N8n Workflow Tester Safe

What Souzix76/n8n-workflow-tester-safe MCP server does

Souzix76/n8n-workflow-tester-safe MCP server provides a focused MCP interface for working with n8n workflows. Its main use is testing: a configuration file defines the target workflow, trigger details, timeout, threshold, and one or more input payloads. The server can run one case, evaluate its result, or execute every case in a suite and return per-payload scores.

The server also supports selected workflow changes. Agents can create a workflow from JSON, replace an existing workflow, remove one by ID, append a node, or connect two nodes. Inspection tools return compact workflow summaries, recent executions, complete execution records, and per-node traces containing timing, errors, and item counts.

How it works

Testing uses two score layers. The infrastructure layer accounts for 70 percent and checks conditions such as HTTP success, timeout behavior, and whether the result contains output. The quality layer contributes 30 percent and evaluates configured fields with checks including contains, equals, minimum or maximum length, and non-empty values.

A case passes when all infrastructure checks succeed, the combined score reaches the configured threshold, and no error-severity issue is reported. The default quality threshold is 85, although a test configuration can set another value. Test configurations are JSON files and can describe webhook or execute-style workflows.

The catalog is separate from live workflow inspection. Catalog tools provide counts, fuzzy node search, trigger listing, node-type validation with close matches, and suggestions based on a natural-language task. Live n8n node-type tools can list types available on the connected instance and return metadata for one type.

Setup and configuration

Build the project locally with Node package installation followed by the repository build command. Copy the example environment file to .env, then set the n8n base URL and API key. DEFAULT_TIMEOUT_MS can provide the default request timeout; individual test configurations may specify their own timeout.

Run the MCP entry point with Node after building. The server uses stdio transport, so an MCP client starts the process and passes environment values in its server configuration. The repository also includes a CLI entry point for running a JSON test configuration from scripts or CI.

Tools and capabilities

The testing tools are test_workflow, evaluate_workflow_result, and run_workflow_suite. Workflow editing is handled by create_workflow, update_workflow, delete_workflow, add_node_to_workflow, and connect_nodes.

For inspection, use get_workflow_summary, list_executions, get_execution, and get_execution_trace. Node discovery uses list_node_types and get_node_type against n8n, while catalog lookup uses get_catalog_stats, search_nodes, list_triggers, validate_node_type, and suggest_nodes_for_task.

Limitations and notes

Souzix76/n8n-workflow-tester-safe MCP server is intentionally not a complete n8n administration layer. It does not manage credentials or secrets, perform restore flows, deploy to production, or run autonomous LLM repair loops. The documented transport is stdio only, with no HTTP server or authentication-management layer included.

Workflow mutation tools are present, so deployments that require strictly read-only behavior should account for that surface. A read-only mode is listed as future work rather than a current feature. The imported catalog contains 436 nodes and 389 credentials according to the repository architecture notes; catalog data and node types exposed by the connected n8n instance are separate sources.