eosjs
Javascript API for integration with EOSIO-based blockchains using EOSIO RPC API.
Documentation can be found here
Installation
NPM
The official distribution package can be found at npm.
Add dependency to your project
yarn add eosjs
Using with Typescript
In order to get access to the TextEncoding
and TextDecoding
types, you need to add @types/text-encoding
as a dev dependency:
yarn add --dev @types/text-encoding
If you're using Node (not a browser) then you'll also need to make sure the dom
lib is referenced in your tsconfig.json
:
{
"compilerOptions": {
"lib": [..., "dom"]
}
}
Browser Distribution
Clone this repository locally then run yarn build-web
. The browser distribution will be located in dist-web
and can be directly copied into your project repository. The dist-web
folder contains minified bundles ready for production, along with source mapped versions of the library for debugging. For full browser usage examples, see the documentation.
Import
ES Modules
Importing using ESM syntax is supported using TypeScript, webpack, or Node.js with --experimental-modules
flag
import { Api, JsonRpc, RpcError } from 'eosjs';
import { JsSignatureProvider } from 'eosjs/dist/eosjs-jssig'; // development only
CommonJS
Importing using commonJS syntax is supported by Node.js out of the box.
const { Api, JsonRpc, RpcError } = require('eosjs');
const { JsSignatureProvider } = require('eosjs/dist/eosjs-jssig'); // development only
const fetch = require('node-fetch'); // node only; not needed in browsers
const { TextEncoder, TextDecoder } = require('util'); // node only; native TextEncoder/Decoder
Basic Usage
Signature Provider
The Signature Provider holds private keys and is responsible for signing transactions.
Using the JsSignatureProvider in the browser is not secure and should only be used for development purposes. Use a secure vault outside of the context of the webpage to ensure security when signing transactions in production
const defaultPrivateKey = "5JtUScZK2XEp3g9gh7F8bwtPTRAkASmNrrftmx4AxDKD5K4zDnr"; // bob
const signatureProvider = new JsSignatureProvider([defaultPrivateKey]);
JSON-RPC
Open a connection to JSON-RPC, include fetch
when on Node.js.
const rpc = new JsonRpc('http://127.0.0.1:8888', { fetch });
API
Include textDecoder and textEncoder when using in Node. You may exclude these when running in a browser since most modern browsers now natively support these. If your browser does not support these (https://caniuse.com/#feat=textencoder), then you can import them as a dependency through the following deprecated npm package: https://www.npmjs.com/package/text-encoding
const api = new Api({ rpc, signatureProvider, textDecoder: new TextDecoder(), textEncoder: new TextEncoder() });
Sending a transaction
transact()
is used to sign and push transactions onto the blockchain with an optional configuration object parameter. This parameter can override the default value of broadcast: true
, and can be used to fill TAPOS fields given expireSeconds
and either blocksBehind
or useLastIrreversible
. Given no configuration options, transactions are expected to be unpacked with TAPOS fields (expiration
, ref_block_num
, ref_block_prefix
) and will automatically be broadcast onto the chain.
(async () => {
const result = await api.transact({
actions: [{
account: 'eosio.token',
name: 'transfer',
authorization: [{
actor: 'useraaaaaaaa',
permission: 'active',
}],
data: {
from: 'useraaaaaaaa',
to: 'useraaaaaaab',
quantity: '0.0001 SYS',
memo: '',
},
}]
}, {
blocksBehind: 3,
expireSeconds: 30,
});
console.dir(result);
})();
Error handling
use RpcError
for handling RPC Errors
...
try {
const result = await api.transact({
...
} catch (e) {
console.log('\nCaught exception: ' + e);
if (e instanceof RpcError)
console.log(JSON.stringify(e.json, null, 2));
}
...
Contributing
License
Important
See LICENSE for copyright and license terms.
All repositories and other materials are provided subject to the terms of this IMPORTANT notice and you must familiarize yourself with its terms. The notice contains important information, limitations and restrictions relating to our software, publications, trademarks, third-party resources, and forward-looking statements. By accessing any of our repositories and other materials, you accept and agree to the terms of the notice.