Langfuse Python SDK

Installation

[!IMPORTANT] The SDK was rewritten in v2 and released on December 17, 2023. Refer to the v2 migration guide for instructions on updating your code.

pip install langfuse

Full documentation: https://docs.langfuse.com/sdk/python

Langchain documentation: https://docs.langfuse.com/langchain

Development

Add Poetry plugins

poetry self add poetry-dotenv-plugin
poetry self add poetry-bumpversion

Install dependencies

poetry install --all-extras

Add Pre-commit

poetry run pre-commit install

Tests

Setup

• Add .env based on .env.example

Run

• Run all

  poetry run pytest -s -v --log-cli-level=INFO
  

• Run a specific test

  poetry run pytest -s -v --log-cli-level=INFO tests/test_sdk.py::test_flush
  

• E2E tests involving OpenAI and Serp API are usually skipped, remove skip decorators in tests/test_langchain.py to run them.

Update openapi spec

1. Generate Fern Python SDK in langfuse and copy the files generated in generated/python into the langfuse/api folder in this repo.
2. Execute the linter by running poetry run ruff format .
3. Rebuild and deploy the package to PyPi.

Publish release

1. poetry version patch
   • poetry version prepatch for pre-release versions
2. poetry install
3. poetry build
4. git commit -am "chore: release v{version}"
5. git push
6. git tag v{version}
7. git push --tags
8. poetry publish
   • Create PyPi API token: https://pypi.org/manage/account/token/
   • Setup: poetry config pypi-token.pypi your-api-token
9. Create a release on GitHub with the changelog