diff --git a/kotlin-code-generation/src/main/kotlin/_types.kt b/kotlin-code-generation/src/main/kotlin/_types.kt
index 16b17bf..7cd9412 100644
--- a/kotlin-code-generation/src/main/kotlin/_types.kt
+++ b/kotlin-code-generation/src/main/kotlin/_types.kt
@@ -2,6 +2,7 @@ package io.toolisticon.kotlin.generation
 
 import com.squareup.kotlinpoet.ClassName
 import java.util.function.Supplier
+import kotlin.reflect.KClass
 
 /**
  * Marks a type as capable of building a new product.
@@ -22,6 +23,22 @@ interface WithClassName {
   val className: ClassName
 }
 
+/**
+ * An implementing type can provide a generic value for a tag key.
+ * Behaves as [com.squareup.kotlinpoet.Taggable] but hides the implementation of the tg provider.
+ */
+interface WithTags {
+  /**
+   * @see [com.squareup.kotlinpoet.Taggable.tag]
+   */
+  fun <T : Any> tag(type: KClass<T>): T?
+}
+
+/**
+ * Reified access to [WithTags.tag].
+ */
+inline fun <reified T : Any> WithTags.tag(): T? = tag(T::class)
+
 /**
  * ClassName when used as a file name for fileSpec.
  */
diff --git a/kotlin-code-generation/src/main/kotlin/spec/KotlinFileSpec.kt b/kotlin-code-generation/src/main/kotlin/spec/KotlinFileSpec.kt
index 8f67751..3ee0072 100644
--- a/kotlin-code-generation/src/main/kotlin/spec/KotlinFileSpec.kt
+++ b/kotlin-code-generation/src/main/kotlin/spec/KotlinFileSpec.kt
@@ -3,6 +3,7 @@ package io.toolisticon.kotlin.generation.spec
 import com.squareup.kotlinpoet.ClassName
 import com.squareup.kotlinpoet.FileSpec
 import io.toolisticon.kotlin.generation.WithClassName
+import io.toolisticon.kotlin.generation.WithTags
 import io.toolisticon.kotlin.generation.poet.FileSpecSupplier
 import kotlin.reflect.KClass
 
@@ -11,7 +12,7 @@ import kotlin.reflect.KClass
  */
 data class KotlinFileSpec(
   private val spec: FileSpec
-) : KotlinGeneratorSpec<KotlinFileSpec, FileSpec, FileSpecSupplier>, KotlinFileSpecSupplier, TaggableSpec, KotlinFileSpecIterable {
+) : KotlinGeneratorSpec<KotlinFileSpec, FileSpec, FileSpecSupplier>, KotlinFileSpecSupplier, WithTags, KotlinFileSpecIterable {
 
   val packageName: String = spec.packageName
   val rootName: String = spec.name
@@ -37,6 +38,7 @@ interface KotlinFileSpecSupplier : KotlinGeneratorSpecSupplier<KotlinFileSpec>,
  * List that contains multiple [KotlinFileSpec]s.
  */
 @JvmInline
+@Suppress("JavaDefaultMethodsNotOverriddenByDelegation")
 value class KotlinFileSpecList(private val fileSpecs: List<KotlinFileSpec>) : List<KotlinFileSpec> by fileSpecs, KotlinFileSpecIterable {
   companion object {
 
diff --git a/kotlin-code-generation/src/main/kotlin/spec/_types.kt b/kotlin-code-generation/src/main/kotlin/spec/_types.kt
index 16f7fa7..9fa7fee 100644
--- a/kotlin-code-generation/src/main/kotlin/spec/_types.kt
+++ b/kotlin-code-generation/src/main/kotlin/spec/_types.kt
@@ -6,9 +6,12 @@ import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
 import com.squareup.kotlinpoet.TypeSpec
 import io.toolisticon.kotlin.generation.KotlinCodeGeneration
 import io.toolisticon.kotlin.generation.WithClassName
-import io.toolisticon.kotlin.generation.poet.*
+import io.toolisticon.kotlin.generation.WithTags
+import io.toolisticon.kotlin.generation.poet.KDoc
+import io.toolisticon.kotlin.generation.poet.PoetSpec
+import io.toolisticon.kotlin.generation.poet.PoetSpecSupplier
+import io.toolisticon.kotlin.generation.poet.TypeSpecSupplier
 import io.toolisticon.kotlin.generation.support.SUPPRESS_UNUSED
-import kotlin.reflect.KClass
 
 interface KotlinGeneratorSpecSupplier<GENERATOR_SPEC> {
   fun spec(): GENERATOR_SPEC
@@ -24,7 +27,7 @@ sealed interface KotlinGeneratorTypeSpec<SELF : KotlinGeneratorTypeSpec<SELF>> :
 }
 
 @ExperimentalKotlinPoetApi
-sealed interface KotlinDocumentableSpec : TaggableSpec {
+sealed interface KotlinDocumentableSpec : WithTags {
   val kdoc: KDoc
 }
 
@@ -41,21 +44,6 @@ fun ToFileTypeSpecSupplier.toFileSpec() = KotlinCodeGeneration.buildFile(classNa
   addType(this@toFileSpec)
 }
 
