LangSmith tracing is available for self-hosted n8n instances only.
Prerequisites
- A LangSmith account and API key
- A self-hosted n8n instance
Set up tracing
-
Set the following environment variables in the environment where you host your n8n instance, in the same way as the rest of your n8n configuration.
Required environment variables:
LANGCHAIN_TRACING_V2— Set totrueto enable tracing.LANGCHAIN_API_KEY— Your LangSmith API key.
LANGCHAIN_ENDPOINT— LangSmith API endpoint. Defaults tohttps://api.smith.langchain.com. Set this if using a self-hosted LangSmith instance or the EU region.LANGCHAIN_PROJECT— Project name for traces. Defaults to"default".LANGCHAIN_CALLBACKS_BACKGROUND— Set totruefor asynchronous trace upload (default), orfalsefor synchronous uploads. (default:true)
- Restart your n8n instance for the environment variables to take effect.
View traces in LangSmith
After running an AI workflow:- Open LangSmith.
- Select your project. If you just created your account, the
"default"project appears after the first trace is sent. - Locate the trace corresponding to your workflow execution.
Additional resources
Connect these docs to Claude, VSCode, and more via MCP for real-time answers.

