name | category |
---|---|
Javascript API |
To make your Ðapp work on Ethereum, you can use the web3
object provided by the web3.js library. Under the hood it communicates to a local node through RPC calls. web3.js works with any Ethereum node, which exposes an RPC layer.
web3
contains the eth
object - web3.eth
(for specifically Ethereum blockchain interactions) and the shh
object - web3.shh
(for Whisper interaction). Over time we'll introduce other objects for each of the other web3 protocols. Working examples can be found here.
If you want to look at some more sophisticated examples using web3.js check out these useful Ðapp patterns.
As this API is designed to work with a local RPC node and all its functions are by default use synchronous HTTP requests.con
If you want to make asynchronous request, you can pass an optional callback as the last parameter to most functions. All callbacks are using an error first callback style:
web3.eth.getBlock(48, function(error, result){
if(!error)
console.log(result)
else
console.error(error);
})
Batch requests allow queuing up requests and processing them at once.
var batch = web3.createBatch();
batch.add(web3.eth.getBalance.request('0x0000000000000000000000000000000000000000', 'latest', callback));
batch.add(web3.eth.contract(abi).at(address).balance.request(address, callback2));
batch.execute();
You will always get a BigNumber object for balance values as JavaScript is not able to handle big numbers correctly. Look at the following examples:
"101010100324325345346456456456456456456"
// "101010100324325345346456456456456456456"
101010100324325345346456456456456456456
// 1.0101010032432535e+38
web3.js depends on the BigNumber Library and adds it automatically.
var balance = new BigNumber('131242344353464564564574574567456');
// or var balance = web3.eth.getBalance(someAddress);
balance.plus(21).toString(10); // toString(10) converts it to a number string
// "131242344353464564564574574567477"
The next example wouldn't work as we have more than 20 floating points, therefore it is recommended to keep you balance always in wei and only transform it to other units when presenting to the user:
var balance = new BigNumber('13124.234435346456466666457455567456');
balance.plus(21).toString(10); // toString(10) converts it to a number string, but can only show max 20 floating points
// "13145.23443534645646666646" // you number would be cut after the 20 floating point
- web3
- version
- isConnected()
- setProvider(provider)
- currentProvider
- reset()
- sha3(string)
- toHex(stringOrNumber)
- toAscii(hexString)
- fromAscii(textString, [padding])
- toDecimal(hexString)
- fromDecimal(number)
- fromWei(numberStringOrBigNumber, unit)
- toWei(numberStringOrBigNumber, unit)
- toBigNumber(numberOrHexString)
- isAddress(hexString)
- net
- eth
- defaultAccount
- defaultBlock
- syncing/getSyncing
- isSyncing
- coinbase/getCoinbase
- hashrate/getHashrate
- gasPrice/getGasPrice
- accounts/getAccounts
- mining/getMining
- blockNumber/getBlockNumber
- register(hexString) (Not implemented yet)
- unRegister(hexString) (Not implemented yet)
- getBalance(address)
- getStorageAt(address, position)
- getCode(address)
- getBlock(hash/number)
- getBlockTransactionCount(hash/number)
- getUncle(hash/number)
- getBlockUncleCount(hash/number)
- getTransaction(hash)
- getTransactionFromBlock(hashOrNumber, indexNumber)
- getTransactionReceipt(hash)
- getTransactionCount(address)
- sendTransaction(object)
- call(object)
- estimateGas(object)
- filter(array (, options) )
- contract(abiArray)
- contract.myMethod()
- contract.myEvent()
- contract.allEvents()
- getCompilers()
- compile.lll(string)
- compile.solidity(string)
- compile.serpent(string)
- namereg
- sendIBANTransaction
- iban
- db
- shh
The web3
object provides all methods.
var Web3 = require('web3');
// create an instance of web3 using the HTTP provider.
// NOTE in mist web3 is already available, so check first if its available before instantiating
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
web3.version.api
// or async
web3.version.getApi(callback(error, result){ ... })
String
- The ethereum js api version.
var version = web3.version.api;
console.log(version); // "0.2.0"
web3.version.node
// or async
web3.version.getClient(callback(error, result){ ... })
String
- The client/node version.
var version = web3.version.node;
console.log(version); // "Mist/v0.9.3/darwin/go1.4.1"
web3.version.network
// or async
web3.version.getNetwork(callback(error, result){ ... })
String
- The network protocol version.
var version = web3.version.network;
console.log(version); // 54
web3.version.ethereum
// or async
web3.version.getEthereum(callback(error, result){ ... })
String
- The ethereum protocol version.
var version = web3.version.ethereum;
console.log(version); // 60
web3.version.whisper
// or async
web3.version.getWhisper(callback(error, result){ ... })
String
- The whisper protocol version.
var version = web3.version.whisper;
console.log(version); // 20
web3.isConnected()
Should be called to check if a connection to a node exists
none
Boolean
if(!web3.isConnected()) {
// show some dialog to ask the user to start a node
} else {
// start web3 filters, calls, etc
}
web3.setProvider(provider)
Should be called to set provider.
none
undefined
web3.setProvider(new web3.providers.HttpProvider('http://localhost:8545')); // 8080 for cpp/AZ, 8545 for go/mist
web3.currentProvider
Will contain the current provider, if one is set. This can be used to check if mist etc. set already a provider.
Object
- The provider set or null
;
// Check if mist etc. already set a provider
if(!web3.currentProvider)
web3.setProvider(new web3.providers.HttpProvider("http://localhost:8545"));
web3.reset(keepIsSyncing)
Should be called to reset state of web3. Resets everything except manager. Uninstalls all filters. Stops polling.
