Recall Kitchen's MCP server lets AI agents look up government-published product, food, vehicle and drug recalls. Most lookups are free; past the free quota (and for photo search) an agent can pay per call with x402 in USDC on Base. Here's exactly how.

(Disclosure: I build Recall Kitchen.)

Docs: https://recallkitchen.com/docs?utm_source=devto&utm_campaign=x402_howto

Paying per call with x402 (no account)

You don't need an account to keep using the server. A few anonymous searches per IP are free (5 an hour, 15 a day), and photo search is never in that free quota. After the quota, an x402-capable client can pay per call: $0.025 in USDC on Base. When a call needs payment, the server returns a normal JSON-RPC result whose content is an x402 "Payment Required" challenge (HTTP 200, isError: true ), not a bare HTTP 402. Your client pays it and retries. The price and pay-to address are published at https://app.recallkitchen.com/.well-known/x402 . x402 covers search and photo search only.…