[MCP] Test and score your n8n workflows with Claude

Hey everyone!

I built an MCP server that lets you test, score, and inspect n8n workflows directly from Claude (or any MCP-compatible client).

What it does

  • Config-driven test suites — define payloads in JSON, run them via webhook or execute endpoint
  • Automatic scoring — two-tier system: Tier 1 checks infrastructure (HTTP, timeout, output), Tier 3 checks quality (field validation, contains, min_length, etc.)
  • Execution traces — lightweight per-node summary without loading full execution JSON
  • Node catalog — search 436+ nodes, validate types, get suggestions for natural-language tasks
  • Safe by design — no credential management, no auto-fix loops, no destructive operations

Example test config

{
  "workflowName": "my-webhook",
  "triggerMode": "webhook",
  "webhookPath": "/webhook/my-handler",
  "qualityThreshold": 85,
  "testPayloads": [
    { "name": "happy-path", "data": { "message": "Hello" } },
    { "name": "empty-input", "data": { "message": "" } }
  ],
  "tier3Checks": [
    { "name": "has-response", "field": "output", "check": "not_empty", "severity": "error" }
  ]
}

Scoring output

{
  "passed": true,
  "score": 93,
  "tier1Score": 100,
  "tier3Score": 80,
  "issues": [{ "tier": "tier3", "severity": "warning", "check": "response-length", "message": "Response too short" }]
}

Quick setup

git clone https://github.com/Souzix76/n8n-workflow-tester-safe.git
cd n8n-workflow-tester-safe
npm install && npm run build
node dist/index.js  # MCP server (stdio)

Works as MCP server for Claude Code or as standalone CLI for CI pipelines. 19 tools total — testing, workflow operations, introspection, and catalog helpers.

MIT licensed. Feedback welcome!

GitHub: GitHub - Souzix76/n8n-workflow-tester-safe: Safe MCP server + CLI for testing, inspecting, and operating n8n workflows with a constrained scope · GitHub