Assay A2A, MCP & x402 Security Verifier & TDQS Observatory

Cryptographic pre-flight security audit, schema conformance & TDQS reputation verifier for A2A, MCP, and x402 endpoints.

Paid verification

How it works

No 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

B+ 82.7 / 100

Availability 40.0 / 40

Endpoint responded (HTTP 200)

Payability 20.0 / 20

✓ Answers a real HTTP 402 challenge
✓ Publishes a /.well-known/x402 descriptor
✓ Payment address on record
✓ Settlement network declared
✓ Price declared

Demand 19.7 / 40

17 distinct payers, 356 USDC transfers in the last 30 days

Owner verified 3.0 / 3

Operator proved control of this domain

Endpoint last checked 5 h ago. On-chain activity last read 2 d ago. Availability and on-chain demand are both re-probed daily; the grade updates automatically on the next pass. This grade sets search order and leaderboards; the readiness score below is shown for reference only.

x402 readiness

B · 81/100

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+, 82.7/100), which weighs availability, payability and on-chain demand. How the two differ

Valid payment requirements	10/10	Payment requirements carry a payee, a mainnet network and a price.
Live 402 challenge	20/25	Endpoint reachable; its 402 challenge was seen earlier (151 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	24/24 probes succeeded over 30 days (100%).
Resource declaration	5/10	Declares 2 paid resource(s).
Verified identity	8/10	Publisher descriptor (/.well-known/x402 or OpenAPI) on record and domain control verified on agent-tools.cloud (company-registry check not available yet).
Freshness + modern flags	3/5	seen within 30 days; declares x402.
Security declaration	n/a	Payment is the access control for an x402 resource.

Applicable criteria total 75 points, scaled to 100.

Responsiveness: Responsive (151 ms; bands ≤2.5 s, ≤5 s, ≤8 s, slower; penalty only).

Payment evidence: x402_challenge — We sent a request and got a live HTTP 402 challenge. Also: x402_manifest, catalog_listing. Qualifies the payment claim; adds no points.

Measured 2026-11-11.

Nine criteria, the same as the A2A readiness score, read from our daily probe of the paid endpoint, its payment requirements and 30-day probe history. Signed descriptor and security declaration are n/a for x402 (payment is the access control), as is an x402 version we have not observed; the remaining points are scaled to 100. Grades: A>=90, B>=75, C>=60, D>=40, F<40. Display only: search order uses the quality grade.

Compared with peers

Against 10,060 reachable x402 APIs in our daily snapshot (2026-11-12 01:39 UTC). Display only; it does not change search order.

Readiness: Higher than 60% of peers; This listing 81 · peer median 78
Latency: Faster than 68% of peers; This listing 151 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 (151 ms).
Resource declaration −5 — Declare each paid resource with its input and output schema.
Now: Declares 2 paid resource(s).
Verified identity −2 — Claim the listing and prove control of its domain.
Now: Publisher descriptor (/.well-known/x402 or OpenAPI) on record and domain control verified on agent-tools.cloud (company-registry check not available yet).

How many agent tools actually work · All statistics

Paid endpoints

2 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://assay.agentdiet.dev/v1/certify

https://assay.agentdiet.dev/api/audit

How to call

cURL · x402-fetch / x402-axios will auto-handle 402

curl -sS -i -X GET https://assay.agentdiet.dev/v1/certify  # expect HTTP 402 Payment Required (about 0.005 USDC/call)

MCP endpoint

https://assay.agentdiet.dev/mcp

/.well-known/x402.json

https://assay.agentdiet.dev/.well-known/x402

Listed in

Directories this entry was found in.

submission since 2026-10-20 x402scan since 2026-10-20