Mistral OCR MCP Server

A Model Context Protocol (MCP) server that provides tools for extracting text and images from PDF and image files using the Mistral OCR API.

Features

• Simple Text Extraction: Extract markdown content from documents without handling images
• Full Extraction with Images: Extract markdown and save embedded images to disk with proper relative links
• Security Sandbox: Restricts file writes to a configured allowed directory
• Zero-Install Deployment: Run with uvx without prior installation
• Supported Formats: PDF (.pdf), PNG (.png), JPEG (.jpg, .jpeg), WebP (.webp), GIF (.gif)

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Client Configuration

Claude Desktop

Add this to your claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "mistral-ocr": {
      "command": "uvx",
      "args": ["mistral-ocr-mcp"],
      "env": {
        "MISTRAL_API_KEY": "your-api-key-here",
        "MISTRAL_OCR_ALLOWED_DIR": "/absolute/path/to/allowed/directory"
      }
    }
  }
}

OpenCode

Add this to the mcp section of your configuration file:

{
  "mcp": {
    "mistral-ocr": {
      "type": "local",
      "command": ["uvx", "mistral-ocr-mcp"],
      "enabled": true,
      "environment": {
        "MISTRAL_API_KEY": "your-api-key-here",
        "MISTRAL_OCR_ALLOWED_DIR": "/absolute/path/to/allowed/directory"
      }
    }
  }
}

Codex

If you use the Codex CLI, you can add the server with:

codex mcp add mistral-ocr -- uvx mistral-ocr-mcp

Make sure the environment variables MISTRAL_API_KEY and MISTRAL_OCR_ALLOWED_DIR are set in your shell environment.

---

Configuration

Required Environment Variables

Variable	Description	Example
MISTRAL_API_KEY	Your Mistral API key (never logged)	sk-abc123...
MISTRAL_OCR_ALLOWED_DIR	Absolute path to allowed write directory	/Users/username/workdir

Security Sandbox

The server enforces a write directory sandbox to prevent unauthorized file writes:

• extract_markdown: No write restrictions (read-only operation)
• extract_markdown_with_images: The output_dir parameter must be within MISTRAL_OCR_ALLOWED_DIR

Validation Examples:

MISTRAL_OCR_ALLOWED_DIR	output_dir	Result
/Users/username/workdir	/Users/username/workdir/project/output	✅ Allowed
/Users/username/workdir	/Users/username/workdir	✅ Allowed (exact match)
/Users/username/workdir	/Users/username/documents	❌ Rejected
/Users/username/workdir	/Users/username/workdir/../documents	❌ Rejected (resolves outside)

Security Notes:

• All paths are canonicalized (symlinks resolved, .. eliminated) before validation
• Image filenames are sanitized to prevent path traversal attacks

---

Tool Reference

Tool 1: extract_markdown

Extract markdown content from a document without saving images.

Arguments:

{
  "file_path": "/absolute/path/to/document.pdf"
}

Parameter	Type	Required	Description
file_path	string	Yes	Absolute path to input file (PDF or image)

Returns:

"# Document Title\n\nExtracted markdown content from all pages..."

Returns a single string containing concatenated markdown from all pages.

Example:

{
  "tool": "extract_markdown",
  "arguments": {
    "file_path": "/Users/username/documents/report.pdf"
  }
}

---

Tool 2: extract_markdown_with_images

Extract markdown content and save embedded images to disk.

Arguments:

{
  "file_path": "/absolute/path/to/document.pdf",
  "output_dir": "/absolute/path/to/output/parent"
}

Parameter	Type	Required	Description
file_path	string	Yes	Absolute path to input file (PDF or image)
output_dir	string	Yes	Absolute path to output parent directory (must exist and be writable, must be within MISTRAL_OCR_ALLOWED_DIR)

Returns:

{
  "output_directory": "/absolute/path/to/output/parent/document",
  "markdown_file": "/absolute/path/to/output/parent/document/content.md",
  "images": ["img_abc123.png", "img_def456.jpeg"]
}

Field	Type	Description
output_directory	string	Absolute path to created subdirectory
markdown_file	string	Absolute path to content.md file
images	array[string]	List of saved image filenames (not full paths)

Behavior:

1. Creates a subdirectory named after the input file stem (e.g., report for report.pdf)
2. If the subdirectory already exists, appends a timestamp: report_20260102_143022
3. Saves all extracted images as <sanitized_id>.<ext> (e.g., img_abc123.png)
4. Saves markdown to content.md with relative image links (e.g., ![](./img_abc123.png))

Example:

