68770a2e14
Implements comprehensive validation error interpretation and systematic fixing guidance. Addresses the validation feedback loop problem (15,107 loops from 19,113 errors). Files created: - 4 evaluations testing error interpretation, false positives, auto-sanitization, validation loop - SKILL.md (690 lines) - Validation philosophy, loop pattern, profiles, auto-sanitization - ERROR_CATALOG.md (865 lines) - 9 error types with examples and fixes - FALSE_POSITIVES.md (669 lines) - 6 false positive patterns with decision framework - README.md (329 lines) - Skill metadata with telemetry statistics Key features: - Error severity levels (errors/warnings/suggestions) - Validation loop pattern (2-3 iterations, 23s+58s average) - 4 validation profiles (minimal/runtime/ai-friendly/strict) - Auto-sanitization system (operator structure fixes) - False positive recognition (~40% of warnings acceptable) - Error distribution analysis (missing_required 45%, invalid_value 28%) - Recovery strategies (progressive validation, error triage, clean connections) - Decision framework for warning acceptance Error catalog: - missing_required (45%) - Required field not provided - invalid_value (28%) - Value doesn't match allowed options - type_mismatch (12%) - Wrong data type - invalid_expression (8%) - Expression syntax errors - invalid_reference (5%) - Referenced node doesn't exist - operator_structure (2%) - Auto-fixed automatically False positive patterns: - Missing error handling (acceptable for dev/test) - No retry logic (acceptable for internal APIs) - Missing rate limiting (acceptable for low volume) - Unbounded queries (acceptable for small datasets) - Missing input validation (acceptable for trusted sources) - Hardcoded credentials (never acceptable!) Validation insights: - 79% of validation errors lead to feedback loops - Average 2-3 iterations to valid configuration - 94% success rate within 3 iterations - ai-friendly profile reduces false positives by 60% - Auto-sanitization handles operator structure issues automatically Total: ~2,553 lines across 8 files Based on analysis of 19,113 validation errors and 15,107 feedback loops. 🤖 Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en
n8n-skills
Expert Claude Code skills for building flawless n8n workflows using the n8n-mcp MCP server
🎯 What is this?
This repository contains 5 complementary Claude Code skills that teach AI assistants how to build production-ready n8n workflows using the n8n-mcp MCP server.
Why These Skills Exist
Based on analysis of 447,557 real MCP tool usage events, we identified:
- 20% failure rate when using certain MCP tools incorrectly
- 15,107 validation feedback loops due to configuration errors
- 813 searches for "webhook" showing common workflow patterns
- 31,917 workflows created revealing proven architectural patterns
These skills solve these problems by teaching Claude:
- ✅ Correct n8n expression syntax ({{}} patterns)
- ✅ How to use n8n-mcp tools effectively
- ✅ Proven workflow patterns from real-world usage
- ✅ Validation error interpretation and fixing
- ✅ Operation-aware node configuration
📚 The 5 Skills
1. n8n Expression Syntax
Teaches correct n8n expression syntax and common patterns.
Activates when: Writing expressions, using {{}} syntax, accessing $json/$node variables, troubleshooting expression errors.
Key Features:
- Core variables ($json, $node, $now, $env)
- Critical gotcha: Webhook data is under
$json.body - Common mistakes catalog with fixes
- When NOT to use expressions (Code nodes!)
2. n8n MCP Tools Expert (HIGHEST PRIORITY)
Expert guide for using n8n-mcp MCP tools effectively.
Activates when: Searching for nodes, validating configurations, accessing templates, managing workflows.
Key Features:
- Tool selection guide (which tool for which task)
- nodeType format differences (nodes-base.* vs n8n-nodes-base.*)
- Validation profiles (minimal/runtime/ai-friendly/strict)
- Smart parameters (branch="true" for IF nodes)
- Auto-sanitization system explained
Impact: Fixes 20% MCP tool failure rate
3. n8n Workflow Patterns
Build workflows using 5 proven architectural patterns from 31,917 real workflows.
Activates when: Creating workflows, connecting nodes, designing automation.
