ADK Kotlin changes

core/src/commonMain/kotlin/com/google/adk/kt/agents/InvocationContext.kt

@@ -531,7 +531,7 @@ data class InvocationContext(
                 functionResponse =
                   FunctionResponse(
                     name = tool.name,
-                    response = toFinalResponseMap(toolResult),
+                    response = toResponseMapPreservingNulls(toolResult),
                     id = toolContext.functionCallId,
                   )
               )
@@ -642,6 +642,24 @@ data class InvocationContext(
   @OptIn(FrameworkInternalApi::class)
   private fun toTraceJson(payload: Any?): JsonElement = anyToJsonElement(payload)
 
+  /**
+   * Like [toFinalResponseMap] but preserves null values in the response dict (e.g. `{result:
+   * null}`); only entries with non-String keys are dropped. The genai `FunctionResponse` allows
+   * null values, so the function-response *event* keeps them. (The after-tool callback path still
+   * receives the null-dropped [toFinalResponseMap] to preserve its non-null `Map<String, Any>`
+   * contract.)
+   *
+   * TODO(b/536808100): unify with [toFinalResponseMap] so the callback path preserves nulls too.
+   */
+  private fun toResponseMapPreservingNulls(payload: Any?): Map<String, Any?> =
+    if (payload !is Map<*, *>) {
+      mapOf(BaseTool.RESULT_KEY to payload)
+    } else {
+      payload.entries
+        .mapNotNull { entry -> (entry.key as? String)?.let { key -> key to entry.value } }
+        .toMap()
+    }
+
   private fun safeCastToMapStringAny(value: Any?): Map<String, Any> {
     if (value !is Map<*, *>) return emptyMap()
     return value.entries

core/src/commonMain/kotlin/com/google/adk/kt/agents/LlmAgentTurn.kt

@@ -419,6 +419,10 @@ internal class LlmAgentTurn(
           partial = response.partial,
           interrupted = response.interrupted,
           cacheMetadata = response.cacheMetadata,
+          modelVersion = response.modelVersion,
+          avgLogProbs = response.avgLogprobs,
+          groundingMetadata = response.groundingMetadata,
+          citationMetadata = response.citationMetadata,
         )
         .populateClientFunctionCallId()
 

core/src/commonMain/kotlin/com/google/adk/kt/events/Event.kt

@@ -28,6 +28,7 @@ import com.google.adk.kt.types.GroundingMetadata
 import com.google.adk.kt.types.UsageMetadata
 import kotlin.time.Clock
 import kotlinx.serialization.Contextual
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 /**
@@ -72,7 +73,7 @@ data class Event(
   val errorMessage: String? = null,
   val finishReason: FinishReason? = null,
   val usageMetadata: UsageMetadata? = null,
-  val avgLogProbs: Double? = null,
+  @SerialName("avgLogprobs") val avgLogProbs: Double? = null,
   val interrupted: Boolean = false,
   val branch: String? = null,
   val groundingMetadata: GroundingMetadata? = null,

core/src/commonMain/kotlin/com/google/adk/kt/types/GenaiConverters.kt

@@ -41,6 +41,7 @@ import com.google.genai.kotlin.types.GenerationConfigRoutingConfigManualRoutingM
 import com.google.genai.kotlin.types.GoogleMaps as GenAiGoogleMaps
 import com.google.genai.kotlin.types.GoogleSearch as GenAiGoogleSearch
 import com.google.genai.kotlin.types.GroundingChunk as GenAiGroundingChunk
+import com.google.genai.kotlin.types.GroundingChunkMaps as GenAiGroundingChunkMaps
 import com.google.genai.kotlin.types.GroundingChunkRetrievedContext as GenAiGroundingChunkRetrievedContext
 import com.google.genai.kotlin.types.GroundingChunkWeb as GenAiGroundingChunkWeb
 import com.google.genai.kotlin.types.GroundingMetadata as GenAiGroundingMetadata
@@ -467,10 +468,11 @@ internal fun GenerateContentResponse.toGenaiSdk(): GenAiGenerateContentResponse
 /** Converts a [GenAiGroundingMetadata] from the GenAI SDK to an ADK [GroundingMetadata]. */
 internal fun GenAiGroundingMetadata.fromGenaiSdk(): GroundingMetadata =
   GroundingMetadata(
-    imageSearchQueries = imageSearchQueries ?: emptyList(),
+    imageSearchQueries = imageSearchQueries,
     groundingChunks = groundingChunks?.map { it.fromGenaiSdk() },
     groundingSupports = groundingSupports?.map { it.fromGenaiSdk() },
     webSearchQueries = webSearchQueries,
+    retrievalQueries = retrievalQueries,
     searchEntryPoint = searchEntryPoint?.fromGenaiSdk(),
     retrievalMetadata = retrievalMetadata?.fromGenaiSdk(),
   )
@@ -482,18 +484,36 @@ internal fun GroundingMetadata.toGenaiSdk(): GenAiGroundingMetadata =
     groundingChunks = groundingChunks?.map { it.toGenaiSdk() },
     groundingSupports = groundingSupports?.map { it.toGenaiSdk() },
     webSearchQueries = webSearchQueries,
+    retrievalQueries = retrievalQueries,
     searchEntryPoint = searchEntryPoint?.toGenaiSdk(),
     retrievalMetadata = retrievalMetadata?.toGenaiSdk(),
   )
 
