • HEX String - an integer block number
  • String "earliest" for the earliest/genesis block
  • String "latest" - for the latest mined block
  • String "pending" - for the pending state/transactions

Curl Examples Explained

The curl options below might return a response where the node complains about the content type, this is because the –data option sets the content type to application/x-www-form-urlencoded . If your node does complain, manually set the header by placing -H “Content-Type: application/json” at the start of the call.

The examples assume a local MOAC node is running and connected to testnet (network id = 101). The URL/IP & port combination is localhost:8545 or ‘127.0.0.1’, which must be the last argument given to curl.

JSON RPC API Reference


Returns the current client version.

none

String - The current client version

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"chain3_clientVersion","params":[],"id":101}' 'localhost:8545'

// Result
{
  "jsonrpc":"2.0",
  "id":101,
  "result":"Moac/v0.8.3-release-ad500ab5/darwin-amd64/go1.10"
}

Returns Keccak-256 (not the standardized SHA3-256) of the given data.

  1. DATA - the data to convert into a SHA3 hash
params: [
  "0x68656c6c6f20776f726c64"
]

DATA - The SHA3 result of the given string.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"chain3_sha3","params":["0x68656c6c6f20776f726c64"],"id":101}' localhost:8545

// Result
{
  "jsonrpc":"2.0",
  "id":101,
  "result":"0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad"
}

Returns the current network id.

none

String - The current network id. - "99": MOAC Mainnet - "101": MOAC Testnet - "100": Devnet

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"net_version","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "101"
}

Returns true if client is actively listening for network connections.

none

Boolean - true when listening, otherwise false.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"net_listening","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc":"2.0",
  "result":true
}

Returns number of peers currently connected to the client.

none

QUANTITY - integer of the number of connected peers.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":101}' localhost:8545

// Result
{
  "id":74,
  "jsonrpc": "2.0",
  "result": "0x4" // 4 net peers are connecting
}

Returns the current MOAC protocol version.

none

String - The current MOAC protocol version

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_protocolVersion","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x3f"
}

Returns an object with data about the sync status or false.

none

Object|Boolean, An object with sync status data or FALSE, when not syncing: - startingBlock: QUANTITY - The block at which the import started (will only be reset, after the sync reached his head) - currentBlock: QUANTITY - The current block, same as mc_blockNumber - highestBlock: QUANTITY - The estimated highest block

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_syncing","params":[],"id":101}' localhost:8545

// Result
{
  "id":1,
  "jsonrpc": "2.0",
  "result": {
    startingBlock: '0x384',
    currentBlock: '0x386',
    highestBlock: '0x454'
  }
}
// Or when not syncing
{
  "id":101,
  "jsonrpc": "2.0",
  "result": false
}

Returns the client coinbase address.

none

DATA, 20 bytes - the current coinbase address.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_coinbase","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x407d73d8a49eeb85d32cf465507dd71d507100c1"
}

Returns true if client is actively mining new blocks.

none

Boolean - returns true of the client is mining, otherwise false.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_mining","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": true
}

Returns the number of hashes per second that the node is mining with.

none

QUANTITY - number of hashes per second.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_hashrate","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x38a"
}

Returns the current price per gas in sha.

none

QUANTITY - integer of the current gas price in sha.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_gasPrice","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x09184e72a000" // 10000000000000
}

Returns a list of addresses owned by client.

none

Array of DATA, 20 Bytes - addresses owned by the client.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_accounts","params":[],"id":101}' localhost:8545

// Result
{
  "id":1,
  "jsonrpc": "2.0",
  "result": ["0x407d73d8a49eeb85d32cf465507dd71d507100c1","0x87dc9d8014e189b9d32c622a9ad1d02f72383979"]
}

Returns the number of most recent block.

none

QUANTITY - integer of the current block number the client is on.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_blockNumber","params":[],"id":101}' 'localhost:8545'

// Result
{
  "id":83,
  "jsonrpc": "2.0",
  "result": "0x4b7" // 1207
}

Returns the balance of the account of given address.

  1. DATA, 20 Bytes - address to check for balance.
  2. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter
params: [
   '0x407d73d8a49eeb85d32cf465507dd71d507100c1',
   'latest'
]

QUANTITY - integer of the current balance in sha.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getBalance","params":["0x87dc9d8014e189b9d32c622a9ad1d02f72383979", "latest"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x12f8b3a319c000" // 5340000000000000
}

Returns the value from a storage position at a given address.

