SDK quickstart

In this quickstart you read the latest BOT Chain block number with @uzolabs/sdk and viem. It takes about two minutes and needs no wallet.

Early release. This is published in @uzolabs/sdk 0.2.0 on npm and you can use it today. The API may change before 1.0, so pin the version.

Everything on this page uses testnet (chain 968). Get free test tokens from the faucet.

What you’ll build

A script that connects to BOT Chain testnet and prints the latest block number. You’ll also see the same script written without the SDK, which shows exactly what the SDK saves you.

Prerequisites

Node.js 18 or later.

Steps

Create a project

mkdir bot-sdk-quickstart
cd bot-sdk-quickstart
npm init -y
npm pkg set type=module
npm install @uzolabs/sdk viem
npm install -D tsx

Write the script

read-block.ts

import { createPublicClient, http } from "viem";
import { botChainTestnet } from "@uzolabs/sdk/chains";

const client = createPublicClient({ chain: botChainTestnet, transport: http() });
const blockNumber = await client.getBlockNumber();
console.log(`${botChainTestnet.name} (${botChainTestnet.id}) is at block ${blockNumber}`);

botChainTestnet includes the chain ID, RPC URL, explorer and Multicall3 address, so you don’t need to pass a URL to http().

Run it

npx tsx read-block.ts

Verify it worked

Output from a run on 2026-10-02:

Output

BOT Chain Testnet (968) is at block 25492960

You’ll see a higher block number. If you run the script again, the number goes up. To read mainnet instead, import botChain.

The same script without the SDK

If you can’t add a dependency, you can define the chain yourself with viem’s defineChain. These are the same values the SDK exports:

read-block-viem.ts

import { createPublicClient, defineChain, http } from "viem";

const botChainTestnet = defineChain({
  id: 968,
  name: "BOT Chain Testnet",
  nativeCurrency: { name: "tBOT", symbol: "tBOT", decimals: 18 },
  rpcUrls: { default: { http: ["https://rpc.bohr.life"] } },
  blockExplorers: { default: { name: "BOTScan", url: "https://scan.bohr.life", apiUrl: "https://scan.bohr.life/api/v2" } },
  contracts: { multicall3: { address: "0x47FA21f684bBAD707A53a0f9BE59F1422F46C265" } },
  testnet: true,
});

const client = createPublicClient({ chain: botChainTestnet, transport: http() });
const blockNumber = await client.getBlockNumber();
console.log(`${botChainTestnet.name} (${botChainTestnet.id}) is at block ${blockNumber}`);

It prints the same line. The downside is that you now maintain these values yourself. If an address or URL changes, you have to update it by hand in every project.

Troubleshooting

HTTP request failed, or status 503

The public testnet RPC is sometimes slow or briefly unavailable. Wait a few seconds and try again. See Known limitations.

Cannot use import statement outside a module

Run npm pkg set type=module, or rename the file to read-block.mts.

Next steps

Contract addresses

Read a BDEX quote with typed addresses.

Explorer client

Look up contracts on BOTScan.

Getting started

Modules

Guides

Reference

What you’ll build

Prerequisites

Steps

Verify it worked

The same script without the SDK

Troubleshooting

Next steps

Contract addresses

Explorer client

​What you’ll build

​Prerequisites

​Steps

​Verify it worked

​The same script without the SDK

​Troubleshooting

​Next steps

Contract addresses

Explorer client

What you’ll build

Prerequisites

Steps

Verify it worked

The same script without the SDK

Troubleshooting

Next steps