Boolean
- Iftrue
it will uninstall all filters, but will keep the web3.eth.isSyncing() polls
undefined
web3.reset();
web3.sha3(string [, callback])
String
- The string to hash using the SHA3 algorithmFunction
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The SHA3 of the given data.
var str = web3.sha3("Some ASCII string to be hashed");
console.log(str); // "0x536f6d6520415343494920737472696e6720746f20626520686173686564"
var hash = web3.sha3(str);
console.log(hash); // "0xb21dbc7a5eb6042d91f8f584af266f1a512ac89520f43562c6c1e37eab6eb0c4"
web3.toHex(mixed);
Converts any value into HEX.
String|Number|Object|Array|BigNumber
- The value to parse to HEX. If its an object or array it will beJSON.stringify
first. If its a BigNumber it will make it the HEX value of a number.
String
- The hex string of mixed
.
var str = web3.toHex({test: 'test'});
console.log(str); // '0x7b2274657374223a2274657374227d'
web3.toAscii(hexString);
Converts a HEX string into a ASCII string.
String
- A HEX string to be converted to ascii.
String
- An ASCII string made from the given hexString
.
var str = web3.toAscii("0x657468657265756d000000000000000000000000000000000000000000000000");
console.log(str); // "ethereum"
web3.fromAscii(string [, padding]);
Converts any ASCII string to a HEX string.
String
- An ASCII string to be converted to HEX.Number
- The number of bytes the returned HEX string should have.
String
- The converted HEX string.
var str = web3.fromAscii('ethereum');
console.log(str); // "0x657468657265756d"
var str2 = web3.fromAscii('ethereum', 32);
console.log(str2); // "0x657468657265756d000000000000000000000000000000000000000000000000"
web3.toDecimal(hexString);
Converts a HEX string to its number representation.
String
- An HEX string to be converted to a number.
Number
- The number representing the data hexString
.
var number = web3.toDecimal('0x15');
console.log(number); // 21
web3.fromDecimal(number);
Converts a number or number string to its HEX representation.
Number|String
- A number to be converted to a HEX string.
String
- The HEX string representing of the given number
.
var value = web3.fromDecimal('21');
console.log(value); // "0x15"
web3.fromWei(number, unit)
Converts a number of wei into the following ethereum units:
kwei
/ada
mwei
/babbage
gwei
/shannon
szabo
finney
ether
kether
/grand
/einstein
mether
gether
tether
Number|String|BigNumber
- A number or BigNumber instance.String
- One of the above ether units.
String|BigNumber
- Either a number string, or a BigNumber instance, depending on the given number
parameter.
var value = web3.fromWei('21000000000000', 'finney');
console.log(value); // "0.021"
web3.toWei(number, unit)
Converts an ethereum unit into wei. Possible units are:
kwei
/ada
mwei
/babbage
gwei
/shannon
szabo
finney
ether
kether
/grand
/einstein
mether
gether
tether
Number|String|BigNumber
- A number or BigNumber instance.String
- One of the above ether units.
String|BigNumber
- Either a number string, or a BigNumber instance, depending on the given number
parameter.
var value = web3.toWei('1', 'ether');
console.log(value); // "1000000000000000000"
web3.toBigNumber(numberOrHexString);
Converts a given number into a BigNumber instance.
See the note on BigNumber.
Number|String
- A number, number string or HEX string of a number.
BigNumber
- A BigNumber instance representing the given value.
var value = web3.toBigNumber('200000000000000000000001');
console.log(value); // instanceOf BigNumber
console.log(value.toNumber()); // 2.0000000000000002e+23
console.log(value.toString(10)); // '200000000000000000000001'
web3.net.listening
// or async
web3.net.getListening(callback(error, result){ ... })
This property is read only and says whether the node is actively listening for network connections or not.
Boolean
- true
if the client is actively listening for network connections, otherwise false
.
var listening = web3.net.listening;
console.log(listening); // true of false
web3.net.peerCount
// or async
web3.net.getPeerCount(callback(error, result){ ... })
This property is read only and returns the number of connected peers.
Number
- The number of peers currently connected to the client.
var peerCount = web3.net.peerCount;
console.log(peerCount); // 4
Contains the ethereum blockchain related methods.
var eth = web3.eth;
web3.eth.defaultAccount
This default address is used for the following methods (optionally you can overwrite it by specifying the from
property):
String
, 20 Bytes - Any address you own, or where you have the private key for.
Default is undefined
.
String
, 20 Bytes - The currently set default address.
var defaultAccount = web3.eth.defaultAccount;
console.log(defaultAccount); // ''
// set the default block
web3.eth.defaultAccount = '0x8888f1f195afa192cfee860698584c030f4c9db1';
web3.eth.defaultBlock
This default block is used for the following methods (optionally you can overwrite the defaultBlock by passing it as the last parameter):
- web3.eth.getBalance()
- web3.eth.getCode()
- web3.eth.getTransactionCount()
- web3.eth.getStorageAt()
- web3.eth.call()
Default block parameters can be one of the following:
Number
- a block numberString
-"earliest"
, the genisis blockString
-"latest"
, the latest block (current head of the blockchain)String
-"pending"
, the currently mined block (including pending transactions)
Default is latest
Number|String
- The default block number to use when querying a state.
var defaultBlock = web3.eth.defaultBlock;
console.log(defaultBlock); // 'latest'
// set the default block
web3.eth.defaultBlock = 231;
web3.eth.syncing
// or async
web3.eth.getSyncing(callback(error, result){ ... })
This property is read only and returns the either a sync object, when the node is syncing or false
.
Object|Boolean
- A sync object as follows, when the node is currently syncing or false
:
startingBlock
:Number
- The block number where the sync started.currentBlock
:Number
- The block number where at which block the node currently synced to already.highestBlock
:Number
- The estimated block number to sync to.
var sync = web3.eth.syncing;
console.log(sync);
/*
{
startingBlock: 300,
currentBlock: 312,
highestBlock: 512
}
*/
web3.eth.isSyncing(callback);
This convenience function calls the callback
everytime a sync starts, updates and stops.
