The JavaScript SDK for Terra and Feather chains

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Feather.js is a JavaScript SDK for writing applications that interact with the Terra blockchain from either Node.js, browser, or React Native environments and provides simple abstractions over core data structures, serialization, key management, and API request generation.

Features

• Written in TypeScript, with type definitions
• Versatile support for key management solutions
• Works in Node.js, in the browser, and React Native
• Exposes the Terra API through LCDClient
• Parses responses into native JavaScript types

We highly suggest using Feather.js with TypeScript, or JavaScript in a code editor that has support for type declarations, so you can take advantage of the helpful type hints that are included with the package.

Installation

Grab the latest version off NPM:

1npm install @terra-money/feather.js

Usage

Feather.js can be used in Node.js, as well as inside the browser. Please check the docs for notes on how to get up and running.

Getting blockchain data

1import { LCDClient, Coin } from '@terra-money/feather.js';
2
3// connect to testnet
4const lcd = LCDClient.fromDefaultConfig('testnet');
5
6// connect to mainnet
7const lcd = LCDClient.fromDefaultConfig('mainnet');
8
9// To use LocalTerra or a custom endpoint
10const lcd = new LCDClient({
11  localterra: {
12    // key must be the chainID
13    lcd: 'http://localhost:1317',
14    chainID: 'localterra',
15    gasAdjustment: 1.75,
16    gasPrices: { uluna: 0.15 },
17    prefix: 'terra', // bech32 prefix, used by the LCD to understand which is the right chain to query
18  },
19});
20
21// get the current balance of `terra1x46rqay4d3cssq8gxxvqz8xt6nwlz4td20k38v`
22// LCD understand automatically the chain to query using the bech32 prefix of the address
23const balance = lcd.bank.balance(
24  'terra1x46rqay4d3cssq8gxxvqz8xt6nwlz4td20k38v'
25);
26console.log(balance);
27
28// get the total circulation supply
29// LCD needs a chainID to understand the chain it should query
30const total = lcd.bank.total('phoenix-1');
31console.log(total);

Broadcasting transactions

First, get some testnet tokens for terra1x46rqay4d3cssq8gxxvqz8xt6nwlz4td20k38v, or use LocalTerra.

1import { LCDClient, MsgSend, MnemonicKey } from '@terra-money/feather.js';
2
3// create a key out of a mnemonic
4const mk = new MnemonicKey({
5  mnemonic:
6    'notice oak worry limit wrap speak medal online prefer cluster roof addict wrist behave treat actual wasp year salad speed social layer crew genius',
7});
8
9// connect to testnet
10const lcd = LCDClient.fromDefaultConfig('testnet');
11
12// a wallet can be created out of any key
13// wallets abstract transaction building
14const wallet = lcd.wallet(mk);
15
16// create a simple message that moves coin balances
17const send = new MsgSend(
18  mk.accAddress('terra'), // .accAddress is now a function which require the prefix as parameter
19  'terra17lmam6zguazs5q5u6z5mmx76uj63gldnse2pdp',
20  { uluna: 1200000 }
21);
22
23wallet
24  .createAndSignTx({
25    msgs: [send],
26    memo: 'test from feather.js!',
27    chainID: 'pisco-1', // now here a chainID must be specified
28  })
29  .then(tx => lcd.tx.broadcast(tx, 'pisco-1')) // same here
30  .then(result => {
31    console.log(`TX hash: ${result.txhash}`);
32  });

Tx with messages from custom modules

1wallet
2  // feather js detect that the tx contains a MsgAminoCustom and will use SIGN_MODE_AMINO_JSON instead of SIGN_MODE_DIRECT
3  .createAndSignTx({
4    msgs: [
5      new MsgAminoCustom({
6        type: 'osmosis/gamm/swap-exact-amount-in',
7        value: {
8          sender: 'osmo1...',
9          routes: [
10            {
11              pool_id: '2',
12              token_out_denom: 'uion',
13            },
14          ],
15          token_in: {
16            denom: 'uosmo',
17            amount: '10000000',
18          },
19          token_out_min_amount: '8538',
20        },
21      }),
22      // you can add more messages here if needed
23    ],
24    memo: 'test from feather.js!',
25    chainID: 'osmosis-1',
26  })
27  .then(tx => lcd.tx.broadcast(tx, 'osmosis-1'))
28  .then(result => {
29    console.log(`TX hash: ${result.txhash}`);
30  });

Feather.js in the browser

You can access all the objects of the @terra-money/feather.js from the global Feather object if you load Feather.js with a <script> tag.

Include the following in your browser:

1<script
2  crossorigin
3  src="https://unpkg.com/@terra-money/feather.js/dist/bundle.js"
4></script>

You can find a small JSFiddle example that refreshes current Oracle votes here.

Feather.js in React Native

In order to use Feather.js inside React Native, you need to add the node-libs-react-native package and react-native-get-random-values package to your React Native app's package.json.

1yarn add node-libs-react-native react-native-get-random-values

You will need to register Node.js native modules in an entry point of your application, such as index.tsx:

1import 'node-libs-react-native/globals';
2import 'react-native-get-random-values';

Also, add resolvers to your metro.config.js

1module.exports {
2  // ...
3  resolver: {
4    // ...
5    extraNodeModules: require('node-libs-react-native'),
6  },
7  // ...
8}

License

This software is licensed under the MIT license. See LICENSE for full disclosure.

© 2022 Terraform Labs, PTE.

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