tarsk
Czlonkowski N8n Skills
Romuald Członkowski avatar
Romuald Członkowski

Using N8n Mcp Skills

Skill

Use when building, editing, validating, testing, or debugging an n8n workflow through the n8n-mcp MCP server — designing a flow, configuring a node, writing an expression or Code node, wiring credentials, or fixing one that misbehaves. The entry-point skill for the n8n-mcp-skills pack: it routes you to the right specialist skill, gives working knowledge of every n8n-mcp tool from turn one, and states the rules that keep workflows from breaking in production. Always consult it first on any n8n, workflow, node, or automation task — even a quick one-off, and even when the user names no skill — because n8n's surface drifts between versions and the specialist skills prevent silent failures.

Source: /skills/using-n8n-mcp-skills/SKILL.md

Install Skill

Using the n8n-mcp Skills

This is a router, not a reference. It tells you which skill owns the rules for what you're about to do. The skill bodies hold the actual guidance — invoke them with the Skill tool. When in doubt, load more skills rather than fewer.

The community n8n-mcp server and n8n itself move faster than any model's training cutoff. Tool names, parameters, node typeVersions, and default behaviors drift between releases. When you spot drift — a tool a skill names doesn't exist, a parameter shape doesn't match what get_node returns, behavior differs from what a skill describes — trust the live tool, tell the user, and suggest updating the pack and the instance.

Non-negotiables

Three rules with no exceptions. Each one prevents a class of workflow that looks correct but breaks in production.

  1. Invoke the relevant skill before any n8n action — not just before MCP calls. Before writing an expression, configuring a node, designing a workflow, wiring a connection, or writing Code, invoke the matching skill. PreToolUse hooks remind you on the highest-impact tool calls, but they exist only in the Claude Code plugin install. Everywhere else — Claude.ai skill uploads, and any client that loads this pack as an Agent Plugin (Codex, Cursor, Copilot and the rest) — nothing nudges you and it's on you. Assume you are un-hooked unless you have seen a hook fire this session.
  2. Validate AND verify before activating. Run validate_workflow (or n8n_validate_workflow by id) before you activate, and call n8n_get_workflow after every create or update to inspect the connections object. Validation alone misses silently dropped wires, Merge index off-by-one, and error outputs that were never wired. Validation passing means the JSON is well-formed — not that the workflow is correct. A green test run isn't proof either: JS errors inside {{ }} resolve silently to null (a Filter with a broken condition drops every item and still shows success), so inspect the output values. See n8n-expression-syntax.
  3. Secrets never go in text fields. Tokens, API keys, and passwords always go through the n8n credential system. If no native node exists, use the HTTP Request node with the official credential type. A Set node holding a token referenced via {{ $json.token }} is a leak with extra steps. See n8n-mcp-tools-expert.

Lean on skills, not training data

n8n changes constantly. "Remembered" parameter names are often silently wrong — they validate as plain strings and then do nothing at runtime. If a skill contradicts your memory, trust the skill. If get_node contradicts a skill, trust the tool and flag the drift.

Strong defaults

These are the defaults; the Code exceptions below are a closed list.

Native node first, Code last. Pick in this order: the service's own node (HTTP Request only when no node covers the operation), then a native node for the job, then a short expression inside that node, then Code. A function body or several statements inside {{ }} is code: it belongs in a Code node.

Job Use
Flag that only picks a route; dropping items conditions in IF / Switch / Filter
Constant, error or return item Edit Fields (Set)
Restore earlier context $('Node').item
Pick rows after a Data Table get the get's order by + limit
Group and sum Summarize
Items to one array / array to items Aggregate / Split Out
Join two lists Merge (combine by fields)
Diff or sync two lists Compare Datasets
Dedupe, also across runs Remove Duplicates
Top-N Sort + Limit
Dates Date & Time, or a Luxon one-liner
XML / HTML / Markdown / CSV / XLSX XML, HTML, Markdown, Extract From File / Convert To File
Paging an API (no service node) HTTP Request's pagination option
Throttle calls HTTP Request's batching option, or Loop + Wait
Hash, HMAC, UUID Crypto (+ Webhook raw body)

