This sample shows how to use Pydantic v1 with Temporal. This is not recommended: use Pydantic v2 if possible, and use the main pydantic_converter sample.

To install, run:

uv sync --group pydantic-converter
uv run pip uninstall pydantic pydantic-core
uv run pip install pydantic==1.10

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

uv run pydantic_converter_v1/worker.py

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

uv run pydantic_converter_v1/starter.py

In the worker terminal, the workflow and its activity will log that it received the Pydantic models. In the starter terminal, the Pydantic models in the workflow result will be logged.

This sample also demonstrates use of datetime inside of Pydantic v1 models. Due to a known issue with the Temporal sandbox, this class is seen by Pydantic v1 as date instead of datetime upon deserialization. This is due to a known Python issue where, when we proxy the datetime class in the sandbox to prevent non-deterministic calls like now(), issubclass fails for the proxy type causing Pydantic v1 to think it's a date instead. In worker.py, we have shown a workaround of disabling restrictions on datetime which solves this issue but no longer protects against workflow developers making non-deterministic calls in that module.