n8n-code-tool

n8n-code-tool is a skill for Claude Code, Codex from PCT-BR/n8n-mcp. It costs 0 tokens per session (4,138 once invoked), scanned A, a copy of n8n-code-tool, MIT.

A guide to writing JavaScript or Python for n8n's Custom Code Tool, a tool that an n8n AI Agent can call during a workflow. It covers this tool specifically, not the regular Code node.

In plain words
What is it for?
Use it to build agent-callable code tools, read a query, define structured inputs, return text, and troubleshoot common tool errors.
Why use it?
It prevents errors caused by confusing the Custom Code Tool with a Code node, especially around input access and the required string output.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to build agent-callable code tools, read a query, define structured inputs, return text, and troubleshoot common tool errors.

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Install with agentmods
npx agentmods add skills/pct-br/n8n-mcp/n8n-code-tool
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add PCT-BR/n8n-mcp --skill n8n-code-tool
Clone the repo
git clone --depth 1 https://github.com/PCT-BR/n8n-mcp

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for n8n-code-tool

README.md
[![agentmods](https://agentmods.dev/badge/skills/pct-br/n8n-mcp/n8n-code-tool.svg)](https://agentmods.dev/skills/pct-br/n8n-mcp/n8n-code-tool)
Your own site
<a href="https://agentmods.dev/skills/pct-br/n8n-mcp/n8n-code-tool"><img src="https://agentmods.dev/badge/skills/pct-br/n8n-mcp/n8n-code-tool.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,138 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.04138
Opus 5 $0.00000 $0.02069
Sonnet 5 $0.00000 $0.00828
Haiku 4.5 $0.00000 $0.00414

Measured 7d ago against content hash 7d3e4654799f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

n8n-code-tool scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to n8n-code-tool — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

data/skills/n8n-code-tool/SKILL.md · 339 lines

How it starts

The opening of the file, as written. The whole thing — 339 lines — stays where its author put it; the contents beside it link to each section on GitHub.


name: n8n-code-tool description: Write JavaScript or Python for the n8n Custom Code Tool (@n8n/n8n-nodes-langchain.toolCode) — the AI-agent-callable tool, NOT the workflow Code node. Use when building a Code Tool attached to an AI Agent, writing code that an LLM will invoke, parsing the query input, returning a string result, defining an input schema for structured arguments (specifyInputSchema, jsonSchemaExample, DynamicStructuredTool), or troubleshooting errors like "Wrong output type returned", "No execution data available", "The response property should be a string, but it is an object", "Cannot assign to read only property 'name'", or an AI agent that refuses to call the tool. Covers the critical differences between Code node and Code Tool: return format (string vs [{json:{...}}]), unavailability of $fromAI/$input/$helpers in the Code Tool sandbox, naming rules for AI invocation, and when to use toolWorkflow/HTTP Request Tool instead.

n8n Custom Code Tool

Expert guidance for writing code inside @n8n/n8n-nodes-langchain.toolCode — the tool an AI Agent can invoke, not the regular workflow Code node.


⚠️ This is NOT the Code node

The Custom Code Tool looks like a Code node in the editor — same JavaScript editor, similar layout — but it is a completely different node from a different package with a different runtime contract.

Code node Custom Code Tool
Node type n8n-nodes-base.code @n8n/n8n-nodes-langchain.toolCode
Package n8n-nodes-base @n8n/n8n-nodes-langchain
Invoked by Previous node (workflow flow) AI Agent (LangChain)
Input $input.all() — item stream query — string or object from LLM
Return [{json: {...}}] (items array) A string
$fromAI() N/A Not available (see Errors)
HTTP helper this.helpers.httpRequest (auth helpers blocked) Not exposed to the tool sandbox
State Per-run execution data No getContext, no $getWorkflowStaticData

Read the full file on GitHub · 339 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 339 lines · 0 tokens per session scan A 7d3e4654799f

Subscribe to this mod's changes

n8n-code-tool is a skill published in the GitHub repository PCT-BR/n8n-mcp (0 stars, last pushed 21d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 4,138 tokens. A static security scan graded it A with 0 findings. It is 100% identical to n8n-code-tool, differing in 2 lines, and is treated as a copy.

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