🤖 CalMate – Smart Google Calendar Booking Assistant

CalMate is a natural language-powered assistant that helps users book meetings in their Google Calendar using plain English like:

"Schedule a call tomorrow at 3 PM"
"Book a meeting next Friday at 10 AM"
"Set a discussion for July 15 at 5 PM"

It supports two modes:

• ⚡ LLM Mode: Uses GPT-3.5 via OpenRouter API for tool-calling and reasoning
• 🧠 LangGraph Mode: Extracts time using dateparser without LLMs (lightweight)

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📦 Features

• ⏰ Smart date/time parsing (dateparser + LangGraph or GPT)
• 📆 Google Calendar integration with availability checking
• 🔐 Secure booking using Google Service Account
• 🖼️ Beautiful conversational UI built with Streamlit
• 🤖 Tool-calling powered by OpenRouter GPT API (LLM mode)
• 🐳 Dockerized deployment for both backend & frontend

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🗂️ Project Structure

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🧠 Modes Explained

• LLM Mode Uses GPT-3.5 via OpenRouter for intelligent parsing and tool-calling
• Manual Mode Uses LangGraph + dateparser to extract datetime without using any LLMs

To switch between them:

• Use main_llm.py for full LLM integration
• Use main_manual.py for lightweight mode

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🛠️ Tech Stack

🐍 Python 3.11

⚡ FastAPI

🤖 OpenRouter + GPT-3.5 (LLM mode)

🧠 LangGraph + DateParser (manual mode)

📅 Google Calendar API

🌐 Streamlit

🐳 Docker

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Hosted Links

Frontend: https://calmate-frontend-qn3r.onrender.com Backend: https://calmate-backend.onrender.com

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🚀 How to Run Locally with Docker

⚠️ Ensure Docker Desktop or Docker Engine is installed.

1. Clone the repo

git clone https://github.com/alucard017/CalMate.git
cd CalMate

2. Add your credentials.json file

• Go to Google Cloud Console and create a Service Account.
• Enable Google Calendar API.
• Generate and download credentials.json.
• Place it at the project root (outside the backend/ folder).

3. Start the project

docker-compose up --build

• FastAPI backend runs at: http://localhost:8000/docs

• Streamlit frontend runs at: http://localhost:8501

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🧪 Example Booking Flow

• Open localhost:8501
• Type commands like : "Book a meeting tomorrow at 11 AM"
• Get confirmation with a clickable Google Calendar event link

🧑‍💻 Developed By

Made with ❤️ by Apurba
👉 GitHub