  1. DATA, 20 Bytes - address of the storage.
  2. QUANTITY - integer of the position in the storage.
  3. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter

DATA - the value at this storage position.

Calculating the correct position depends on the storage to retrieve. Consider the following contract deployed at 0x02701dc451e126316ece6870fd70ea140efa7b15 by address 0xa8863fc8ce3816411378685223c03daae9770ebb.

contract Storage {
    uint pos0;
    mapping(address => uint) pos1;

    function Storage() {
        pos0 = 1234;
        pos1[msg.sender] = 5678;
    }
}

Retrieving the value of pos0 is straight forward:

curl -X POST --data '{"jsonrpc":"2.0", "method": "mc_getStorageAt", "params": ["0x02701dc451e126316ece6870fd70ea140efa7b15", "0x0", "latest"], "id": 101}' localhost:8545

{"jsonrpc":"2.0","id":1,"result":"0x00000000000000000000000000000000000000000000000000000000000004d2"}

Retrieving an element of the map is harder. The position of an element in the map is calculated with:

keccack(LeftPad32(key, 0), LeftPad32(map position, 0))

This means to retrieve the storage on pos1[“0x391694e7e0b0cce554cb130d723a9d27458f9298”] we need to calculate the position with:

keccak(decodeHex("000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"))

The moac console which comes with the chain3 library can be used to make the calculation:

> var key = "000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"
undefined
> chain3.sha3(key, {"encoding": "hex"})
"0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9"

Now to fetch the storage:

curl -X POST --data '{"jsonrpc":"2.0", "method": "mc_getStorageAt", "params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9", "latest"], "id": 101}' localhost:8545

{"jsonrpc":"2.0","id":101,"result":"0x000000000000000000000000000000000000000000000000000000000000162e"}

Returns the number of transactions sent from an address.

  1. DATA, 20 Bytes - address.
  2. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter
params: [
   '0x407d73d8a49eeb85d32cf465507dd71d507100c1',
   'latest' // state at the latest block
]

QUANTITY - integer of the number of transactions send from this address.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getTransactionCount","params":["0x57d83802a772adf506a89f5021c93a05749e3c6e","latest"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x29" // 41
}

Returns the number of transactions in a block from a block matching the given block hash.

  1. DATA, 32 Bytes - hash of a block
params: [
   '0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238'
]

QUANTITY - integer of the number of transactions in this block.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getBlockTransactionCountByHash","params":["0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238"],"id":101}' localhost:8545

// Result
{
  "id":1,
  "jsonrpc": "2.0",
  "result": "0xb" // 11
}

Returns the number of transactions in a block matching the given block number.
  1. QUANTITY|TAG - integer of a block number, or the string "earliest", "latest" or "pending", as in the default block parameter.
params: [
   '0xe8', // 232
]

QUANTITY - integer of the number of transactions in this block.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getBlockTransactionCountByNumber","params":["0xe8"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0xa" // 10
}

Returns the number of uncles in a block from a block matching the given block hash.

  1. DATA, 32 Bytes - hash of a block
params: [
   '0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238'
]

QUANTITY - integer of the number of uncles in this block.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getUncleCountByBlockHash","params":["0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x1" // 1
}

Returns the number of uncles in a block from a block matching the given block number.

  1. QUANTITY|TAG - integer of a block number, or the string “latest”, “earliest” or “pending”, see the default block parameter
params: [
   '0xe8', // 232
]

QUANTITY - integer of the number of uncles in this block.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getUncleCountByBlockNumber","params":["0xe8"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x1" // 1
}

Returns code at a given address.

  1. DATA, 20 Bytes - address
  2. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter
params: [
   '0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b',
   '0x2'  // 2
]

DATA - the code from the given address.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getCode","params":["0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x2"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x600160008035811a818181146012578301005b601b6001356025565b8060005260206000f25b600060078202905091905056"
}

The sign method calculates an MOAC specific signature with: sign(keccak256("\x19MOAC Signed Message:\n" + len(message) + message))).

By adding a prefix to the message makes the calculated signature recognisable as an MOAC specific signature. This prevents misuse where a malicious DApp can sign arbitrary data (e.g. transaction) and use the signature to impersonate the victim.

