diff --git a/kotlin-sdk-core/api/kotlin-sdk-core.api b/kotlin-sdk-core/api/kotlin-sdk-core.api
index 089572293..84e36559d 100644
--- a/kotlin-sdk-core/api/kotlin-sdk-core.api
+++ b/kotlin-sdk-core/api/kotlin-sdk-core.api
@@ -390,6 +390,7 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CallToolRequest : io
 	public final fun getName ()Ljava/lang/String;
 	public fun getParams ()Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;
 	public synthetic fun getParams ()Lio/modelcontextprotocol/kotlin/sdk/types/RequestParams;
+	public final fun getTask ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }
@@ -421,17 +422,19 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CallToolRequestBuild
 
 public final class io/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams : io/modelcontextprotocol/kotlin/sdk/types/RequestParams {
 	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams$Companion;
-	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lkotlinx/serialization/json/JsonObject;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lkotlinx/serialization/json/JsonObject;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ljava/lang/String;
 	public final fun component2 ()Lkotlinx/serialization/json/JsonObject;
-	public final fun component3-VI-3G7E ()Lkotlinx/serialization/json/JsonObject;
-	public final fun copy-EDEVuBg (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;
-	public static synthetic fun copy-EDEVuBg$default (Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;
+	public final fun component3 ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
+	public final fun component4-VI-3G7E ()Lkotlinx/serialization/json/JsonObject;
+	public final fun copy-6R815Ik (Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;
+	public static synthetic fun copy-6R815Ik$default (Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/types/CallToolRequestParams;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getArguments ()Lkotlinx/serialization/json/JsonObject;
 	public fun getMeta-VI-3G7E ()Lkotlinx/serialization/json/JsonObject;
 	public final fun getName ()Ljava/lang/String;
+	public final fun getTask ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }
@@ -1157,6 +1160,7 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequest
 	public synthetic fun getParams ()Lio/modelcontextprotocol/kotlin/sdk/types/RequestParams;
 	public final fun getStopSequences ()Ljava/util/List;
 	public final fun getSystemPrompt ()Ljava/lang/String;
+	public final fun getTask ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
 	public final fun getTemperature ()Ljava/lang/Double;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
@@ -1201,11 +1205,12 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequest
 
 public final class io/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams : io/modelcontextprotocol/kotlin/sdk/types/RequestParams {
 	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams$Companion;
-	public synthetic fun <init> (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lkotlinx/serialization/json/JsonObject;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public synthetic fun <init> (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lkotlinx/serialization/json/JsonObject;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()I
 	public final fun component10 ()Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;
-	public final fun component11-VI-3G7E ()Lkotlinx/serialization/json/JsonObject;
+	public final fun component11 ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
+	public final fun component12-VI-3G7E ()Lkotlinx/serialization/json/JsonObject;
 	public final fun component2 ()Ljava/util/List;
 	public final fun component3 ()Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;
 	public final fun component4 ()Ljava/lang/String;
@@ -1214,8 +1219,8 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequest
 	public final fun component7 ()Ljava/util/List;
 	public final fun component8 ()Lkotlinx/serialization/json/JsonObject;
 	public final fun component9 ()Ljava/util/List;
-	public final fun copy-APmi5RE (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;
-	public static synthetic fun copy-APmi5RE$default (Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;
+	public final fun copy-7OuPiQU (ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;
+	public static synthetic fun copy-7OuPiQU$default (Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;ILjava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;Ljava/lang/String;Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;Ljava/lang/Double;Ljava/util/List;Lkotlinx/serialization/json/JsonObject;Ljava/util/List;Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequestParams;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getIncludeContext ()Lio/modelcontextprotocol/kotlin/sdk/types/IncludeContext;
 	public final fun getMaxTokens ()I
@@ -1225,6 +1230,7 @@ public final class io/modelcontextprotocol/kotlin/sdk/types/CreateMessageRequest
 	public final fun getModelPreferences ()Lio/modelcontextprotocol/kotlin/sdk/types/ModelPreferences;
 	public final fun getStopSequences ()Ljava/util/List;
 	public final fun getSystemPrompt ()Ljava/lang/String;
+	public final fun getTask ()Lio/modelcontextprotocol/kotlin/sdk/types/TaskMetadata;
 	public final fun getTemperature ()Ljava/lang/Double;
 	public final fun getToolChoice ()Lio/modelcontextprotocol/kotlin/sdk/types/ToolChoice;
 	public final fun getTools ()Ljava/util/List;
diff --git a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/sampling.kt b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/sampling.kt
index 452640598..28d2ca12c 100644
--- a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/sampling.kt
+++ b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/sampling.kt
@@ -182,6 +182,12 @@ public data class CreateMessageRequest(override val params: CreateMessageRequest
     public val metadata: JsonObject?
         get() = params.metadata
 
