@coinbase/x402

The official Coinbase facilitator package for the x402 Payment Protocol. This package provides direct access to Coinbase's hosted facilitator service, enabling seamless payment verification and settlement.

Installation

npm install @coinbase/x402

Environment Variables

This package optionally uses CDP API keys from the Coinbase Developer Platform for authenticated operations:

• CDP_API_KEY_ID: Your CDP API key ID
• CDP_API_KEY_SECRET: Your CDP API key secret

Endpoint Authentication Requirements

| Endpoint | Authentication Required | Purpose | |----------|------------------------|---------| | list | ❌ No | Discover available bazaar items and payment options | | verify | ✅ Yes | Verify payment transactions | | settle | ✅ Yes | Settle completed payments |

Note: Environment variables are only required when using the verify and settle endpoints. The list endpoint can be used without authentication to discover bazaar items.

Quick Start

// Option 1: Import the default facilitator config
// Works for list endpoint without credentials, or with CDP_API_KEY_ID and CDP_API_KEY_SECRET environment variables for verify/settle
import { facilitator } from "@coinbase/x402";

// Option 2: Create a facilitator config, passing in credentials directly
import { createFacilitatorConfig } from "@coinbase/x402";

const facilitator = createFacilitatorConfig("your-cdp-api-key-id", "your-cdp-api-key-secret"); // Pass in directly from preferred secret management

// Use the facilitator config in your x402 integration

Integration Examples

With Express Middleware

import express from "express";
import { paymentMiddleware } from "x402-express";
import { facilitator } from "@coinbase/x402";

const app = express();

// Requires CDP_API_KEY_ID and CDP_API_KEY_SECRET environment variables
// for payment verification and settlement
app.use(paymentMiddleware(
  "0xYourAddress",
  {
    "/protected": {
      price: "$0.10",
      network: "base-sepolia"
    }
  },
  facilitator // Use Coinbase's facilitator
));