Eosjs

General purpose library for EOSIO blockchains.

Install

if you are using npm

npm install eosforce

if you are using yarn

yarn add eosforce

Usage

Ways to instantiate eosforce.

Eos = require('eosforce')

// Private key or keys (array) provided statically or by way of a function.
// For multiple keys, the get_required_keys API is used (more on that below).
keyProvider: '5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3'

// Localhost Testnet (run ./docker/up.sh)
eos = Eos({keyProvider})

// Connect to a testnet or mainnet
eos = Eos({httpEndpoint, chainId, keyProvider})

// Cold-storage
eos = Eos({httpEndpoint: null, chainId, keyProvider})

// Read-only instance when 'eosjs' is already a dependency
eos = Eos.modules.api({/*config*/})

// Read-only instance when an application never needs to write (smaller library)
EosApi = require('eosjs-api')
eos = EosApi({/*config*/})

No-arguments prints usage.

eos.getBlock()

USAGE
getBlock - Fetch a block from the blockchain.

PARAMETERS
{
  "block_num_or_id": "string"
}

Start a nodeosd process. The docker in this repository provides a setup the supports the examples in this README.

cd ./docker && ./up.sh

All functions read only or transactional follow this pattern for parameters.

// If the last argument is a function it is treated as a callback
eos.getBlock(1, (error, result) => {})

// If a callback is not provided, a Promise is returned
eos.getBlock(1) // @returns {Promise}

// Parameters can be positional or an object
eos.getBlock({block_num_or_id: 1})

// An API with no parameters is invoked with an empty object or callback (avoids logging usage)
eos.getInfo({}) // @returns {Promise}
eos.getInfo((error, result) => { console.log(error, result) })

Chain and history API functions are available after creating the eos object. API methods and documentation are generated from the chain and history json files.

• chain.json
• history.json

Until we generate a markdown for these, please convert the names in these json to camel case functions.

• "get_info": .. is eos.getInfo(..)

Configuration

Eos = require('eosjs')

// Default configuration (additional options below)
config = {
  chainId: null, // 32 byte (64 char) hex string
  keyProvider: ['PrivateKeys...'], // WIF string or array of keys..
  httpEndpoint: 'http://127.0.0.1:8888',
  expireInSeconds: 60,
  broadcast: true,
  verbose: false, // API activity
  sign: true
}

eos = Eos(config)

• chainId hex - Unique ID for the blockchain you're connecting too. This is required for valid transaction signing. The chainId is provided via the get_info API call.

  Identifies a chain by its initial genesis block. All transactions signed will only be valid the blockchain with this chainId. Verify the chainId for security reasons.

• keyProvider [array<string>|string|function] - Provides private keys used to sign transaction. If multiple private keys are found, the API get_required_keys is called to discover which signing keys to use. If a function is provided, this function is called for each transaction.

• httpEndpoint string - http or https location of a nodeosd server providing a chain API. When using eosjs from a browser remember to configure the same origin policy in nodeosd or proxy server. For testing, nodeosd configuration access-control-allow-origin = * could be used.

  Set this value to null for a cold-storage (no network) configuration.

• expireInSeconds number - number of seconds before the transaction will expire. The time is based on the nodeosd's clock. An unexpired transaction that may have had an error is a liability until the expiration is reached, this time should be brief.

• broadcast [boolean=true] - post the transaction to the blockchain. Use false to obtain a fully signed transaction.

• verbose [boolean=false] - verbose logging such as API activity.

• debug [boolean=false] - low level debug logging (serialization).

• sign [boolean=true] - sign the transaction with a private key. Leaving a transaction unsigned avoids the need to provide a private key.

• mockTransactions (advanced)

  • mockTransactions: () => null // 'pass', or 'fail'
  • pass - do not broadcast, always pretend that the transaction worked
  • fail - do not broadcast, pretend the transaction failed
  • null|undefined - broadcast as usual

• transactionHeaders (advanced) - manually calculate transaction header. This may be provided so eosjs does not need to make header related API calls to nodeos. Used in environments like cold-storage. This callback is called for every transaction. Headers are documented here eosjs-api#headers.

  • transactionHeaders: (expireInSeconds, callback) => {callback(null/*error*/, headers)}

• logger - default logging configuration.

  logger: {
    log: config.verbose ? console.log : null,
    error: console.error // null to disable
  }

  Turn off all error logging: config.logger = {error: null}

Options

Options may be provided after parameters.

options = {
  authorization: 'alice@active',
  broadcast: true,
  sign: true
}

eos.transfer('alice', 'bob', '1.0000 SYS', '', options)

• authorization [array<auth>|auth] - identifies the signing account and permission typically in a multisig configuration. Authorization may be a string formatted as account@permission or an object<{actor: account, permission}>.

