Onedrive

Minimal, secure MCP server for OneDrive file sharing via Microsoft Graph API.

Built as a secure alternative after a security audit found 4 CRITICAL vulnerabilities in elyxlz/microsoft-mcp and the official microsoft/files-mcp-server lacked sharing link support.

Features

Tool	Description
list_files	List files and folders at any OneDrive path
get_file_metadata	Get size, type, dates, creator for a file
search_files	Full-text search across file names and content
upload_file	Upload local files (resumable for >4 MB)
download_file	Download files with path-traversal protection
create_sharing_link	Generate view or edit sharing links

Quick Start

Option A: HTTP mode (recommended for enterprise — zero-config SSO)

pip install git+https://github.com/MrFixit96/onedrive-mcp-server.git
onedrive-mcp --http

The MCP client (VS Code, Claude Code) handles all OAuth automatically. When it first needs OneDrive access, VS Code shows its standard "Sign in with Microsoft" prompt. No device codes, no app registration, no environment variables.

Option B: Stdio mode (with MSAL device-code auth)

pip install git+https://github.com/MrFixit96/onedrive-mcp-server.git
onedrive-mcp auth   # One-time sign-in
onedrive-mcp        # Start server

Security

• Zero-config auth (HTTP mode): MCP client handles OAuth via RFC 9728 Protected Resource Metadata — no client IDs, no app registration, no environment variables
• Enterprise-friendly: Works in tenants that block third-party app consent — the MCP client uses its own pre-approved credentials
• Passthrough token validation: Bearer tokens decoded for audit logging; Microsoft Graph validates cryptographically on every API call
• Windows SSO: WAM broker integration uses your existing Windows Microsoft account
• OS keyring token storage: Windows Credential Vault, macOS Keychain, or Linux SecretService (falls back to owner-only file)
• Narrow OAuth scopes: Only Files.ReadWrite + User.Read — no mail, calendar, or contacts access
• Error sanitization: Bearer tokens, correlation IDs, and internal URLs stripped from all error messages before reaching the LLM
• Audit logging: Structured JSON to stderr — every tool invocation logged with timing, redacted args, and status
• Path traversal protection: Download paths validated against a safe base directory
• No eval/literal_eval: Zero use of eval, ast.literal_eval, or exec

Installation

# Clone and install
git clone https://github.com/MrFixit96/onedrive-mcp-server.git
cd onedrive-mcp-server
pip install -e .

# Optional: install Windows SSO broker support
pip install -e ".[broker]"

# Optional: install dev tools (pytest, ruff)
pip install -e ".[dev]"

Authentication

HTTP Mode (recommended)

onedrive-mcp --http              # Start on default port 3001
onedrive-mcp --http --port 8080  # Custom port

No setup needed. The MCP client (VS Code) handles the entire OAuth flow:

1. Client discovers required scopes via /.well-known/oauth-protected-resource
2. Client authenticates with Microsoft using its own approved credentials
3. Client passes Bearer tokens to the server on every request
4. Microsoft Graph validates the token server-side

Stdio Mode (fallback)

# Just sign in — no environment variables needed
onedrive-mcp auth

On Windows (with broker installed): A native SSO popup appears using your existing Windows Microsoft account. One click, done.

On other platforms: Device code flow — visit the URL shown, enter the code, sign in with your corporate email. Your org's SSO/identity provider handles the login automatically.

Tokens are cached securely in your OS keyring (Windows Credential Vault / macOS Keychain / Linux SecretService).

Advanced: Custom Azure AD App

If your organization requires a specific app registration, you can override the default:

export ONEDRIVE_MCP_CLIENT_ID=<your-client-id>
export ONEDRIVE_MCP_TENANT_ID=<your-tenant-id>
onedrive-mcp auth

MCP Server Configuration

Claude Code (HTTP mode — recommended)

{
  "mcpServers": {
    "onedrive": {
      "type": "http",
      "url": "http://localhost:3001/mcp"
    }
  }
}

Claude Code (stdio mode)

{
  "mcpServers": {
    "onedrive": {
      "command": "onedrive-mcp"
    }
  }
}

VS Code Copilot (HTTP mode)

{
  "mcp": {
    "servers": {
      "onedrive": {
        "type": "http",
        "url": "http://localhost:3001/mcp"
      }
    }
  }
}

Environment Variables

Variable	Required	Default	Description
ONEDRIVE_MCP_CLIENT_ID	No	Office Desktop ID	Override with custom Azure AD app client ID (stdio mode only)
ONEDRIVE_MCP_TENANT_ID	No	organizations	Azure AD tenant (stdio mode only)
ONEDRIVE_MCP_PORT	No	3001	HTTP server port (HTTP mode only)
ONEDRIVE_MCP_DOWNLOAD_DIR	No	. (cwd)	Base directory for file downloads
ONEDRIVE_MCP_LOG_LEVEL	No	INFO	Audit log level (DEBUG, INFO, WARNING, ERROR)

Usage Examples

Once configured as an MCP server, tools are available to your AI assistant:

"List my OneDrive files"
→ calls list_files("/")

"Upload docs/report.docx to my OneDrive Documents folder"
→ calls upload_file("C:\path\to\docs\report.docx", "Documents/report.docx")

"Create a sharing link for Documents/report.docx"
→ calls create_sharing_link("Documents/report.docx", "view", "organization")

"Search for files about quarterly budget"
→ calls search_files("quarterly budget")

Development

# Install dev dependencies
pip install -e ".[dev]"

# Run tests (43 tests)
pytest tests/ -v

# Lint
ruff check src/ tests/

# Auto-fix lint issues
ruff check src/ tests/ --fix

Architecture

src/onedrive_mcp/
├── __init__.py       # Package metadata
├── __main__.py       # CLI: auth subcommand + server startup
├── auth.py           # SSO broker + device-code flow + OS keyring cache
├── graph.py          # Async Microsoft Graph client (httpx) + error sanitization
└── server.py         # FastMCP server with 6 tools + audit logging

• ~400 lines of core logic (auth + graph + server)
• 47 tests covering auth, graph API, server tools, error sanitization, HTTP mode, token verifier
• Dual transport: stdio (MSAL auth) + HTTP (RFC 9728 Bearer token passthrough)
• Zero third-party MCP wrappers — uses official mcp SDK
• Async httpx for HTTP, sync MSAL wrapped via asyncio.to_thread
• Stdio transport (standard MCP protocol)

Auth Flow

HTTP Mode (--http):
  MCP Client (VS Code)
      │
      ├─ GET /.well-known/oauth-protected-resource
      │     → learns required scopes + auth server
      │
      ├─ OAuth with Microsoft (client's own credentials)
      │
      └─ POST /mcp with Authorization: Bearer <token>
            → server passes token to Graph API

Stdio Mode (default):
  onedrive-mcp auth
      │
      ├─ Cached token? ──→ Silent refresh ──→ Done
      │
      ├─ Windows + broker? ──→ Native SSO popup ──→ Done
      │
      └─ Device code flow ──→ microsoft.com/devicelogin
                                   │
                                   └─ Org SSO ──→ Done

License

MIT