# Java-gradle-plugin gradleApi() api dependency problem **URL:** \ **Category:** Help/Discuss\ **Created:** [July 11, 2020, 9:28am UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858 "2020-07-11T09:28:30Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![MrRogerHuang](https://avatars.discourse-cdn.com/v4/letter/m/2acd7d/32.png) [@MrRogerHuang](https://discuss.gradle.org/u/MrRogerHuang)\ **Post date:** [July 11, 2020, 9:28am UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858/1 "2020-07-11T09:28:30Z")
By the document: [https://docs.gradle.org/current/userguide/java\_gradle\_plugin.html](https://docs.gradle.org/current/userguide/java_gradle_plugin.html) the plugin `java-gradle-plugin` adds the `gradleApi()` dependency to the `api` configuration. I developed a Gradle plugin by `java-gradle-plugin`: > **[MrRogerHuang/GradleProjectInfoPlugin](https://github.com/MrRogerHuang/GradleProjectInfoPlugin)** > > Contribute to MrRogerHuang/GradleProjectInfoPlugin development by creating an account on GitHub. and I provide an example to use the plugin: > **[MrRogerHuang/GradleProjectInfoPlugin](https://github.com/MrRogerHuang/GradleProjectInfoPlugin/tree/master/example)** > > Contribute to MrRogerHuang/GradleProjectInfoPlugin development by creating an account on GitHub. However, I find if I remove the line `implementation gradleApi()` from example/build.gradle, the example will run (`./gradlew :example:run`) to fail with the errors ```gradle Exception in thread "main" java.lang.NoClassDefFoundError: org/gradle/tooling/GradleConnector at com.github.MrRogerHuang.GradleProjectRunner.run(GradleProjectRunner.kt:33) at com.github.MrRogerHuang.GradleProjectRunner.run$default(GradleProjectRunner.kt:32) at com.github.MrRogerHuang.ExampleKt.main(Example.kt:6) at com.github.MrRogerHuang.ExampleKt.main(Example.kt) Caused by: java.lang.ClassNotFoundException: org.gradle.tooling.GradleConnector at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522) ... 4 more ``` I check `build/publish-generated-resources/pom.xml` generated by `./gradlew publishPlugins` and find there is no dependencies tag related to any Gradle API. Why does `java-gradle-plugin` add `gradleApi()` api dependency, but not generate any dependencies tag to pom.xml? ---
**Author:** ![Chris\_Dore](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/chris_dore/32/7592_2.png) [@Chris\_Dore](https://discuss.gradle.org/u/Chris_Dore)\ **Post date:** [July 12, 2020, 4:50am UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858/2 "2020-07-12T04:50:57Z")
The example project should only need to depend on `org.gradle:gradle-tooling-api`, instead of `gradleApi()`. [https://docs.gradle.org/current/userguide/third\_party\_integration.html#sec:embedding\_quickstart](https://docs.gradle.org/current/userguide/third_party_integration.html#sec:embedding_quickstart) `$toolingApiVersion` should be a version chosen by you. ---
**Author:** ![MrRogerHuang](https://avatars.discourse-cdn.com/v4/letter/m/2acd7d/32.png) [@MrRogerHuang](https://discuss.gradle.org/u/MrRogerHuang)\ **Post date:** [July 12, 2020, 7:21am UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858/3 "2020-07-12T07:21:38Z")
Thanks. Yes, I agree only `org.gradle:gradle-tooling-api` is needed. However, I think that `org.gradle:gradle-tooling-api` is part of `gradleApi()` and `java-gradle-plugin` adds the `api gradleApi()` to my plugin, thus gradleApi() would be transitively exposed to the example implementing the plugin, isn’t it? With the transitive expose, the example build.gradle could be simplified by removing the an explicitly dependency to either `org.gradle:gradle-tooling-api` or `gradleApi()`. But in my example run, it looks like `api gradleApi()` added by `java-gradle-plugin` is not transitive… ---
**Author:** ![Chris\_Dore](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/chris_dore/32/7592_2.png) [@Chris\_Dore](https://discuss.gradle.org/u/Chris_Dore)\ **Post date:** [July 12, 2020, 4:26pm UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858/4 "2020-07-12T16:26:54Z")
`gradleAPI()` is not intended to be a published set of artifacts that you depend on in your plugin’s pom. The API is provided by Gradle at runtime of your plugin. Your plugin can be applied to projects running different versions of Gradle and that specific version’s API will be made available on the plugin’s classpath. You need to be aware about what features of the Gradle API you use in your plugin (you maintain the compatibility). If the plugin uses something added in Gradle 6 and the plugin is used in a Gradle 5 project, it will fail. The model interfaces should not contain Gradle API classes. This maintains an abstraction between the consumer of the model and any Gradle version specific API details. My personal suggestion is that you split the model classes into their own project. This helps enforce the abstraction and prevents the model from accidentally using Gradle API classes. In summary: - Plugin project - Depends on `gradleAPI()` and Model - Model project - Application/Consumer project - Depends on `gradle-tooling-api` and Model. ---
**Author:** ![MrRogerHuang](https://avatars.discourse-cdn.com/v4/letter/m/2acd7d/32.png) [@MrRogerHuang](https://discuss.gradle.org/u/MrRogerHuang)\ **Post date:** [July 13, 2020, 12:52am UTC](https://discuss.gradle.org/t/java-gradle-plugin-gradleapi-api-dependency-problem/36858/5 "2020-07-13T00:52:06Z")
Thanks for your information and suggestions.