Tachi SDK

TypeScript SDK for the Tachi Protocol - enabling pay-per-crawl access to web content with automatic USDC micropayments on Base.

Installation

npm install @tachiprotocol/sdk

Quick Start

import { TachiSDK } from '@tachiprotocol/sdk';

const sdk = new TachiSDK({
  network: 'base',
  rpcUrl: 'https://mainnet.base.org',
  privateKey: process.env.PRIVATE_KEY as `0x${string}`,
  usdcAddress: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
  paymentProcessorAddress: '0xF09C29E5d3a12c0A766e6Dc65E2cb42CCf080abA'
});

// Fetch with automatic payment
const result = await sdk.fetch('https://gateway.tachi.ai/article/ai-training');

console.log(result.content); // Protected content
console.log(result.transactionHash); // Payment tx hash

Features

• 🔄 Automatic 402 Detection - Detects payment-required responses
• 💸 Auto-Payment - Pays via USDC on Base L2
• ⚡ Instant Settlement - ~2 second finality
• 🔒 Verifiable Logs - All payments recorded on-chain
• 🛡️ Type-Safe - Full TypeScript support

API Reference

new TachiSDK(config)

Create a new SDK instance.

Config:

• network: 'base' or 'base-sepolia'
• rpcUrl: Base RPC endpoint URL
• privateKey: Your wallet's private key (as 0x${string})
• usdcAddress: USDC contract address on Base
• paymentProcessorAddress: Tachi PaymentProcessor address
• debug?: Enable debug logging (optional)

sdk.fetch(url, options?)

Fetch content with automatic payment handling.

Returns: Promise<TachiResponse>

interface TachiResponse {
  content: string;
  statusCode: number;
  headers: Record<string, string>;
  paymentRequired: boolean;
  paymentAmount?: string;
  transactionHash?: Hash;
}

sdk.getBalance()

Get your USDC balance.

Returns: Promise<{wei: bigint, formatted: string}>

sdk.getAddress()

Get your wallet address.

Returns: Address

Advanced Usage

Custom Headers

const result = await sdk.fetch('https://api.example.com/data', {
  method: 'GET',
  headers: {
    'X-Custom-Header': 'value'
  }
});

Error Handling

try {
  const result = await sdk.fetch(url);
} catch (error) {
  if (error.message.includes('Insufficient USDC')) {
    console.log('Top up your USDC balance');
  }
}

Environment Variables

For security, store your private key in environment variables:

# .env
PRIVATE_KEY=your_private_key_here
BASE_RPC_URL=https://mainnet.base.org

Then load it:

import 'dotenv/config';
import { TachiSDK } from '@tachiprotocol/sdk';

const sdk = new TachiSDK({
  network: 'base',
  rpcUrl: process.env.BASE_RPC_URL!,
  privateKey: `0x${process.env.PRIVATE_KEY}` as `0x${string}`,
  // ... other config
});

Network Addresses

Base Mainnet

• USDC: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• PaymentProcessor: 0xF09C29E5d3a12c0A766e6Dc65E2cb42CCf080abA

Base Sepolia (Testnet)

• USDC: 0x036CbD53842c5426634e7929541eC2318f3dCF7e
• PaymentProcessor: 0xF09C29E5d3a12c0A766e6Dc65E2cb42CCf080abA

Examples

See the demo.mjs in the main repo for a complete example.

License

MIT

Links

• Protocol Website
• Documentation
• GitHub
• Discord