AIP Versioning

This AIP defines the versioning scheme of the AIPs.


  • The AIPs must be versioned by date, using the ISO-8601 format of YYYY-MM-DD, that corresponds to the date the version was added.
  • AIPs versions must be available as a tag on the source control system used to store the AIPs, of the format v{version}. Example: v2023-03-28.
  • The AIPs must have a new version when there is a significant change to one or more AIPs.
  • Each AIP must include a changelog section, with the date the change was made and a short description.


Versions serve as reference points to AIPs at a specific point in time. They are crucial since guidance on an AIP can be reversed, or include significant changes such that they are no longer similar to the original design. APIs using AIPs may need to reference older AIP guidance to justify their design choice.

Rationale for date-based versioning

With date-based versioning, a client can easily find the AIP guidance at the time an API was authored.

Why not individually versioned AIPs

An alternative to a universal version is to have specific versions attached to each AIP.

AIPs often cross-reference one another. If each AIP had a specific version, then cross-references would also have to specify specific versions of those referenced AIPs to provide complete guidance.