presign-guard — agent-tools.cloud

Check before your AI agent or wallet signs: green/orange/red verdict for EVM transactions, token approvals, EIP-712 signatures and tokens, with reasons. Signed answers; $0.01 via x402 on Base.

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

A 70.8 / 100

Availability 20.0 / 20

Endpoint responded (HTTP 402)

Payability 15.0 / 15

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

Demand 12.6 / 35

41 distinct payers, 278 USDC transfers in the last 30 days; the wallet is shared by 5 listings, so each is credited 1/5

Performance 10.0 / 10

Last probe answered in 179 ms (full marks at 200 ms or less)

Readiness 13.2 / 15

Agent readiness 88/100

Owner verified 0.0 / 5

Nobody has claimed this listing yet

Endpoint last checked 20 h ago. On-chain activity last read 3 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 · 88/100

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 A, 70.8/100), 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	25/25	Paid endpoint answers with an HTTP 402 challenge (179 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 6 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.

Applicable criteria total 75 points, scaled to 100.

Responsiveness: Responsive (179 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. It also feeds 15 points of the x402 quality grade.

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 80% of peers; This listing 88 · peer median 78
Latency: Faster than 58% of peers; This listing 179 ms · peer median 205 ms

Where it loses the most points, and how to win them back

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.

How many agent tools actually work · All statistics

Paid endpoints

6 resource(s) advertised by this origin. Each price below is that resource's own x402 price; the headline price is the range across them.

POST https://presign-guard.fizzl.eu/v1/check

Is this transaction, approval or signature safe to sign? green/orange/red with reason codes, for EVM, Solana, XRP Ledger, Algorand and Stellar.

POST https://presign-guard.fizzl.eu/v1/check/explain

The pre-sign verdict plus a plain-language explanation for the person who has to decide (English or Dutch).

GET https://presign-guard.fizzl.eu/v1/token

Is this token safe to buy, hold or accept? Honeypot, impersonation, mint and freeze powers and tax, for Solana, EVM and Algorand tokens.

GET https://presign-guard.fizzl.eu/v1/approvals

Every open token approval of a wallet: who the spender is, a grade, and which approvals to revoke.

GET https://presign-guard.fizzl.eu/v1/screen

Is this wallet sanctioned? Any chain's address against the OFAC SDN list, plus theft and phishing reports for EVM addresses.

POST https://presign-guard.fizzl.eu/v1/injection

Is this text a trap for your agent? A page, email, tool result or message that tries to make it pay, leak keys or ignore its instructions.

How to call

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

curl -sS -i -X GET https://presign-guard.fizzl.eu/v1/token  # expect HTTP 402 Payment Required (about 0.01 USDC/call)

/.well-known/x402.json

https://presign-guard.fizzl.eu/.well-known/x402

Listed in

Directories this entry was found in.

submission since 2026-09-28 mcp since 2026-09-28 x402scan since 2026-10-13 x402 since 2026-10-13