8.1 million+ provenance stamped US government and scientific records, sold per call to autonomous agents over x402 USDC on Base. No API key, no signup, no contract.
Most screening services cover sanctions. Sanctions lists are commoditized and widely mirrored. The harder question is whether a counterparty is barred from federal contracting or excluded from Medicare and Medicaid, and that lives in a different set of registers. OSF screens all of them in the same call:
| Authority | What it answers | Records |
|---|---|---|
| SAM.gov Exclusions | barred from US federal contracting | 168,000+ |
| HHS OIG LEIE | excluded from Medicare and Medicaid | 83,600+ |
| World Bank | debarment and cross debarment | 5,200+ |
| Federal Reserve Board | enforcement actions | 2,880+ |
| OFAC, EU, UK, UN, CSL, FBI | sanctions and denied parties | 32,600+ |
And your agent does not need an account to ask. SAM.gov's own Exclusions API
returns HTTP 403 without an api_key, that key requires a registered
SAM.gov account, and a non federal account with no assigned role is capped at
10 requests per day. An autonomous agent cannot complete that registration.
OSF screens those same exclusions plus ten other authorities with no key, no account and no registration. That is the difference OSF sells: not the data, which is public, but the absence of the gate in front of it.
curl "https://api.osf-master-server.com/x402/free/screen/sanctions/Wagner%20Group"Five free screens per UTC day. Every response carries
screening_evidence: the terms actually searched, how many records were in scope per
authority, how fresh they are, and whether the scan completed. A negative is only returned as
NO_MATCH when the complete candidate set was examined; otherwise you get
INCOMPLETE_SCREEN, which is not a clearance.
npx -y osf-data-marketplaceclaude mcp add --transport http osf https://api.osf-master-server.com/mcphttps://api.osf-master-server.com/mcp21 tools. 15 are free and take no payment at all, including the catalog and a real
sanctions and debarment screen, so an agent can confirm the data it needs exists before anything is
funded. Also on the MCP Registry as
io.github.onefreeman1337/osf-data-marketplace.
| Vertical | Coverage | Records |
|---|---|---|
| Federal court opinions | SCOTUS all time plus all 13 circuits, via CourtListener | 1,558,000+ |
| Tax exempt organizations | IRS EO Business Master File | 1,983,000+ |
| Cyber and vulnerabilities | NVD, CVE Program, EU EUVD, CISA KEV, EPSS, CWE, ATT&CK | ~1,550,000 |
| Scholarly research | arXiv, Crossref, PubMed, OpenAlex, Semantic Scholar | ~1,341,000 |
| SEC filings and holdings | EDGAR filings plus 13F institutional holdings | 375,000+ |
| Aircraft registry | FAA US civil aircraft registrations | 320,000+ |
| Federal spending | USASpending awards and contracts | 154,000+ |
| Healthcare providers | CMS NPI registry | 107,000+ |
The complete, live, machine readable inventory is coverage.json: all 80 sources with record count, freshness date and the route that queries each one. Free, no payment, no key. Read it to decide whether OSF covers your workload before you spend anything.
| What | Price | Limit |
|---|---|---|
| MCP search tools (15 of 21) | free | no daily cap, no wallet |
| Free screening door | free | 5 screens per UTC day |
Trial on any priced URL, add ?trial=1 | free | 1 real call per route per hour |
| Vertical search | $0.05 | no cap |
| Sample record | $0.001 | full record |
Paid calls settle in USDC on Base via the x402 protocol. No account is created, no card is stored and no subscription exists. The trial is on the same URL you would pay on, so switching from evaluating to buying costs you eight characters, not an integration.
Every record links back to its authoritative primary source. Every search response carries proof of work on every result including an empty one: the terms actually searched, how many records were in scope per source, how fresh they are, whether the scan completed or was truncated, and on an empty result a known good control query re-measured live in the same request. The point is that a negative from OSF is something you can defend later, not something you have to trust.