Align the Kotlin SDK with agent-client-protocol pr 576 that flattens type and value at the top level

acp-model/api/acp-model.api

@@ -3602,17 +3602,6 @@ public final class com/agentclientprotocol/model/SetSessionConfigOptionRequest :
 	public fun toString ()Ljava/lang/String;
 }
 
-public final synthetic class com/agentclientprotocol/model/SetSessionConfigOptionRequest$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
-	public static final field INSTANCE Lcom/agentclientprotocol/model/SetSessionConfigOptionRequest$$serializer;
-	public final fun childSerializers ()[Lkotlinx/serialization/KSerializer;
-	public final fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lcom/agentclientprotocol/model/SetSessionConfigOptionRequest;
-	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
-	public final fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
-	public final fun serialize (Lkotlinx/serialization/encoding/Encoder;Lcom/agentclientprotocol/model/SetSessionConfigOptionRequest;)V
-	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
-	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
-}
-
 public final class com/agentclientprotocol/model/SetSessionConfigOptionRequest$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }

acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Requests.kt

@@ -766,7 +766,7 @@ public data class ResumeSessionResponse(
  * Request to set a configuration option for a session.
  */
 @UnstableApi
-@Serializable
+@Serializable(with = SetSessionConfigOptionRequestSerializer::class)
 public data class SetSessionConfigOptionRequest(
     override val sessionId: SessionId,
     val configId: SessionConfigId,

acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/SessionConfig.kt

@@ -24,7 +24,10 @@ import kotlinx.serialization.json.JsonPrimitive
 import kotlinx.serialization.json.boolean
 import kotlinx.serialization.json.booleanOrNull
 import kotlinx.serialization.json.jsonArray
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.buildJsonObject
 import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.put
 
 /**
  * **UNSTABLE**
@@ -286,3 +289,116 @@ internal object SessionConfigOptionValueSerializer : KSerializer<SessionConfigOp
         }
     }
 }
+
+/**
+ * **UNSTABLE**
+ *
+ * This capability is not part of the spec yet, and may be removed or changed at any point.
+ *
+ * Custom serializer for [SetSessionConfigOptionRequest] that flattens the [SessionConfigOptionValue]
+ * `type` and `value` fields at the top level of the JSON object.
+ *
+ * Boolean values serialize as: `{"sessionId":"s","configId":"c","type":"boolean","value":true}`
+ * String values serialize as: `{"sessionId":"s","configId":"c","value":"code"}` (no `type` field)
+ * This ensures backward compatibility: the select/value-id format is unchanged.
+ */
+@OptIn(UnstableApi::class)
+internal object SetSessionConfigOptionRequestSerializer : KSerializer<SetSessionConfigOptionRequest> {
+    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("SetSessionConfigOptionRequest")
+
+    override fun serialize(encoder: Encoder, value: SetSessionConfigOptionRequest) {
+        val jsonEncoder = encoder as? JsonEncoder
+            ?: throw SerializationException("SetSessionConfigOptionRequestSerializer supports only JSON")
+        val jsonElement = buildJsonObject {
+            put("sessionId", value.sessionId.value)
+            put("configId", value.configId.value)
+            when (val v = value.value) {
+                is SessionConfigOptionValue.BoolValue -> {
+                    put("type", "boolean")
+                    put("value", v.value)
+                }
+                is SessionConfigOptionValue.StringValue -> {
+                    put("value", v.value)
+                }
+                is SessionConfigOptionValue.UnknownValue -> {
+                    // Preserve unknown fields - if it was an object with type+value, re-flatten them
+                    val raw = v.rawElement
+                    if (raw is JsonObject) {
+                        for ((key, element) in raw) {
+                            put(key, element)
+                        }
+                    } else {
+                        put("value", raw)
+                    }
+                }
+            }
+            if (value._meta != null) {
+                put("_meta", value._meta)
+            }
+        }
+        jsonEncoder.encodeJsonElement(jsonElement)
+    }
+
+    override fun deserialize(decoder: Decoder): SetSessionConfigOptionRequest {
+        val jsonDecoder = decoder as? JsonDecoder
+            ?: throw SerializationException("SetSessionConfigOptionRequestSerializer supports only JSON")
+        val jsonObject = jsonDecoder.decodeJsonElement().jsonObject
+
+        val sessionId = SessionId(jsonObject["sessionId"]?.let {
+            (it as? JsonPrimitive)?.content
+        } ?: throw SerializationException("Missing 'sessionId'"))
+
+        val configId = SessionConfigId(jsonObject["configId"]?.let {
+            (it as? JsonPrimitive)?.content
+        } ?: throw SerializationException("Missing 'configId'"))
+
+        val type = (jsonObject["type"] as? JsonPrimitive)?.content
+        val rawValue = jsonObject["value"]
+            ?: throw SerializationException("Missing 'value'")
+
+        val value: SessionConfigOptionValue = when (type) {
+            "boolean" -> {
+                val primitive = rawValue as? JsonPrimitive
+                    ?: throw SerializationException("Expected boolean primitive for type 'boolean'")
+                if (primitive.booleanOrNull != null) {
+                    SessionConfigOptionValue.BoolValue(primitive.boolean)
+                } else {
+                    SessionConfigOptionValue.UnknownValue(rawValue)
+                }
+            }
+            null -> {
+                // No type field = backward-compatible primitive value
+                val primitive = rawValue as? JsonPrimitive
+                if (primitive != null) {
+                    when {
+                        primitive.isString ->
+                            SessionConfigOptionValue.StringValue(primitive.content)
+                        primitive.booleanOrNull != null ->
+                            SessionConfigOptionValue.BoolValue(primitive.boolean)
+                        else ->
+                            SessionConfigOptionValue.UnknownValue(rawValue)
+                    }
+                } else {
+                    SessionConfigOptionValue.UnknownValue(rawValue)
+                }
+            }
+            else -> {
+                // Unknown type - forward compatibility: preserve both type and value
+                val unknownWrapper = buildJsonObject {
+                    put("type", JsonPrimitive(type))
+                    put("value", rawValue)
+                }
+                SessionConfigOptionValue.UnknownValue(unknownWrapper)
+            }
+        }
+
+        val meta = jsonObject["_meta"]
+
+        return SetSessionConfigOptionRequest(
+            sessionId = sessionId,
+            configId = configId,
+            value = value,
+            _meta = meta
+        )
+    }
+}

