Debug a Failing n8n Workflow in 2 Minutes Using Claude — MCP Labs
Sometimes workflows break. Expressions go wrong, data doesn't flow the way you expected, and normally that means opening n8n, clicking through nodes, and hunting for the problem yourself.
In this video I debug a failing workflow with Claude — from spotting the error to fixing it and verifying it works, without touching the n8n UI once.
The workflow is a Brand Monitor I built for MCP Labs. It runs on a schedule, uses an AI agent to search Google for brand mentions via SerpAPI, summarises the results, and saves them to Supabase. It was failing on the save step — and I wanted to see how fast Claude could find and fix it.
Here's what happens:
Claude reads the execution history and pinpoints the exact error — a "Day of month" field being sent to Supabase that doesn't exist in the table
It pulls up the node config and identifies the root cause — autoMapInputData was overriding the field mappings and sending Schedule Trigger fields through to the database
One config change later, it re-runs the workflow and confirms success — execution 41, 36 seconds, no errors
The whole thing took about two minutes. On a 5-node workflow that's impressive enough — but on a workflow with 30, 50, or 75 nodes and multiple branches, this is where it really earns its keep. Claude doesn't just find the error, it understands the data flow through the whole workflow.
Want Claude to debug your n8n workflows?
👉 https://www.mcplabs.co.uk/products/n8... — free trial, up and running in 5 minutes.