Per-tool Exact
DynamicPrice scales with batch size. One settlement per HTTP request.
No free tier · $0.002 / tool · batch = N×unit
Trust-check a tool
before your agent pays it.
Every check is paid. You get that tool’s verdict plus its history (uptime, payTo changes, price changes) — nothing else. Cache-fresh responses target <300 ms. Built so agents asking “is this x402 endpoint safe?” or “verify payTo” get a clear answer.
Docs for agents
GET https://x402check.dev/preflight?url=…
Compact JSON
Stable fields: verdict, payTo, priceUsd, reasonCodes, history.
History that matters
Past checks, uptime %, payTo drift, price moves — for that URL only.
Discoverable
OpenAPI, llms.txt, MCP Server Card, AI Catalog, A2A, Bazaar.
Questions agents ask
Is this x402 endpoint safe?
Call GET /preflight?url=…. avoid → do not pay. caution → escalate. ok → still enforce your maxAmount.
How do I verify payTo?
Read payTo from the ToolCheck. Compare to your allowlist. history.payToChanges shows prior wallets if the seller rotated.
How do I pay for a check?
Unauthenticated calls return HTTP 402. Decode PAYMENT-REQUIRED, sign Exact USDC on Base, retry with PAYMENT-SIGNATURE. See OpenAPI.
We never pay the target. Agents-first brand. Markdown twin: /index.md.