This sample shows you how you can use Temporal to orchestrate workflows for LangChain. It includes an interceptor that makes LangSmith traces work seamlessly across Temporal clients, workflows and activities.

For this sample, the optional langchain dependency group must be included. To include, run:

uv sync --group langchain

Export your OpenAI API key as an environment variable. Replace YOUR_API_KEY with your actual OpenAI API key.

export OPENAI_API_KEY='...'

To run, first see README.md for prerequisites. Then, run the following from this directory to start the worker:

uv run worker.py

This will start the worker. Then, in another terminal, run the following to execute a workflow:

uv run starter.py

Then, in another terminal, run the following command to translate a phrase:

curl -X POST "http://localhost:8000/translate?phrase=hello%20world&language1=Spanish&language2=French&language3=Russian"

Which should produce some output like:

{"translations":{"French":"Bonjour tout le monde","Russian":"Привет, мир","Spanish":"Hola mundo"}}

Check LangSmith for the corresponding trace.