KEP: Eliminating Internal API Types

[jpbetz]

Enhancement Description

• One-line enhancement description (can be used as a release note): By eliminating needless conversions to the internal type we can reduce kube-apiserver peak memory by up to 46% for our highest-traffic APIs
• Kubernetes Enhancement Proposal: KEP-6164: Add internal version elimination KEP #6165
• Discussion Link: discussed in the May 27, 2026 SIG API Machinery meeting
• PRs by stage and milestone:
• Alpha - N/A This is a internal only change to how we manage go source code and so it is not possible to feature gate it. So, like we did for master/keps/sig-api-machinery/5589-gogo-dependency we are making this as stable on the first release because the nature of the change is that it is going straight to production once merged with no way to turn it off.
• Beta - N/ A Same rationale as Alpha
• Stable - v1.37
  • KEP (k/enhancements) update PR(s): KEP-6164: Add internal version elimination KEP #6165
  • Code (k/k) update PR(s):
    • KEP-6164: Add internal version elimination KEP #6165
  • Docs (k/website) update(s):

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

[jpbetz]

/sig api-machinery
/label lead-opted-in
/milestone v1.37

[whtssub]

Hello @jpbetz 👋, v1.37 Enhancements team here.

This is a reminder of the upcoming PRR freeze on PRR Freeze on Tuesday 9 June 2026 (AoE) / Wednesday 10 June 2026 12:00 UTC.

This enhancement is targeting stage alpha for v1.37 (correct me, if otherwise)

Here's where this enhancement currently stands:

• PR open or merged with the KEP's PRR questionnaire filled out.
• PR open or merged with kep.yaml updated with the stage, latest-milestone, and milestone struct filled out.
• PR open or merged with a PRR approval file with the PRR approver listed for the stage the KEP is targeting.

Note that the PR is not required to be approved or merged by the PRR freeze deadline. Having the PRR questionnaire filled out by the deadline will help ensure that the PRR team has enough time to review your KEP before enhancements freeze on Tuesday 16th June 2026 (AoE) / Wednesday 17th June 2026, 12:00 UTC. For more information on the PRR process, see here.

The status of this enhancement is marked as At risk for PRR freeze. Please keep the issue description up-to-date with appropriate stages as well.

If you anticipate missing PRR freeze, you can file an exception request in advance. Thank you!

[jpbetz]

Thanks @whtssub I've expanded on the PRR questionnaire. If you still any sections missing/incomplete would you please let me which once so I can I expand on them by tomorrow. This is an internal only machinery change (non-user facing) where we are using the KEP to help communicate the change with the community, so it's a bit unusual from an enhancements perspective and many PRR questions don't apply (I'm also a PRR approver so quite familiar with these questions).

[whtssub]

Hello @jpbetz I'm a little confused here, the KEP targets stage alpha, however the milestone struct has stage for v1.37 release set to stable and also the graduation criteria mentions this below Alpha stage:

Not possible for this change. SIG Leads agreed that we should communicate the nature of this
change by marking it as sable on the first release. This matches how we've handled
other internal changes.