Note the address to sign with must be unlocked.

account, message

  1. DATA, 20 Bytes - address
  2. DATA, N Bytes - message to sign

DATA: Signature

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_sign","params":["0x57d83802a772adf506a89f5021c93a05749e3c6e", "0xdeadbeaf"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0xefa354f816ab378a7da6ec25afe9e6393b72a3c06b2d08550815cc43d1993f6c58afbf228559df6a39ac419bef847ca2dc3047886df6a0f06a4c5e6a4e2dc9a61c"
}

An example how to use solidity ecrecover to verify the signature calculated with mc_sign can be found here. The contract is deployed on the testnet Ropsten and Rinkeby.


Creates new message call transaction or a contract creation, if the data field contains code.

Note the address to sign with must be unlocked.

  1. Object - The transaction object
  • from: DATA, 20 Bytes - The address the transaction is send from.
  • to: DATA, 20 Bytes - (optional when creating new contract) The address the transaction is directed to.
  • gas: QUANTITY - (optional, default: 90000) Integer of the gas provided for the transaction execution. It will return unused gas.
  • gasPrice: QUANTITY - (optional, default: To-Be-Determined) Integer of the gasPrice used for each paid gas
  • value: QUANTITY - (optional) Integer of the value sent with this transaction
  • data: DATA - The compiled code of a contract OR the hash of the invoked method signature and encoded parameters. For details see Ethereum Contract ABI
  • nonce: QUANTITY - (optional) Integer of a nonce. This allows to overwrite your own pending transactions that use the same nonce.
params: [{
  "from": "0xb60e8dd61c5d32be8058bb8eb970870f07233155",
  "to": "0xd46e8dd67c5d32be8058bb8eb970870f07244567",
  "gas": "0x76c0", // 30400
  "gasPrice": "0x9184e72a000", // 10000000000000
  "value": "0x9184e72a", // 2441406250
  "data": "0xd46e8dd67c5d32be8d46e8dd67c5d32be8058bb8eb970870f072445675058bb8eb970870f072445675"
}]

DATA, 32 Bytes - the transaction hash, or the zero hash if the transaction is not yet available.

Use mc_getTransactionReceipt to get the contract address, after the transaction was mined, when you created a contract.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_sendTransaction","params":[{see above}],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331"
}

Creates new message call transaction or a contract creation for signed transactions.

  1. DATA, The signed transaction data.
params: ["0xd46e8dd67c5d32be8d46e8dd67c5d32be8058bb8eb970870f072445675058bb8eb970870f072445675"]

DATA, 32 Bytes - the transaction hash, or the zero hash if the transaction is not yet available.

Use mc_getTransactionReceipt to get the contract address, after the transaction was mined, when you created a contract.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_sendRawTransaction","params":[{see above}],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331"
}

Executes a new message call immediately without creating a transaction on the block chain.

  1. Object - The transaction call object
  • from: DATA, 20 Bytes - (optional) The address the transaction is sent from.
  • to: DATA, 20 Bytes - The address the transaction is directed to.
  • gas: QUANTITY - (optional) Integer of the gas provided for the transaction execution. mc_call consumes zero gas, but this parameter may be needed by some executions.
  • gasPrice: QUANTITY - (optional) Integer of the gasPrice used for each paid gas
  • value: QUANTITY - (optional) Integer of the value sent with this transaction
  • data: DATA - (optional) Hash of the method signature and encoded parameters. For details see Ethereum Contract ABI
  1. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter

DATA - the return value of executed contract.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_call","params":[{see above}],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x"
}

Generates and returns an estimate of how much gas is necessary to allow the transaction to complete. The transaction will not be added to the blockchain. Note that the estimate may be significantly more than the amount of gas actually used by the transaction, for a variety of reasons including EVM mechanics and node performance.

See mc_call parameters, expect that all properties are optional. If no gas limit is specified moac uses the block gas limit from the pending block as an upper bound. As a result the returned estimate might not be enough to executed the call/transaction when the amount of gas is higher than the pending block gas limit.

QUANTITY - the amount of gas used.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_estimateGas","params":[{see above}],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x5208" // 21000
}

Returns information about a block by hash.

