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.

Listed in Anthropic's MCP Directory — one-click install in Claude Desktop.

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

Privacy Policy

Redacta runs entirely on your device.

• Data collection: none. Redacta does not collect, transmit, or log any of the text you pass to it.
• Usage & storage: input text is processed in memory to produce the redacted output and token map, then discarded. Nothing is persisted by the server. The token map is returned to you (the caller) and never stored or sent anywhere.
• Third-party sharing: none. The server makes no network calls.
• Data retention: none. No data is retained after a request completes.
• Contact: [email protected]

Full policy: https://www.pharmatools.ai/privacy-policy

Desktop extension (MCPB) for the Claude Connectors Directory

Redacta is a local stdio server, so it's distributed to Claude as a Desktop Extension (MCPB), not a remote connector.

npm run build:mcpb                      # bundles mcpb/server.mjs (+ icon)
npx @anthropic-ai/mcpb pack mcpb        # produces redacta-<version>.mcpb

All three tools are annotated readOnlyHint: true (no side effects), and the manifest declares no network access and links the privacy policy.

Automated releases (Anthropic MCP Directory)

Redacta is published in the Anthropic MCP Directory via a pull-based flow — no submission form per release. The workflow at .github/workflows/mcpb-pack.yaml builds the bundle, packs a versioned .mcpb, and attaches it to the GitHub Release whenever a tag matching redacta-* is pushed. The directory review cycle then picks the new tag up automatically.

First decide whether the engine changed. The workflow publishes only redacta-mcp — not the shared @pharmatools/redacta engine. So:

• Engine changed? Publish it first, otherwise the MCP build picks up the old version:

  # in npm-package/: bump version, then
  npm publish
  # then bump the "@pharmatools/redacta" range in mcp-server/package.json to match
  

• MCP server only? Skip the above and go straight to tagging.

To cut the release:

# from repo root, after bumping the version in mcp-server/package.json
git tag redacta-1.3.0
git push origin redacta-1.3.0

The workflow syncs package.json + mcpb/manifest.json to the tag version, builds, and publishes redacta-1.3.0.mcpb to the release. Tag convention: redacta-<version> → asset redacta-<version>.mcpb.

Registered with the directory as: repo nickjlamb/redacta, tag pattern redacta-*. For a one-off / first manual submission, pack locally and upload the .mcpb via the Desktop extension submission form.

The same tag also fans out to the other distribution channels:

1. GitHub Release — attaches redacta-<version>.mcpb (Anthropic directory).
2. npm — publishes redacta-mcp@<version> (publish-npm job).
3. Official MCP Registry — publishes io.github.nickjlamb/redacta-mcp (publish-registry job, after npm has indexed the version).

One-time setup — no secrets required; both npm and the registry authenticate with tokenless GitHub OIDC (id-token: write):

• npm Trusted Publishing — on npmjs.com, open the redacta-mcp package → Settings → Trusted Publisher → GitHub Actions, and register: repository nickjlamb/redacta, workflow mcpb-pack.yaml. After that the publish-npm job publishes via OIDC (and gets build provenance for free).
• MCP Registry — needs no setup; the io.github.nickjlamb/* namespace is granted automatically because the workflow runs in a repo owned by that account.

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.