n8n-mcp/docs/phase2-improvements.md

Phase 2 Improvements - v2.4.2

🎯 Overview

Following the successful implementation of operation-aware validation, Phase 2 adds professional-grade features that make the validation system even more powerful and flexible.

✅ Implemented Features

1. Validation Profiles 🎨

Different validation levels for different use cases:

validate_node_operation({
  nodeType: "nodes-base.slack",
  config: { ... },
  profile: "minimal" // or "runtime", "ai-friendly", "strict"
})

Available Profiles:

Profile	Purpose	What it checks
minimal	Quick check	Only missing required fields
runtime	Pre-execution	Critical errors + security warnings
ai-friendly	Balanced (default)	Errors + helpful warnings
strict	Code review	Everything + best practices

2. New Node Validators 🔧

Added comprehensive validators for commonly used nodes:

Webhook Validator

• Path format validation (no spaces, special chars)
• Response mode checks
• HTTP method validation
• Authentication warnings

PostgreSQL Validator

• SQL injection detection
• DELETE/UPDATE without WHERE warnings
• Operation-specific validation (insert, update, delete, execute)
• Query safety checks

MySQL Validator

• Similar to PostgreSQL
• MySQL-specific syntax checks
• Timezone configuration suggestions

3. validate_node_minimal Tool ⚡

Lightning-fast validation for just required fields:

{
  "nodeType": "nodes-base.slack",
  "displayName": "Slack",
  "valid": false,
  "missingRequiredFields": ["Channel"]
}

• No warnings
• No suggestions
• No examples
• Just missing required fields
• Perfect for quick checks

4. SQL Safety Features 🛡️

Comprehensive SQL query validation:

• Detects template expressions that could be vulnerable
• Warns about DELETE/UPDATE without WHERE
• Catches dangerous operations (DROP, TRUNCATE)
• Suggests parameterized queries
• Database-specific checks (PostgreSQL $$ quotes, MySQL backticks)

📊 Impact

Before Phase 2:

• Single validation mode
• Limited node coverage (4 nodes)
• No SQL safety checks
• Fixed validation behavior

After Phase 2:

• 4 validation profiles for different needs
• 7+ nodes with specific validators
• Comprehensive SQL injection prevention
• Flexible validation based on use case
• Ultra-fast minimal validation option

🚀 Usage Examples

Using Validation Profiles:

// Quick check - just required fields
validate_node_minimal({
  nodeType: "nodes-base.webhook",
  config: { responseMode: "lastNode" }
})
// Result: Missing required field "path"

// Pre-execution validation
validate_node_operation({
  nodeType: "nodes-base.postgres",
  config: { 
    operation: "execute",
    query: "DELETE FROM users WHERE id = ${userId}"
  },
  profile: "runtime"
})
// Result: SQL injection warning

// Strict validation for code review
validate_node_operation({
  nodeType: "nodes-base.slack",
  config: { /* valid config */ },
  profile: "strict"
})
// Result: Suggestions for best practices

🎉 Summary

Phase 2 transforms the validation system from a simple checker into a comprehensive validation framework:

1. Flexibility - Choose validation level based on your needs
2. Safety - SQL injection detection and prevention
3. Speed - Minimal validation for quick checks
4. Coverage - More nodes with specific validation logic
5. Intelligence - Context-aware suggestions and warnings

The validation system now provides professional-grade safety and flexibility while maintaining the simplicity that makes it useful for AI agents.