Mailhub

Mailhub is a local, MCP-first personal-operations hub for AI assistants and their humans.

Features

• Mail — Gmail, Microsoft Graph (Outlook.com), IMAP/SMTP
• Calendar — Google Calendar, Microsoft Graph, CalDAV
• Contacts — Google People, Microsoft Graph, CardDAV
• Tasks — Microsoft To Do (Graph), CalDAV VTODO
• MCP-first — stdio MCP server for AI agents (read-only + full modes)
• REST API — localhost-only HTTP server for scripts/CLI
• CLI — mailhub (admin) and mail (user) commands

Quick Start

# Install
uv tool install --editable .

# Initialize config & state
mailhub init

# Configure OAuth clients (one-time)
mailhub config setup-google    # Opens Google Cloud Console, guides OAuth setup
mailhub config setup-microsoft # Opens Entra ID, guides app registration

# Add accounts
mailhub config add-account --alias me --provider gmail --capabilities mail --email me@gmail.com
mailhub config add-account --alias work --provider graph --capabilities mail --email me@outlook.com

# Authorize accounts (opens browser, paste redirect URL)
mailhub auth gmail me --code '<pasted-redirect-url>'
mailhub auth graph work --code '<pasted-redirect-url>'

# Verify health
mailhub doctor

# Start REST server (localhost only)
mailhub serve

# Or run MCP server (read-only by default)
mailhub mcp --mode ro
# Or full mode for mutations
mailhub mcp --mode full

Using the mail CLI

The mail command is a thin HTTP client to the REST API (requires mailhub serve running):

# List accounts
mail accounts

# List folders
mail folders me

# Search messages
mail search me "from:github.com newer_than:7d"
mail search work "hasAttachments:true"

# Get message
mail get me <message-id>

# Send (requires --confirm)
mail send me --to someone@example.com --subject "Hello" --body "Test" --confirm

# Create draft
mail draft me --to someone@example.com --subject "Draft" --body "Content"

Systemd Service (Auto-start)

# Install service files
mkdir -p ~/.config/systemd/user
cp deploy/*.service deploy/*.timer ~/.config/systemd/user/

# Enable and start
systemctl --user daemon-reload
systemctl --user enable --now mailhub.service mailhub-doctor.timer
loginctl enable-linger  # keeps user services alive after logout

Configuration

Config lives at ~/.config/mailhub/config.toml:

[server]
host = "127.0.0.1"
port = 8787

[auth]
ro_token = "..."      # read-only token
full_token = "..."    # full-access token

[send]
allowlist = ["*@example.com"]  # glob patterns
# allow_anywhere = true        # disable allowlist

[gmail]
client_id = "..."
client_secret = "..."

[graph]
client_id = "..."

[accounts.personal]
provider = "gmail"
capabilities = ["mail", "calendar", "contacts"]

[accounts.work]
provider = "graph"
capabilities = ["mail", "calendar", "contacts", "tasks"]

Security

• REST server binds only to 127.0.0.1 (never 0.0.0.0)
• No hard-delete — only trash/cancel
• Mutations require confirm=true + recipient allowlist
• Audit log (~/.local/state/mailhub/audit.jsonl) never records tokens/bodies
• Credentials stored with 0600 permissions, atomic writes, fcntl lock
• OAuth PKCE with random state
• Message bodies treated as untrusted input

Development

uv sync --extra dev
uv run pytest
uv run mailhub init
uv run mailhub status
uv run mailhub mcp --mode ro

Architecture

mailhub/
├── config.py      # TOML config, validation, provider capabilities
├── store.py       # Credential store (atomic, 0600, fcntl lock)
├── oauth.py       # PKCE OAuth for Google/Microsoft
├── core.py        # Policy engine, allowlist, audit, retry, adapters
├── util.py        # HTML→text, MIME, address parsing
├── gmail.py       # Gmail API adapter
├── graph.py       # Microsoft Graph adapter
├── gcal.py        # Google Calendar adapter
├── gcal_graph.py  # Graph Calendar adapter
├── caldav.py      # CalDAV adapter (read)
├── people.py      # Google People adapter
├── people_graph.py # Graph People adapter
├── carddav.py     # CardDAV adapter (read)
├── tasks.py       # Tasks domain
├── tasks_graph.py # Graph Tasks adapter
├── tasks_caldav.py # CalDAV VTODO adapter (read)
├── app.py         # FastAPI REST server (127.0.0.1 only)
├── cli.py         # mailhub admin CLI
├── mail_cli.py    # mail user CLI (thin REST client)
├── mcp.py         # MCP server (ro + full modes)
├── backup.py      # Backup/restore utilities
└── deploy/        # systemd user units