Code is right only for: loops or recursion no node expresses, state across runs, parsing no node handles, libraries, heavy all-items work on queue-mode workers (thousands of items, stated or measured), or one short Code node (~15 lines) replacing 4+ glue nodes that only reshape data. Every Code or HTTP Request node that stays gets the note Why Code: <native node considered> — <reason> (or Why HTTP:). See n8n-node-configuration and n8n-code-javascript.

  • A Set that only re-maps fields for the next node is the antipattern. Put those expressions in the next node. Edit Fields as a named step is fine. See n8n-expression-syntax.
  • Per-item iteration is automatic. Don't add a Loop Over Items node to "make it loop" when default per-item execution already handles the case.
  • Configure from the live schema, never from memory. get_node before you set parameters. See n8n-node-configuration.

Red flags: "about to ___" → invoke ___

If you catch yourself thinking any of these, stop and invoke the named skill first.

Thought Invoke
"This workflow is simple, I'll just build it" n8n-workflow-patterns — most "simple" flows ship at 10+ nodes
"I'll add a Set node to map these fields" n8n-expression-syntax — a Set that only re-maps for the next node is the antipattern; named steps are fine
"I'll just use a Code node, it's easier" the job table above, then n8n-code-javascript — Code only for the closed list, with a Why Code: note
"The user mentioned data, I'll write Python" n8n-code-javascript — default JS; Python (n8n-code-python) only on explicit ask
"I'm writing code an AI agent will call" n8n-code-tool — a different runtime contract from the Code node
"I'll call this API with HTTP Request" n8n-mcp-tools-expert — search_nodes for the service's own node first; a kept HTTP node gets Why HTTP:
"I'll wire a Merge with 3 sources" n8n-node-configuration — Merge defaults to 2 inputs (numberInputs); the 3rd silently drops
"Validation passed, I'm ready to activate" n8n-validation-expert + n8n-workflow-patterns — run the antipattern scan
"Validation threw an error I don't understand" n8n-validation-expert — what each error and warning means, and which are must-fix vs. best-practice advice
"I'll reference $json.x here" n8n-expression-syntax — prefer $('Node').item.json.x in branchy workflows
"This webhook/scheduled flow is happy-path only" n8n-error-handling — wire an error branch on every fallible node; 4xx caller faults, 5xx yours
"I'll pass this file/image through as JSON" n8n-binary-and-data — file contents live in $binary, and can't cross the agent-tool boundary
"I'll wire up an AI agent and give the model some tools" n8n-agents — tool names & descriptions ARE the prompt; memory, structured output, and topology have traps
"I'll copy this logic into another workflow" / "this is getting big" n8n-subworkflows — extract a reusable sub-workflow; search before building
"I'll create that credential / open that workflow" (account has >1 instance) n8n-multi-instance — name the target with instance: "<name>"; unnamed calls hit a default other chats can move

