with-custom-facilitator

BYO Facilitator Agent

Demonstrates how to use a custom x402 payment facilitator via app/accepts.ts. Instead of the default x402.org facilitator, you can point to any x402-compatible service for payment verification.

Quick Start

bun install

# Create .env.local with your keys
echo "OPENAI_API_KEY=sk-..." > .env.local

bun run dev

Project Structure

app/
├── agent.ts            # Agent with temperature conversion tool
├── accepts.ts          # Custom facilitator configuration
└── tools/
    └── temperature.ts  # Temperature conversion tool

How It Works

app/accepts.ts points to a custom facilitator URL:

import { HTTPFacilitatorClient } from "aixyz/accepts";

export const facilitator = new HTTPFacilitatorClient({
  url: process.env.X402_FACILITATOR_URL ?? "https://www.x402.org/facilitator",
});

The build pipeline automatically picks up app/accepts.ts — no custom server.ts needed.

Environment Variables

Variable	Description
OPENAI_API_KEY	OpenAI API key
X402_FACILITATOR_URL	Custom facilitator URL (defaults to x402.org)

API Endpoints

Endpoint	Description
/.well-known/agent-card.json	A2A agent card
POST /agent	A2A JSON-RPC endpoint
POST /mcp	MCP tool endpoint

Payment

Charges $0.005 per request via x402 on Base Sepolia.

Build & Deploy

bun run build
vercel