Machine-payable API products. Payment via the
x402 protocol (HTTP 402 + USDC on Base,
CDP facilitator). POST without payment returns a 402 envelope
with full payment instructions — point any x402 client at the endpoints below.
what-am-i-signing — Decode an EVM signature request
(EIP-712 typed data, Permit/Permit2, or ERC-20 approve calldata) into a
structured intent: token, spender, amount, expiry, plus risk_flags
and an action_hint. Deterministic, no LLM.
x402-listing-doctor — Why is my x402 service not listed in the Bazaar? We fetch your 402 envelope, run the exact SDK validation and extraction functions the CDP facilitator runs, check catalog presence, and return per-check fix hints — including the undocumented buyer-side settle requirement. Deterministic, no LLM.
Liveness probe.
No ghost responses: every paid call returns real computed output, or your
input echoed back as unknown with evidence. Catalog snapshot for
listing-doctor: /catalog_urls.json.