redact-pdf-mcp

Redact PDF MCP server

An MCP server that permanently redacts PII from PDFs. Give an agent a PDF, get back a PDF with the sensitive text removed from the file — not covered with a black rectangle that anyone can select, copy, or delete.

Most "redaction" MCP servers scrub PII out of prompt text. This one takes a real document and returns a real redacted document.

It also anonymizes. With mode: "pseudonymize" every person, company and address becomes a consistent tag such as [Person 1] instead of a black box, so the document stays readable (e.g. before pasting a contract into ChatGPT or Claude), and you get the tag → original table to restore the names.

claude mcp add redact-pdf -- npx -y redact-pdf-mcp

Then ask: "Redact the personal data in ~/Documents/contract.pdf", or "Anonymize ~/Documents/contract.pdf with placeholders so I can paste it into an AI".

---

Your data

You are sending the document the agent is meant to protect, so this comes first.

• Never used to train AI models — not ours, not Microsoft's, not anyone's. The Azure AI services used for OCR and PII detection run with content logging disabled, so document content is not retained or used for model improvement.
• Processed in the EU and Switzerland on Microsoft Azure.
• Encrypted with TLS 1.2+ in transit and AES-256 at rest.
• The original is deleted after processing under the default ephemeral retention. The redacted output is kept for your account's retention window (14 days by default, configurable) and can be purged at any time with DELETE /v1/jobs/{job_id}.
• Certified infrastructure. Azure holds SOC 2 Type II, ISO 27001, ISO 27017 and ISO 27018 certifications and is HIPAA-eligible under Microsoft's BAA. Redact PDF AI itself is not independently audited for these frameworks; it is built so legal, medical and finance teams can use it inside their own compliance posture.
• The MCP server sends no telemetry of its own — see what the server does locally.

Details: redact-pdf.ai/security · privacy policy

Why not let the agent redact it itself?

An agent can find names in text. It cannot make a PDF safe on its own:

• A black box is not a redaction. Drawing a rectangle over text leaves the text layer underneath; anyone can select, copy or extract it. This server rasterizes each page and drops the text layer and metadata, so there is nothing left to recover.
• Scans have no text to search. Contracts, IDs and statements are often images. OCR runs first, in 100+ languages, then PII detection runs over what it read.
• Detection is a model, not a regex. Names, addresses and organizations do not follow a pattern. The detector is purpose-built for PII, and your always-redact and never-redact lists cover the rest.

Examples

Prompts that work as-is once the server is installed:

• "Redact the personal data in ~/Documents/lease.pdf before I send it to the agency."
• "Redact names, emails and IBANs in every PDF in ~/Downloads/statements, keep our company name visible." — the agent passes pii_excluded_terms for the company name and fans out with redact_pdf.
• "Here is a screenshot of a customer ticket. Remove the phone number and address, then give me a PDF I can attach." — images go in directly, no conversion.
• "Try the redact-pdf demo on ~/Documents/contract.pdf so I can see what it does." — keyless, first page only.

Try it with no API key

The server ships a keyless tool, try_demo. Give it a file and it redacts the first page for real — no key, no account — and tells the agent what it found:

You: Use the redact-pdf server's try_demo tool on ~/Documents/contract.pdf.

Claude: Redacted the first page of contract.pdf (4 pages). Personal data removed on that page: Person, Email. Here is the redacted page (link valid 14 days). To redact all 4 pages, a free account gets the first document (up to 5 pages) done in full, no card.

Call it with no file and it runs a built-in synthetic sample instead, which is the zero-configuration connectivity check. Same thing from a terminal, no install:

curl https://www.redact-pdf.ai/v1/demo
curl -F [email protected] https://www.redact-pdf.ai/v1/demo/redact

What it does

• Permanent, irreversible redaction. The underlying text is deleted, not masked. It cannot be recovered by copy-paste, text extraction, or "remove object" in a PDF editor.
• PDFs and images. Pass a PDF, JPEG or PNG. Photos and screenshots do not need converting first; the output is a redacted PDF either way.
• Scanned documents. OCR handles image-only PDFs and photos of documents.
• 100+ languages for entity detection.
• Eight entity types: Person, Email, PhoneNumber, Address, Organization, Date, IBAN, CreditCard — plus your own always-redact and never-redact term lists.
• EU/Swiss processing, never used for AI training — see Your data.
• Pseudonymize instead of black boxes. mode: "pseudonymize" replaces each entity with a consistent tag ([Person 1], [Org 1], [Address 1]...), identical on every page and for every variant of a name, so the document stays readable for a colleague or another AI. The text is still removed, not covered, and redact_pdf_and_wait also returns the tag → original table (CSV).
• Human review when it matters. retention: "studio" keeps the detected masks so a person can check and adjust them before export.

