bsv-x402

A JavaScript client library for the x402 payment protocol. Wraps fetch() to handle HTTP 402 payment flows transparently.

How It Works

import { x402Fetch } from 'bsv-x402'

const response = await x402Fetch('https://api.example.com/paid-endpoint')

When the server responds with 402 Payment Required, the library:

1. Parses the X402-Challenge header
2. Constructs a payment transaction via the browser wallet (BRC-100 / window.CWI)
3. Broadcasts the transaction to the BSV network
4. Retries the original request with an X402-Proof header

The app developer just uses x402Fetch in place of fetch. The browser wallet handles key management and signing.

Installation

npm install bsv-x402

Development

npm install       # Install dependencies
npm run build     # Compile TypeScript → dist/
npm test          # Run tests
npm run typecheck # Type-check without emitting

Status

Early development. The fetch wrapper and challenge parsing are in place; the BRC-100 wallet integration (constructProof) is not yet implemented.