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Added warning against migration to built-in kotlin #13634

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Merged
jesswrd merged 7 commits into from
Aug 5, 2026
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Merged

Added warning against migration to built-in kotlin #13634

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5602a88
added warnings to only migrate to built-in kotlin only if project alr…
jesswrd Jul 27, 2026
560fb28
Merge branch 'main' into migration-warning
jesswrd Jul 28, 2026
2026164
ensure plugin authors are updating example plugin apps to agp 9+ when…
jesswrd Jul 28, 2026
7f67bbf
added directions on how to locate and verify kgp application also add…
jesswrd Jul 30, 2026
3111461
Update sites/docs/src/content/release/breaking-changes/migrate-to-bui…
jesswrd Aug 3, 2026
8679640
added missing android/ directory
jesswrd Aug 3, 2026
b3605d7
Merge branch 'migration-warning' of github.com:jesswrd/website into m…
jesswrd Aug 3, 2026
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19 changes: 19 additions & 0 deletions ...ntent/release/breaking-changes/migrate-to-built-in-kotlin/for-app-developers.md
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Expand Up @@ -11,6 +11,23 @@ an AGP version created before 9.0.0 to an AGP version 9.0.0+.
You should also use the minimum compatible dependency versions
listed in the [Android Gradle Plugin docs][AGP block].

:::warning
This guide only applies to apps that already use the
Kotlin Gradle Plugin (KGP).
Comment on lines +15 to +16

@parlough parlough Jul 30, 2026

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What about the requirement to add android.newDsl=false mentioned in the next section? Do apps that don't use KGP or add-to-app apps need to add that either way?

@jesswrd jesswrd Aug 3, 2026

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android.newDsl=false is completely separate from KGP/migrating to built-in kotlin. Whether or not an app is applying KGP, android.newDsl=false must be set to succesfully build an app using AGP 9. So there are technically two parts to successfully building on AGP 9:

  1. migrate to built-in kotlin (if applicable)
  2. android.newDsl is false (this only has to be manually set for add-to-app scenarios)

This guide is specifically for those migrating to built-in kotlin. I do think the above^ is important to communicate. Any guidance for how to communicate it? (as a part of this guide? another doc?).

@parlough parlough Aug 3, 2026

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Thanks for the clarification. I would consider creating an additional short and focused migration doc, potentially limited to the add-to-app scenario?

@jesswrd jesswrd Aug 5, 2026

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Sounds good. I'll do that in a different change.


To verify whether your app applies KGP,
find the `kotlin-android` plugin
(or the `org.jetbrains.kotlin.android` plugin).
It is likely located in the
`<app-src>/android/app/build.gradle` or
`<app-src>/android/app/build.gradle.kts` file.
To view the KGP application code,
see [Update the Gradle file](#update-the-gradle-file).
Comment on lines +24 to +25

@gemini-code-assist gemini-code-assist Bot Aug 5, 2026

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medium

The phrase 'KGP application code' can be confusing because 'application' is often interpreted as an Android application (app) rather than the act of applying a plugin. Consider rephrasing this to 'how KGP is applied' or 'examples of how KGP is applied' to improve clarity.

Suggested change
To view the KGP application code,
see [Update the Gradle file](#update-the-gradle-file).
To see how KGP is applied,
see [Update the Gradle file](#update-the-gradle-file).


If your app doesn't currently apply KGP,
don't migrate to built-in Kotlin.
:::
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jesswrd marked this conversation as resolved.

:::note
To update Flutter plugins to use built-in Kotlin,
follow the [migration guide for plugin authors][].
Expand Down Expand Up @@ -299,6 +316,8 @@ kotlin {
Before enabling built-in Kotlin,
confirm that you have migrated your application
and any Flutter plugins it uses.
Also, confirm that you updated your app
to AGP 9+, because built-in Kotlin requires AGP 9+.

To enable built-in Kotlin,
set the `android.builtInKotlin` property to `true`
Expand Down
23 changes: 21 additions & 2 deletions ...ntent/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors.md
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Expand Up @@ -6,6 +6,23 @@ description: >-

This guide outlines the migration steps specifically for plugin authors.

:::warning
This guide only applies to plugins that already use the
Kotlin Gradle Plugin (KGP).

To verify whether your plugin applies KGP,
find the `kotlin-android` plugin
(or the `org.jetbrains.kotlin.android` plugin).
It is likely located in the
`<plugin-project>/android/build.gradle` or
`<plugin-project>/android/build.gradle.kts` file.
To view the KGP application code,
see [Update the Gradle file](#update-the-gradle-file).
Comment on lines +19 to +20

@gemini-code-assist gemini-code-assist Bot Aug 5, 2026

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medium

The phrase 'KGP application code' is confusing here, especially for plugin authors, as 'application' typically refers to an Android application rather than the act of applying a plugin. Rephrasing this to 'how KGP is applied' or 'examples of how KGP is applied' would be much clearer.

Suggested change
To view the KGP application code,
see [Update the Gradle file](#update-the-gradle-file).
To see how KGP is applied,
see [Update the Gradle file](#update-the-gradle-file).


If your plugin project doesn't currently apply KGP,
don't migrate to built-in Kotlin.
:::
Comment thread
jesswrd marked this conversation as resolved.

:::note
To update Flutter apps to use built-in Kotlin,
follow the [migration guide for app developers][].
Expand All @@ -24,9 +41,9 @@ follow the instructions to
First, find the `kotlin-android` plugin
(or the `org.jetbrains.kotlin.android` plugin).
It is likely located in the `plugins` block of the
`<plugin-project>/build.gradle` or the `<plugin-project>/build.gradle.kts` file.
`<plugin-project>/android/build.gradle` or the `<plugin-project>/android/build.gradle.kts` file.
If you use the legacy `apply` syntax,
it will be located in the Groovy-based `<plugin-project>/build.gradle` file,
it will be located in the Groovy-based `<plugin-project>/android/build.gradle` file,
as this syntax isn't supported in Kotlin DSL.

The following examples demonstrate how to migrate a Flutter plugin:
Expand Down Expand Up @@ -422,6 +439,8 @@ the newly released plugin version:
Before enabling built-in Kotlin,
confirm that you have migrated your plugin example app
and any Flutter plugins it uses.
Also, confirm that you updated your plugin example app
to AGP 9+, because built-in Kotlin requires AGP 9+.

To enable built-in Kotlin,
set the `android.builtInKotlin` property to `true`
Expand Down
7 changes: 7 additions & 0 deletions ...s/docs/src/content/release/breaking-changes/migrate-to-built-in-kotlin/index.md
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Expand Up @@ -7,6 +7,13 @@ description: >-

{% render "docs/breaking-changes.md" %}

:::warning
This guide only applies to apps and plugins that already use the
Kotlin Gradle Plugin (KGP).
If your project doesn't currently apply KGP,
don't migrate to built-in Kotlin.
:::
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## Summary

To build a Flutter app for Android,
Expand Down
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