Skill index

Skill Reach for it when
using-n8n-mcp-skills This router (auto-loaded). Names the skill that owns your task.
n8n-mcp-tools-expert Choosing or calling any n8n-mcp tool; node discovery; credentials; data tables; security audit; templates
n8n-workflow-patterns Designing or building a workflow; picking an architecture (webhook / HTTP API / database / AI agent / scheduled / batch)
n8n-node-configuration Configuring any node; operation-aware required fields; property dependencies; surgical field edits
n8n-expression-syntax Writing {{ }}, $json/$node/$now; mapping data between nodes; the transform gatekeeper; Set-node discipline
n8n-validation-expert Interpreting validation errors/warnings; false positives; the validation loop; auto-fix; reviewing an existing workflow
n8n-code-javascript Any Code node in JavaScript; data access; this.helpers; DateTime; SplitInBatches loop patterns
n8n-code-python A Code node specifically requested in Python; native runtime (_items/_item only, imports blocked by default, legacy _input code fails)
n8n-code-tool The AI-agent-callable Custom Code Tool (toolCode) — returns a string, no $fromAI/$input
n8n-error-handling Webhook/API or unattended workflows; wiring error outputs; retries; 4xx/5xx response shapes; silent failures
n8n-binary-and-data Files, images, PDFs, attachments, uploads/downloads, vision; passing a file to/from an agent tool
n8n-subworkflows Reusable / multi-step builds; Execute Workflow; extracting shared logic; Define-Below inputs; all-vs-each; exposing a workflow as an agent tool
n8n-agents AI Agent / LLM-with-tools / Text Classifier; tool design & $fromAI; system prompts; structured output; memory; RAG; human review; chat bots
n8n-multi-instance Accounts with several instances (n8n_instances present); the per-call instance argument; parallel agents; switch; credential writes; an unexpected NOT_FOUND, wrong/empty reads, INSTANCE_* errors
n8n-self-hosting Deployment, not workflow-building — self-hosting / installing / deploying n8n on a VM (Docker Compose + Caddy, single vs queue mode), or updating / backing up / hardening it. Triggers on its own; not part of the build flow above.

n8n-mcp tools — working knowledge from turn one

Qualified names look like mcp__<server>__<tool> (<server> is usually n8n-mcp).

Two tiers, and how to tell which one you have. The documentation and validation tools below work offline and are always present. The n8n_* management tools talk to a live n8n instance and appear only once one is connected. If they are absent, nothing is broken and nothing needs a retry — say so and point the user at the fix for their install:

  • Hosted (https://api.n8n-mcp.com/mcp) — sign in through the client's OAuth prompt on first use, then connect the n8n instance in the dashboard. No env vars or API keys in config.
  • Self-hosted (npx n8n-mcp, Docker) — the server needs N8N_API_URL and N8N_API_KEY in its environment, exported before the client starts.

n8n_health_check confirms a working connection and returns the resolved instance.

Discovery & docs

  • tools_documentation — meta-docs for every tool; {topic, depth:"full"} with ai_agents_guide or (n8n-mcp 2.97+) expression_helpers.
  • search_nodes — find nodes by keyword.
  • get_node — node info. Takes a single SHORT-form nodeType (nodes-base.httpRequest, nodes-langchain.agent), plus detail (minimal/standard/full) and mode (info/docs/search_properties/versions).
  • validate_node — validate one node's config in isolation (profiles: minimal/runtime/ai-friendly/strict).
  • search_templates / get_template — the template library (by keyword, nodes, task, metadata).

Build & edit

  • n8n_create_workflow — create from full workflow JSON.
  • n8n_update_partial_workflow — incremental diff ops ({id, operations:[…]}): addNode, updateNode, patchNodeField, addConnection, setNodeGroups, activateWorkflow, etc. Preferred for edits.
  • Canvas groups (n8n 2.28+) survive your edits; adjustments show in details.warnings. Create or change them with the setNodeGroups op. See n8n-mcp-tools-expert.
  • n8n_update_full_workflow — full replacement.
  • n8n_autofix_workflow — auto-fix common issues.
  • n8n_deploy_template — deploy a template to the instance.

Validate (necessary, not sufficient — always pair with the antipattern scan)

  • validate_workflow — full JSON in, errors/warnings/fixes out. Node types here are LONG form (n8n-nodes-base.set).
  • n8n_validate_workflow — validate a deployed workflow by {id} (no node JSON to inspect).

Inspect & lifecycle

  • n8n_get_workflow — fetch a workflow (full / structure / active / filtered / minimal). Use it to verify connections after edits; mode="filtered" + nodeNames reads one heavy node without pulling a whole workflow that can truncate client-side.
  • n8n_list_workflows — list/filter (search before duplicating logic).
  • n8n_delete_workflow; n8n_workflow_versions (history/rollback/diff; source: "native" includes UI edits); n8n_instances (multi-instance accounts only; every n8n tool also takes a per-call instance name — see n8n-multi-instance); n8n_health_check (resolved instanceName, plus officialMcp: is the instance-level server below reachable).

