Redacta MCP server

An MCP server that pseudonymises patient identifiers and PII in text — and restores them. Gives any MCP client (Claude Desktop, Cursor, etc.) three tools:

• redact — replace identifiers with labelled tokens ([NHS_NUMBER_1], [PATIENT_NAME_1], …). Returns the redacted text, a report, a token_map (token → original, for re-identification), and a self-check.
• reinstate — reverse a redaction using a token map, to put real values back into output generated from redacted text.
• self_check — re-scan redacted text for anything that still looks like an identifier.

Everything runs locally in the server process: no network calls, no storage. Same engine as the Redacta skill and the Redacta for Miro app.

Detection

Deterministic patterns with checksum validation — NHS numbers (Modulus-11), UK National Insurance numbers, dates of birth (keyword-anchored; appointment dates preserved), UK postcodes, US SSNs/ZIPs, hospital/MRN numbers, emails, phones — plus general PII (URLs, IPs, Luhn-validated cards, IBANs, account numbers, UK vehicle regs) and keyword-anchored patient/relative/carer names (clinician names preserved by design). Names in free prose are not caught; review the output.

Use with Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "redacta": {
      "command": "npx",
      "args": ["-y", "redacta-mcp"]
    }
  }
}

Restart Claude Desktop. Then: "Redact this letter before I share it" → the redact tool runs; "put the real details back using this token map" → reinstate.

Local development

npm install
npm run build
npm test          # engine tests (vitest)
npm start         # run the server on stdio

Publishing

To npm (powers the npx redacta-mcp install above):

npm publish

Then list it on the MCP registries for discovery:

• Official MCP registry — https://registry.modelcontextprotocol.io
• Smithery — smithery mcp publish
• Glama — auto-indexes published npm MCP servers; verify the listing
• mcp.so / PulseMCP — community submission
• awesome-mcp-servers — open a PR adding the entry

Limits

Deterministic + keyword-anchored detection only — not a guarantee, and not a substitute for formal data-protection processes. Always review the result, and treat the token_map as the key that reverses the redaction: store it with the same care as the original data.

License

MIT-0. Built by PharmaTools.AI.