# Is Annotator backend-only?

**URL:** <https://platform.jetbrains.com/t/is-annotator-backend-only/4219>\
**Category:** IntelliJ Platform\
**Tags:** remote-development, api, split-mode\
**Created:** [May 8, 2026, 3:08pm UTC](https://platform.jetbrains.com/t/is-annotator-backend-only/4219 "2026-05-08T15:08:10Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jansorg](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/jansorg/32/52_2.png) [@jansorg](https://platform.jetbrains.com/u/jansorg)\
**Post date:** [May 8, 2026, 3:08pm UTC](https://platform.jetbrains.com/t/is-annotator-backend-only/4219/1 "2026-05-08T15:08:10Z")

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With 2026.2 in a split-mode plugin, I got a warning about an annotator:

 ![image](https://us1.discourse-cdn.com/flex001/uploads/jetbrains_platform/original/2X/7/799cd8e51df50b2ec55300492e5c49440087a565.png)

The annotator is in a frontend module because it only updates syntax highlighting (based on PSI) and PSI is supposed to be shared with frontend and backend.  
Is the warning correct and what’s the reason that annotator is backend-only?

intellij-community has at least one frontend annotator 😁 : `com.intellij.editorconfig.frontend.highlighting.EditorConfigAnnotator`.

Thanks!

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**Author:** ![Nikita.Katkov](https://avatars.discourse-cdn.com/v4/letter/n/bcef8e/32.png) [@Nikita.Katkov](https://platform.jetbrains.com/u/Nikita.Katkov)\
**Post date:** [May 8, 2026, 7:09pm UTC](https://platform.jetbrains.com/t/is-annotator-backend-only/4219/3 "2026-05-08T19:09:37Z")

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Good catch!

The assumption about annotator was that it more frequently does some heavy lifting and effectively needs backend.

However I agree, that in case it is lightweight, it can be in frontend. We’ll consider adjusting the inspection. Should you see any reports that sound irrelevant, please share. It is very valuable for us and for all external plugin developers 💟

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**Author:** ![yuriy.artamonov](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/yuriy.artamonov/32/48_2.png) [@yuriy.artamonov](https://platform.jetbrains.com/u/yuriy.artamonov)\
**Post date:** [May 8, 2026, 7:13pm UTC](https://platform.jetbrains.com/t/is-annotator-backend-only/4219/4 "2026-05-08T19:13:59Z")

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Do not forget though that `.resolve()` in frontend annotator is usually pointless if relies on indexes