Project API

https://project-api-gamma-sable.vercel.app/paid/arxiv/search

● healthy search

Paid public-data feeds. Unpaid requests return HTTP 402. Prices are USDC on Base.

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

B 59.3 / 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 10.5 / 35

14 distinct payers, 30 USDC transfers in the last 30 days; the wallet is shared by 2 listings, so each is credited 1/2

Performance 0.0 / 10

Last probe answered in 3955 ms (full marks at 200 ms or less)

Readiness 13.8 / 15

Agent readiness 92/100

Owner verified 0.0 / 5

Nobody has claimed this listing yet

Endpoint last checked 18 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

A · 92/100

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, 59.3/100), 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	24/25	Paid endpoint answers with an HTTP 402 challenge (3955 ms); slow response -1.
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 50 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	5/5	seen in a source within 7 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: Slow (3955 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 92% of peers; This listing 92 · peer median 78
Latency: Faster than 4% of peers; This listing 3,955 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.
Live 402 challenge −1 — Answer the paid path with a valid 402 challenge.
Now: Paid endpoint answers with an HTTP 402 challenge (3955 ms); slow response -1.

How many agent tools actually work · All statistics

Paid endpoints

50 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 https://project-api-gamma-sable.vercel.app/paid/hello

Smoke / connectivity check

GET https://project-api-gamma-sable.vercel.app/paid/sam/opportunities

SAM.gov contract opportunities (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/usaspending/awards

USASpending.gov award search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/federalregister/documents

Federal Register rules/notices/EOs (slim JSON + html uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/openfda/drug-events

openFDA FAERS drug adverse events (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/clinicaltrials/studies

ClinicalTrials.gov studies search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/nhtsa/recalls

NHTSA vehicle recalls by make/model/year (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/usgs/earthquakes

USGS earthquake events (slim GeoJSON features + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/openfda/device-events

openFDA MAUDE device adverse events (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/sec/company-tickers

SEC company tickers (CIK/ticker/title + Edgar uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/nih/reporter/projects

NIH RePORTER project search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/openalex/works

OpenAlex works search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/fema/disasters

FEMA disaster declarations (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/openfda/food-enforcement

openFDA food enforcement recalls (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/nws/alerts

NWS/NOAA active weather alerts by state (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/treasury/debt-to-penny

Treasury Fiscal Data debt to the penny (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/nsf/awards

NSF Award Search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/pubmed/search

NCBI PubMed bibliographic search via esearch (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/sec/submissions

SEC EDGAR submissions by CIK (entity + capped recent filings + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/eric/search

ERIC education literature search via IES/ED (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/noaa/coops

NOAA CO-OPS water levels / tide predictions (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/ecfr/search

eCFR full-text regulatory search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/europepmc/search

Europe PMC life-sci article search (slim JSON + uiLink; OA IDs)

GET https://project-api-gamma-sable.vercel.app/paid/cms/nppes

CMS NPPES NPI Registry provider search (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/gleif/lei

GLEIF LEI legal-entity identity lookup (slim JSON + uiLink; ≠ yente)

GET https://project-api-gamma-sable.vercel.app/paid/worldbank/indicator

World Bank v2 country indicator time series (slim JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/wikidata/sparql

Wikidata SPARQL SELECT/ASK (bounded JSON + uiLink)

GET https://project-api-gamma-sable.vercel.app/paid/arxiv/search

arXiv Atom API preprint search (slim JSON + abs/pdf links)

GET https://project-api-gamma-sable.vercel.app/paid/usitc/hts

USITC Harmonized Tariff Schedule search (slim JSON + duty rates)

GET https://project-api-gamma-sable.vercel.app/paid/epa/echo

EPA ECHO facility compliance search (slim JSON + facility report link)

GET https://project-api-gamma-sable.vercel.app/paid/nhtsa/vpic

NHTSA vPIC VIN decode (slim JSON; not the recalls feed)

GET https://project-api-gamma-sable.vercel.app/paid/nist/nvd

NIST NVD CVE/CPE search with CISA KEV flags (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/ror/org

Research Organization Registry lookup (slim JSON)

GET https://project-api-gamma-sable.vercel.app/paid/datacite/doi

DataCite DOI metadata (slim JSON)

GET https://project-api-gamma-sable.vercel.app/paid/cfpb/hmda

CFPB HMDA data-browser aggregations (slim JSON, not raw LAR)

GET https://project-api-gamma-sable.vercel.app/paid/fdic/banks

FDIC BankFind institution search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/cms/open-payments

CMS Open Payments Sunshine Act search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/senate/lda

Senate LDA lobbying filings (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/zenodo/records

Zenodo research record search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/cpsc/recalls

CPSC consumer-product recalls (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/cfpb/complaints

CFPB consumer complaint search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/usgs/water

USGS water daily or continuous observations (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/nyfed/rates

NY Fed latest SOFR and reference rates (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/opencitations/count

OpenCitations citation count for a DOI (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/core/works

CORE.ac.uk works search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/who/gho

WHO GHO indicator values (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/gbif/species

GBIF species name match (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/ietf/rfc

IETF RFC metadata (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/loc/search

Library of Congress search (slim JSON, no key)

GET https://project-api-gamma-sable.vercel.app/paid/openlibrary/search

Open Library book search (slim JSON, no key)

How to call

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

curl -sS -i -X GET https://project-api-gamma-sable.vercel.app/paid/arxiv/search  # expect HTTP 402 Payment Required (about $0.001/call)

/.well-known/x402.json

https://project-api-gamma-sable.vercel.app/.well-known/x402

Listed in

Directories this entry was found in.

x402scan since 2026-10-04