Key Features:
- 5 proven patterns (webhook processing, HTTP API, database, AI, scheduled)
- Workflow creation checklist
- Real examples from 2,653 templates
- Connection best practices
- Pattern selection guide
Impact: Addresses 27.6% of all workflows (webhook processing)
4. n8n Validation Expert
Interpret validation errors and guide fixing.
Activates when: Validation fails, debugging workflow errors, handling false positives.
Key Features:
- Validation loop workflow
- Real error catalog
- Auto-sanitization behavior explained
- False positives guide
- Profile selection for different stages
5. n8n Node Configuration
Operation-aware node configuration guidance.
Activates when: Configuring nodes, understanding property dependencies, setting up AI workflows.
Key Features:
- Property dependency rules (e.g., sendBody → contentType)
- Operation-specific requirements
- AI connection types (8 types for AI Agent workflows)
- Common configuration patterns
🚀 Installation
Prerequisites
- n8n-mcp MCP server installed and configured (Installation Guide)
- Claude Code, Claude.ai, or Claude API access
.mcp.jsonconfigured with n8n-mcp server
Claude Code
# 1. Clone this repository
git clone https://github.com/czlonkowski/n8n-skills.git
# 2. Copy skills to your Claude Code skills directory
cp -r n8n-skills/skills/* ~/.claude/skills/
# 3. Reload Claude Code
# Skills will activate automatically
Claude.ai
- Download individual skill folders from
skills/ - Zip each skill folder
- Upload via Settings → Capabilities → Skills
API / SDK
See docs/INSTALLATION.md for detailed instructions.
💡 Usage
Skills activate automatically when relevant queries are detected:
"How do I write n8n expressions?"
→ Activates: n8n Expression Syntax
"Find me a Slack node"
→ Activates: n8n MCP Tools Expert
"Build a webhook workflow"
→ Activates: n8n Workflow Patterns
"Why is validation failing?"
→ Activates: n8n Validation Expert
"How do I configure the HTTP Request node?"
→ Activates: n8n Node Configuration
Skills Work Together
When you ask: "Build and validate a webhook to Slack workflow"
- n8n Workflow Patterns identifies webhook processing pattern
- n8n MCP Tools Expert searches for webhook and Slack nodes
- n8n Node Configuration guides node setup
- n8n Expression Syntax helps with data mapping
- n8n Validation Expert validates the final workflow
All 5 skills compose seamlessly!
📖 Documentation
- Installation Guide - Detailed installation for all platforms
- Usage Guide - How to use skills effectively
- Development Guide - Contributing and testing
- MCP Testing Log - Real tool responses used in skills
🔬 Data-Driven Design
These skills are based on telemetry analysis of:
- 447,557 MCP tool usage events
- 31,917 workflows created
- 19,113 validation errors
- 15,107 validation feedback loops
- 2,653 workflow templates
Key insights:
search_nodes → get_node_essentialsis the most common pattern (9,835 occurrences, 18s avg)n8n_update_partial_workflowis the most-used tool (38,287 uses, 99.0% success)- Validation loops average 23s thinking, 58s fixing
- Webhook workflows represent 27.6% of all workflows (813 searches)
🧪 Testing
Each skill includes 3+ evaluations for quality assurance:
# Run evaluations (if testing framework available)
npm test
# Or manually test with Claude
claude-code --skill n8n-expression-syntax "Test webhook data access"
🤝 Contributing
Contributions welcome! Please see DEVELOPMENT.md for guidelines.
Development Approach
- Evaluation-First: Write test scenarios before implementation
- MCP-Informed: Test tools, document real responses
- Iterative: Test against evaluations, iterate until 100% pass
- Concise: Keep SKILL.md under 500 lines
- Real Examples: All examples from real templates/tools
📝 License
MIT License - see LICENSE file for details.
🙏 Credits
Conceived by Romuald Członkowski
- Website: www.aiadvisors.pl/en
- Part of the n8n-mcp project
🔗 Related Projects
📊 Repository Stats
- 5 complementary skills
- ~3,220 lines of skill content
- 15-20 evaluation scenarios
- 88% documentation coverage (from n8n-mcp)
- 537 nodes supported
- 2,653 templates available
Ready to build flawless n8n workflows? Get started now! 🚀