Object
- a isSyncing object with the following methods:
syncing.addCallback()
: Adds another callback, which will be called when the node starts or stops syncing.syncing.stopWatching()
: Stops the syncing callbacks.
Boolean
- The callback will be fired withtrue
when the syncing starts and withfalse
when it stopped.Object
- While syncing it will return the syncing object:startingBlock
:Number
- The block number where the sync started.currentBlock
:Number
- The block number where at which block the node currently synced to already.highestBlock
:Number
- The estimated block number to sync to.
web3.eth.isSyncing(function(error, sync){
if(!error) {
// stop all app activity
if(sync === true) {
// we use `true`, so it stops all filters, but not the web3.eth.syncing polling
web3.reset(true);
// show sync info
} else if(sync) {
console.log(sync.currentBlock);
// re-gain app operation
} else {
// run your app init function...
}
}
});
web3.eth.coinbase
// or async
web3.eth.getCoinbase(callback(error, result){ ... })
This property is read only and returns the coinbase address were the mining rewards go to.
String
- The coinbase address of the client.
var coinbase = web3.eth.coinbase;
console.log(coinbase); // "0x407d73d8a49eeb85d32cf465507dd71d507100c1"
web3.eth.mining
// or async
web3.eth.getMining(callback(error, result){ ... })
This property is read only and says whether the node is mining or not.
Boolean
- true
if the client is mining, otherwise false
.
var mining = web3.eth.mining;
console.log(mining); // true or false
web3.eth.hashrate
// or async
web3.eth.getHashrate(callback(error, result){ ... })
This property is read only and returns the number of hashes per second that the node is mining with.
Number
- number of hashes per second.
var hashrate = web3.eth.hashrate;
console.log(hashrate); // 493736
web3.eth.gasPrice
// or async
web3.eth.getGasPrice(callback(error, result){ ... })
This property is read only and returns the current gas price. The gas price is determined by the x latest blocks median gas price.
BigNumber
- A BigNumber instance of the current gas price in wei.
See the note on BigNumber.
var gasPrice = web3.eth.gasPrice;
console.log(gasPrice.toString(10)); // "10000000000000"
web3.eth.accounts
// or async
web3.eth.getAccounts(callback(error, result){ ... })
This property is read only and returns a list of accounts the node controls.
Array
- An array of addresses controlled by client.
var accounts = web3.eth.accounts;
console.log(accounts); // ["0x407d73d8a49eeb85d32cf465507dd71d507100c1"]
web3.eth.blockNumber
// or async
web3.eth.getBlockNumber(callback(error, result){ ... })
This property is read only and returns the current block number.
Number
- The number of the most recent block.
var number = web3.eth.blockNumber;
console.log(number); // 2744
web3.eth.register(addressHexString [, callback])
(Not Implemented yet)
Registers the given address to be included in web3.eth.accounts
. This allows non-private-key owned accounts to be associated as an owned account (e.g., contract wallets).
String
- The address to registerFunction
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
?
web3.eth.register("0x407d73d8a49eeb85d32cf465507dd71d507100ca")
web3.eth.unRegister(addressHexString [, callback])
(Not Implemented yet) Unregisters a given address.
String
- The address to unregister.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
?
web3.eth.unregister("0x407d73d8a49eeb85d32cf465507dd71d507100ca")
web3.eth.getBalance(addressHexString [, defaultBlock] [, callback])
Get the balance of an address at a given block.
String
- The address to get the balance of.Number|String
- (optional) If you pass this parameter it will not use the default block set with web3.eth.defaultBlock.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- A BigNumber instance of the current balance for the given address in wei.
See the note on BigNumber.
var balance = web3.eth.getBalance("0x407d73d8a49eeb85d32cf465507dd71d507100c1");
console.log(balance); // instanceof BigNumber
console.log(balance.toString(10)); // '1000000000000'
console.log(balance.toNumber()); // 1000000000000
web3.eth.getStorageAt(addressHexString, position [, defaultBlock] [, callback])
Get the storage at a specific position of an address.
String
- The address to get the storage from.Number
- The index position of the storage.Number|String
- (optional) If you pass this parameter it will not use the default block set with web3.eth.defaultBlock.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The value in storage at the given position.
var state = web3.eth.getStorageAt("0x407d73d8a49eeb85d32cf465507dd71d507100c1", 0);
console.log(state); // "0x03"
web3.eth.getCode(addressHexString [, defaultBlock] [, callback])
Get the code at a specific address.
String
- The address to get the code from.Number|String
- (optional) If you pass this parameter it will not use the default block set with web3.eth.defaultBlock.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The data at given address addressHexString
.
var code = web3.eth.getCode("0xd5677cf67b5aa051bb40496e68ad359eb97cfbf8");
console.log(code); // "0x600160008035811a818181146012578301005b601b6001356025565b8060005260206000f25b600060078202905091905056"
web3.eth.getBlock(blockHashOrBlockNumber [, returnTransactionObjects] [, callback])
Returns a block matching the block number or block hash.