-/**
- * Marks Spec as [com.squareup.kotlinpoet.Taggable].
- */
-sealed interface TaggableSpec {
-  /**
-   * @see [com.squareup.kotlinpoet.Taggable.tag]
-   */
-  fun <T : Any> tag(type: KClass<T>): T?
-}
-
-/**
- * Reified access to [TaggableSpec.tag].
- */
-inline fun <reified T : Any> TaggableSpec.tag(): T? = tag(T::class)
-
 /**
  * Tags a spec with extra type.
  */
diff --git a/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationContext.kt b/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationContext.kt
index da4d300..bf8be9f 100644
--- a/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationContext.kt
+++ b/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationContext.kt
@@ -1,6 +1,7 @@
 package io.toolisticon.kotlin.generation.spi
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
+import io.toolisticon.kotlin.generation.WithTags
 import kotlin.reflect.KClass
 
 /**
@@ -13,7 +14,7 @@ import kotlin.reflect.KClass
  * Hint: for implementing a concrete context, use the [io.toolisticon.kotlin.generation.spi.context.KotlinCodeGenerationContextBase].
  */
 @ExperimentalKotlinPoetApi
-interface KotlinCodeGenerationContext<SELF : KotlinCodeGenerationContext<SELF>> {
+interface KotlinCodeGenerationContext<SELF : KotlinCodeGenerationContext<SELF>> : WithTags {
 
   /**
    * SELF type of the context implementation, used to verify against [io.toolisticon.kotlin.generation.spi.KotlinCodeGenerationSpi.contextType].
@@ -38,6 +39,8 @@ interface KotlinCodeGenerationContext<SELF : KotlinCodeGenerationContext<SELF>>
   fun <PROCESSOR : KotlinCodeGenerationProcessor<CONTEXT, INPUT, BUILDER>, CONTEXT : KotlinCodeGenerationContext<CONTEXT>, INPUT : Any, BUILDER : Any> processors(
     processorType: KClass<PROCESSOR>
   ): List<PROCESSOR> = registry.processors.filterIsInstance(processorType.java)
+
+  override fun <T : Any> tag(type: KClass<T>): T? = null
 }
 
 /**
diff --git a/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationSpi.kt b/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationSpi.kt
index 52d6ade..ebde895 100644
--- a/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationSpi.kt
+++ b/kotlin-code-generation/src/main/kotlin/spi/KotlinCodeGenerationSpi.kt
@@ -1,6 +1,7 @@
 package io.toolisticon.kotlin.generation.spi
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
+import io.toolisticon.kotlin.generation.WithTags
 import java.util.function.BiPredicate
 import kotlin.reflect.KClass
 import kotlin.reflect.full.isSubclassOf
@@ -14,7 +15,7 @@ import kotlin.reflect.full.isSubclassOf
  * * [KotlinCodeGenerationProcessor] - visitor pattern to modify spec builders before the spec is build.
  */
 @ExperimentalKotlinPoetApi
-sealed interface KotlinCodeGenerationSpi<CONTEXT : KotlinCodeGenerationContext<CONTEXT>, INPUT : Any> : Comparable<KotlinCodeGenerationSpi<*, *>>, BiPredicate<CONTEXT, Any> {
+sealed interface KotlinCodeGenerationSpi<CONTEXT : KotlinCodeGenerationContext<CONTEXT>, INPUT : Any> : Comparable<KotlinCodeGenerationSpi<*, *>>, BiPredicate<CONTEXT, Any>, WithTags {
   companion object {
     val metaInfServices = "META-INF/services/${KotlinCodeGenerationSpi::class.qualifiedName}"
     const val DEFAULT_ORDER = 0
@@ -57,4 +58,6 @@ sealed interface KotlinCodeGenerationSpi<CONTEXT : KotlinCodeGenerationContext<C
    * @return `true` when the spi shoud be applied.
    */
   override fun test(context: CONTEXT, input: Any): Boolean = context::class.isSubclassOf(contextType) && input::class.isSubclassOf(inputType)
+
+  override fun <T : Any> tag(type: KClass<T>): T? = null
 }
diff --git a/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt b/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
index 69499f3..479886f 100644
--- a/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
+++ b/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
@@ -1,4 +1,3 @@
-
 package io.toolisticon.kotlin.generation._test
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
diff --git a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
index 80e8b86..b2c26a9 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
@@ -24,9 +24,7 @@ internal class KotlinCodeGenerationServiceRepositoryTest {
     contextType = TestContext::class,
     inputType = TestInput::class,
   ) {
-    override fun invoke(context: TestContext, input: TestInput): KotlinDataClassSpec {
-      TODO("Not yet implemented")
-    }
+    override fun invoke(context: TestContext, input: TestInput): KotlinDataClassSpec = TODO("Not yet implemented")
 
     override val specType: KClass<KotlinDataClassSpec> = KotlinDataClassSpec::class
 
diff --git a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
index 58bcdde..767b1fd 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
@@ -1,4 +1,3 @@
-
 package io.toolisticon.kotlin.generation.spi
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
@@ -16,6 +15,7 @@ import io.toolisticon.kotlin.generation.spi.strategy.executeAll
 import io.toolisticon.kotlin.generation.spi.strategy.executeSingle
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
+import kotlin.reflect.KClass
 
 @OptIn(ExperimentalKotlinPoetApi::class)
 class KotlinCodeGenerationStrategyListTest {
@@ -24,6 +24,8 @@ class KotlinCodeGenerationStrategyListTest {
     override fun invoke(context: EmptyContext, input: InputA): KotlinDataClassSpec = buildDataClass(input.className) {
       input.fields.map { (k, v) -> buildConstructorProperty(k, v) }.forEach(this::addConstructorProperty)
     }
+
+    override fun <T : Any> tag(type: KClass<T>): T? = TODO("Not yet implemented")
   }
 
   class BStrategy : DataClassBStrategy() {