x402-agent-data

Pay-per-call data tools for AI agents, settled per call in USDC on Base via the x402 protocol. The buyer is another agent: it discovers an endpoint, auto-pays per request (HTTP 402 → payment → data), and gets structured JSON back. No API key, no signup, no account — the seller's only setup is one public wallet address.

Live at https://x402.charliemorrison.dev — also listed as a remote MCP server in the Official MCP Registry as dev.charliemorrison/agent-web-reader.

Tools

Free, unpaid routes:

• GET / — discovery doc (service + paid-endpoint metadata, x402-aware)

• GET /healthz — liveness

• GET /.well-known/mcp.json — MCP discovery manifest

• GET /.well-known/agent.json — A2A Agent Card

• POST /mcp — remote MCP server (Streamable HTTP). Lists the three tools; an unpaid tools/call returns the decoded x402 payment-required challenge, and a call carrying an x402 payment returns the data.

Related MCP server: API for Chads

How payment works

1. Agent calls a paid route with no payment → server responds HTTP 402 with an x402 challenge (amount, asset = USDC, network = base, payTo address).

2. Agent's x402 client signs a payment authorization and retries with the X-PAYMENT header.

3. Server verifies/settles via an x402 facilitator and returns the data.

No private key ever lives in this server's config — it only receives. Settlement is delegated to an x402 facilitator (default: a zero-fee, gas-sponsored facilitator; Coinbase CDP facilitator is supported via env and inert unless configured).

Run it

npm install
PAY_TO=0xYourReceivingAddress node server.js   # listens on :4021

Environment:

• PAY_TO — your receiving wallet (USDC on Base). Required for real revenue.

• PORT — default 4021.

• CDP_API_KEY_ID / CDP_API_KEY_SECRET — optional; switches settlement to the Coinbase CDP facilitator. Omitted by default.

Why this shape

The buyer is a machine and distribution is a registry — there's no cold human audience to recruit, which is the wall that kills most indie API/tool launches. Seller setup is a single wallet address; every call is zero-marginal-cost public data.

License

MIT