Before your agent pays an x402 endpoint, ask it about it first — we paid ~550 of them real USDC so yours doesn't have to find out the hard way

If you're building agents that spend money over x402, you've probably done what everyone does: hardcode the three endpoints you trust and ignore discovery, because a directory listing tells you nothing about whether the thing actually works when paid. So we built the directory that answers that question with receipts. It's machine-readable, meant to be queried by agents, not browsed by humans. What your agent gets before spending a cent: A discover endpoint — search by capability, cap by price, filter by minimum score. Ranked by continuously-verified behavior, never by payment. Ranking is not for sale. A resolve endpoint — the pre-spend check for a URL your agent already holds: probe history, whether the 402 answers correctly right now, and whether the payment address has been stable or recently rotated (a rotation fully resets a listing's reputation — old trust never carries over to an unproven wallet). An MCP server with three tools (find_paid_service, get_service_details, resolve_endpoint) — one line to add, and any MCP-capable agent has all of it natively. Connection snippet in the first comment. Why the signal is different from every other list: Every listing is probed from our infrastructure every ~15 minutes — never self-reported. Cadence is doubt-weighted: stable listings coast, anything flapping or newly changed gets hammered. We pay listings real USDC and require on-chain settlement proof for the paid-verified badge. 292 listings currently carry it; every settlement is a public Base transaction you can check yourself. Payer reports are cryptographically bound to the wallet that actually paid (an EIP-191 signature must recover to the on-chain payer) — no review bombing, no astroturf, and dust payments can't mint voters. Things we found by actually paying that no probe would ever catch: ~1.7% of "paid" endpoints accept your payment authorization and never collect it. Your agent gets data, nobody gets paid, and something in that pipeline is broken you'd never see. One 8-endpoint cluster settles real money for data that labels itself "source: mock" in the response body. Structurally perfect, procedurally generated, passes every schema check. One endpoint charged us twice and returned invalid JSON both times. The single biggest problem isn't fraud: ~130 listings can't be called without undocumented required params. If you run an x402 API — publish a sample query. It's the difference between being discoverable and being noise. And when our own verifier got it wrong, we published that too: it recently false-negatived 9 endpoints (it trusted only the settlement header; they settle fine but report elsewhere). We caught it pre-publication, fixed it to verify against the chain directly, restored the badges, and put the whole audit trail in the repo. There's a methodology page covering everything we verify — and, just as important, what we deliberately don't. The point of that page is that you shouldn't have to trust us: every verdict recomputes from public data. Free to query, free to list (submissions start unverified and earn status like everything else). If your agent needs something we don't carry, the failed query itself tells us what to index next — this morning an operator listed nine endpoints hours after an agent searched for their host and missed. What's your agent's current pre-spend check? Genuinely curious what people are doing today.