Public types from non-transitive dependencies

PUBLIC_TYPE_FROM_NON_TRANSITIVE_DEPENDENCY reports dependency types in public signatures when their artifacts are not available transitively to consumers.

Diagnostic	PUBLIC_TYPE_FROM_NON_TRANSITIVE_DEPENDENCY
Default severity	Always an error
Gradle property	publicTypesMustBeTransitiveDependencies
Exemption	none

Library consumers must be able to resolve every type in the public API. A type from an implementation dependency is available while the library itself compiles, but it is absent from the consumer's compile classpath. The consumer then cannot use the affected declaration.

build.gradle.kts

dependencies {
    implementation("com.example:models:1.0")
}

Library.kt

@file:JvmName("Library")

/** Loads the current external model. */
public fun loadModel(): ExternalModel = TODO()

Publish the dependency transitively when one of its types is part of the API:

dependencies {
    api("com.example:models:1.0")
}

The check covers return, receiver, value and context parameter types, nested type arguments, generic bounds, class supertypes, and public type aliases. It is always reported as an error and cannot be suppressed in source or demoted to a warning.

@PublishedApi internal declarations are included because public inline bodies can copy calls to them into consumer binaries, whose linkage still requires every type in those signatures.

If dependency exposure is deliberately managed outside Gradle metadata, disable the check for the module:

apiWatchdog {
    publicTypesMustBeTransitiveDependencies = false
}

The check needs Gradle's dependency model and therefore does not run during direct compiler invocation.