 // --- GroundingChunk ---
 /** Converts a [GenAiGroundingChunk] from the GenAI SDK to an ADK [GroundingChunk]. */
 internal fun GenAiGroundingChunk.fromGenaiSdk(): GroundingChunk =
-  GroundingChunk(web = web?.fromGenaiSdk(), retrievedContext = retrievedContext?.fromGenaiSdk())
+  GroundingChunk(
+    web = web?.fromGenaiSdk(),
+    retrievedContext = retrievedContext?.fromGenaiSdk(),
+    maps = maps?.fromGenaiSdk(),
+  )
 
 /** Converts an ADK [GroundingChunk] to a [GenAiGroundingChunk] for the GenAI SDK. */
 internal fun GroundingChunk.toGenaiSdk(): GenAiGroundingChunk =
-  GenAiGroundingChunk(web = web?.toGenaiSdk(), retrievedContext = retrievedContext?.toGenaiSdk())
+  GenAiGroundingChunk(
+    web = web?.toGenaiSdk(),
+    retrievedContext = retrievedContext?.toGenaiSdk(),
+    maps = maps?.toGenaiSdk(),
+  )
+
+// --- GroundingChunkMaps ---
+/** Converts a [GenAiGroundingChunkMaps] from the GenAI SDK to an ADK [GroundingChunkMaps]. */
+internal fun GenAiGroundingChunkMaps.fromGenaiSdk(): GroundingChunkMaps =
+  GroundingChunkMaps(uri = uri, title = title, placeId = placeId)
+
+/** Converts an ADK [GroundingChunkMaps] to a [GenAiGroundingChunkMaps] for the GenAI SDK. */
+internal fun GroundingChunkMaps.toGenaiSdk(): GenAiGroundingChunkMaps =
+  GenAiGroundingChunkMaps(uri = uri, title = title, placeId = placeId)
 
 // --- GroundingChunkWeb ---
 /** Converts a [GenAiGroundingChunkWeb] from the GenAI SDK to an ADK [GroundingChunkWeb]. */
@@ -761,6 +781,7 @@ internal fun GenAiGenerateContentResponseUsageMetadata.fromGenaiSdk(): UsageMeta
     cachedContentTokenCount = cachedContentTokenCount,
     promptTokensDetails = promptTokensDetails?.map { it.fromGenaiSdk() },
     candidatesTokensDetails = candidatesTokensDetails?.map { it.fromGenaiSdk() },
+    toolUsePromptTokensDetails = toolUsePromptTokensDetails?.map { it.fromGenaiSdk() },
   )
 
 /**
@@ -777,6 +798,7 @@ internal fun UsageMetadata.toGenaiSdk(): GenAiGenerateContentResponseUsageMetada
     cachedContentTokenCount = cachedContentTokenCount,
     promptTokensDetails = promptTokensDetails?.map { it.toGenaiSdk() },
     candidatesTokensDetails = candidatesTokensDetails?.map { it.toGenaiSdk() },
+    toolUsePromptTokensDetails = toolUsePromptTokensDetails?.map { it.toGenaiSdk() },
   )
 
 // --- Part ---

core/src/commonMain/kotlin/com/google/adk/kt/types/GroundingChunk.kt

@@ -25,4 +25,6 @@ data class GroundingChunk(
   val web: GroundingChunkWeb? = null,
   /** A chunk sourced from a retrieval (RAG) context. */
   val retrievedContext: GroundingChunkRetrievedContext? = null,
+  /** A chunk sourced from Google Maps grounding. */
+  val maps: GroundingChunkMaps? = null,
 )

core/src/commonMain/kotlin/com/google/adk/kt/types/GroundingChunkMaps.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.adk.kt.types
+
+import kotlinx.serialization.Serializable
+
+/** A grounding chunk sourced from Google Maps. */
+@Serializable
+data class GroundingChunkMaps(
+  /** The URI of the place on Google Maps. */
+  val uri: String? = null,
+  /** The title (name) of the place. */
+  val title: String? = null,
+  /** The Google Maps place id (e.g. `places/ChIJ...`). */
+  val placeId: String? = null,
+)

