What Agents Buy.

Preflight is live: before your agent pays any x402 API, it gets one verdict, CLEAR, HOLD, or ABORT. As it stands today, 20 of 1,081 sellers are payment traps and 80 resell data you can get for free.

An AI agent can hold a wallet and spend it on its own, but until now it had no way to ask one simple question before the money left: is this seller safe to pay, and will it actually deliver? Preflight answers that in a single call. Point it at any x402 endpoint and it returns one verdict the agent can gate on, CLEAR, HOLD, or ABORT, built from everything this site has measured by paying the market with a real wallet.

• What it is. One pre-payment verdict per seller, folding four measured signals into a single light: payment safety (does the live 402 price and payment address match the listing, is the paywall even real), delivery (has a paid call to this host come up short of its promised fields, confirmed on two calls), demand realness, and whether the data is something you can get free upstream. Green is CLEAR, yellow is HOLD, red is ABORT, gray is unrated. As it stands today, across 1,081 sellers: 994 clear, 58 hold, 20 to abort, and 80 quietly reselling data available free from an exchange, the chain, a weather service, or a plain web search.
• How to use it. Have your agent call preflight(url) on the free MCP server, or GET the host out of /api/preflight.json, or read the human directory at /preflight. Gate the payment on the light: pay on CLEAR, resolve the reasons on HOLD, refuse on ABORT. Every seller page carries its verdict as a badge, and the full contract is at /preflight/spec. One rule overrides the verdict every time: read the payment address and the amount out of the live 402 on the call you are about to make, and sign against those, never a listing.
• Why we built it. Agentic commerce has working payments and no verdict at the moment of decision. The press keeps asking whether any of this demand is real; an agent about to spend needs something narrower and more useful, one checkable answer before it commits. Preflight turns a month of paying this market and keeping the receipts into something an agent calls before every payment, rather than a page a human reads afterward. A red light only ever comes from evidence that money or goods have actually gone wrong: a payment address that disagrees with the listing, a phantom paywall, or a paid call that returned none of what it promised, confirmed twice. Nothing here is sponsored, and every verdict is reproducible.