  1. DATA, 32 Bytes - Hash of a block.
  2. Boolean - If true it returns the full transaction objects, if false only the hashes of the transactions.
params: [
   '0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331',
   true
]

Object - A block object, or null when no block was found:

  • number: QUANTITY - the block number. null when its pending block.
  • hash: DATA, 32 Bytes - hash of the block. null when its pending block.
  • parentHash: DATA, 32 Bytes - hash of the parent block.
  • nonce: DATA, 8 Bytes - hash of the generated proof-of-work. null when its pending block.
  • sha3Uncles: DATA, 32 Bytes - SHA3 of the uncles data in the block.
  • logsBloom: DATA, 256 Bytes - the bloom filter for the logs of the block. null when its pending block.
  • transactionsRoot: DATA, 32 Bytes - the root of the transaction trie of the block.
  • stateRoot: DATA, 32 Bytes - the root of the final state trie of the block.
  • receiptsRoot: DATA, 32 Bytes - the root of the receipts trie of the block.
  • miner: DATA, 20 Bytes - the address of the beneficiary to whom the mining rewards were given.
  • difficulty: QUANTITY - integer of the difficulty for this block.
  • totalDifficulty: QUANTITY - integer of the total difficulty of the chain until this block.
  • extraData: DATA - the “extra data” field of this block.
  • size: QUANTITY - integer the size of this block in bytes.
  • gasLimit: QUANTITY - the maximum gas allowed in this block.
  • gasUsed: QUANTITY - the total used gas by all transactions in this block.
  • timestamp: QUANTITY - the unix timestamp for when the block was collated.
  • transactions: Array - Array of transaction objects, or 32 Bytes transaction hashes depending on the last given parameter.
  • uncles: Array - Array of uncle hashes.
// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getBlockByHash","params":["0x9d88f2a2a348eec743b149f461fddcf0843d3920ddf998896672cee476b99127", true],"id":101}' localhost:8545

// Result
{
"jsonrpc":"2.0",
"id":101,
"result":{
  "difficulty":"0x9ad5136",
  "extraData":"0xdd854d4f41432d85302e382e332d87676f312e382e338777696e646f7773",
  "gasLimit":"0x895440",
  "gasUsed":"0x0",
  "hash":"0x9d88f2a2a348eec743b149f461fddcf0843d3920ddf998896672cee476b99127",
  "logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  "miner":"0x0a2168d2f08161c01745fec4e6e8fe06f314ab41",
  "mixHash":"0xd6e9f8d36f8f0f57abff5ccf6390ece4d5a14eb624779628fd6e6119451589e2",
  "nonce":"0x423e7acb4d05a23c",
  "number":"0x4803d",
  "parentHash":"0xc494dbda1ef4f673fd14fc487a1346a7747a41910d1a1f0e72d6e0e660c0e792",
  "receiptsRoot":"0x9287370eb27f11b0c2188431cbc58a23b685f02dbd851ed4d974f932bd780839",
  "sha3Uncles":"0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
  "size":"0x24e",
  "stateRoot":"0xff791a26fd0cb6addfe4bec0287b3905bf44898f0fd71e446cb1385f94333e18",
  "timestamp":"0x5b1f3a14",
  "totalDifficulty":"0x325dc638b38e",
  "transactions":[{"blockHash":"0x9d88f2a2a348eec743b149f461fddcf0843d3920ddf998896672cee476b99127","blockNumber":"0x4803d","from":"0x0000000000000000000000000000000000000064","gas":"0x0","gasPrice":"0x4a817c800","hash":"0x52ccd05bdfb137fcbb6154f1cb7c006ba53cd8ce80511841d2e7b3c6324d49df","input":"0xc1c0e9c4","nonce":"0x4803c","syscnt":"0x65","to":"0x0000000000000000000000000000000000000065","transactionIndex":"0x0","value":"0x0","v":"0x0","r":"0x0","s":"0x0","shardingFlag":"0x0"}],
  "transactionsRoot":"0xa29e25d8e3db000e44122a594cc52a7bf050850b3a7e028fd54cb83784fc1bc3",
  "uncles":[]
  }
}

Returns information about a block by block number.

  1. QUANTITY|TAG - integer of a block number, or the string "earliest", "latest" or "pending", as in the default block parameter.
  2. Boolean - If true it returns the full transaction objects, if false only the hashes of the transactions.
params: [
   '0x1b4', // 436
   true
]

See mc_getBlockByHash

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getBlockByNumber","params":["0x1b4", true],"id":101}' localhost:8545

Result see mc_getBlockByHash


Returns the information about a transaction requested by transaction hash.