License

MIT

Man Pages

Install man pages system-wide:

sudo cp docs/man/mailhub.1 /usr/local/share/man/man1/
sudo cp docs/man/mail.1 /usr/local/share/man/man1/
sudo mandb

Then view with:

man mailhub
man mail

Or view locally without installing:

man -l docs/man/mailhub.1
man -l docs/man/mail.1

Shell Completions

Generate completion scripts for your shell:

mailhub --generate-completion bash  > ~/.local/share/bash-completion/completions/mailhub
mailhub --generate-completion zsh   > ${fpath[1]}/_mailhub
mailhub --generate-completion fish  > ~/.config/fish/completions/mailhub.fish

The completion script also covers the mail command (same stub).

Docker Usage

Mailhub provides official Docker images via GitHub Container Registry:

# Quick start with docker-compose
docker compose up -d

# View logs
docker compose logs -f mailhub

# Run MCP server only
docker compose run --rm mailhub-mcp

# Build locally
docker build -t zc-mailhub .
docker run -p 8787:8787 zc-mailhub serve

docker-compose.yml

The provided docker-compose.yml runs two services:

Configuration and state are persisted via Docker volumes:

volumes:
  mailhub-config:
  mailhub-state:

Building Locally

# Build image
docker build -t zc-mailhub .

# Run REST API
docker run -p 8787:8787 zc-mailhub serve

# Run MCP server
docker run -it zc-mailhub mcp --mode full

Security

The Docker image follows security best practices:

• Multi-stage build — builder stage for dependencies, minimal runtime image
• Non-root user — runs as mailhub user (UID/GID 999)
• No secrets in image — configuration and credentials mounted as volumes
• Read-only root filesystem (when deployed with read_only: true)
• Dropped capabilities — cap_drop: ["ALL"], no-new-privileges:true

Volumes

Configuration and state are persisted via Docker volumes:

volumes:
  mailhub-config:
  mailhub-state:

These correspond to ~/.config/mailhub/ and ~/.local/state/mailhub/ on the host.

MCP Configuration

Mailhub's MCP server runs over stdio and works with all major AI clients. Configure it in your client's MCP settings:

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json on macOS, ~/.config/claude/claude_desktop_config.json on Linux)

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

Cursor (.cursor/mcp.json in project root)

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

VS Code / GitHub Copilot (.vscode/mcp.json in project root)

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

Windsurf (~/.config/windsurf/mcp.json)

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

Continue.dev (~/.continue/config.json)

{
  "mcpServers": [
    {
      "name": "mailhub",
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  ]
}

Zed (~/.config/zed/settings.json)

{
  "mcp": {
    "servers": {
      "mailhub": {
        "command": "mailhub",
        "args": ["mcp", "--mode", "full"],
        "env": {
          "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
        }
      }
    }
  }
}

Sourcegraph Cody (.cody/mcp.json in project root)

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

Using Docker (Local)

{
  "mcpServers": {
    "mailhub": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "zc-mailhub", "mcp", "--mode", "full"],
      "env": {
        "MAILHUB_CONFIG": "/home/mailhub/.config/mailhub/config.toml"
      }
    }
  }
}

Using SSH (Remote VPS)

{
  "mcpServers": {
    "mailhub": {
      "command": "ssh",
      "args": ["user@your-vps", "mailhub", "mcp", "--mode", "full"],
      "env": {}
    }
  }
}

Using SSH + Docker (Remote VPS with Docker)

{
  "mcpServers": {
    "mailhub": {
      "command": "ssh",
      "args": ["user@your-vps", "docker", "run", "--rm", "-i", "zc-mailhub", "mcp", "--mode", "full"],
      "env": {}
    }
  }
}

Read-Only Mode

For read-only access (no mutations), change --mode full to --mode ro:

{
  "mcpServers": {
    "mailhub": {
      "command": "mailhub",
      "args": ["mcp", "--mode", "ro"],
      "env": {
        "MAILHUB_CONFIG": "/home/youruser/.config/mailhub/config.toml"
      }
    }
  }
}

MCP Server Capabilities

The MCP server exposes the following capabilities in its initialize response:

• Tools: All mail operations (search, get, send, draft, move, trash, folders) + status
• Resources: Not implemented (mail data accessed via tools)
• Prompts: Not implemented
• Logging: Supported

Server info returned on initialize:

• server_name: "mailhub"
• server_version: "0.1.1" (current package version)
• instructions: Description of the server and usage hints