+    /**
+     * Task metadata, if the caller is requesting task-augmented execution.
+     */
+    public val task: TaskMetadata?
+        get() = params.task
+
     /**
      * Metadata for this request. May include a progressToken for out-of-band progress notifications.
      */
@@ -216,6 +222,8 @@ public data class CreateMessageRequest(override val params: CreateMessageRequest
  * @property toolChoice Optional policy controlling how the model uses the provided [tools].
  * The client MUST return an error if this field is present but the client did not advertise
  * [ClientCapabilities.Sampling.tools].
+ * @property task If specified, the caller is requesting task-augmented execution. The request
+ * will return a [CreateTaskResult] immediately, and the actual result can be retrieved later via `tasks/result`.
  * @property meta Optional metadata for this request. May include a progressToken for
  * out-of-band progress notifications.
  */
@@ -231,6 +239,7 @@ public data class CreateMessageRequestParams(
     val metadata: JsonObject? = null,
     val tools: List<Tool>? = null,
     val toolChoice: ToolChoice? = null,
+    val task: TaskMetadata? = null,
     @SerialName("_meta")
     override val meta: RequestMeta? = null,
 ) : RequestParams
diff --git a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/tools.kt b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/tools.kt
index 2ff890a1e..106c4361c 100644
--- a/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/tools.kt
+++ b/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types/tools.kt
@@ -203,6 +203,12 @@ public data class CallToolRequest(override val params: CallToolRequestParams) :
     public val arguments: JsonObject?
         get() = params.arguments
 
+    /**
+     * Task metadata, if the caller is requesting task-augmented execution.
+     */
+    public val task: TaskMetadata?
+        get() = params.task
+
     /**
      * Metadata for this request. May include a progressToken for out-of-band progress notifications.
      */
@@ -216,6 +222,8 @@ public data class CallToolRequest(override val params: CallToolRequestParams) :
  * @property name The name of the tool to invoke.
  * @property arguments Arguments to pass to the tool. Keys are argument names, values are the argument values.
  * The structure must match the tool's input schema.
+ * @property task If specified, the caller is requesting task-augmented execution. The request
+ * will return a [CreateTaskResult] immediately, and the actual result can be retrieved later via `tasks/result`.
  * @property meta Optional metadata for this request. May include a progressToken for
  * out-of-band progress notifications.
  */
@@ -223,6 +231,7 @@ public data class CallToolRequest(override val params: CallToolRequestParams) :
 public data class CallToolRequestParams(
     val name: String,
     val arguments: JsonObject? = null,
+    val task: TaskMetadata? = null,
     @SerialName("_meta")
     override val meta: RequestMeta? = null,
 ) : RequestParams
diff --git a/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/SamplingTest.kt b/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/SamplingTest.kt
index b2c8cf0cd..b7bc5cf08 100644
--- a/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/SamplingTest.kt
+++ b/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/SamplingTest.kt
@@ -367,6 +367,26 @@ class SamplingTest {
         decoded.toolChoice shouldBe ToolChoice(mode = ToolChoice.Mode.Required)
     }
 
+    @Test
+    fun `CreateMessageRequestParams task defaults to null and is omitted when encoding`() {
+        val params = CreateMessageRequestParams(maxTokens = 100, messages = emptyList())
+        params.task shouldBe null
+        val encoded = McpJson.encodeToString(CreateMessageRequestParams.serializer(), params)
+        assertEquals(false, "\"task\"" in encoded)
+    }
+
+    @Test
+    fun `CreateMessageRequestParams round-trips task`() {
+        val original = CreateMessageRequestParams(
+            maxTokens = 100,
+            messages = emptyList(),
+            task = TaskMetadata(ttl = 60_000L),
+        )
+        val encoded = McpJson.encodeToString(CreateMessageRequestParams.serializer(), original)
+        val decoded = McpJson.decodeFromString(CreateMessageRequestParams.serializer(), encoded)
+        decoded.task shouldBe TaskMetadata(ttl = 60_000L)
+    }
+
     @Test
     fun `StopReason ToolUse serialises as toolUse`() {
         StopReason.ToolUse.value shouldBe "toolUse"
diff --git a/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/ToolsTest.kt b/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/ToolsTest.kt
index d5e1d5a94..358866a10 100644
--- a/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/ToolsTest.kt
+++ b/kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/types/ToolsTest.kt
@@ -319,6 +319,57 @@ class ToolsTest {
         assertEquals(ProgressToken(77), params.meta?.progressToken)
     }
 
+    @Test
+    fun `should serialize CallToolRequest with task augmentation`() {
+        val request = CallToolRequest(
+            CallToolRequestParams(
+                name = "long-running",
+                arguments = buildJsonObject { put("query", "MCP protocol") },
+                task = TaskMetadata(ttl = 60_000L),
+            ),
+        )
+
+        verifySerialization(
+            request,
+            McpJson,
+            """
+            {
+              "method": "tools/call",
+              "params": {
+                "name": "long-running",
+                "arguments": {
+                  "query": "MCP protocol"
+                },
+                "task": {
+                  "ttl": 60000
+                }
+              }
+            }
+            """.trimIndent(),
+        )
+
+        assertEquals(TaskMetadata(ttl = 60_000L), request.task)
+    }
+
+    @Test
+    fun `should omit task from CallToolRequest when null`() {
+        val request = CallToolRequest(CallToolRequestParams(name = "plain"))
+
+        assertEquals(null, request.task)
+        verifySerialization(
+            request,
+            McpJson,
+            """
+            {
+              "method": "tools/call",
+              "params": {
+                "name": "plain"
+              }
+            }
+            """.trimIndent(),
+        )
+    }
+
     @Test
     fun `should serialize CallToolResult with structured content`() {
         val result = CallToolResult(