n8n-validation-expert

Fix n8n validation errors iteratively: run validate_node with the runtime profile, read each error message carefully, fix one error at a time, then re-validate. Most configurations require 2-3 iterations before passing validation.

A missing_required error means a mandatory field was not provided in the node configuration, such as a Slack channel or HTTP Request URL. Use get_node to list required fields for the node type, then add the missing property with a valid value.

Use the runtime profile for most pre-deployment validation since it balances coverage and noise. Use ai-friendly to reduce false positives by about 60 percent, minimal for quick checks during editing, and strict only for production-critical workflows.

No, roughly 40 percent of warnings are acceptable depending on context. Warnings about missing error handling or retry logic are fine for development, testing, or non-critical workflows, but security warnings and production workflow issues should always be fixed.

Invalid expression errors usually come from missing double curly braces around expressions, typos in referenced node names, or accessing webhook data without the .body prefix. Wrap expressions in {{}} and verify referenced nodes exist in the workflow.

Auto-sanitization fixes operator structure issues on every workflow save, such as removing singleValue from binary operators like equals and adding it to unary operators like isEmpty. It also adds IF and Switch metadata, but cannot fix broken connections or branch count mismatches.