acp-model/src/commonTest/kotlin/com/agentclientprotocol/model/SessionConfigSelectOptionsSerializerTest.kt

@@ -8,6 +8,7 @@ import com.agentclientprotocol.rpc.JsonRpcRequest
 import com.agentclientprotocol.rpc.JsonRpcResponse
 import kotlinx.serialization.json.JsonNull
 import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonObject
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertIs
@@ -479,6 +480,7 @@ class SessionConfigSelectOptionsSerializerTest {
               "params": {
                 "sessionId": "sess_abc123def456",
                 "configId": "auto_approve",
+                "type": "boolean",
                 "value": true
               }
             }
@@ -504,6 +506,9 @@ class SessionConfigSelectOptionsSerializerTest {
         )
 
         val encoded = ACPJson.encodeToString(SetSessionConfigOptionRequest.serializer(), original)
+        // Verify the encoded JSON contains "type":"boolean" at top level
+        val encodedJson = ACPJson.parseToJsonElement(encoded)
+        assertEquals("boolean", encodedJson.jsonObject["type"]?.let { (it as? JsonPrimitive)?.content })
         val decoded = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), encoded)
         assertEquals(original.sessionId, decoded.sessionId)
         assertEquals(original.configId, decoded.configId)
@@ -520,6 +525,9 @@ class SessionConfigSelectOptionsSerializerTest {
         )
 
         val encoded = ACPJson.encodeToString(SetSessionConfigOptionRequest.serializer(), original)
+        // Verify the encoded JSON does NOT contain "type" field for string values
+        val encodedJson = ACPJson.parseToJsonElement(encoded)
+        assertEquals(null, encodedJson.jsonObject["type"])
         val decoded = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), encoded)
         assertEquals(original.sessionId, decoded.sessionId)
         assertEquals(original.configId, decoded.configId)
@@ -546,27 +554,39 @@ class SessionConfigSelectOptionsSerializerTest {
     }
 
