Tessera SDK

TypeScript SDK for AI agents to access paywalled content via x402 micropayments.

Installation

pnpm add @tessera/sdk

Quick Start

import { TesseraClient } from '@tessera/sdk'

const client = new TesseraClient({
  gatewayUrl: 'http://localhost:3001',
  privateKey: process.env.AGENT_PRIVATE_KEY  // Wallet with USDC
})

// Preview (free)
const preview = await client.preview('http://publisher.com/article/123')
console.log(preview.title, preview.price)

// Fetch (paid)
const content = await client.fetch('http://publisher.com/article/123')
console.log(content.markdown)

API

new TesseraClient(config)

const client = new TesseraClient({
  gatewayUrl: string,      // Gateway URL
  privateKey: string,      // Wallet private key (0x...)
  apiKey?: string          // (future)
})

client.preview(url)

Get free preview of content.

Returns: { url, title, preview, price, publisher, fetch_url }

client.fetch(url)

Fetch full content (auto-pays with USDC).

Returns: { url, markdown, title, publisher, price, paid, fetched_at }

How It Works

1. Agent calls fetch() → Gateway returns 402 Payment Required
2. SDK signs EIP-3009 TransferWithAuthorization (USDC)
3. SDK retries with X-Payment header
4. Gateway validates + returns content as Markdown

Payment Details

• Token: USDC on Avalanche Fuji (0x5425890298aed601595a70AB815c96711a31Bc65)
• Method: EIP-3009 signature-based transfer (gasless)
• Prices: $0.05-$0.50 per article

Example

See examples/research-agent for agent implementation.

Development

pnpm build  # Build SDK