  1. DATA, 32 Bytes - hash of a transaction
params: [
   "0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238"
]

Object - A transaction object, or null when no transaction was found:

  • hash: DATA, 32 Bytes - hash of the transaction.
  • nonce: QUANTITY - the number of transactions made by the sender prior to this one.
  • blockHash: DATA, 32 Bytes - hash of the block where this transaction was in. null when its pending.
  • blockNumber: QUANTITY - block number where this transaction was in. null when its pending.
  • transactionIndex: QUANTITY - integer of the transactions index position in the block. null when its pending.
  • from: DATA, 20 Bytes - address of the sender.
  • to: DATA, 20 Bytes - address of the receiver. null when its a contract creation transaction.
  • value: QUANTITY - value transferred in Wei.
  • gasPrice: QUANTITY - gas price provided by the sender in Wei.
  • gas: QUANTITY - gas provided by the sender.
  • input: DATA - the data send along with the transaction.
// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getTransactionByHash","params":["0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238"],"id":101}' localhost:8545

// Result
{
"id":101,
"jsonrpc":"2.0",
"result": {
    "hash":"0xc6ef2fc5426d6ad6fd9e2a26abeab0aa2411b7ab17f30a99d3cb96aed1d1055b",
    "nonce":"0x",
    "blockHash": "0xbeab0aa2411b7ab17f30a99d3cb9c6ef2fc5426d6ad6fd9e2a26a6aed1d1055b",
    "blockNumber": "0x15df", // 5599
    "transactionIndex":  "0x1", // 1
    "from":"0x407d73d8a49eeb85d32cf465507dd71d507100c1",
    "to":"0x85h43d8a49eeb85d32cf465507dd71d507100c1",
    "value":"0x7f110", // 520464
    "gas": "0x7f110", // 520464
    "gasPrice":"0x09184e72a000",
    "input":"0x603880600c6000396000f300603880600c6000396000f3603880600c6000396000f360",
  }
}

Returns information about a transaction by block hash and transaction index position.

  1. DATA, 32 Bytes - hash of a block.
  2. QUANTITY - integer of the transaction index position.
params: [
   '0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331',
   '0x0' // 0
]

See mc_getTransactionByHash

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getTransactionByBlockHashAndIndex","params":["0xc6ef2fc5426d6ad6fd9e2a26abeab0aa2411b7ab17f30a99d3cb96aed1d1055b", "0x0"],"id":101}' localhost:8545

Result see mc_getTransactionByHash


Returns information about a transaction by block number and transaction index position.

  1. QUANTITY|TAG - a block number, or the string "earliest", "latest" or "pending", as in the default block parameter.
  2. QUANTITY - the transaction index position.
params: [
   '0x29c', // 668
   '0x0' // 0
]

See mc_getTransactionByHash

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getTransactionByBlockNumberAndIndex","params":["0x29c", "0x0"],"id":101}' localhost:8545

Result see mc_getTransactionByHash


Returns the receipt of a transaction by transaction hash.

Note That the receipt is not available for pending transactions.

  1. DATA, 32 Bytes - hash of a transaction
params: [
   '0x7bb694c3462764cb113e9b742faaf06adc728e70b607f8b7aa95207ee32b1c5e'
]

Object - A transaction receipt object, or null when no receipt was found:

  • transactionHash: DATA, 32 Bytes - hash of the transaction.
  • transactionIndex: QUANTITY - integer of the transactions index position in the block.
  • blockHash: DATA, 32 Bytes - hash of the block where this transaction was in.
  • blockNumber: QUANTITY - block number where this transaction was in.
  • cumulativeGasUsed: QUANTITY - The total amount of gas used when this transaction was executed in the block.
  • gasUsed: QUANTITY - The amount of gas used by this specific transaction alone.
  • contractAddress: DATA, 20 Bytes - The contract address created, if the transaction was a contract creation, otherwise null.
  • logs: Array - Array of log objects, which this transaction generated.
  • logsBloom: DATA, 256 Bytes - Bloom filter for light clients to quickly retrieve related logs.