     @Test
-    fun `numeric value in config option deserializes as UnknownValue`() {
-        val json = """{"sessionId":"s","configId":"c","value":42}"""
+    fun `decode set config option request without type field is backward compatible`() {
+        // Old format without "type" field should still work as StringValue
+        val json = """{"sessionId":"s","configId":"c","value":"model-1"}"""
         val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
-        val unknown = assertIs<SessionConfigOptionValue.UnknownValue>(request.value)
-        assertEquals(JsonPrimitive(42), unknown.rawElement)
+        assertEquals(SessionId("s"), request.sessionId)
+        assertEquals(SessionConfigId("c"), request.configId)
+        val stringValue = assertIs<SessionConfigOptionValue.StringValue>(request.value)
+        assertEquals("model-1", stringValue.value)
     }
 
     @Test
-    fun `array value in config option deserializes as UnknownValue`() {
-        val json = """{"sessionId":"s","configId":"c","value":["a","b"]}"""
+    fun `decode set config option request with type boolean`() {
+        val json = """{"sessionId":"s","configId":"c","type":"boolean","value":true}"""
         val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
-        assertIs<SessionConfigOptionValue.UnknownValue>(request.value)
+        val boolValue = assertIs<SessionConfigOptionValue.BoolValue>(request.value)
+        assertEquals(true, boolValue.value)
     }
 
     @Test
-    fun `object value in config option deserializes as UnknownValue`() {
-        val json = """{"sessionId":"s","configId":"c","value":{"key":"val"}}"""
+    fun `decode set config option request with unknown type falls back to UnknownValue`() {
+        val json = """{"sessionId":"s","configId":"c","type":"multi_select","value":["a","b"]}"""
         val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
         assertIs<SessionConfigOptionValue.UnknownValue>(request.value)
     }
 
+    @Test
+    fun `numeric value in config option without type deserializes as UnknownValue`() {
+        val json = """{"sessionId":"s","configId":"c","value":42}"""
+        val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
+        val unknown = assertIs<SessionConfigOptionValue.UnknownValue>(request.value)
+        assertEquals(JsonPrimitive(42), unknown.rawElement)
+    }
+
     @Test
     fun `UnknownValue roundtrip preserves raw element`() {
         val json = """{"sessionId":"s","configId":"c","value":42}"""
@@ -616,4 +636,32 @@ class SessionConfigSelectOptionsSerializerTest {
         assertEquals(true, boolValue.value)
     }
 
+    @Test
+    fun `boolean value without type field deserializes as BoolValue`() {
+        val json = """{"sessionId":"s","configId":"c","value":true}"""
+        val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
+        val boolValue = assertIs<SessionConfigOptionValue.BoolValue>(request.value)
+        assertEquals(true, boolValue.value)
+    }
+
+    @Test
+    fun `false value without type field deserializes as BoolValue`() {
+        val json = """{"sessionId":"s","configId":"c","value":false}"""
+        val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
+        val boolValue = assertIs<SessionConfigOptionValue.BoolValue>(request.value)
+        assertEquals(false, boolValue.value)
+    }
+
+    @Test
+    fun `unknown type roundtrip preserves type and value`() {
+        val json = """{"sessionId":"s","configId":"c","type":"multi_select","value":["a","b"]}"""
+        val request = ACPJson.decodeFromString(SetSessionConfigOptionRequest.serializer(), json)
+        assertIs<SessionConfigOptionValue.UnknownValue>(request.value)
+        // Re-serialize and verify the type and value are preserved
+        val encoded = ACPJson.encodeToString(SetSessionConfigOptionRequest.serializer(), request)
+        val reDecoded = ACPJson.parseToJsonElement(encoded).jsonObject
+        assertEquals("multi_select", (reDecoded["type"] as? JsonPrimitive)?.content)
+        assertNotNull(reDecoded["value"])
+    }
+
 }

build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 private val buildNumber: String? = System.getenv("GITHUB_RUN_NUMBER")
 private val isReleasePublication = System.getenv("RELEASE_PUBLICATION")?.toBoolean() ?: false
 
-private val baseVersion = "0.16.5"
+private val baseVersion = "0.16.6"
 
 allprojects {
     group = "com.agentclientprotocol"