The source code of Pythas is split among multiple repositories:

  • The main repository contains the Python source handling all the interaction with the Python runtime system.

  • Pythas-FFI contains the back end responsible for parsing Haskell modules and transpiling them into FFI exports.

  • Pythas-Types defines the custom Haskell types required to exchange nested data types in between the two languages. Their Python equivalents are defined in pythas.types.

  • C-structs is a Haskell package for variably typed, correctly aligned C structs.

Contributions are welcome in all of these repositories. Please be advised to checkout the respective file first. The preferred contribution workflow is to first raise an issue on github, then issue a pull request only after the issue’s discussion was successful.


Most code of the Pythas package is licensed under the LGPLv3 license. This license is valid for all source code if not explicitly stated otherwise. Some parts are licensed under the MIT license, notably the C-structs Haskell package. Please refer to the respective COPYING and COPYING.LESSER or LICENSE files for details.