Install

Claude Code

claude mcp add redact-pdf --env REDACT_PDF_API_KEY=your_key -- npx -y redact-pdf-mcp

Claude Desktop

claude_desktop_config.json:

{
  "mcpServers": {
    "redact-pdf": {
      "command": "npx",
      "args": ["-y", "redact-pdf-mcp"],
      "env": { "REDACT_PDF_API_KEY": "your_key" }
    }
  }
}

Cursor

.cursor/mcp.json:

{
  "mcpServers": {
    "redact-pdf": {
      "command": "npx",
      "args": ["-y", "redact-pdf-mcp"],
      "env": { "REDACT_PDF_API_KEY": "your_key" }
    }
  }
}

VS Code

code --add-mcp '{"name":"redact-pdf","command":"npx","args":["-y","redact-pdf-mcp"],"env":{"REDACT_PDF_API_KEY":"your_key"}}'

Get an API key at redact-pdf.ai/sign-up. A free account gets its first document (up to 5 pages) redacted in full, no card. Without a key, try_demo still works; everything else will tell the agent to ask you for one.

A client that can't pass the key in the environment (Cowork drops a plugin MCP server whose config references a plugin setting, so the Claude plugin passes none) can save it instead: give the agent the key and it calls set_api_key, which checks the key against the API and, when the client supports MCP elicitation, asks you to approve the account (email and the key's last four characters). A confirmed key is written to ~/.config/redact-pdf-mcp/key (or $XDG_CONFIG_HOME/redact-pdf-mcp/key), readable by your user only, and is never replaced without the same confirmation. A client without elicitation gets the key for that session only, in memory, never over a key that still works, and every tool result names the account. That keeps a key planted in a processed document from silently redirecting your files. The tool never returns the key. You can also write the file yourself once (see the plugin README for the one-line command). REDACT_PDF_API_KEY takes priority when it is set; an empty value, or an unsubstituted placeholder such as ${user_config.api_key}, counts as unset.

Tools

Tool	What it does
redact_pdf_and_wait	Start here. Upload, redact, wait, return the finished PDF. One call.
redact_pdf	Start a job and return immediately, for redacting several documents in parallel.
get_job_status	Poll a job: uploaded → analyzing → redacting → redacted | error.
download_redacted	Fetch the redacted output for one document.
download_correspondence	Fetch the tag → original table of a pseudonymized document (mode: "pseudonymize").
try_demo	Keyless. With a file: redact its first page for real. Without: run the built-in sample.
restore_names	Local only. Put the real names back into a .md, .txt or .docx the agent wrote from the pseudonymized text. Returns the output path and counts, never a name.
get_account_status	Check the API key is valid and see the account, before a big batch.
set_api_key	Local only. Check a key the user gives in the conversation and save it user-only on this machine, for clients that can't pass REDACT_PDF_API_KEY. Never returns the key.

Redaction rules, on either redact tool:

Argument	Effect
pii_categories	Restrict to specific entity types. Omit for account defaults.
pii_included_terms	Always redact these, even if not detected as PII (codenames, case numbers).
pii_excluded_terms	Never redact these, even if detected (your own company name).
retention	ephemeral (default) deletes the original after processing. studio keeps masks for human review.
mode	redact (default) draws black boxes. pseudonymize draws consistent tags such as [Person 1] and returns the correspondence table (stdio: written next to the PDF as *-correspondence.csv; remote: inline as correspondence_csv) plus the document as text with the tags in place (document_text, or document_text_path / document_text_url past 32 KB). Also accepted by try_demo.

Anonymize → let the AI work → put the names back

The local server closes the loop without the model ever seeing a name:

1. redact_pdf_and_wait with mode: "pseudonymize" returns the redacted PDF, the correspondence table on disk, and document_text: the document as text, every name replaced by its tag. The agent works from that text.
2. The agent writes its answer (summary, memo, letter) to a .md, .txt or .docx file, keeping the tags as written.
3. restore_names with that file and the correspondence_path writes <name>-restored.<ext> with the real names, and returns only the path and counts.

The agent must not open the original document first, nor the correspondence CSV or the restored file afterwards: any of those reads puts the personal data back into the conversation. The server instructions and tool descriptions say so explicitly.

Remote server

The package also ships a streamable-HTTP server for hosted use, where the API key travels per request instead of in the environment:

npx redact-pdf-mcp-http     # listens on :8080/mcp

POST /mcp
X-API-Key: your_key          (or: Authorization: Bearer your_key)

It is stateless — no sessions, no stored keys, nothing kept between requests — so each request gets its own short-lived server instance and one caller's key can never leak into another's tool call.

