ocrmypdf-mcp

A minimal MCP server that exposes ocrmypdf as a single tool, ocr_pdf, so Claude can OCR scanned PDFs and then hand them to markitdown (or any text tool) for downstream work.

Why this exists: the obvious "just call ocrmypdf" approach falls over on Windows with the Microsoft Store (MSIX) build of Claude Desktop, because MSIX launches MCP servers with a stripped-down PATH that doesn't include Tesseract or Ghostscript. This server auto-detects the standard Windows install locations and prepends them to PATH at startup, so OCR Just Works without futzing with system environment variables.

Works on Linux and macOS too — the PATH augmentation is a no-op outside Windows.

Prerequisites (Windows)

Two system installers, then pip install.

1. Tesseract OCR

UB-Mannheim build (the standard Windows distribution): https://github.com/UB-Mannheim/tesseract/wiki

Accept the default install location (C:\Program Files\Tesseract-OCR). Add language packs during install if you need anything beyond English.

2. Ghostscript

AGPL release for Windows (free): https://www.ghostscript.com/releases/gsdnld.html

Accept the default install location (C:\Program Files\gs\gs<version>\).

3. Verify (optional)

tesseract --version
gswin64c --version

If either says "not recognized," reopen PowerShell so it picks up the updated PATH, then retry.

Install the server

git clone https://github.com/jcm4TX/ocrmypdf-mcp
cd ocrmypdf-mcp
pip install --user .

This installs ocrmypdf, the mcp SDK, and the ocrmypdf-mcp executable. On Windows it lands at:

C:\Users\<you>\AppData\Roaming\Python\Python313\Scripts\ocrmypdf-mcp.exe

Wire it up in Claude Desktop

Edit claude_desktop_config.json. On the MSIX (Microsoft Store) build of Claude Desktop, the path is:

%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\claude_desktop_config.json

On the regular non-MSIX installer it's:

%APPDATA%\Claude\claude_desktop_config.json

Add an ocrmypdf-mcp entry under mcpServers:

{
  "mcpServers": {
    "ocrmypdf-mcp": {
      "command": "C:\\Users\\<you>\\AppData\\Roaming\\Python\\Python313\\Scripts\\ocrmypdf-mcp.exe",
      "args": []
    }
  }
}

Then fully quit Claude Desktop — right-click the tray icon and pick Quit, not just close the window — and relaunch.

Verify it loaded

In a new chat, ask "what MCP tools do you have for OCR?" — Claude should report ocr_pdf. If not, check the server log:

%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\logs\mcp-server-ocrmypdf-mcp.log

Tool API

ocr_pdf(input_path, output_path?, language?, force_ocr?, deskew?)

Arg	Type	Default	Meaning
input_path	str	required	Absolute path to input PDF
output_path	str	<stem>-ocr.pdf next to input	Where to write the OCR'd PDF
language	str	"eng"	Tesseract language code; join multiple with +, e.g. "eng+spa"
force_ocr	bool	false	Re-OCR pages that already have a text layer
deskew	bool	true	Straighten skewed pages before OCR

Default behavior: pages without an existing text layer get OCR'd, pages that already have text pass through unchanged. Safe to run on mixed PDFs.

Typical workflow

1. You hand Claude a scanned PDF path.
2. Claude calls ocr_pdf(input_path="...").
3. Claude calls markitdown.convert_to_markdown on the resulting -ocr.pdf.
4. Claude reads the markdown and answers your question.

Known limitations

• The MCP protocol enforces a per-request timeout (~4 minutes in current Claude Desktop). Large multi-page documents may exceed this and surface as a client-side timeout even though the underlying ocrmypdf process completes successfully — the output PDF will still be on disk. If you hit this regularly, split the input into smaller page ranges first.
• Complex multi-column scanned layouts (legal, probate, ledgers) can produce messy markdown when piped to markitdown afterward, because Tesseract interprets visual alignment as table structure. Post-processing the markdown to drop empty table-pipe rows recovers most of it.

License

MIT