Test & run

  • n8n_test_workflow — runs real nodes (Code, HTTP, DB writes, sends all fire). Ask the user before running when side effects exist. method picks the path: auto (default) and trigger fire a webhook/form/chat trigger over HTTP on an active workflow; prepare/pinned/direct go through n8n's own MCP server and run workflows with no HTTP trigger (Manual, Schedule, sub-workflow) — see n8n-mcp-tools-expert.
  • n8n_executions — list/inspect executions. There is no execute_workflow tool.
  • n8n_evaluations — evaluation runs, metrics and per-case results (n8n ≥ 2.30); run/cancel (≥ 2.32). run fires real nodes across the whole dataset, so ask the user first. For a 403, see n8n-mcp-tools-expert.

Data, folders, credentials, audit

  • n8n_manage_datatable — Data Table CRUD, filtering, dry-run. addColumn/deleteColumn/renameColumn change an existing table's columns (the Public API cannot) through n8n's MCP server — deleteColumn drops the column's values along with it.
  • n8n_manage_folders — folder CRUD (n8n ≥ 2.19). Place workflows with parentFolderId or the moveToFolder op; verify via the folder's get counts, not the workflow. delete without transferToFolderId ARCHIVES the folder's workflows. See n8n-mcp-tools-expert.
  • n8n_manage_credentials — credential CRUD + getSchema discovery.
  • n8n_audit_instance — security audit (hardcoded secrets, unauthenticated webhooks, error-handling gaps).

Instance-level MCP server — a second endpoint alongside the Public API, gated on N8N_MCP_ACCESS_TOKEN (n8n 2.34+). n8n_health_check reports whether it is reachable; without it these calls answer NOT_CONFIGURED.

  • n8n_manage_agents — persisted n8n Agents: a standalone assistant artifact with its own lifecycle (model, instructions, skills, tasks, memory, channels), not the AI Agent workflow node. call runs it live with real credentials and may return approvals[]; publish only when the user asks. See n8n-agents.
  • n8n_explore_node_resources — resolve a node's live dropdown / resource-locator values through a real credential instead of guessing an ID. See n8n-node-configuration.
  • n8n_list_catalog — list projects (to get a projectId) or tags. The one tool here that also works without the token.
  • The same server backs n8n_test_workflow prepare/pinned/direct, source: "native" versions and Data Table column actions, gated per workflow: WORKFLOW_NOT_EXPOSED means "Available in MCP" is off, and turning it on (exposeToMcp: true) is a persistent change — ask the user first.

Node-type form trap: get_node / validate_node take SHORT form (nodes-base.set); workflow JSON inside validate_workflow / n8n_create_workflow uses LONG form (n8n-nodes-base.set). Mixing them is a common, silent mistake — see n8n-mcp-tools-expert.

The protocol, in order

  1. Recognize the matching skill from the index and invoke it before the first MCP call.
  2. Skim tools_documentation once per session to refresh the tool surface if you're unsure.
  3. get_node before configuring any node — read the live schema, don't assume.
  4. Build / edit, then validate_workflow before activating and n8n_get_workflow after to check connections.
  5. Surface any drift you notice (missing tool, changed parameter, diverging behavior).

When in doubt

  • Can't find a workflow the user built in the UI? The most common cause is per-workflow MCP access being off. Ask them to open it in n8n, go to Settings, and enable MCP access.
  • User says it's broken? Believe them. Re-check parameters against get_node, trace data references, inspect the execution. See n8n-validation-expert.
  • No skill fits and the task is non-trivial? Ask before guessing.

These are opinionated best practices, not laws. Disagree with a call? It's all markdown — edit the skill.