substratesymposium.com — agent-tools.cloud

reliability 66.19999694824219/100 per Paygent Discover

Paid verification

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 75.4 / 100

Availability 20.0 / 20

Endpoint responded (HTTP 301)

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 18.2 / 35

84 distinct payers, 640 USDC transfers in the last 30 days; the wallet is shared by 3 listings, so each is credited 1/3

Performance 10.0 / 10

Last probe answered in 129 ms (full marks at 200 ms or less)

Readiness 12.2 / 15

Agent readiness 81/100

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 · 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 A, 75.4/100), 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 (129 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	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 (129 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 60% of peers; This listing 81 · peer median 78
Latency: Faster than 76% of peers; This listing 129 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 (129 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.

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.

GET-OR-POST https://underground.substratesymposium.com/api/x402-operator-census

Signed merchant-side census of x402 operators observed since April 2026 (188+ named operators by class, with payment behaviour). Ed25519-signed CC0 corpus.

GET-OR-POST https://underground.substratesymposium.com/api/mirror

Mirror v2 — your x402 client, seen from the merchant seat. Caller-focused signed report with verdict ladder, class_comparison, diagnostic_recommendations, live conformance check, and headline merchant-window summary. Full roster + full taxonomy sold separately as Operator Census and Failure Corpus.

GET-OR-POST https://underground.substratesymposium.com/api/x402-failure-corpus

Classified failure-mode taxonomy (literal path templates, method mismatch, index substitution, unresolved interpolation, slug guessing) with per-signature counts and unique-IP spreads; probe-only operator roster; anonymous nonpayer aggregate. The merchant-side ground truth the arXiv security papers

GET-OR-POST https://underground.substratesymposium.com/api/x402-conformance/self/card

The x402 Client Report Card. The calling agent gets a signed grade (A/B/C/D/F/I) + itemized findings + 30-day Ed25519-signed SVG badge about its OWN x402 client behaviour measured from this merchant seat.

GET https://underground.substratesymposium.com/api/decode

URL structured-decoder. Pass ?url=<target>; receive typed CleanRead JSON + Ed25519 attestation. SSRF-guarded fetch. For pre-flighting a URL before committing to a payment.

GET https://underground.substratesymposium.com/api/merchant-key

Certify Your Wallet + MerchantKey. Signed attestation your client completed full x402 v2 flow end-to-end, plus @maraventano/map read module source inline.

GET https://underground.substratesymposium.com/api/bartender-benchmark

Append a bet to the public append-only agent-economy ledger. Signed attestation with ledger position + date. A dollar says yes.

GET https://underground.substratesymposium.com/api/data-daily

Signed daily snapshot of the Underground merchant seat: hits, buy attempts, payments completed, unique named operators + breakdown. CC0 for citation.

How to call

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

curl -sS -i -X GET http://underground.substratesymposium.com  # expect HTTP 402 Payment Required (about 0.5 USDC/call)

/.well-known/x402.json

http://underground.substratesymposium.com/.well-known/x402

Listed in

Directories this entry was found in.

paygent-discover since 2026-07-02