Calendar Pa

A production-grade Google Calendar MCP server with a Telegram bot interface. Manage your calendar in plain English — schedule meetings, find free slots, set up recurring events, and get reminders — all through Claude or Telegram.

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Features

• Natural language scheduling — "Schedule a team sync tomorrow at 3pm for an hour"
• Conflict detection — automatically checks for clashes before creating events
• Smart slot finder — "Find me a 2 hour deep work block this week" (AI-powered reasoning)
• Complex recurring events — "Every second Tuesday of the month", "Every weekday until December"
• Reminders — configurable popup and email reminders on any event
• Session memory — remembers context and preferences across sessions
• Two interfaces — Claude Desktop (MCP) and Telegram bot

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Architecture

Google Calendar API
        ↑
MCP Server (Python)
        ↑
   ┌────┴────┐
Claude    Telegram Bot
Desktop   (Claude API + MCP tools)

The MCP server exposes tools that any MCP-compatible client can use. The Telegram bot calls the same tool handlers directly, giving you a mobile-friendly interface with the same intelligence.

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Quick Start

Requirements

• Python 3.12+
• A Google Cloud project with the Calendar API enabled
• An Anthropic API key (for the Telegram bot)
• A Telegram bot token (for the Telegram bot)

1. Clone and set up

git clone https://github.com/Richardilemon/calendar-pa.git
cd calendar-pa

python3 -m venv venv
source venv/bin/activate  # Windows: venv\Scripts\activate

pip install -r requirements.txt

2. Google Calendar OAuth

1. Go to Google Cloud Console
2. Create a new project (or use an existing one)
3. Enable the Google Calendar API
4. Go to APIs & Services → Credentials → Create Credentials → OAuth 2.0 Client ID
5. Application type: Desktop app
6. Download the JSON file, rename it to credentials.json, place it in the project root
7. Add your Google account as a test user under OAuth consent screen → Test users

3. Configure environment

cp .env.example .env

Edit .env with your values:

# Google Calendar
CALENDAR_ID=primary
CREDENTIALS_FILE=/absolute/path/to/calendar-pa/credentials.json
TOKEN_FILE=/absolute/path/to/calendar-pa/token.json

# Session context storage
CONTEXT_FILE=/absolute/path/to/calendar-pa/data/session_context.json

# Telegram bot (required for bot interface)
TELEGRAM_BOT_TOKEN=your_telegram_bot_token
ANTHROPIC_API_KEY=your_anthropic_api_key

4. Authenticate with Google

python -c "from src.auth import get_calendar_service; get_calendar_service(); print('authenticated')"

This opens your browser for OAuth authorization. A token.json file is saved for future sessions.

5. Run the MCP server

python -m src.server

6. Connect to Claude Desktop

Add to your claude_desktop_config.json:

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

{
  "mcpServers": {
    "calendar-pa": {
      "command": "/absolute/path/to/calendar-pa/venv/bin/python",
      "args": ["/absolute/path/to/calendar-pa/src/server.py"],
      "cwd": "/absolute/path/to/calendar-pa"
    }
  }
}

Restart Claude Desktop. You should see calendar-pa in the connectors list.

7. Run the Telegram bot (optional)

Create a Telegram bot via @BotFather and add the token to .env, then:

python src/bot.py

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MCP Tools

Tool	Description
get_events	Fetch events by date, date range, or keyword
create_event	Create event with automatic conflict detection
update_event	Reschedule, rename, or update any event
delete_event	Delete with confirmation step
find_free_slot	AI-powered free slot finder
create_recurring_event	Natural language recurring events
set_reminder	Add popup or email reminders
get_session_context	Load persistent session state
update_session_context	Save state across sessions

Resources

Resource	URI	Description
Today's schedule	calendar://today	Live events for today
This week's schedule	calendar://week	Live events for the week
Tool statistics	system://tool-stats	Tool call metrics

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Usage Examples

Claude Desktop:

• "What's on my calendar this week?"
• "Schedule a FANAP planning session tomorrow at 10am for 2 hours"
• "Find me a free 90 minute slot on Thursday"
• "Create a recurring team standup every Monday at 9am"
• "Move my 3pm meeting to Friday"

Telegram bot:

• /today — today's schedule
• /week — this week at a glance
• Or just type naturally — the bot understands plain English

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Self-Hosting Notes

This is a self-hosted tool — you run your own instance with your own credentials. There is no shared hosted service.

Each user needs:

• Their own Google OAuth credentials (credentials.json)
• Their own Anthropic API key (for the Telegram bot)
• Their own Telegram bot token (for the Telegram bot)

None of these are included in the repo — they stay on your machine only.

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Deployment

To run the Telegram bot as an always-on service, deploy src/bot.py to any Python-compatible host:

• Railway — recommended, generous free tier
• Render — Background Worker, $7/month
• Fly.io — free tier available
• Any VPS — run with python src/bot.py or set up as a systemd service

For cloud deployment, store credentials.json and token.json as base64-encoded environment variables:

base64 -i credentials.json | tr -d '\n'  # → GOOGLE_CREDENTIALS_B64
base64 -i token.json | tr -d '\n'        # → GOOGLE_TOKEN_B64

The server decodes these at startup via src/setup.py.

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Project Structure

calendar-pa/
├── src/
│   ├── server.py          # MCP server — tools, resources, routing
│   ├── auth.py            # Google OAuth flow
│   ├── bot.py             # Telegram bot
│   ├── setup.py           # Cloud deployment credential setup
│   └── tools/
│       ├── calendar.py    # All calendar tool handlers
│       └── context.py     # Session context tools
├── data/                  # Session context storage (gitignored)
├── credentials.json       # Google OAuth credentials (gitignored)
├── token.json             # Google OAuth token (gitignored)
├── .env                   # Environment variables (gitignored)
├── .env.example           # Environment variable template
├── requirements.txt
└── Procfile               # For cloud deployment

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Roadmap

v1 (current)

• Core calendar operations with conflict detection
• Smart slot finder with AI reasoning
• Complex recurring events
• Session memory
• Telegram bot interface

v2 (planned)

• Multi-calendar support
• Per-user OAuth for hosted deployment
• React Native app for alarm-based notifications
• Meeting suggestions with attendee availability

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Built With

• MCP Python SDK
• Google Calendar API
• python-telegram-bot
• Anthropic Claude API

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License

MIT