{
  "tool": "extract_markdown_with_images",
  "arguments": {
    "file_path": "/Users/username/documents/quarterly-report.pdf",
    "output_dir": "/Users/username/workdir/extracted"
  }
}

Output Structure:

/Users/username/workdir/extracted/
  quarterly-report/
    content.md          # Markdown with relative image links
    img_abc123.png      # First extracted image
    img_def456.jpeg     # Second extracted image

---

Example Client Usage

Here's a minimal Python example using the MCP SDK to call the tools:

import asyncio
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

async def extract_document():
    server_params = StdioServerParameters(
        command="mistral-ocr-mcp",
        env={
            "MISTRAL_API_KEY": "your-api-key",
            "MISTRAL_OCR_ALLOWED_DIR": "/Users/username/workdir"
        }
    )
    
    async with stdio_client(server_params) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            
            # Simple extraction
            result = await session.call_tool(
                "extract_markdown",
                arguments={"file_path": "/path/to/document.pdf"}
            )
            print(result.content[0].text)
            
            # Extraction with images
            result = await session.call_tool(
                "extract_markdown_with_images",
                arguments={
                    "file_path": "/path/to/document.pdf",
                    "output_dir": "/Users/username/workdir/output"
                }
            )
            print(result.content[0].text)

asyncio.run(extract_document())

---

Troubleshooting

Error	Cause	Solution
Missing required environment variable: MISTRAL_API_KEY	MISTRAL_API_KEY not set	Set the environment variable before running the server
Missing required environment variable: MISTRAL_OCR_ALLOWED_DIR	MISTRAL_OCR_ALLOWED_DIR not set	Set the environment variable to an absolute path
MISTRAL_OCR_ALLOWED_DIR must be an absolute path	Relative path provided (e.g., ~/documents)	Use an absolute path (e.g., /Users/username/documents)
MISTRAL_OCR_ALLOWED_DIR does not exist	Directory does not exist on filesystem	Create the directory first: mkdir -p /path/to/dir
MISTRAL_OCR_ALLOWED_DIR is not a directory	Path points to a file, not a directory	Ensure the path is a directory
validate file_path: must be an absolute path: {path}	Relative path provided for input file	Use an absolute path (e.g., /Users/username/file.pdf)
validate file_path: resolve failed, path does not exist: {path}	Input file does not exist	Check the file path and ensure the file exists
validate file_path: unsupported file type '{suffix}'. Supported types: ...	File extension not supported	Use .pdf, .png, .jpg, .jpeg, .webp, or .gif
validate output_dir: resolve failed, path does not exist: {path}	Output directory does not exist	Create the directory first: mkdir -p {path}
validate output_dir: path is not a directory: {path}	Path points to a file, not a directory	Ensure the path is a directory
validate output_dir: writability check failed, directory not writable: {path}	Output directory exists but is not writable	Check directory permissions: chmod u+w {path}
output_dir must be within the allowed directory	output_dir is outside MISTRAL_OCR_ALLOWED_DIR	Use a path within the allowed directory
Mistral OCR request failed (status=401): {message}	Invalid API key	Check your MISTRAL_API_KEY
Mistral OCR request failed (status=429): {message}	Rate limit exceeded	Wait and retry, or check your API quota

---

Development

Setup

Clone the repository and install with development dependencies:

git clone https://github.com/ORDIS-Co-Ltd/mistral-ocr-mcp
cd mistral-ocr-mcp
pip install -e '.[dev]'

Run the server locally:

MISTRAL_API_KEY="your-key" \
MISTRAL_OCR_ALLOWED_DIR="/path/to/allowed/dir" \
python -m mistral_ocr_mcp

Run Tests

pytest

Project Structure

mistral-ocr-mcp/
├── src/
│   └── mistral_ocr_mcp/
│       ├── __init__.py
│       ├── __main__.py          # Entry point
│       ├── server.py            # MCP server and tool definitions
│       ├── config.py            # Configuration loading and validation
│       ├── extraction.py        # OCR orchestration logic
│       ├── mistral_client.py    # Mistral API client
│       ├── images.py            # Image parsing and saving
│       ├── markdown_rewrite.py  # Markdown link rewriting
│       └── path_sandbox.py      # Path validation and sandbox enforcement
├── tests/                       # Unit tests
├── pyproject.toml              # Package configuration
└── README.md                   # This file

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License

MIT

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Contributing

Contributions are welcome! Please open an issue or submit a pull request.

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Links

• GitHub Repository: https://github.com/ORDIS-Co-Ltd/mistral-ocr-mcp
• MCP Specification: https://modelcontextprotocol.io
• Mistral AI: https://mistral.ai