String|Number
- The block number or hash. Or the string"earliest"
,"latest"
or"pending"
as in the default block parameter.Boolean
- (optional, defaultfalse
) Iftrue
, the returned block will contain all transactions as objects, iffalse
it will only contains the transaction hashes.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- The block object:
number
:Number
- the block number.null
when its pending block.hash
:String
, 32 Bytes - hash of the block.null
when its pending block.parentHash
:String
, 32 Bytes - hash of the parent block.nonce
:String
, 8 Bytes - hash of the generated proof-of-work.null
when its pending block.sha3Uncles
:String
, 32 Bytes - SHA3 of the uncles data in the block.logsBloom
:String
, 256 Bytes - the bloom filter for the logs of the block.null
when its pending block.transactionsRoot
:String
, 32 Bytes - the root of the transaction trie of the blockstateRoot
:String
, 32 Bytes - the root of the final state trie of the block.miner
:String
, 20 Bytes - the address of the beneficiary to whom the mining rewards were given.difficulty
:BigNumber
- integer of the difficulty for this block.totalDifficulty
:BigNumber
- integer of the total difficulty of the chain until this block.extraData
:String
- the "extra data" field of this block.size
:Number
- integer the size of this block in bytes.gasLimit
:Number
- the maximum gas allowed in this block.gasUsed
:Number
- the total used gas by all transactions in this block.timestamp
:Number
- 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.
var info = web3.eth.block(3150);
console.log(info);
/*
{
"number": 3,
"hash": "0xef95f2f1ed3ca60b048b4bf67cde2195961e0bba6f70bcbea9a2c4e133e34b46",
"parentHash": "0x2302e1c0b972d00932deb5dab9eb2982f570597d9d42504c05d9c2147eaf9c88",
"nonce": "0xfb6e1a62d119228b",
"sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"transactionsRoot": "0x3a1b03875115b79539e5bd33fb00d8f7b7cd61929d5a3c574f507b8acf415bee",
"stateRoot": "0xf1133199d44695dfa8fd1bcfe424d82854b5cebef75bddd7e40ea94cda515bcb",
"miner": "0x8888f1f195afa192cfee860698584c030f4c9db1",
"difficulty": BigNumber,
"totalDifficulty": BigNumber,
"size": 616,
"extraData": "0x",
"gasLimit": 3141592,
"gasUsed": 21662,
"timestamp": 1429287689,
"transactions": [
"0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b"
],
"uncles": []
}
*/
web3.eth.getBlockTransactionCount(hashStringOrBlockNumber [, callback])
Returns the number of transaction in a given block.
String|Number
- The block number or hash. Or the string"earliest"
,"latest"
or"pending"
as in the default block parameter.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Number
- The number of transactions in the given block.
var number = web3.eth.getBlockTransactionCount("0x407d73d8a49eeb85d32cf465507dd71d507100c1");
console.log(number); // 1
web3.eth.getUncle(blockHashStringOrNumber, uncleNumber [, returnTransactionObjects] [, callback])
Returns a blocks uncle by a given uncle index position.
String|Number
- The block number or hash. Or the string"earliest"
,"latest"
or"pending"
as in the default block parameter.Number
- The index position of the uncle.Boolean
- (optional, defaultfalse
) Iftrue
, the returned block will contain all transactions as objects, iffalse
it will only contains the transaction hashes.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- the returned uncle. For a return value see web3.eth.getBlock().
Note: An uncle doesn't contain individual transactions.
var uncle = web3.eth.getUncle(500, 0);
console.log(uncle); // see web3.eth.getBlock
web3.eth.getTransaction(transactionHash [, callback])
Returns a transaction matching the given transaction hash.
String
- The transaction hash.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- A transaction object its hash transactionHash
:
hash
:String
, 32 Bytes - hash of the transaction.nonce
:Number
- the number of transactions made by the sender prior to this one.blockHash
:String
, 32 Bytes - hash of the block where this transaction was in.null
when its pending.blockNumber
:Number
- block number where this transaction was in.null
when its pending.transactionIndex
:Number
- integer of the transactions index position in the block.null
when its pending.from
:String
, 20 Bytes - address of the sender.to
:String
, 20 Bytes - address of the receiver.null
when its a contract creation transaction.value
:BigNumber
- value transferred in Wei.gasPrice
:BigNumber
- gas price provided by the sender in Wei.gas
:Number
- gas provided by the sender.input
:String
- the data sent along with the transaction.
var blockNumber = 668;
var indexOfTransaction = 0
var transaction = web3.eth.getTransaction(blockNumber, indexOfTransaction);
console.log(transaction);
/*
{
"hash": "0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b",
"nonce": 2,
"blockHash": "0xef95f2f1ed3ca60b048b4bf67cde2195961e0bba6f70bcbea9a2c4e133e34b46",
"blockNumber": 3,
"transactionIndex": 0,
"from": "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
"to": "0x6295ee1b4f6dd65047762f924ecd367c17eabf8f",
"value": BigNumber,
"gas": 314159,
"gasPrice": BigNumber,
"input": "0x57cb2fc4"
}
*/
getTransactionFromBlock(hashStringOrNumber, indexNumber [, callback])
Returns a transaction based on a block hash or number and the transactions index position.
String
- A block number or hash. Or the string"earliest"
,"latest"
or"pending"
as in the default block parameter.Number
- The transactions index position.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- A transaction object, see web3.eth.getTransaction:
var transaction = web3.eth.getTransactionFromBlock('0x4534534534', 2);
console.log(transaction); // see web3.eth.getTransaction
web3.eth.getTransactionReceipt(hashString [, callback])
Returns the receipt of a transaction by transaction hash.
Note That the receipt is not available for pending transactions.
String
- The transaction hash.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- A transaction receipt object, or null
when no receipt was found:
blockHash
:String
, 32 Bytes - hash of the block where this transaction was in.blockNumber
:Number
- block number where this transaction was in.transactionHash
:String
, 32 Bytes - hash of the transaction.transactionIndex
:Number
- integer of the transactions index position in the block.from
:String
, 20 Bytes - address of the sender.to
:String
, 20 Bytes - address of the receiver.null
when its a contract creation transaction.cumulativeGasUsed
:Number
- The total amount of gas used when this transaction was executed in the block.gasUsed
:Number
- The amount of gas used by this specific transaction alone.contractAddress
:String
- 20 Bytes - The contract address created, if the transaction was a contract creation, otherwisenull
.logs
:Array
- Array of log objects, which this transaction generated.
var receipt = web3.eth.getTransactionReceipt('0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b');
console.log(receipt);
{
"transactionHash": "0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b",
"transactionIndex": 0,
"blockHash": "0xef95f2f1ed3ca60b048b4bf67cde2195961e0bba6f70bcbea9a2c4e133e34b46",
"blockNumber": 3,
"contractAddress": "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
"cumulativeGasUsed": 314159,
"gasUsed": 30234,
"logs": [{
// logs as returned by getFilterLogs, etc.