It also returns either :

  • root : DATA 32 bytes of post-transaction stateroot (pre Byzantium)
  • status: QUANTITY either 1 (success) or 0 (failure)
// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getTransactionReceipt","params":["0x7bb694c3462764cb113e9b742faaf06adc728e70b607f8b7aa95207ee32b1c5e"],"id":101}' localhost:8545

// Result
{
{"jsonrpc":"2.0",
"id":101,
"result":{
"blockHash":"0xad7d2eec610b3e04ea4676c11a3184cb07df43ed7ab717f331d3c952fc1b55cf",
"blockNumber":"0x1b943",
"contractAddress":"0xf2f4eec6c2adfcf780aae828de0b25f86506ffae",
"cumulativeGasUsed":"0x1b337c",
"from":"0x7312f4b8a4457a36827f185325fd6b66a3f8bb8b",
"gasUsed":"0x1b337c",
"logs":[],
"logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"status":"0x1",
"to":null,
"transactionHash":"0x7bb694c3462764cb113e9b742faaf06adc728e70b607f8b7aa95207ee32b1c5e",
"transactionIndex":"0x1"}
}

Returns information about a uncle of a block by hash and uncle index position.

  1. DATA, 32 Bytes - hash a block.
  2. QUANTITY - the uncle’s index position.
params: [
   '0xc6ef2fc5426d6ad6fd9e2a26abeab0aa2411b7ab17f30a99d3cb96aed1d1055b',
   '0x0' // 0
]

See mc_getBlockByHash

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getUncleByBlockHashAndIndex","params":["0x696d389aa9b6b44e08af9f3528c51587aac435b75a54ece42f4b2d1289043497", "0x0"],"id":101}' localhost:8545

Result see mc_getBlockByHash

Note: An uncle doesn’t contain individual transactions.


Returns information about a uncle of a block by number and uncle index position.

  1. QUANTITY|TAG - a block number, or the string "earliest", "latest" or "pending", as in the default block parameter.
  2. QUANTITY - the uncle’s index position.
params: [
   '0x29c', // 668
   '0x0' // 0
]

See mc_getBlockByHash

Note: An uncle doesn’t contain individual transactions.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getUncleByBlockNumberAndIndex","params":["0x29c", "0x0"],"id":101}' localhost:8545

Result see mc_getBlockByHash


Creates a filter object, based on filter options, to notify when the state changes (logs). To check if the state has changed, call mc_getFilterChanges.

Topics are order-dependent. A transaction with a log with topics [A, B] will be matched by the following topic filters: * [] “anything” * [A] “A in first position (and anything after)” * [null, B] “anything in first position AND B in second position (and anything after)” * [A, B] “A in first position AND B in second position (and anything after)” * [[A, B], [A, B]] “(A OR B) in first position AND (A OR B) in second position (and anything after)”

  1. Object - The filter options:
  • fromBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
  • toBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
  • address: DATA|Array, 20 Bytes - (optional) Contract address or a list of addresses from which logs should originate.
  • topics: Array of DATA, - (optional) Array of 32 Bytes DATA topics. Topics are order-dependent. Each topic can also be an array of DATA with “or” options.
params: [{
  "fromBlock": "0x1",
  "toBlock": "0x2",
  "address": "0x8888f1f195afa192cfee860698584c030f4c9db1",
  "topics": ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", null, ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x0000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebccc"]]
}]

QUANTITY - A filter id.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_newFilter","params":[{"topics":["0x12341234"]}],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": "0x1" // 1
}

Creates a filter in the node, to notify when a new block arrives. To check if the state has changed, call mc_getFilterChanges.

None

QUANTITY - A filter id.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_newBlockFilter","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc":  "2.0",
  "result": "0x244afc5c2cb35b24c5b91bba7f7ab19d" // 1
}

Creates a filter in the node, to notify when new pending transactions arrive. To check if the state has changed, call mc_getFilterChanges.

None

QUANTITY - A filter id.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_newPendingTransactionFilter","params":[],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc":  "2.0",
  "result": "0x1" // 1
}

Uninstalls a filter with given id. Should always be called when watch is no longer needed. Additonally Filters timeout when they aren’t requested with mc_getFilterChanges for a period of time.

  1. QUANTITY - The filter id.
params: [
  "0xb" // 11
]

Boolean - true if the filter was successfully uninstalled, otherwise false.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_uninstallFilter","params":["0xb"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc": "2.0",
  "result": true
}

Polling method for a filter, which returns an array of logs which occurred since last poll.

  1. QUANTITY - the filter id.
params: [
  "0x16" // 22
]

Array - Array of log objects, or an empty array if nothing has changed since last poll.

