N8n Validation Expert

Interpret validation errors and guide fixing them. Use when encountering validation errors, validation warnings, false positives, operator structure issues, or need help understanding validation results. Also use when asking about validation profiles, error types, the validation loop process, or auto-fix capabilities. Consult this skill whenever a validate_node or validate_workflow call returns errors or warnings — it knows which warnings are false positives and which errors need real fixes.

6,554 stars 1,077 forksProductivity & Notes

Install

skills CLI (Claude Code, Cursor, Codex and more)

npx skills add czlonkowski/n8n-skills --skill n8n-validation-expert

Manual install

git clone --depth 1 https://github.com/czlonkowski/n8n-skills.git /tmp/n8n-skills
mkdir -p ~/.claude/skills
cp -r /tmp/n8n-skills/skills/n8n-validation-expert ~/.claude/skills/n8n-validation-expert

Personal skills live in ~/.claude/skills. Use .claude/skills in a project folder to share a skill with your team.

From the SKILL.md

# n8n Validation Expert

Expert guide for interpreting and fixing n8n validation errors.

---

## Validation Philosophy

**Validate early, validate often**

Validation is typically iterative:
- Expect validation feedback loops
- Usually 2-3 validate → fix cycles
- Average: 23s thinking about errors, 58s fixing them

**Key insight**: Validation is an iterative process, not one-shot!

---

## Error Severity Levels

### 1. Errors (Must Fix)
**Blocks workflow execution** - Must be resolved before activation

**Types**:
- `missing_required` - Required field not provided
- `invalid_value` - Value doesn't match allowed options
- `type_mismatch` - Wrong data type (string instead of number)
- `invalid_reference` - Referenced node doesn't exist
- `invalid_expression` - Expression syntax error

**Example**:
```json
{
  "type": "missing_required",
  "property": "channel",
  "message": "Channel name is required",
  "fix": "Provide a channel name (lowercase, no spaces, 1-80 characters)"
}
```

### 2. Warnings (Should Fix)
**Doesn't block execution** - Workflow can be activated but may have issues

**Types**:
- `best_practice` - Recommended but not required — surfaces under `ai-friendly` / `strict` only
- `deprecated` - Using old API/feature — surfaces under every profile
- `security` - Hardcoded secrets, unauthenticated webhooks — surfaces under every profile
- `performance` - Potential performance issue — advisory, `ai-friendly` / `strict`

Read the full skill on GitHub

Details

Skill name: n8n-validation-expert
Repository: czlonkowski/n8n-skills
Path: skills/n8n-validation-expert/SKILL.md
License: MIT
Repo updated: 24 October 2026
Listed in: VoltAgent/awesome-agent-skills

FAQ

What does the N8n Validation Expert skill do?

How do I install the N8n Validation Expert skill?

skills CLI (Claude Code, Cursor, Codex and more): npx skills add czlonkowski/n8n-skills --skill n8n-validation-expert. Skills go in ~/.claude/skills (personal) or .claude/skills (project), and Claude loads them automatically when a task matches the description.

Is N8n Validation Expert popular?

It lives in czlonkowski/n8n-skills, which has 6,554 GitHub stars and 1,077 forks, and is included in 1 curated skill list.

Related skills

N8n Code Javascript

6.6k

czlonkowski/n8n-skills

Write, review, or debug JavaScript in an n8n Code node. Use when a Code node is already in the workflow (editing it, fixing an error, choosing its mode, making it faster), or when a new one is justified: no native node fits (check the job-to-node table in using-n8n-mcp-skills first) and the job is on the closed list — loops or recursion no node expresses, state across runs, parsing no node handles, an allowlisted library, heavy all-items work, or one short node replacing 4+ glue nodes. Covers $input/$json/$node in code, this.helpers, Luxon, SplitInBatches loops, cross-iteration data, pairedIte

Software DevelopmentIn 1 list1.1k

N8n Code Python

6.6k

czlonkowski/n8n-skills

Write Python in n8n Code nodes (native Python, `language` pythonNative, n8n 2.x). Use when the user explicitly wants Python in a Code node, when migrating old Pyodide/"Python (Beta)" code that used _input/_json/_node/_now, or when a Python Code node fails with NameError, "Security violations detected", "Import of standard library module … is disallowed", "__build_class__ not found", "A 'json' property isn't a dictionary", or "Python runner unavailable". Covers the only two variables (_items/_item), dict-only access, imports blocked by default, the sandbox's denied builtins, accepted return sha

Software DevelopmentIn 1 list1.1k

N8n Expression Syntax

6.6k

czlonkowski/n8n-skills

Validate n8n expression syntax and fix common errors. Use when writing n8n expressions, using {{}} syntax, accessing $json/$node variables, troubleshooting expression errors, mapping data between nodes, or referencing webhook data in workflows. Use this skill whenever configuring node fields that reference data from previous nodes — expressions are how n8n passes data between nodes, and getting the syntax wrong is the most common source of workflow errors. Also use when asked whether a complex expression hurts performance.

Productivity & NotesIn 1 list1.1k

N8n Workflow Patterns

6.6k

czlonkowski/n8n-skills

Proven workflow architectural patterns from real n8n workflows. Use when building new workflows, designing workflow structure, choosing workflow patterns, planning workflow architecture, or asking about webhook processing, HTTP API integration, database operations, AI agent workflows, batch processing, or scheduled tasks. Always consult this skill when the user asks to create, build, or design an n8n workflow, automate a process, or connect services — even if they don't explicitly mention 'patterns'. Covers webhook, API, database, AI, batch processing, and scheduled automation architectures. A

Productivity & NotesIn 1 list1.1k

N8n MCP Tools Expert

6.6k

czlonkowski/n8n-skills

Expert guide for using n8n-mcp MCP tools effectively. Use when searching for nodes, validating configurations, accessing templates, managing workflows, organizing workflows into folders, managing credentials, auditing instance security, or using any n8n-mcp tool. Provides tool selection guidance, parameter formats, and common patterns. IMPORTANT — Always consult this skill before calling any n8n-mcp tool — it prevents common mistakes like wrong nodeType formats, incorrect parameter structures, and inefficient tool usage. If the user mentions n8n, workflows, nodes, or automation and you have n8

Productivity & NotesIn 1 list1.1k

Obsidian Second Brain

5.1k

eugeniughelbur/obsidian-second-brain

Operate any Obsidian vault as a living, self-rewriting second brain (an evolution of Karpathy's LLM Wiki pattern: sources rewrite existing pages, contradictions reconcile automatically, scheduled agents maintain the vault while you sleep). Use this skill whenever the user asks Claude to read, write, update, search, or manage their Obsidian vault - including saving notes from conversation, creating daily entries, updating kanban boards, logging dev work, managing people notes, capturing decisions, tracking deals, or maintaining any vault structure. Also triggers when the user wants to bootstrap

Productivity & Notes625

Browse the most popular Claude skills, all productivity & notes skills, or write your own with the skills generator.