}, ...]
}
web3.eth.getTransactionCount(addressHexString [, defaultBlock] [, callback])
Get the numbers of transactions sent from this address.
String
- The address to get the numbers of transactions from.Number|String
- (optional) If you pass this parameter it will not use the default block set with web3.eth.defaultBlock.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Number
- The number of transactions sent from the given address.
var number = web3.eth.getTransactionCount("0x407d73d8a49eeb85d32cf465507dd71d507100c1");
console.log(number); // 1
web3.eth.sendTransaction(transactionObject [, callback])
Sends a transaction to the network.
Object
- The transaction object to send:
from
:String
- The address for the sending account. Uses the web3.eth.defaultAccount property, if not specified.to
:String
- (optional) The destination address of the message, left undefined for a contract-creation transaction.value
:Number|String|BigNumber
- (optional) The value transferred for the transaction in Wei, also the endowment if it's a contract-creation transaction.gas
:Number|String|BigNumber
- (optional, default: To-Be-Determined) The amount of gas to use for the transaction (unused gas is refunded).gasPrice
:Number|String|BigNumber
- (optional, default: To-Be-Determined) The price of gas for this transaction in wei, defaults to the mean network gas price.data
:String
- (optional) Either a byte string containing the associated data of the message, or in the case of a contract-creation transaction, the initialisation code.nonce
:Number
- (optional) Integer of a nonce. This allows to overwrite your own pending transactions that use the same nonce.
Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The 32 Bytes transaction hash as HEX string.
If the transaction was a contract creation use web3.eth.getTransactionReceipt() to get the contract address, after the transaction was mined.
// compiled solidity source code using https://chriseth.github.io/cpp-ethereum/
var code = "603d80600c6000396000f3007c01000000000000000000000000000000000000000000000000000000006000350463c6888fa18114602d57005b600760043502
8060005260206000f3";
web3.eth.sendTransaction({data: code}, function(err, address) {
if (!err)
console.log(address); // "0x7f9fade1c0d57a7af66ab4ead7c2eb7b11a91385"
});
web3.eth.call(callObject [, defaultBlock] [, callback])
Executes a message call transaction, which is directly executed in the VM of the node, but never mined into the blockchain.
Object
- A transaction object see web3.eth.sendTransaction, with the difference that for calls thefrom
property is optional as well.Number|String
- (optional) If you pass this parameter it will not use the default block set with web3.eth.defaultBlock.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The returned data of the call, e.g. a codes functions return value.
var result = web3.eth.call({
to: "0xc4abd0339eb8d57087278718986382264244252f",
data: "0xc6888fa10000000000000000000000000000000000000000000000000000000000000003"
});
console.log(result); // "0x0000000000000000000000000000000000000000000000000000000000000015"
web3.eth.estimateGas(callObject [, defaultBlock] [, callback])
Executes a message call or transaction, which is directly executed in the VM of the node, but never mined into the blockchain and returns the amount of the gas used.
See web3.eth.sendTransaction, expect that all properties are optional.
Number
- the used gas for the simulated call/transaction.
var result = web3.eth.estimateGas({
to: "0xc4abd0339eb8d57087278718986382264244252f",
data: "0xc6888fa10000000000000000000000000000000000000000000000000000000000000003"
});
console.log(result); // "0x0000000000000000000000000000000000000000000000000000000000000015"
// can be 'latest' or 'pending'
var filter = web3.eth.filter(filterString);
// OR object are log filter options
var filter = web3.eth.filter(options);
// watch for changes
filter.watch(function(error, result){
if (!error)
console.log(result);
});
// Additionally you can start watching right away, by passing a callback:
web3.eth.filter(options, function(error, result){
if (!error)
console.log(result);
});
String|Object
- The string"latest"
or"pending"
to watch for changes in the latest block or pending transactions respectively. Or a filter options object as follows:
fromBlock
:Number|String
- The number of the earliest block (latest
may be given to mean the most recent andpending
currently mining, block). By defaultlatest
.toBlock
:Number|String
- The number of the latest block (latest
may be given to mean the most recent andpending
currently mining, block). By defaultlatest
.address
:String
- An address or a list of addresses to only get logs from particular account(s).topics
:Array of Strings
- An array of values which must each appear in the log entries. The order is important, if you want to leave topics out usenull
, e.g.[null, '0x00...']
. You can also pass another array for each topic with options for that topic e.g.[null, ['option1', 'option2']]
Object
- A filter object with the following methods:
filter.get(callback)
: Returns all of the log entries that fit the filter.filter.watch(callback)
: Watches for state changes that fit the filter and calls the callback. See this note for details.filter.stopWatching()
: Stops the watch and uninstalls the filter in the node. Should always be called once it is done.
String
- When using the"latest"
parameter, it returns the block hash of the last incoming block.String
- When using the"pending"
parameter, it returns a transaction hash of the last add pending transaction.Object
- When using manual filter options, it returns a log object as follows:logIndex
:Number
- integer of the log index position in the block.null
when its pending log.transactionIndex
:Number
- integer of the transactions index position log was created from.null
when its pending log.transactionHash
:String
, 32 Bytes - hash of the transactions this log was created from.null
when its pending log.blockHash
:String
, 32 Bytes - hash of the block where this log was in.null
when its pending.null
when its pending log.blockNumber
:Number
- the block number where this log was in.null
when its pending.null
when its pending log.address
:String
, 32 Bytes - address from which this log originated.data
:String
- contains one or more 32 Bytes non-indexed arguments of the log.topics
:Array of Strings
- Array of 0 to 4 32 BytesDATA
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 theanonymous
specifier.)
