MCP Debugger vs N8n MCP

workflow_generate

Generate a valid n8n workflow JSON from a plain-English description. Handles webhook/schedule/RSS triggers, common action nodes (Slack, Google Sheets, Discord, Gmail, Notion, HTTP), and AI Agent setups (LangChain root agent + chat model + memory + optional HTTP tool, wired with ai_languageModel / ai_memory / ai_tool connections). Returns workflow JSON with unique node IDs, connections, positions, and typeVersion on every node. Output is non-deterministic (random node IDs and webhook paths).

workflow_lint

Lint an n8n workflow JSON. Returns concrete errors and warnings: missing credentials, deprecated node types (Function -> Code, spreadsheetFile -> convertToFile/extractFromFile), broken connections, missing or non-numeric typeVersion, duplicate node names or IDs, AI Agent missing ai_languageModel sub-node, Webhook missing webhookId, IF node still on v1 condition schema, rate-sensitive nodes without retries, Code-node sandbox violations, expression staleness (`$('NodeName')` referencing missing nodes), manualTrigger in active workflows, disabled-but-wired nodes, empty Set nodes, HTTP method/body mismatches, Schedule trigger DST risk, credential drift, webhook test paths in active workflows. Deterministic, rule-based.

workflow_diff

Semantic diff between two workflows. Reports nodes added / removed / modified (with field-level deltas: type, typeVersion, parameters, credentials, disabled, position), connection topology changes, and settings drift. Ignores noise (small position deltas, createdAt/updatedAt). Pair with workflow_get to compare deployed vs local. Deterministic.

execution_explain

Diagnose a failed or surprising n8n execution. Paste the execution JSON (from the n8n UI 'Show details' or `GET /executions/:id?includeData=true`); returns a per-node summary highlighting nodes that returned 0 items, unresolved `={{ ... }}` expressions, errors with hints, and LLM token usage. Hits the most common debugging pain point: items 'silently disappearing' between nodes. Deterministic, rule-based.

execution_replay

Build a self-contained replay workflow that exercises a single node from a larger workflow. The replay workflow is Manual Trigger -> Replay Seed (Code node with pinned items) -> target node. Optional `inputItems` or an `execution` payload pins what the target sees. Useful for iterating on one stubborn node without re-running the whole pipeline. Returns workflow JSON ready to import or push via workflow_create.

execution_timeline

Render an n8n execution as a per-node timeline: start offset, duration, items in/out, error flag. Complements execution_explain — that one surfaces *why*, this surfaces *when*. Output is a markdown table sorted by start time. Deterministic.

workflow_list

List workflows from a live n8n instance (requires N8N_API_URL + N8N_API_KEY env vars). Returns id, name, active, nodeCount, updatedAt, tags. Filter by active, tags, name. Use this when the user asks 'what workflows do I have?' or before workflow_get.

workflow_get

Fetch a single workflow JSON by id from a live n8n instance (requires N8N_API_URL + N8N_API_KEY). Returns the full nodes/connections payload — pair with workflow_lint to audit a deployed workflow.

workflow_create

Create a workflow on a live n8n instance (requires N8N_API_URL + N8N_API_KEY). Strips read-only fields (id, active, createdAt, ...) before posting. Workflows are created inactive — call workflow_activate afterward. Pairs with workflow_generate for end-to-end 'describe -> deploy'.

workflow_activate

Activate or deactivate a workflow on a live n8n instance (requires N8N_API_URL + N8N_API_KEY). Pass `active: false` to deactivate. Idempotent — re-activating an already-active workflow is a no-op on n8n's side.

execution_list

List recent executions from a live n8n instance (requires N8N_API_URL + N8N_API_KEY). Filter by workflowId, status (success|error|waiting), limit. Pass `includeData: true` to get the full execution body (large) — pair with execution_explain to diagnose a specific failure.