  • If missing default authorizations will be calculated.
  • If provided additional authorizations will not be added.
  • Performs deterministic sorting by account name

  If a default authorization is calculated the action's 1st field must be an account_name. The account_name in the 1st field gets added as the active key authorization for the action.

• broadcast [boolean=true] - post the transaction to the blockchain. Use false to obtain a fully signed transaction.

• sign [boolean=true] - sign the transaction with a private key. Leaving a transaction unsigned avoids the need to provide a private key.

Transaction

The transaction function accepts the standard blockchain transaction.

Required transaction header fields will be added unless your signing without a network connection (httpEndpoint == null). In that case provide you own headers:

// only needed in cold-storage or for offline transactions
const headers = {
  expiration: '2018-06-14T18:16:10'
  ref_block_num: 1,
  ref_block_prefix: 452435776
}

Create and send (broadcast) a transaction:

/** @return {Promise} */
eos.transaction(
  {
    // ...headers,
    actions: [
      {
        account: 'eosio.token',
        name: 'transfer',
        authorization: [{
          actor: 'inita',
          permission: 'active'
        }],
        data: {
          from: 'inita',
          to: 'initb',
          quantity: '7.0000 SYS',
          memo: ''
        }
      }
    ]
  }
  // options -- example: {broadcast: false}
)

Named action functions

More concise functions are provided for applications that may use actions more frequently. This avoids having lots of JSON in the code.

// Run with no arguments to print usage.
eos.transfer()

// Callback is last, when omitted a promise is returned
eos.transfer('inita', 'initb', '1.0000 SYS', '', (error, result) => {})
eos.transfer('inita', 'initb', '1.1000 SYS', '') // @returns {Promise}

// positional parameters
eos.transfer('inita', 'initb', '1.2000 SYS', '')

// named parameters
eos.transfer({from: 'inita', to: 'initb', quantity: '1.3000 SYS', memo: ''})

// options appear after parameters
options = {broadcast: true, sign: true}

// `false` is a shortcut for {broadcast: false}
eos.transfer('inita', 'initb', '1.4000 SYS', '', false)

Read-write API methods and documentation are generated from the eosio token and system.

For more advanced signing, see keyProvider and signProvider in index.test.js.

Shorthand

Shorthand is available for some types such as Asset and Authority. This syntax is only for concise functions and does not work when providing entire transaction objects to eos.transaction..

For example:

• permission inita defaults inita@active
• authority 'EOS6MRy..' expands {threshold: 1, keys: [key: 'EOS6MRy..', weight: 1]}
• authority inita expands {{threshold: 1, accounts: [..actor: 'inita', permission: 'active', weight: 1]}}

New Account

New accounts will likely require some staked tokens for RAM and bandwidth.

wif = '5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3'
pubkey = 'EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV'

eos.transaction(tr => {
  tr.newaccount({
    creator: 'eosio',
    name: 'myaccount',
    owner: pubkey,
    active: pubkey
  })

  tr.buyrambytes({
    payer: 'eosio',
    receiver: 'myaccount',
    bytes: 8192
  })

  tr.delegatebw({
    from: 'eosio',
    receiver: 'myaccount',
    stake_net_quantity: '10.0000 SYS',
    stake_cpu_quantity: '10.0000 SYS',
    transfer: 0
  })
})

Contract

Deploy and call smart contracts.

Compile

If you're loading a wasm file, you do not need binaryen. If you're loading a wast file you can include and configure the binaryen compiler, this is used to compile to wasm automatically when calling setcode.

Versions of binaryen may be problematic.

$ npm install [email protected]

binaryen = require('binaryen')
eos = Eos({keyProvider, binaryen})

Deploy

wasm = fs.readFileSync(`docker/contracts/eosio.token/eosio.token.wasm`)
abi = fs.readFileSync(`docker/contracts/eosio.token/eosio.token.abi`)

// Publish contract to the blockchain
eos.setcode('myaccount', 0, 0, wasm) // @returns {Promise}
eos.setabi('myaccount', JSON.parse(abi)) // @returns {Promise}

Fetch a smart contract

// @returns {Promise}
eos.contract('myaccount', [options], [callback])

// Run immediately, `myaction` returns a Promise
eos.contract('myaccount').then(myaccount => myaccount.myaction(..))

