n8n-validation

name	n8n-validation
description	Expert guidance on interpreting and fixing n8n validation errors. [SAFE]

n8n Validation Expert

Master guide for troubleshooting and fixing n8n workflow errors.

Error vs. Warning

• Errors (Must Fix): Block workflow activation (e.g., missing_required, invalid_value, invalid_expression).
• Warnings (Should Fix): Recommended but don't block execution (e.g., best_practice, deprecated).
• Suggestions (Optional): Performance or logic optimizations.

Iterative Process

Validation is iterative. Expect 2-3 cycles of validate_node → Fix → validate_node again.

Common Error Types

1. missing_required: A mandatory field is empty. Use get_node to see the schema.
2. type_mismatch: Expected a number but got a string (e.g., limit: "10" ❌ vs limit: 10 ✅).
3. invalid_expression: Syntax error in {{ }}.
4. invalid_reference: Referring to a node that doesn't exist or has a typo.

Auto-Fix Capabilities

Use n8n_autofix_workflow to automatically resolve:

• Missing = prefix in expressions.
• Duplicate onError settings.
• Stale connections.
• Outdated node versions.

Profiles

• runtime (Recommended): Standard pre-deployment check.
• strict: Extensive check for production, including best practices.
• ai-friendly: Reduced noise, more tolerant for AI-generated logic.