Free MCP · on-device · nothing uploaded
Check PDF redactions from Claude
Add one MCP server and ask Claude "did I actually redact this?" It checks the file on your machine and tells you whether the SSNs and account numbers are still sitting under the black boxes. The PDF never leaves your computer.
Quick walkthrough
Install the Omitly MCP in seconds
Download the bundle, add it to Claude Desktop, and start checking PDFs locally.
Add it to your client
Claude Desktop: one-click download, nothing else needed. Everything else: Node 18+, runs via npx — no separate install.
Or configure manually — edit claude_desktop_config.json (Settings → Developer → Edit Config), then fully quit and reopen.
{
"mcpServers": {
"omitly-leak-check": {
"command": "npx",
"args": ["-y", "omitly-mcp"]
}
}
}One command in your terminal:
claude mcp add omitly-leak-check -- npx -y omitly-mcpAdd to ~/.cursor/mcp.json (or .cursor/mcp.json in a project):
{
"mcpServers": {
"omitly-leak-check": {
"command": "npx",
"args": ["-y", "omitly-mcp"]
}
}
}Add to ~/.codeium/windsurf/mcp_config.json, then reload:
{
"mcpServers": {
"omitly-leak-check": {
"command": "npx",
"args": ["-y", "omitly-mcp"]
}
}
}Then just ask
"Did I actually redact /path/to/report.pdf?"
"Scan this PDF for any SSNs or card numbers still in the text."
"Check the exhibits in this folder and tell me which ones leak."
What a leak actually looks like
Most "redacted" PDFs are just a black rectangle drawn on top of the page — a shape, not a
removal. The original characters are still sitting in the file's content stream underneath
it, selectable and copyable the moment someone drags across the box or runs
pdftotext on the file.
How Omitly actually removes it
goes into the technical detail (content-stream removal under ISO 32000-2, not an overlay).
check_redaction on a file like that reports back, in plain text — illustrative example:
⚠️ Text-layer LEAK: this "redacted" PDF still contains 2 sensitive item(s)
(1 ssn, 1 email) in its text layer — the redaction only painted over them.
Text hidden under redaction marks (HIGH RISK):
- Page 3: ssn (***-**-4821)
- Page 3: email (j***@example.com)
Previews are masked; raw values stayed on-device. To actually remove this
data (not cover it) with independent verification + a signed audit log,
redact it in Omitly.Claude reads that back directly — which page, what kind of data, and that the box didn't actually remove it. Every preview stays masked; nothing is uploaded. You can see the same check without any setup at all in the free browser leak checker — same detector, no MCP client required.
The free tools
check_redaction Audit a 'redacted' PDF and report any PII still in the text layer underneath the boxes.
find_sensitive_regions List PII candidates (emails, SSNs, phone, card numbers) with page and coordinates.
locate_text Find exact strings — names, addresses, account refs — and their positions.
All three work with zero setup, are read-only and detect-only — they never modify a file. If you already have Omitly installed, this package also has tools that redact and generate PDFs for real; see "Already have Omitly installed?" in the FAQ below.
This finds the problem. Omitly fixes it.
Detecting a leak is free. Removing the data for real — stripping the characters from the file, verifying nothing survives, and writing a signed audit log — means using Omitly: the desktop app, or this same MCP server once it's pointed at your install (see the FAQ). Detection is also pattern-based: names, addresses and image-only text aren't covered, so a clean result isn't proof of completeness, but a leak is conclusive. Note that even then, Claude itself never does the redacting — the same deterministic WASM detector runs either way, on-device; see why asking an LLM to redact a PDF directly is unsafe.
Get OmitlyQuestions
What is the Omitly leak-check MCP?
It's a free Model Context Protocol server that gives Claude (or any MCP client) three tools to inspect PDFs on your machine, out of the box: check whether a 'redacted' file still leaks PII, find sensitive regions, and locate specific text. These run a WebAssembly build of Omitly's detector locally — your documents never leave the machine, and no setup beyond npx is needed.
Does it upload my PDFs?
No. Every tool runs inside the MCP process on your computer. Nothing is sent to a server. You can run it offline.
Can it redact a PDF for me?
Out of the box, no — the zero-config tools above are detect-only: they tell you a redaction leaked, they never modify a file. If you already have the Omitly desktop app installed, the same npm package also has tools for real redaction and PDF creation that drive the app's own engine — see 'Already have Omitly installed?' below. Without that, actually removing the data (with independent verification and a signed audit log) means using Omitly — either the desktop app directly, or this MCP once it's pointed at your install.
Already have Omitly installed? What else can this MCP do?
Point it at your install with the OMITLY_ENGINE_DIR environment variable (see the README) and three more tools become available: redact_pdf and redact_by_entity actually remove PDF content and return a signed audit log, and create_pdf generates a clean PDF from Markdown. Those three drive the exact same engine as the desktop app, so they're gated the same way — your 14-day trial, then a Personal or Pro licence. There's also a fourth, verify_redaction, that's free and needs no configuration either way — it just gets stronger once configured, reusing the audit sidecar redact_pdf/redact_by_entity write instead of falling back to a general re-scan. Without OMITLY_ENGINE_DIR set, calling redact_pdf, redact_by_entity or create_pdf returns a clear 'not configured' error rather than silently failing.
Do I need to install anything?
For Claude Desktop, no — download the .mcpb bundle above and drag it in. For any other client (Claude Code, Cursor, Windsurf), just Node 18+ — the server runs via npx, so there's no separate install step. Real redaction and PDF creation (see above) additionally need the Omitly desktop app installed and OMITLY_ENGINE_DIR pointed at it.
Is it really free?
Yes. Detecting a leak is free and unlimited, no licence required. Actually redacting or generating a PDF through this MCP follows the same trial/licence terms as the Omitly desktop app, because it's the same engine.