// Group actions. `transaction` returns a Promise but `myaction` does not
eos.transaction('myaccount', myaccount => { myaccount.myaction(..) })

// Transaction with multiple contracts
eos.transaction(['myaccount', 'myaccount2'], ({myaccount, myaccount2}) => {
   myaccount.myaction(..)
   myaccount2.myaction(..)
})

Custom Token

(async function() {

  // more on the contract / transaction syntax below

  await eos.transaction('myaccount', myaccount => {

    // Create the initial token with its max supply
    // const options = {authorization: 'myaccount'} // default
    myaccount.create('myaccount', '10000000.000 TOK')//, options)

    // Issue some of the max supply for circulation into an arbitrary account
    myaccount.issue('myaccount', '10000.000 TOK', 'issue')
  })

  const balance = await eos.getCurrencyBalance('myaccount', 'myaccount', 'TOK')
  console.log('Currency Balance', balance)

})()

Calling Actions

Other ways to use contracts and transactions.

(async function() {

  // if either transfer fails, both will fail (1 transaction, 2 messages)
  await eos.transaction(eos =>
    {
      eos.transfer('inita', 'initb', '1.0000 SYS', ''/*memo*/)
      eos.transfer('inita', 'initc', '1.0000 SYS', ''/*memo*/)
      // Returning a promise is optional (but handled as expected)
    }
    // [options],
    // [callback]
  )

  // transaction on a single contract
  await eos.transaction('myaccount', myaccount => {
    myaccount.transfer('myaccount', 'inita', '10.000 TOK@myaccount', '')
  })

  // mix contracts in the same transaction
  await eos.transaction(['myaccount', 'eosio.token'], ({myaccount, eosio_token}) => {
    myaccount.transfer('inita', 'initb', '1.000 TOK@myaccount', '')
    eosio_token.transfer('inita', 'initb', '1.0000 SYS', '')
  })

  // The contract method does not take an array so must be called once for
  // each contract that is needed.
  const myaccount = await eos.contract('myaccount')
  await myaccount.transfer('myaccount', 'inita', '1.000 TOK', '')

  // a transaction to a contract instance can specify multiple actions
  await myaccount.transaction(myaccountTr => {
    myaccountTr.transfer('inita', 'initb', '1.000 TOK', '')
    myaccountTr.transfer('initb', 'inita', '1.000 TOK', '')
  })

})()

Development

From time-to-time the eosjs and nodeos binary format will change between releases so you may need to start nodeos with the --skip-transaction-signatures parameter to get your transactions to pass.

Note, package.json has a "main" pointing to ./lib. The ./lib folder is for es2015 code built in a separate step. If you're changing and testing code, import from ./src instead.

Eos = require('./src')

// forceActionDataHex = false helps transaction readability but may trigger back-end bugs
config = {verbose: true, debug: false, broadcast: true, forceActionDataHex: true, keyProvider}

eos = Eos(config)

Fcbuffer

The eos instance can provide serialization:

// 'asset' is a type but could be any struct or type like: transaction or uint8
type = {type: 1, data: '00ff'}
buffer = eos.fc.toBuffer('extensions_type', type)
assert.deepEqual(type, eos.fc.fromBuffer('extensions_type', buffer))

// ABI Serialization
eos.contract('eosio.token', (error, eosio_token) => {
  create = {issuer: 'inita', maximum_supply: '1.0000 SYS'}
  buffer = eosio_token.fc.toBuffer('create', create)
  assert.deepEqual(create, eosio_token.fc.fromBuffer('create', buffer))
})

Use Node v10+ for package-lock.json.

Related Libraries

These libraries are integrated into eosjs seamlessly so you probably do not need to use them directly. They are exported here giving more API access or in some cases may be used standalone.

var {format, api, ecc, json, Fcbuffer} = Eos.modules

• format ./format.md

  • Blockchain name validation
  • Asset string formatting

• eosjs-api [Github, NPM]

  • Remote API to an EOS blockchain node (nodeos)
  • Use this library directly if you need read-only access to the blockchain (don't need to sign transactions).

• eosjs-ecc [Github, NPM]

  • Private Key, Public Key, Signature, AES, Encryption / Decryption
  • Validate public or private keys
  • Encrypt or decrypt with EOS compatible checksums
  • Calculate a shared secret

• json {api, schema},

  • Blockchain definitions (api method names, blockchain schema)

• eosjs-keygen [Github, NPM]

  • private key storage and key management

• Fcbuffer [Github, NPM]

  • Binary serialization used by the blockchain
  • Clients sign the binary form of the transaction
  • Allows client to know what it is signing

Browser

git clone https://github.com/eosforce/eosjs
cd eosjs
npm install
npm run build_browser
# builds: ./dist/eos.js load with ./dist/index.html

npm run build_browser_test
# builds: ./dist/test.js run with ./dist/test.html

<script src="eos.js"></script>
<script>
var eos = Eos()
//...
</script>

Environment

Node and browser (es2015)