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Kotlin Symbol Processing API

Welcome to KSP!

Kotlin Symbol Processing (KSP) is an API that you can use to develop lightweight compiler plugins. KSP provides a simplified compiler plugin API that leverages the power of Kotlin while keeping the learning curve at a minimum. Compared to KAPT, annotation processors that use KSP can run up to 2x faster.

Most of the documentation of KSP can be found on Here are some handy links:

For debugging and testing processors, as well as KSP itself, please check

KSP2 is in Beta!

KSP2 is a new implementation of the KSP API. It will be faster and easier to use than KSP 1.x. Please refer to the KSP2 introduction for more details.

Nightly Builds

Nightly builds of KSP for the latest Kotlin stable releases are published here.


Feedback and Bug Reporting

Please let us know what you think about KSP by filing a Github issue or connecting with our team in the #ksp channel in the Kotlin Slack workspace!

If you are interested in sending PRs, please also check out the Contributor guide.

Ongoing and Future Works

Here are some planned features that have not yet been completely implemented:

  • Improve support to multiplatform. E.g., running KSP on a subset of targets / sharing computations between targets
  • Improve performance. There are a bunch of optimizations to be done!
  • Keep fixing bugs!