AI Customer Support Chatbot with Knowledge Base

## Setup Guide
1. **Webhook**: Send a POST request to the webhook URL with a JSON body: `{"message": "How do I reset my password?"}`.
2. **Knowledge Base**: The 'Search Knowledge Base' node simulates a vector store lookup. In a real scenario, replace this with a Vector Store Tool or HTTP Request to your embedding database.
3. **OpenAI**: Configure your OpenAI credentials in the 'AI Agent' node.
4. **Error Handling**: If the input message is empty, the workflow stops with an error.