# Atdpy: derive safe JSON interfaces for Python **URL:** \ **Category:** Ecosystem\ **Tags:** metaprogramming, atd, atdgen, announce\ **Created:** [March 21, 2022, 6:50pm UTC](https://discuss.ocaml.org/t/atdpy-derive-safe-json-interfaces-for-python/9544 "2022-03-21T18:50:54Z")\ **Posts on this page:** 1\ **Showing post:** 1
**Author:** ![mjambon](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/mjambon/32/6180_2.png) [@mjambon](https://discuss.ocaml.org/u/mjambon)\ **Post date:** [March 21, 2022, 6:50pm UTC](https://discuss.ocaml.org/t/atdpy-derive-safe-json-interfaces-for-python/9544/1 "2022-03-21T18:50:54Z")
On behalf of the ATD team, I’d like to announce atdpy, which is part of the release 2.3.x of the ATD tools. For now, the best installation method with via opam: ```auto $ opam install atdpy ``` Atdpy is a new backend for [ATD](https://github.com/ahrefs/atd). It takes a collection of type definitions and derives Python classes with mypy type annotations that validate the JSON data. A [short introduction](https://atd.readthedocs.io/en/latest/atdpy.html) is included in the documentation. Use cases: - Safe communication with another program that also uses an ATD interface. Other supported languages are OCaml (including Bucklescript), Java, and Scala. - Need for [mostly] type-safe Python methods via mypy. - Need for a good Python API to communicate with an OCaml executable or service. - Need for sum types (variants, algebraic data types, tagged unions). ATD sum types are ordinary types that include pure enums. Atdpy was developed as part of our work on [Semgrep](https://semgrep.dev/) at [r2c](https://r2c.dev/). Many thanks to @mseri for his massive help during the opam release of the 7 ATD packages, and to the Ahrefs folks and @Khady in particular for supporting the project. --- _[View the full topic](https://discuss.ocaml.org/t/atdpy-derive-safe-json-interfaces-for-python/9544)._