The handshake, tools/list, and try_demo work without a key, so a client can connect and verify the server before anyone signs up; every other tool returns 401 with a WWW-Authenticate challenge.

Documents are supplied as file_base64 (the remote server has no access to your filesystem).

Fetching a document by URL is off by default on the remote server. The address check is real — URLs resolving to loopback, private, or link-local addresses are refused, and every redirect hop is re-checked — but the socket resolves the hostname a second time after that check, so a DNS-rebinding attacker with a short TTL can still have the server validate one address and connect to another. Closing that requires pinning the connection to the validated address, which is not implemented yet, so an internet-reachable server does not offer the surface at all.

Set REDACT_PDF_ENABLE_URL_INPUT=1 to accept file_url, and only where you have your own egress controls (a network policy or allowlisting proxy) in front of the server. REDACT_PDF_ALLOW_PRIVATE_URLS=1 additionally permits private addresses, for a self-hosted instance fetching from internal storage.

stdio mode is unaffected: it runs on your own machine, where fetching a URL carries no privilege you do not already have.

Variable	Default	Purpose
REDACT_PDF_API_KEY	—	API key (stdio mode only; remote takes it per request). Empty or ${...} counts as unset, and the key saved by set_api_key is used instead.
REDACT_PDF_BASE_URL	https://www.redact-pdf.ai	Point at a different API host.
PORT	8080	HTTP server port.
REDACT_PDF_MCP_PATH	/mcp	HTTP endpoint path.
REDACT_PDF_ENABLE_URL_INPUT	unset	Accept file_url on the remote server. Off by default — see the DNS-rebinding note above.
REDACT_PDF_ALLOW_PRIVATE_URLS	unset	Self-hosted only: permit file_url to reach private addresses. Never set this on a publicly reachable server.

What the server does locally

• No telemetry. The server makes exactly the API calls its tools describe, and nothing else. No analytics, no error reporting, no phone-home.
• Stateless. No database, no cache, no disk writes except the files you asked for, at the paths you asked for, and the key file when you call set_api_key.
• Your originals stay yours. In stdio mode the input file is read and never modified. Under the default ephemeral retention the API deletes the original after processing.
• Idempotent by default. The idempotency key is derived from the file bytes and the redaction settings, so an agent that retries the same call gets the same job back instead of redacting — and billing — twice. That cache lasts 24 hours; pass an explicit idempotency_key when you genuinely want a second, separate redaction of the same file.
• Never overwrites. In stdio mode the redacted PDF is written atomically and the tool refuses to clobber an existing file.

Privacy Policy

The full policy is at redact-pdf.ai/privacy. It covers the website, the app and the API this server calls. In short:

• What is collected. The documents you send, their processing metadata (status, page count, selected PII categories) and the redaction masks; your account identifier and email if you use an API key; billing data if you pay. This MCP server itself collects nothing and sends no telemetry.
• How it is used. To run the redaction you asked for, and to operate, secure and bill your account. Documents are processed for OCR and PII detection only and are never used to train AI models.
• Where it is stored. Microsoft Azure in the EU and Switzerland, encrypted in transit (TLS 1.2+) and at rest (AES-256).
• Who it is shared with. Documents go only to Microsoft Azure (storage, OCR and PII detection). Account and billing data go to Clerk and Stripe. Internal operational alerts, which can include a file name, go to the team's Slack. The policy lists every subprocessor.
• How long it is kept. Under the default ephemeral retention the original is deleted after processing; the redacted output follows your account's retention window (14 days by default) and can be deleted at any time. Files sent to the keyless try_demo are deleted after the first page is redacted; that page is kept 14 days.
• Contact. [email protected] for privacy requests and questions.

Limits

• 50 MB per PDF, 10 MB per image, 100 files per job.
• PDF, JPEG and PNG in; always a PDF out. Convert other formats (DOCX, TIFF, HEIC) to PDF first.
• On the remote server, base64 inflates a document by about a third, so prefer file_url for anything large.
• Passing an empty pii_categories list is rejected: to the API an empty list means "redact nothing", which would return an untouched file reported as redacted. Omit the argument to use your account defaults.
• Billed per page against your plan quota and credit packs, after the free first document. A quota_exceeded error means top up — the tools tell the agent not to retry it.

Development

npm install
npm run build
npm test                 # offline unit + tool tests
npm run test:integration # hits the live keyless demo endpoint; no key needed

Links

• API docs: redact-pdf.ai/developers
• Security and data handling: redact-pdf.ai/security
• OpenAPI spec: redact-pdf.ai/openapi.yaml
• LLM index: redact-pdf.ai/llms.txt

Support questions about redaction quality, billing, or your account go to [email protected] — GitHub issues here are for the MCP server itself.

MIT licensed.