X402 Tools · underscoredone bundle Inspect x402 pay-per-call endpoints without paying — decode the payment challenge to see the real price, accepted blockchains, pay-to address, and how to call the endpoint; and read an API's openapi.json, comparing it against the live endpoint. Use whenever an x402, HTTP 402, or "payment required" endpoint comes up; when someone asks what an agent API costs, which networks or tokens it takes, or whether they can afford to call it; when a paid API call fails and the reason is unclear; when checking whether your own x402 endpoint emits what you think it does; or when reading, finding, or validating an openapi.json for any API. TRIGGERS: x402, 402, payment required, payment-required header, X-PAYMENT, pay per call, agent payments, USDC endpoint, what does this API cost, inspect endpoint, openapi.json, check my API spec, agentic payments, Bazaar, x402scan