  • For filters created with mc_newBlockFilter the return are block hashes (DATA, 32 Bytes), e.g. ["0x3454645634534..."].
  • For filters created with mc_newPendingTransactionFilter the return are transaction hashes (DATA, 32 Bytes), e.g. ["0x6345343454645..."].
  • For filters created with mc_newFilter logs are objects with following params:
  • removed: TAG - true when the log was removed, due to a chain reorganization. false if its a valid log.
  • logIndex: QUANTITY - integer of the log index position in the block. null when its pending log.
  • transactionIndex: QUANTITY - integer of the transactions index position log was created from. null when its pending log.
  • transactionHash: DATA, 32 Bytes - hash of the transactions this log was created from. null when its pending log.
  • blockHash: DATA, 32 Bytes - hash of the block where this log was in. null when its pending. null when its pending log.
  • blockNumber: QUANTITY - the block number where this log was in. null when its pending. null when its pending log.
  • address: DATA, 20 Bytes - address from which this log originated.
  • data: DATA - contains one or more 32 Bytes non-indexed arguments of the log.
  • topics: Array of DATA - Array of 0 to 4 32 Bytes DATA of indexed log arguments. (In solidity: The first topic is the hash of the signature of the event (e.g. Deposit(address,bytes32,uint256)), except you declared the event with the anonymous specifier.)
// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getFilterChanges","params":["0x16"],"id":101}' localhost:8545

// Result
{
  "id":101,
  "jsonrpc":"2.0",
  "result": [{
    "logIndex": "0x1", // 1
    "blockNumber":"0x1b4", // 436
    "blockHash": "0x8216c5785ac562ff41e2dcfdf5785ac562ff41e2dcfdf829c5a142f1fccd7d",
    "transactionHash":  "0xdf829c5a142f1fccd7d8216c5785ac562ff41e2dcfdf5785ac562ff41e2dcf",
    "transactionIndex": "0x0", // 0
    "address": "0x16c5785ac562ff41e2dcfdf829c5a142f1fccd7d",
    "data":"0x0000000000000000000000000000000000000000000000000000000000000000",
    "topics": ["0x59ebeb90bc63057b6515673c3ecf9438e5058bca0f92585014eced636878c9a5"]
    },{
      ...
    }]
}

Returns an array of all logs matching filter with given id.

  1. QUANTITY - The filter id.
params: [
  "0x16" // 22
]

See mc_getFilterChanges

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getFilterLogs","params":["0x16"],"id":101}' localhost:8545

Result see mc_getFilterChanges


Returns an array of all logs matching a given filter object.

  1. Object - the filter object, see mc_newFilter parameters.
params: [{
  "topics": ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b"]
}]

See mc_getFilterChanges

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getLogs","params":[{"topics":["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b"]}],"id":101}'

Result see mc_getFilterChanges


Returns the hash of the current block, the seedHash, and the boundary condition to be met (“target”).

none

Array - Array with the following properties: 1. DATA, 32 Bytes - current block header pow-hash 2. DATA, 32 Bytes - the seed hash used for the DAG. 3. DATA, 32 Bytes - the boundary condition (“target”), 2^256 / difficulty.

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"mc_getWork","params":[],"id":101}' localhost:8545

// Result
{
"jsonrpc":"2.0",
"id":101,
"result":["0x367ebe7ed77dde0a4cc134adaa769f93a833e08a86a0d38ab18e32cc3740b5f8","0x9b2baad7528ecec612c5751a6bd525905892d7892e155c3b05e61363154a940b","0x0000001dd67ebb66a2c0fc63b9907077f70b5315e1780a8b74f33d40e2a9a7e4"]
}

Used for submitting a proof-of-work solution.

  1. DATA, 8 Bytes - The nonce found (64 bits)
  2. DATA, 32 Bytes - The header’s pow-hash (256 bits)
  3. DATA, 32 Bytes - The mix digest (256 bits)
params: [
  "0x0000000000000001",
  "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "0xD1FE5700000000000000000000000000D1FE5700000000000000000000000000"
]

Boolean - returns true if the provided solution is valid, otherwise false.

// Request
curl -X POST --data '{"jsonrpc":"2.0", "method":"mc_submitWork", "params":["0x0000000000000001", "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef", "0xD1GE5700000000000000000000000000D1GE5700000000000000000000000000"],"id":101}'

// Result
{
  "id":101,
  "jsonrpc":"2.0",
  "result": true
}