Note For event filter return values see Contract Events
var filter = web3.eth.filter('pending');
filter.watch(function (error, log) {
console.log(log); // {"address":"0x0000000000000000000000000000000000000000", "data":"0x0000000000000000000000000000000000000000000000000000000000000000", ...}
});
// get all past logs again.
var myResults = filter.get(function(error, logs){ ... });
...
// stops and uninstalls the filter
filter.stopWatching();
web3.eth.contract(abiArray)
Creates a contract object for a solidity contract, which can be used to initiate contracts on an address. You can read more about events here.
Array
- ABI array with descriptions of functions and events of the contract.
Object
- A contract object, which can be initiated as follows:
var MyContract = web3.eth.contract(abiArray);
// instantiate by address
var contractInstance = MyContract.at([address]);
// deploy new contract
var contractInstance = MyContract.new([contructorParam1] [, contructorParam2], {data: '0x12345...', from: myAccount, gas: 1000000});
// Get the data to deploy the contract manually
var contractData = MyContract.new.getData([contructorParam1] [, contructorParam2], {data: '0x12345...'});
// contractData = '0x12345643213456000000000023434234'
And then you can either initiate an existing contract on an address, or deploy the contract using the compiled byte code:
// Instantiate from an existing address:
var myContractInstance = MyContract.at(myContractAddress);
// Or deploy a new contract:
// Deploy the contract asyncronous:
var myContractReturned = MyContract.new(param1, param2, {
data: myContractCode,
gas: 300000,
from: mySenderAddress}, function(err, myContract){
if(!err) {
// NOTE: The callback will fire twice!
// Once the contract has the transactionHash property set and once its deployed on an address.
// e.g. check tx hash on the first call (transaction send)
if(!myContract.address) {
console.log(myContract.transactionHash) // The hash of the transaction, which deploys the contract
// check address on the second call (contract deployed)
} else {
console.log(myContract.address) // the contract address
}
// Note that the returned "myContractReturned" === "myContract",
// so the returned "myContractReturned" object will also get the address set.
}
});
// Deploy contract syncronous: The address will be added as soon as the contract is mined.
// Additionally you can watch the transaction by using the "transactionHash" property
var myContractInstance = MyContract.new(param1, param2, {data: myContractCode, gas: 300000, from: mySenderAddress});
myContractInstance.transactionHash // The hash of the transaction, which created the contract
myContractInstance.address // undefined at start, but will be auto-filled later
Note When you deploy a new contract, you should check for the next 12 blocks or so if the contract code is still at the address (using web3.eth.getCode()), to make sure a fork didn't change that.
// contract abi
var abi = [{
name: 'myConstantMethod',
type: 'function',
constant: true,
inputs: [{ name: 'a', type: 'string' }],
outputs: [{name: 'd', type: 'string' }]
}, {
name: 'myStateChangingMethod',
type: 'function',
constant: false,
inputs: [{ name: 'a', type: 'string' }, { name: 'b', type: 'int' }],
outputs: []
}, {
name: 'myEvent',
type: 'event',
inputs: [{name: 'a', type: 'int', indexed: true},{name: 'b', type: 'bool', indexed: false]
}];
// creation of contract object
var MyContract = web3.eth.contract(abi);
// initiate contract for an address
var myContractInstance = MyContract.at('0xc4abd0339eb8d57087278718986382264244252f');
// call constant function
var result = myContractInstance.myConstantMethod('myParam');
console.log(result) // '0x25434534534'
// send a transaction to a function
myContractInstance.myStateChangingMethod('someParam1', 23, {value: 200, gas: 2000});
// short hand style
web3.eth.contract(abi).at(address).myAwesomeMethod(...);
// create filter
var filter = myContractInstance.myEvent({a: 5}, function (error, result) {
if (!error)
console.log(result);
/*
{
address: '0x8718986382264244252fc4abd0339eb8d5708727',
topics: "0x12345678901234567890123456789012", "0x0000000000000000000000000000000000000000000000000000000000000005",
data: "0x0000000000000000000000000000000000000000000000000000000000000001",
...
}
*/
});
// Automatically determines the use of call or sendTransaction based on the method type
myContractInstance.myMethod(param1 [, param2, ...] [, transactionObject] [, callback]);
// Explicitly calling this method
myContractInstance.myMethod.call(param1 [, param2, ...] [, transactionObject] [, callback]);
// Explicitly sending a transaction to this method
myContractInstance.myMethod.sendTransaction(param1 [, param2, ...] [, transactionObject] [, callback]);
// Explicitly sending a transaction to this method
myContractInstance.myMethod.sendTransaction(param1 [, param2, ...] [, transactionObject] [, callback]);
// Get the call data, so you can call the contract through some other means
var myCallData = myContractInstance.myMethod.getData(param1 [, param2, ...]);
// myCallData = '0x45ff3ff6000000000004545345345345..'
The contract object exposes the contracts methods, which can be called using parameters and a transaction object.
String|Number
- (optional) Zero or more parameters of the function.Object
- (optional) The (previous) last parameter can be a transaction object, see web3.eth.sendTransaction parameter 1 for more.Function
- (optional) If you pass a callback as the last parameter the HTTP request is made asynchronous. See this note for details.
String
- If its a call the result data, if its a send transaction a created contract address, or the transaction hash, see web3.eth.sendTransaction for details.
