Astropy Affiliated Packages

A major part of the Astropy Project is the concept of “Astropy affiliated packages”. An affiliated package is an astronomy-related Python package that is not part of the astropy core package, and is not managed by the project but is a part of the Astropy Project community. These packages demonstrate a commitment to Astropy’s goals of improving reuse, interoperability, and interface standards for Python astronomy and astrophysics packages. In many (but not all) cases, affiliated packages also follow similar development processes and package templates as for the core package.

If you are a developer interested in signing up as an affiliated package, details are in the Becoming an Affiliated Package section.

Astropy Coordinated Packages

A related concept is that of “Astropy coordinated packages”. Coordinated packages are similar to affiliated packages, but the Astropy Project as a whole maintains them. In practice this means the Astropy coordination committee has administrative control of a coordinated package repository (delegated to the maintainers), and that maintainers of these packages have formal roles in the Astropy Project. The most prominent of these coordinated packages is the Astropy core package itself. In some cases these are packages identified by the core team as needing development separate from the core (either they are experimental or problem space-focused), while others started as affiliated packages but have become so important to the ecosystem that they grew to become coordinated.

Astropy Infrastructure Packages

One final related category are the "Astropy infrastructure packages". These packages are those that are necessary infrastructure for Astropy packages - e.g. testing and documentation machinery. While occasionally these have astro-specific functionality, in general they are more generic packages that are useful to packages outside of astronomy, and as a result may have some maintainers outside the Astropy project. But some are also Astropy coordinated packages, with maintainers drawn from the infrastructure roles.

Installing Affiliated and Coordinated Packages

All packages should be available on PyPI. Some are available via conda, particularly through the conda-forge channel. That said, affiliated packages are developed independently of the Astropy core library. You should refer to the package's documentation first if you encounter problems.

Coordinated Packages

The following table lists all current Astropy coordinated packages.

Total number of coordinated packages:


Affiliated Packages Registry

The following table lists all currently registered affiliated packages.

NOTE: The listing is currently empty because Astropy has just accepted APE 22 in January 2024. We are in the midst of transitioning to the new process in partnership with pyOpenSci, so we really appreciate your patience.

Affiliated Packages Registry (Pre-APE 22)

This section contains the listing of Astropy Affiliated Packages that pre-dated APE 22. This section is frozen as of March 6, 2024.

Total number of pre-APE 22 affiliated packages:


Becoming an Affiliated Package

Astropy uses the pyOpenSci peer review process to vet affiliated packages. If you are a developer of an astronomy package and would like your package to become affiliated with the Astropy Project, you submit your package directly to pyOpenSci. Astropy will be involved in the review, which will allow your package to become an affiliated package through that review process. You can also opt to be fast tracked through JOSS if desired. Read the pyOpenSci author guide to learn how to get started with submitting a package to pyOpenSci through their affiliated partner program Guidebook.

In addition to pyOpenSci criteria, we also apply Astropy-specific guidelines for reviewing affiliated packages. This will give you a sense of whether your package is ready for review. Broadly speaking, your package should:

In addition, you should make an effort to connect with the Astropy developer community, including developers from the core astropy package or any related affiliated packages. If your package is determined to meet the above standards, it will be accepted and added to the affiliated package registry. Note however that if packages become unmaintained or do not meet the standards anymore, they may be removed from the list of affiliated packages, as per pyOpenSci policy.

Package Template

If you are considering creating a new astronomy package and would like it to be an Astropy affiliated package, you can use the OpenAstronomy packaging guide to make it much easier to meet these standards. It reflects up-to-date Python packaging techniques to generate documentation like that used in the astropy package, a ready-to-use testing framework, and a variety of tools that streamline tasks like user configuration, caching downloaded files, or linking C-compiled extensions. More details on this template are available in the usage instructions for the template.

Additionally, it is also acceptable to use pyOpenSci Python Package Guide if you think that better suits your package needs.

We recommend that you join the astropy-affiliated-maintainers mailing list to be kept informed of any dicussions related to affiliated packages.

Affiliated Package: FAQs

I want my package to be Astropy Affiliated

Thank you for your interest! Please see Becoming an Affiliated Package above. When in doubt, feel free to contact Astropy Affiliated Editors for advice.

I no longer have time to maintain my Astropy Affiliated package

Please contact pyOpenSci, as per Peer Review Guidelines & Policies.

I want to delist my package as Astropy Affiliated

Please see Requesting package removal from the pyOpenSci ecosystem.

I am a new Editor

Welcome and thank you! We usually do not switch out all our Editors at the same time, so the incumbent co-Editor could help you contact pyOpenSci to add you to pyOpenSci editorial board with the understanding that we are taking the person you are replacing off that board and that your role is Astropy- and astronomy-focused.

Your name would also be added to Astropy Team under the same role.

I am a new reviewer

Welcome and thank you! Please submit the sign-up form that can be found under Become a pyOpenSci reviewer. Do not forget to check "Astropy"/"astronomy"/"astrophysics" when you see them as options.

It is important that you understand your reviews will be done in public. There is no option to remain anonymous.