x402 Builder Skills

Teach your coding agent to ship an API that other AI agents can pay per call in USDC, the way we run 8 paid x402 routes in production.

The 4 skills

x402-paywall-setup: prices, v2 + v1 402 responses, settle-on-success, discovery metadata
x402-endpoint-audit: audit any endpoint without paying; script exits 0/1/2, --json
x402-settlement-verify: prove a payment settled on Base from the tx hash; no keys
x402-discovery-listing: indexes, MCP registries and directories in the right order

9 offline tests ship with it; scripts are Python 3.9+ standard library only.

Our free checker at /verify-endpoint runs the same kind of audit.

Zip, 14 KB, v1.0.

What is x402?: An open protocol that uses HTTP 402 “Payment Required” so an AI agent can pay for an API call with a stablecoin, without an account or API key.
Do the scripts need my wallet or keys?: No. The audit sends one unpaid request; the settlement checker reads a public transaction receipt.
Which networks?: Base mainnet USDC by default; the setup skill covers Solana too.
Which agents can use the skills?: Any that load SKILL.md: Claude Code, Cursor, OpenClaw, Hermes Agent, Codex, Grok Bot.
Refunds?: 14 days if it doesn’t work and we can’t fix it: hello@youraitools.co.
Can I pay with crypto?: Yes. Pay the same price in USDC or USDT on Base, Ethereum, Arbitrum, Optimism, Polygon or Solana from the "Pay with crypto" button, with no account or KYC. We check the payment on-chain and show your download links as soon as it confirms.

4 SKILL.md skills to ship, audit, verify and list a pay-per-call x402 API.

$29 one-time

Download$19

Cloudflare Worker that charges AI agents per request in USDC. MIT licensed.

Servicefrom $150

We make your API payable by AI agents with x402, list it and check the first payment.

Download$29

Paid endpoint templates in TypeScript and FastAPI: 402 terms, settle-then-work, capped payer scripts.