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Connect your agent to data it can re-check.

One paste, and Claude, Cursor, or any MCP client can resolve U.S. healthcare providers, read federal exclusion lists, and get every fact stamped with a source, a snapshot date, and a re-checkable Ed25519 attestation. Read-only, no account — start on the free demo key.

Add Fonteum to your agent Read the API reference →

One paste to connect

The server is the npm package @fonteum/mcp, started by npx. The default key pk_dx_sample is a free, read-only demo key — 100 requests/hour, no signup.

Claude Desktop — claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "fonteum": {
      "command": "npx",
      "args": ["-y", "@fonteum/mcp"],
      "env": { "FONTEUM_API_KEY": "pk_dx_sample" }
    }
  }
}

Claude Code — one command

terminal

claude mcp add fonteum -- npx -y @fonteum/mcp

Cursor (and any client that reads mcpServers)

mcp.json

// ~/.cursor/mcp.json (global) or .cursor/mcp.json (project)
{
  "mcpServers": {
    "fonteum": {
      "command": "npx",
      "args": ["-y", "@fonteum/mcp"]
    }
  }
}

Remote (streamable-HTTP) clients — point at the hosted server

endpoint

# Clients that speak remote (streamable-HTTP) MCP can point
# straight at the hosted server — no local process:
https://fonteum.com/api/mcp

Discovery card: https://fonteum.com/.well-known/mcp.json. Then restart your client and ask it to look up a provider — e.g. “Look up NPI 1234567893 with Fonteum.”

Three core tools

Read-only by charter — the agent reads facts, it never writes them. Think of them as lookup a record, search records, and a re-checkable integrity signal.

fonteum_get_providerlookup a record
Look up one provider by NPI (10-digit, Luhn-checked) and get the reconciled record — every field carrying its 14-tuple provenance contract.
fonteum_search_providersearch records
Search providers by specialty + state (optional county), up to 100 per call. Each hit is dated to the source snapshot it came from.
fonteum_check_exclusionre-checkable integrity signal
Check an NPI against federal + state exclusion / sanction lists (OIG LEIE, SAM.gov, state Medicaid) — an exclusion & sanction-list monitoring signal for billing / program-integrity compliance. Re-confirm matches against the primary source.

Plus two more

fonteum_list_sources
List the federal source families behind every field — authority, tier, refresh cadence, and official URL. Read-only.
fonteum_dataset_info
Read the methodology version and the fourteen-field provenance contract that ships with each dataset.

What it looks like in the loop

The agent calls a tool, gets a fact with its source and snapshot date, and cites the re-checkable attestation back — so its answer is auditable, not asserted.

Illustrative transcript · the cite-your-source loop

user

Is NPI 1234567893 clear to bill? Cite a source I can re-check.

→ tool call

fonteum_check_exclusion({ npi: "1234567893" })

← tool result{
  "npi": "1234567893",
  "excluded": false,
  "excluded_by": [],
  "checked": ["OIG LEIE", "SAM.gov", "state Medicaid"],
  "_source": "OIG LEIE",
  "_snapshot": "2026-06-01",
  "_attestation": "/verify/1042"
}

assistant

NPI 1234567893 is not on any federal or state exclusion list as of the 2026-06-01 OIG LEIE snapshot, so it carries no billing / program-integrity flag. Source: OIG LEIE via Fonteum — re-check the signed attestation yourself at fonteum.com/verify/1042.

Every fact carries its source, snapshot date, and a re-checkable attestation id — so the agent’s answer is auditable, not asserted.

Re-check what your agent cites

Every attestation the tools reference lands at /verify/<id>. Paste a snapshot id to pull the signed envelope and re-derive the hash yourself — the same proof your agent hands its user.

Re-check it yourself

Every snapshot ships with a SHA-256 attestation. Look one up to get its source archive, published hash, and Ed25519 chain head — then re-hash the bytes yourself.

example attestation envelope

source OIG-LEIE · oig.hhs.gov

snapshot 2026-05-01

sha256 a3f7…e92c

✓Ed25519 chain head signed & attested

Or run the full flow at /verify · curl /verify/<id>