n8n GPT-5 Mini Chat Agent Workflow: Conversational Coding Help

Turn chat questions into actionable coding answers with an n8n GPT-5 Mini Chat Agent workflow

This n8n automation exposes a public chat webhook that accepts programming questions and returns OpenAI-powered coding help—while maintaining short-term conversation context across messages.

What this workflow does

• Receives a new chat message via a public n8n chat webhook.
• Loads recent context using sessionId: it uses the provided body.sessionId to retrieve the last 10 messages from windowed buffer memory.
• Sends the user’s message + saved context to an OpenAI-powered Chat model with a system prompt tailored for coding support.
• Returns the assistant response back to the chat as the next message.

Use cases

• Developer support inside your app: embed the webhook URL in a customer-facing UI for “How do I implement X?” questions.
• Debugging and code explanation: keep context across follow-ups so answers remain consistent as users refine requirements.
• Automation engineering Q&A: help n8n users troubleshoot workflows by asking about nodes, logic, or integration patterns.

Technical details

• Trigger: n8nn8n-nodes-langchainchat trigger (public chat webhook)
• Context memory: n8nn8n-nodes-langchainmemory buffer window (windowed buffer, last 10 messages)
• AI model: n8nn8n-nodes-langchainlm chat open ai (OpenAI Chat model with coding-support system prompt)
• Agent orchestration: n8nn8n-nodes-langchainagent

Setup (quick)

• Add an OpenAI API credential (or select an existing one) for the OpenAI Chat model node.
• Copy the chat webhook URL from the trigger and send requests from your client/app.
• Ensure your payload includes body.message and a stable body.sessionId to maintain conversation context.