core/src/commonMain/kotlin/com/google/adk/kt/types/GroundingMetadata.kt

@@ -21,13 +21,16 @@ import kotlinx.serialization.Serializable
 /** Metadata returned to client when grounding is enabled. */
 @Serializable
 data class GroundingMetadata(
-  val imageSearchQueries: List<String> = emptyList(),
+  /** The image search queries used to retrieve grounding sources. */
+  val imageSearchQueries: List<String>? = null,
   /** The cited source chunks that ground the response. */
   val groundingChunks: List<GroundingChunk>? = null,
   /** Maps response segments to the grounding chunks that support them. */
   val groundingSupports: List<GroundingSupport>? = null,
   /** The web search queries used to retrieve grounding sources. */
   val webSearchQueries: List<String>? = null,
+  /** The retrieval queries used to retrieve grounding sources. */
+  val retrievalQueries: List<String>? = null,
   /** The Google Search entry point for rendering search suggestions. */
   val searchEntryPoint: SearchEntryPoint? = null,
   /** Metadata about the retrieval step. */

core/src/commonMain/kotlin/com/google/adk/kt/types/UsageMetadata.kt

@@ -37,4 +37,8 @@ data class UsageMetadata(
   val promptTokensDetails: List<ModalityTokenCount>? = null,
   /** A per-modality breakdown of the candidates token count. */
   val candidatesTokensDetails: List<ModalityTokenCount>? = null,
+  /** A per-modality breakdown of the tool-use prompt token count. */
+  val toolUsePromptTokensDetails: List<ModalityTokenCount>? = null,
+  /** The traffic type for the request (e.g. "ON_DEMAND", "PROVISIONED_THROUGHPUT"). */
+  val trafficType: String? = null,
 )

core/src/commonTest/kotlin/com/google/adk/kt/types/GenaiConvertersTest.kt

@@ -367,6 +367,7 @@ class GenaiConvertersTest {
     val adkGroundingMetadata =
       GroundingMetadata(
         webSearchQueries = listOf("kotlin coroutines"),
+        retrievalQueries = listOf("kotlin release date"),
         groundingChunks =
           listOf(
             GroundingChunk(
@@ -376,7 +377,15 @@ class GenaiConvertersTest {
                   title = "Example",
                   domain = "example.com",
                 )
-            )
+            ),
+            GroundingChunk(
+              maps =
+                GroundingChunkMaps(
+                  uri = "https://maps.google.com/?cid=1",
+                  title = "Googleplex",
+                  placeId = "places/ABC",
+                )
+            ),
           ),
         groundingSupports =
           listOf(
@@ -392,7 +401,8 @@ class GenaiConvertersTest {
 
     val genaiGroundingMetadata = adkGroundingMetadata.toGenaiSdk()
     assertEquals(listOf("kotlin coroutines"), genaiGroundingMetadata.webSearchQueries)
-    assertEquals("example.com", genaiGroundingMetadata.groundingChunks?.single()?.web?.domain)
+    assertEquals("example.com", genaiGroundingMetadata.groundingChunks?.get(0)?.web?.domain)
+    assertEquals("places/ABC", genaiGroundingMetadata.groundingChunks?.get(1)?.maps?.placeId)
 
     val convertedBack = genaiGroundingMetadata.fromGenaiSdk()
     assertEquals(adkGroundingMetadata, convertedBack)
@@ -655,6 +665,8 @@ class GenaiConvertersTest {
           listOf(ModalityTokenCount(modality = MediaModality.TEXT, tokenCount = 1)),
         candidatesTokensDetails =
           listOf(ModalityTokenCount(modality = MediaModality.IMAGE, tokenCount = 2)),
+        toolUsePromptTokensDetails =
+          listOf(ModalityTokenCount(modality = MediaModality.TEXT, tokenCount = 7)),
       )
     val genaiUsageMetadata = adkUsageMetadata.toGenaiSdk()
     assertEquals(1, genaiUsageMetadata.promptTokenCount)

settings.gradle.kts

@@ -61,3 +61,10 @@ project(":google-adk-kotlin-litertlm").projectDir = file("litertlm")
 include(":google-adk-kotlin-examples-android")
 
 project(":google-adk-kotlin-examples-android").projectDir = file("examples/android")
+
+// copybara:strip_begin(internal)
+// Internal-only module (config API + conformance harness), stripped from the public GitHub mirror.
+include(":google-adk-kotlin-internal-conformance")
+
+project(":google-adk-kotlin-internal-conformance").projectDir =
+  file("internal/conformance") // copybara:strip_end

webserver/build.gradle.kts

@@ -16,7 +16,6 @@
 
 plugins {
   kotlin("jvm")
-  id("application")
   id("java-library")
   id("maven-publish")
 }
@@ -44,6 +43,7 @@ sourceSets {
 dependencies {
   implementation(project(":google-adk-kotlin-core"))
   implementation(libs.kotlinx.datetime)
+  implementation(libs.kotlinx.coroutines.core)
 
