Release Cycle and Major Dependency Support Policy

This document describes a general plan for releasing the ASDF library, along with how long we intend to support each release. Moreover, it also describes our policy for how long we plan to support versions of CPython and NumPy. Note that this is a living document, and may be updated at any time.

Backwards Compatibility and Semantic Versioning

ASDF will maintain a backwards compatible API for all minor and patch versions. Any breaking API changes will only be included in major releases (where the major version number will be increased). We follow Semantic Versioning.


We are planning to clean up the public API following the 2.15 release. We will attempt to do so with the smallest number of major version changes. If there are portions of the ASDF API that you are using that are not documented in the User API or Developer API please open an issue.

Release Cycle

As ASDF is still under active development, it will continue to be developed on a rolling release cycle. This means that ASDF will not have a fixed release schedule, but rather will be released as needed.

Dependency Support Policy

ASDF primarily depends on CPython and NumPy. As a scientific Python library, we have chosen to abide by the policy laid out in NEP 29. The following table summarizes this policy:




Jan 31, 2023



Apr 14, 2023



Jun 23, 2023



Jan 01, 2024



Apr 05, 2024



Jun 22, 2024



Dec 18, 2024



Apr 04, 2025



Apr 24, 2026



CPython and NumPy Drop Schedule

On Jan 31, 2023 drop support for NumPy 1.20 (initially released on Jan 31, 2021)
On Apr 14, 2023 drop support for Python 3.8 (initially released on Oct 14, 2019)
On Jun 23, 2023 drop support for NumPy 1.21 (initially released on Jun 22, 2021)
On Jan 01, 2024 drop support for NumPy 1.22 (initially released on Dec 31, 2021)
On Apr 05, 2024 drop support for Python 3.9 (initially released on Oct 05, 2020)
On Jun 22, 2024 drop support for NumPy 1.23 (initially released on Jun 22, 2022)
On Dec 18, 2024 drop support for NumPy 1.24 (initially released on Dec 18, 2022)
On Apr 04, 2025 drop support for Python 3.10 (initially released on Oct 04, 2021)
On Apr 24, 2026 drop support for Python 3.11 (initially released on Oct 24, 2022)

Support for Other Dependencies

ASDF also depends on several other Python packages. We currently do not have a formal policy for how long we intend to support these dependencies. However, we will try to support as many versions of these dependencies as possible.

In general, we will pin each of these dependencies from below with the oldest version that we guarantee will work with ASDF. We will also try to test against the latest version of each of these dependencies and release bugfixes to supported versions of ASDF on an as-needed basis. We will try our best to announce when we need to bump the support of these dependencies, and will always record doing so (and why) in the changelog.

If you find any issues with ASDF dependencies which affect a currently-supported version of ASDF, please open an issue in the ASDF repository.