LangGraph Stateless Chat Bot

A simple stateless chat bot built with LangGraph that responds to user messages and uses a get_current_time tool to provide the current UTC time in ISO-8601 format when requested (e.g., {"utc": "2025-06-04T14:57:00+00:00"}).

Setup

1. Clone the Repository:

   git clone <your_repo>
   cd <your_repo>

2. Create and Activate a Virtual Environment:

   python -m venv .venv
   source .venv/bin/activate  # On Windows: .venv\Scripts\activate

3. Install Dependencies:

   pip install -r requirements.txt

4. Set API Keys:

   • Create a .env file (use .env.example as a template):

     OPENAI_API_KEY=your-openai-key
     LANGCHAIN_API_KEY=your-langsmith-key
     

   • Or set manually:

     export OPENAI_API_KEY='your-openai-key'
     export LANGCHAIN_API_KEY='your-langsmith-key'

   • Note: LANGCHAIN_API_KEY is required for LangGraph Studio. If not provided, you can still test via python main.py or client.py.

5. Run the Application:

   • Console Mode:

     python main.py

     • Type messages like "What time is it?" to get the current UTC time.
     • Type "exit" or "quit" to stop.
   • Server Mode with langgraph dev:

     langgraph dev

     • Access LangGraph Studio at https://smith.langchain.com/studio/?baseUrl=http://127.0.0.1:2024.
     • Input example:

       {
         "messages": [
           {
             "role": "user",
             "content": "What time is it?"
           }
         ]
       }

     • Alternatively, interact via WebSocket using client.py (optional):

       python client.py

       • Note: client.py is an additional script for testing via WebSocket and is not required for the task.

Usage

• In console mode (python main.py), interact directly in the terminal.
• In server mode (langgraph dev), use LangGraph Studio or client.py to send requests.
• Example input: "What time is it?"
• Expected output: "The current UTC time is 2025-06-04T14:57:00+00:00." (time will vary).

Requirements

• Python 3.8+
• OpenAI API key with sufficient credits
• LangSmith API key (optional for Studio)
• Dependencies listed in requirements.txt

Notes

• The bot uses the gpt-4o model via OpenAI.
• Ensure the OpenAI API key has sufficient credits.
• If running on WSL, you may see a gio error when langgraph dev tries to open the browser. Ignore it and open the Studio URL manually.
• Screenshots of the working application (via python main.py and Studio) are available in the screenshots folder.