Experiment

Local AI Lab 002: First n8n to Ollama Workflow

Sending real content from n8n to a locally hosted Ollama model and receiving a structured AI summary.

  • ai
  • ollama
  • n8n
  • docker
  • homelab
  • workflow

Question

Send content from n8n to a locally hosted Ollama model and receive an AI-generated summary.

Hypothesis

If n8n sends properly formatted JSON to Ollama, then a local model should be able to return a structured response that can be reused inside an automation workflow.

Setup

  • n8n running on the home server
  • Ollama serving qwen2.5:3b
  • HTTP Request node configured to call the Ollama API
  • Test content passed from n8n into the request body

Steps

Manual Trigger
    ↓
Set / Input Content
    ↓
HTTP Request
    ↓
Ollama
    ↓
qwen2.5:3b
    ↓
Structured Response

Result

n8n successfully passed content to Ollama running qwen2.5:3b on the home server.

The model returned a structured response containing:

  • Summary
  • Key takeaways
  • Action items
  • Follow-up questions

What Worked

  • Separating instructions from the content body made the prompt easier to manage.
  • Sending JSON directly to Ollama produced reusable output for workflow steps.
  • The local model was sufficient for summarization and simple structure.

What Failed

  • Invalid JSON caused by multiline content.
  • Incorrect body format when using Form-Data instead of JSON.
  • Boolean type mismatch for the stream parameter.

Lessons Learned

  • APIs often require strict JSON formatting.
  • Data types matter. A string like "false" is not the same as a boolean false.
  • Building prompts from separate instruction and content fields creates more maintainable workflows.
  • Streaming responses can be useful for real-time output, but they are harder to process in automation workflows.

Next Experiment

Configure the workflow to return a single JSON response and automatically save the generated output into a Markdown note.