// creation of contract object
var MyContract = web3.eth.contract(abi);
// initiate contract for an address
var myContractInstance = MyContract.at('0x78e97bcc5b5dd9ed228fed7a4887c0d7287344a9');
var result = myContractInstance.myConstantMethod('myParam');
console.log(result) // '0x25434534534'
myContractInstance.myStateChangingMethod('someParam1', 23, {value: 200, gas: 2000}, function(err, result){ ... });
var event = myContractInstance.MyEvent({valueA: 23} [, additionalFilterObject])
// watch for changes
event.watch(function(error, result){
if (!error)
console.log(result);
});
// Or pass a callback to start watching immediately
var event = myContractInstance.MyEvent([{valueA: 23}] [, additionalFilterObject] , function(error, result){
if (!error)
console.log(result);
});
You can use events like filters and they have the same methods, but you pass different objects to create the event filter.
Object
- Indexed return values you want to filter the logs by, e.g.{'valueA': 1, 'valueB': [myFirstAddress, mySecondAddress]}
. By default all filter values are set tonull
. It means, that they will match any event of given type sent from this contract.Object
- Additional filter options, see filters parameter 1 for more. By default filterObject has field 'address' set to address of the contract. Also first topic is the signature of event.Function
- (optional) If you pass a callback as the last parameter it will immediately start watching and you don't need to callmyEvent.watch(function(){})
. See this note for details.
Object
- An event object as follows:
args
:Object
- The arguments coming from the event.event
:String
- The event name.logIndex
:Number
- integer of the log index position in the block.transactionIndex
:Number
- integer of the transactions index position log was created from.transactionHash
:String
, 32 Bytes - hash of the transactions this log was created from.address
:String
, 32 Bytes - address from which this log originated.blockHash
:String
, 32 Bytes - hash of the block where this log was in.null
when its pending.blockNumber
:Number
- the block number where this log was in.null
when its pending.
var MyContract = web3.eth.contract(abi);
var myContractInstance = MyContract.at('0x78e97bcc5b5dd9ed228fed7a4887c0d7287344a9');
// watch for an event with {some: 'args'}
var myEvent = myContractInstance.MyEvent({some: 'args'}, {fromBlock: 0, toBlock: 'latest'});
myEvent.watch(function(error, result){
...
});
// would get all past logs again.
var myResults = myEvent.get(function(error, logs){ ... });
...
// would stop and uninstall the filter
myEvent.stopWatching();
var events = myContractInstance.allEvents([additionalFilterObject]);
// watch for changes
events.watch(function(error, event){
if (!error)
console.log(event);
});
// Or pass a callback to start watching immediately
var events = myContractInstance.allEvents([additionalFilterObject,] function(error, log){
if (!error)
console.log(log);
});
Will call the callback for all events which are created by this contract.
Object
- Additional filter options, see filters parameter 1 for more. By default filterObject has field 'address' set to address of the contract. Also first topic is the signature of event.Function
- (optional) If you pass a callback as the last parameter it will immediately start watching and you don't need to callmyEvent.watch(function(){})
. See this note for details.
Object
- See Contract Events for more.
var MyContract = web3.eth.contract(abi);
var myContractInstance = MyContract.at('0x78e97bcc5b5dd9ed228fed7a4887c0d7287344a9');
// watch for an event with {some: 'args'}
var events = myContractInstance.allEvents({fromBlock: 0, toBlock: 'latest'});
events.watch(function(error, result){
...
});
// would get all past logs again.
events.get(function(error, logs){ ... });
...
// would stop and uninstall the filter
myEvent.stopWatching();
web3.eth.getCompilers([callback])
Gets a list of available compilers.
Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Array
- An array of strings of available compilers.
var number = web3.eth.getCompilers();
console.log(number); // ["lll", "solidity", "serpent"]
web3.eth.compile.solidity(sourceString [, callback])
Compiles solidity source code.
String
- The solidity source code.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- Contract and compiler info.
var source = "" +
"contract test {\n" +
" function multiply(uint a) returns(uint d) {\n" +
" return a * 7;\n" +
" }\n" +
"}\n";
var compiled = web3.eth.compile.solidity(source);
console.log(compiled);
// {
"test": {
"code": "0x605280600c6000396000f3006000357c010000000000000000000000000000000000000000000000000000000090048063c6888fa114602e57005b60376004356041565b8060005260206000f35b6000600782029050604d565b91905056",
"info": {
"source": "contract test {\n\tfunction multiply(uint a) returns(uint d) {\n\t\treturn a * 7;\n\t}\n}\n",
"language": "Solidity",
"languageVersion": "0",
"compilerVersion": "0.8.2",
"abiDefinition": [
{
"constant": false,
"inputs": [
{
"name": "a",
"type": "uint256"
}
],
"name": "multiply",
"outputs": [
{
"name": "d",
"type": "uint256"
}
],
"type": "function"
}
],
"userDoc": {
"methods": {}
},
"developerDoc": {
"methods": {}
}
}
}
}
web3. eth.compile.lll(sourceString [, callback])
Compiles LLL source code.
String
- The LLL source code.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The compiled LLL code as HEX string.
var source = "...";
var code = web3.eth.compile.lll(source);
console.log(code); // "0x603880600c6000396000f3006001600060e060020a600035048063c6888fa114601857005b6021600435602b565b8060005260206000f35b600081600702905091905056"
web3.eth.compile.serpent(sourceString [, callback])
Compiles serpent source code.
String
- The serpent source code.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- The compiled serpent code as HEX string.
var source = "...";
var code = web3.eth.compile.serpent(source);
console.log(code); // "0x603880600c6000396000f3006001600060e060020a600035048063c6888fa114601857005b6021600435602b565b8060005260206000f35b600081600702905091905056"
web3.eth.namereg
Returns GlobalRegistrar object.
see namereg example
web3.db.putString(db, key, value)
This method should be called, when we want to store a string in the local leveldb database.
String
- The database to store to.String
- The name of the store.String
- The string value to store.
Boolean
- true
if successfull, otherwise false
.
param is db name, second is the key, and third is the string value.
web3.db.putString('testDB', 'key', 'myString') // true
web3.db.getString(db, key)
This method should be called, when we want to get string from the local leveldb database.
