x402.fairseal.io — agent-tools.cloud

Pay $0.01 for an instant verifiable random number backed by a Wesolowski VDF chain with on-chain Merkle anchor. For the free commit-reveal protocol: POST /v1/rng/commit (free), then GET the reveal_url returned — reveal is always free. Bias-resistant; do not construct reveal paths yourself.

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+ 67.3 / 100

Availability 20.0 / 20

Endpoint responded (HTTP 200)

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 11.4 / 35

15 distinct payers, 205 USDC transfers in the last 30 days; the wallet is shared by 3 listings, so each is credited 1/3

Performance 7.8 / 10

Last probe answered in 589 ms (full marks at 200 ms or less)

Readiness 13.0 / 15

Agent readiness 87/100

Owner verified 0.0 / 5

Nobody has claimed this listing yet

Endpoint last checked 19 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 · 84/100

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+, 67.3/100), 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 (589 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 8 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	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 (589 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, bazaar_feed. 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 67% of peers; This listing 84 · peer median 78
Latency: Faster than 13% of peers; This listing 589 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 (589 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 −2 — Keep the listing current in the registry or source it comes from.
Now: seen within 30 days; declares x402.

How many agent tools actually work · All statistics

Paid endpoints

8 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://x402.fairseal.io/v1/rng/commit

Commit to a future VDF epoch before its output is computable. Returns signed commitment receipt.

GET https://x402.fairseal.io/v1/rng/reveal/{commitment_id}

Retrieve the committed epoch output after VDF computation. Permissionless — anyone can verify.

GET https://x402.fairseal.io/v1/rng/latest

Demo/sandbox: retrieve a pre-computed verifiable random number. For production use commit/reveal.

POST https://x402.fairseal.io/v2/anchor

Anchor a SHA-256 payload hash (64 lowercase hex chars) into a Merkle batch on Base mainnet. Payment: $0.02 USDC per submission. Returns anchor_id (202 Accepted); poll status_url for anchored receipt with Merkle proof + on-chain tx hash. Verify offline (pure SHA-256 fold) or on-chain via MerkleAnchor

POST https://x402.fairseal.io/v1/notarize

Notarize an AI agent decision or audit record. POST {schema, payload_hash (SHA-256 hex, 64 chars), metadata}. Schemas: agent_decision (agent_id, decided_at, input_hash, decision_hash), audit_evidence, probe_record. Returns receipt_id with pending_anchor immediately; Merkle proof and on-chain anchor

POST https://x402.fairseal.io/v1/veo/verify

VEO-2 object verification: schema validation, hash integrity, optional signature check. Returns signed verdict.

POST https://x402.fairseal.io/v1/pii/detect

PII pattern detection (regex-based; no cryptographic receipt): emails, US/Canada (NANP) phones only (non-NANP international numbers not detected), dash-formatted numeric national IDs (partial coverage; alphanumeric formats such as Taiwan A123456789 and Korean 6+7-digit formats are not matched), loos

POST https://x402.fairseal.io/v1/break

Commit-before-entropy spot assignment for live card breaks, giveaways, raffles, and spot-assignment contests. POST {spots[], participants[], label?}: spots and participants are arrays of 1..500 strings (max 100 chars each; participants must not exceed spots). Returns commitment immediately (break_id

How to call

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

curl -sS -i -X GET https://x402.fairseal.io  # expect HTTP 402 Payment Required (about $0.001/call)

/.well-known/x402.json

https://x402.fairseal.io/.well-known/x402

Listed in

Directories this entry was found in.

cdp-bazaar since 2026-08-19 x402 since 2026-10-10