GateCheck by LarryBuildsAI
https://proofbeforepay.vercel.app/gatecheck/mcpOne-cent x402 and MCP readiness checks plus fixed-price marketplace launch packs.
Paid verification
How it worksNo sponsored paid call yet.
Pay this endpoint once from your own wallet (Base USDC, up to $1.00) and we call it and record what came back. Your wallet pays the listed recipient directly; Agent Tools never holds funds. Sponsored checks prove delivery; they do not count as demand.
Quality grade
How grading works- ✓ Answers a real HTTP 402 challenge
- ✓ Publishes a /.well-known/x402 descriptor
- ✓ Payment address on record
- ✓ Settlement network declared
- ✗ Price declared
x402 readiness
Readiness is how fully this listing follows its protocol and how it behaved in our probes over 30 days. It is shown for reference and does not move it in search. Search order and leaderboards use the separate quality grade (here B, 56.0/100), which weighs availability, payability and on-chain demand. How the two differ
| Valid payment requirements | 9/10 | Findings: missing: price declared.
|
| Live 402 challenge | 20/25 | Endpoint reachable; its 402 challenge was seen earlier (138 ms). |
| x402 version | n/a | x402 version not observed yet. |
| Signed descriptor | n/a | No x402 standard defines a signed descriptor. |
| Uptime (30 days) | 15/15 | 32/32 probes succeeded over 30 days (100%). |
| Resource declaration | 10/10 | Declares 5 paid resource(s). |
| Verified identity | 5/10 | Publisher descriptor (/.well-known/x402 or OpenAPI) on record; claim this listing to verify domain control. |
| Freshness + modern flags | 1/5 | not seen in a source for over 30 days; declares x402. |
| Security declaration | n/a | Payment is the access control for an x402 resource. |
Compared with peers
Against 10,082 reachable x402 APIs in our daily snapshot (2026-11-12 06:46 UTC). Display only; it does not change search order.
- Readiness
- Higher than 55% of peers
- This listing 80 · peer median 78
- Latency
- Faster than 72% of peers
- This listing 138 ms · peer median 205 ms
Where it loses the most points, and how to win them back
- Live 402 challenge −5
— Answer the paid path with a valid 402 challenge.
Now: Endpoint reachable; its 402 challenge was seen earlier (138 ms).
- Verified identity −5
— Claim the listing and prove control of its domain.
Now: Publisher descriptor (/.well-known/x402 or OpenAPI) on record; claim this listing to verify domain control.
- Freshness + modern flags −4
— Keep the listing current in the registry or source it comes from.
Now: not seen in a source for over 30 days; declares x402.
Paid endpoints
5 resource(s) advertised by this origin. Each price below is that resource's own x402 price; the headline price is the range across them.
https://proofbeforepay.vercel.app/v1/x402/scan
Scan a target URL for /.well-known/x402, /openapi.json, resource counts, pricing, listing staleness, and next-step issues.
https://proofbeforepay.vercel.app/v1/x402/health/probe
Probe a paid endpoint without payment, parse its x402 402 challenge, compare expected network/asset/price, and return a health receipt.
https://proofbeforepay.vercel.app/v1/x402/agent-tools/readiness
GateCheck readiness v1: quick/deep/report readiness checks that compose x402 scans, agent discovery checks (/llms.txt, /agents.txt, /.well-known/mcp.json, /mcp), optional unpaid paid-path probes, and metadata/report guidance.
https://proofbeforepay.vercel.app/v1/x402/launch-pack
x402 Launch Pack Generator v0: listing copy, buyer FAQ, launch checklist, approval packet, and marketplace-safe claim boundaries for x402/MCP sellers.
https://proofbeforepay.vercel.app/v1/receipts/check
Return a Boundary Guard-style receipt for submitted request metadata, policy decision, hashes, result summary, and next-step guidance.
How to call
curl -sS -i -X GET https://proofbeforepay.vercel.app/gatecheck/mcp # expect HTTP 402 Payment Required (price advertised in the 402 response)
https://proofbeforepay.vercel.app/gatecheck/mcp
Listed in
Directories this entry was found in.