String
- The database string name to retrieve from.String
- The name of the store.
String
- The stored value.
param is db name and second is the key of string value.
var value = web3.db.getString('testDB', 'key');
console.log(value); // "myString"
web3.db.putHex(db, key, value)
This method should be called, when we want to store binary data in HEX form in the local leveldb database.
String
- The database to store to.String
- The name of the store.String
- The HEX string to store.
Boolean
- true
if successfull, otherwise false
.
web3.db.putHex('testDB', 'key', '0x4f554b443'); // true
web3.db.getHex(db, key)
This method should be called, when we want to get a binary data in HEX form from the local leveldb database.
String
- The database to store to.String
- The name of the store.
String
- The stored HEX value.
param is db name and second is the key of value.
var value = web3.db.getHex('testDB', 'key');
console.log(value); // "0x4f554b443"
var shh = web3.shh;
web3.shh.post(object [, callback])
This method should be called, when we want to post whisper message to the network.
Object
- The post object:
from
:String
, 60 Bytes HEX - (optional) The identity of the sender.to
:String
, 60 Bytes HEX - (optional) The identity of the receiver. When present whisper will encrypt the message so that only the receiver can decrypt it.topics
:Array of Strings
- Array of topicsStrings
, for the receiver to identify messages.payload
:String|Number|Object
- The payload of the message. Will be autoconverted to a HEX string before.priority
:Number
- The integer of the priority in a rang from ... (?).ttl
:Number
- integer of the time to live in seconds.
Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Boolean
- returns true
if the message was send, otherwise false
.
var identity = web3.shh.newIdentity();
var topic = 'example';
var payload = 'hello whisper world!';
var message = {
from: identity,
topics: [topic],
payload: payload,
ttl: 100,
workToProve: 100 // or priority TODO
};
web3.shh.post(message);
web3.shh.newIdentity([callback])
Should be called to create new identity.
Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
String
- A new identity HEX string.
var identity = web3.shh.newIdentity();
console.log(identity); // "0xc931d93e97ab07fe42d923478ba2465f283f440fd6cabea4dd7a2c807108f651b7135d1d6ca9007d5b68aa497e4619ac10aa3b27726e1863c1fd9b570d99bbaf"
web3.shh.hasIdentity(identity, [callback])
Should be called, if we want to check if user has given identity.
String
- The identity to check.Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Boolean
- returns true
if the identity exists, otherwise false
.
var identity = web3.shh.newIdentity();
var result = web3.shh.hasIdentity(identity);
console.log(result); // true
var result2 = web3.shh.hasIdentity(identity + "0");
console.log(result2); // false
// TODO: not implemented yet
// TODO: not implemented yet
var filter = web3.shh.filter(options)
// watch for changes
filter.watch(function(error, result){
if (!error)
console.log(result);
});
Watch for incoming whisper messages.
Object
- The filter options:
topics
:Array of Strings
- Filters messages by this topic(s). You can use the following combinations:['topic1', 'topic2'] == 'topic1' && 'topic2'
['topic1', ['topic2', 'topic3']] == 'topic1' && ('topic2' || 'topic3')
[null, 'topic1', 'topic2'] == ANYTHING && 'topic1' && 'topic2'
->null
works as a wildcard
to
: Filter by identity of receiver of the message. If provided and the node has this identity, it will decrypt incoming encrypted messages.
Function
- (optional) If you pass a callback the HTTP request is made asynchronous. See this note for details.
Object
- The incoming message:
from
:String
, 60 Bytes - The sender of the message, if a sender was specified.to
:String
, 60 Bytes - The receiver of the message, if a receiver was specified.expiry
:Number
- Integer of the time in seconds when this message should expire (?).ttl
:Number
- Integer of the time the message should float in the system in seconds (?).sent
:Number
- Integer of the unix timestamp when the message was sent.topics
:Array of String
- Array ofString
topics the message contained.payload
:String
- The payload of the message.workProved
:Number
- Integer of the work this message required before it was send (?).
var txHash = web3.eth.sendIBANTransaction('0x00c5496aee77c1ba1f0854206a26dda82a81d6d8', 'XE81ETHXREGGAVOFYORK', 0x100);
Sends IBAN transaction from user account to destination IBAN address.
string
- address from which we want to send transactionstring
- IBAN address to which we want to send transactionvalue
- value that we want to send in IBAN transaction
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var i = web3.eth.iban.fromAddress('0x00c5496aee77c1ba1f0854206a26dda82a81d6d8');
console.log(i.toString()); // 'XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS
var i = web3.eth.iban.fromBban('ETHXREGGAVOFYORK');
console.log(i.toString()); // "XE81ETHXREGGAVOFYORK"
var i = web3.eth.iban.createIndirect({
institution: "XREG",
identifier: "GAVOFYORK"
});
console.log(i.toString()); // "XE81ETHXREGGAVOFYORK"
var valid = web3.eth.iban.isValid("XE81ETHXREGGAVOFYORK");
console.log(valid); // true
var valid2 = web3.eth.iban.isValid("XE82ETHXREGGAVOFYORK");
console.log(valid2); // false, cause checksum is incorrect
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var valid3 = i.isValid();
console.log(valid3); // true
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var direct = i.isDirect();
console.log(direct); // false
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var indirect = i.isIndirect();
console.log(indirect); // true
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var checksum = i.checksum();
console.log(checksum); // "81"
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var institution = i.institution();
console.log(institution); // 'XREG'
var i = new web3.eth.iban("XE81ETHXREGGAVOFYORK");
var client = i.client();
console.log(client); // 'GAVOFYORK'
var i = new web3.eth.iban('XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS');
var address = i.address();
console.log(address); // '00c5496aee77c1ba1f0854206a26dda82a81d6d8'
var i = new web3.eth.iban('XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS');
console.log(i.toString()); // 'XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS'