Stacks Blockchain API Basics

A Typescript client library is available for use of the Stacks API. The client library enables type-safe REST and WebSocket communication with the Stacks API endpoints.

The client is made up of three components:

1. Generated HTTP API client
2. Typescript definitions for Clarity values
3. WebSocket client

The following sections demonstrate common usages of the TypeScript API client.

HTTP API client sample

The Typescript client library requires you to specify the underlying HTTP request library to handle HTTP communication. The example below uses the universal fetch API cross-fetch:

import fetch from 'cross-fetch';
import { Configuration, AccountsApi } from '@stacks/blockchain-api-client';
(async () => {
  const apiConfig = new Configuration({
    fetchApi: fetch,
    // for mainnet, replace `testnet` with `mainnet`
    basePath: 'https://api.testnet.hiro.so', // defaults to http://localhost:3999
  });
  // initiate the /accounts API with the basepath and fetch library
  const accountsApi = new AccountsApi(apiConfig);
  // get transactions for a specific account
  const txs = await accountsApi.getAccountTransactions({
    principal: 'ST000000000000000000002AMW42H',
  });
  console.log(txs);
})().catch(console.error);

TypeScript sample

The following sample shows how generated TypeScript models can be used for type-safety:

import fetch from 'cross-fetch';
import {
  Configuration,
  AccountsApi,
  AccountsApiInterface,
  AddressBalanceResponse,
  AddressBalanceResponseStx,
} from '@stacks/blockchain-api-client';
(async () => {
  const apiConfig: Configuration = new Configuration({
    fetchApi: fetch,
    // for mainnet, replace `testnet` with `mainnet`
    basePath: 'https://api.testnet.hiro.so', // defaults to http://localhost:3999
  });
  const principal: string = 'ST000000000000000000002AMW42H';
  // initiate the /accounts API with the basepath and fetch library
  const accountsApi: AccountsApiInterface = new AccountsApi(apiConfig);
  // get balance for a specific account
  const balance: AddressBalanceResponse = await accountsApi.getAccountBalance({
    principal,
  });
  // get STX balance details
  const stxAmount: AddressBalanceResponseStx = balance.stx;
  console.log(stxAmount);
})().catch(console.error);

WebSocket sample

The WebSocket components enable you to subscribe to specific updates, providing a near real-time display of updates on transactions and accounts.

import { connectWebSocketClient } from '@stacks/blockchain-api-client';
const client = await connectWebSocketClient('ws://api.hiro.so/');
const sub = await client.subscribeAddressTransactions(contractCall.txId, event => {
  console.log(event);
});
await sub.unsubscribe();