n8n Custom Code Tool

When to Use

Use this skill specifically for code executed by the AI-agent-callable n8n Custom Code Tool. Use the separate JavaScript or Python Code-node skills for ordinary workflow Code nodes.

Do not hardcode secrets or accept arbitrary executable code from untrusted input. Constrain inputs with a schema, validate outputs, allowlist any network destinations, and ask before testing a tool whose code can write data or invoke an external service.

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.