   implementation(libs.graphviz.java)
 

webserver/src/jvmMain/kotlin/com/google/adk/kt/webserver/AdkWebServer.kt

@@ -17,11 +17,13 @@
 package com.google.adk.kt.webserver
 
 import com.google.adk.kt.artifacts.ArtifactService
+import com.google.adk.kt.plugins.Plugin
 import com.google.adk.kt.runners.Runner
 import com.google.adk.kt.sessions.SessionService
 import com.google.adk.kt.telemetry.TelemetryConfig
 import com.google.adk.kt.webserver.AdkWebServer.StatusAwareLogger
 import com.google.adk.kt.webserver.loaders.AgentLoader
+import com.google.adk.kt.webserver.models.VersionInfo
 import com.google.adk.kt.webserver.routes.appRoutes
 import com.google.adk.kt.webserver.routes.artifactRoutes
 import com.google.adk.kt.webserver.routes.debugRoutes
@@ -32,8 +34,10 @@ import com.google.adk.kt.webserver.routes.sessionRoutes
 import com.google.adk.kt.webserver.routes.staticRoutes
 import com.google.adk.kt.webserver.telemetry.ApiServerSpanExporter
 import com.google.adk.kt.webserver.telemetry.OpenTelemetryConfig
+import com.google.gson.GsonBuilder
 import com.google.gson.TypeAdapter
 import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonToken
 import com.google.gson.stream.JsonWriter
 import io.ktor.serialization.gson.gson
 import io.ktor.server.application.Application
@@ -46,6 +50,7 @@ import io.ktor.server.plugins.callloging.CallLogging
 import io.ktor.server.plugins.contentnegotiation.ContentNegotiation
 import io.ktor.server.request.httpMethod
 import io.ktor.server.request.uri
+import io.ktor.server.response.respond
 import io.ktor.server.response.respondText
 import io.ktor.server.routing.get
 import io.ktor.server.routing.routing
@@ -68,6 +73,8 @@ class AdkWebServer(
   private val agentLoader: AgentLoader,
   private val apiServerSpanExporter: ApiServerSpanExporter,
   private val captureMessageContent: Boolean = false,
+  private val plugins: List<Plugin> = emptyList(),
+  private val gsonConfigurer: (GsonBuilder.() -> Unit)? = null,
 ) {
   @Deprecated(
     message = "Use constructor without runner",
@@ -96,6 +103,9 @@ class AdkWebServer(
 
   companion object {
     private val logger = LoggerFactory.getLogger(AdkWebServer::class.java)
+
+    /** The ADK Kotlin version reported by the `/version` endpoint. */
+    fun adkVersion(): String = com.google.adk.kt.VERSION
   }
 
   private var server: ApplicationEngine? = null
@@ -111,6 +121,8 @@ class AdkWebServer(
             agentLoader,
             apiServerSpanExporter,
             captureMessageContent,
+            plugins,
+            gsonConfigurer,
           )
         }
         .start(wait = wait)
@@ -133,7 +145,7 @@ class AdkWebServer(
     }
 
     override fun read(reader: JsonReader): Instant? {
-      if (reader.peek() == com.google.gson.stream.JsonToken.NULL) {
+      if (reader.peek() == JsonToken.NULL) {
         reader.nextNull()
         return null
       }
@@ -158,6 +170,8 @@ fun Application.adkModule(
   agentLoader: AgentLoader,
   apiServerSpanExporter: ApiServerSpanExporter,
   captureMessageContent: Boolean = false,
+  plugins: List<Plugin> = emptyList(),
+  gsonConfigurer: (GsonBuilder.() -> Unit)? = null,
 ) {
   install(CallLogging) {
     level = Level.INFO
@@ -173,6 +187,8 @@ fun Application.adkModule(
     gson {
       setPrettyPrinting()
       registerTypeAdapter(Instant::class.java, AdkWebServer.InstantTypeAdapter())
+      // Callers can register extra Gson type adapters here.
+      gsonConfigurer?.invoke(this)
     }
   }
 
@@ -199,12 +215,21 @@ fun Application.adkModule(
 
   routing {
     get("/api/health") { call.respondText("OK") }
+    get("/version") {
+      call.respond(
+        VersionInfo(
+          version = AdkWebServer.adkVersion(),
+          language = "kotlin",
+          languageVersion = System.getProperty("java.version", "unknown"),
+        )
+      )
+    }
     appRoutes(agentLoader)
     artifactRoutes(artifactService)
     debugRoutes(apiServerSpanExporter)
     evalRoutes()
     graphRoutes(agentLoader, sessionService)
-    runRoutes(agentLoader, sessionService, artifactService)
+    runRoutes(agentLoader, sessionService, artifactService, plugins)
     sessionRoutes(sessionService)
     staticRoutes(this@adkModule)
   }