Merge pull request #976 from devoxx/fix/task-200

fix: omit top_p parameter for GPT-5 models

Author: stephanj

backlog/tasks/task-193 - Fix-packaged-plugin-Skiko-native-runtime-mismatch.md

@@ -1,11 +1,12 @@
 ---
 id: TASK-193
 title: Fix packaged plugin Skiko native runtime mismatch
-status: In Progress
+status: Done
+priority: medium
 assignee:
   - Codex
 created_date: '2026-03-07 15:22'
-updated_date: '2026-03-07 15:29'
+updated_date: '2026-03-08 11:35'
 labels:
   - build
   - plugin-distribution
@@ -14,21 +15,19 @@ dependencies: []
 references:
   - /Users/stephan/IdeaProjects/DevoxxGenieIDEAPlugin/build.gradle.kts
   - >-
-    /Users/stephan/IdeaProjects/DevoxxGenieIDEAPlugin/build/idea-sandbox/IC-2024.3/plugins/DevoxxGenie/lib
+documentation: []
+ordinal: 1000
 ---
 
-## Description
-
 <!-- SECTION:DESCRIPTION:BEGIN -->
 The built plugin distribution currently packages Skiko AWT classes at version 0.9.37.4 while the platform-specific skiko-awt-runtime native jars are pinned to 0.8.18. On macOS this causes UnsatisfiedLinkError in MetalApiKt when the Compose tool window initializes. The build should package matching Skiko runtime artifacts so the distributed plugin starts cleanly.
 <!-- SECTION:DESCRIPTION:END -->
 
 ## Acceptance Criteria
-<!-- AC:BEGIN -->
+
 - [x] #1 The plugin build configuration no longer mixes Skiko AWT classes and skiko-awt-runtime native jars from different versions.
 - [x] #2 Rebuilding the plugin distribution produces a ZIP whose packaged Skiko runtime jars match the resolved Skiko AWT version.
 - [x] #3 The packaged plugin no longer includes the previously mismatched 0.8.18 Skiko runtime jars alongside skiko-awt 0.9.37.4.
-<!-- AC:END -->
 
 ## Implementation Plan
 
@@ -47,3 +46,4 @@ User retested the rebuilt ZIP in IDEA and still hit the same MetalApi Unsatisfie
 
 Rebuilt the plugin after stripping platform-provided Compose/Kotlin runtime jars from `prepareSandbox`. Verified that neither `build/idea-sandbox/IC-2024.3/plugins/DevoxxGenie/lib` nor `build/distributions/DevoxxGenie-1.0.0.zip` contains `skiko-*`, Compose desktop jars, `kotlin-stdlib*`, or `kotlinx-coroutines-core*` anymore. Awaiting runtime retest in IDEA.
 <!-- SECTION:NOTES:END -->
+

backlog/tasks/task-200 - OpenAI-GPT-5-does-not-support-top_p-parameter.md

@@ -0,0 +1,47 @@
+---
+id: TASK-200
+title: OpenAI GPT-5 does not support top_p parameter
+status: Done
+priority: medium
+assignee: []
+created_date: '2026-03-08 11:29'
+updated_date: '2026-03-08 11:35'
+labels:
+  - bug
+  - openai
+  - gpt-5
+dependencies: []
+references:
+  - >-
+documentation: []
+ordinal: 1000
+---
+
+<!-- SECTION:DESCRIPTION:BEGIN -->
+When using OpenAI GPT-5, the plugin sends the `top_p` parameter which is not supported by this model, causing a runtime error.
+
+**Error:**
+```
+ExecutionException - Error occurred while processing chat message
+Caused by: CompletionException - com.devoxx.genie.service.prompt.error.ModelException: Provider unavailable:
+{
+  "error": {
+    "message": "Unsupported parameter: 'top_p' is not supported with this model.",
+    "type": "invalid_request_error",
+    "param": "top_p",
+    "code": "unsupported_parameter"
+  }
+}
+```
+
+**Root Cause:** The OpenAI chat model factory sends `top_p` as a parameter when building the chat model request, but GPT-5 does not accept it.
+
+**Suggested Fix:** Conditionally omit `top_p` (and potentially `top_k`) for models that don't support these parameters. This could be handled in the `OpenAiChatModelFactory` by checking the model name or by catching the error and retrying without the unsupported parameter.
+<!-- SECTION:DESCRIPTION:END -->
+
+## Acceptance Criteria
+
+- [ ] #1 GPT-5 model works without top_p error
+- [ ] #2 Other OpenAI models that support top_p continue to work as before
+- [ ] #3 No regression in other cloud providers
+

src/main/java/com/devoxx/genie/chatmodel/cloud/openai/OpenAIChatModelFactory.java

@@ -47,12 +47,18 @@ public List<LanguageModel> getModels() {
     }
 
     private ChatRequestParameters createChatContextParameters(@NotNull CustomChatModel customChatModel) {
-        boolean isO1 = customChatModel.getModelName().toLowerCase().startsWith("o1");
-        boolean isO3 = customChatModel.getModelName().toLowerCase().startsWith("o3");
+        String modelName = customChatModel.getModelName().toLowerCase();
+        boolean isReasoningModel = modelName.startsWith("o1") || modelName.startsWith("o3");
+        boolean isGpt5 = modelName.startsWith("gpt-5");
 
-        if (isO1 || isO3) {
+        if (isReasoningModel) {
             // o1 and o3 models do not support temperature and topP
             return ChatRequestParameters.builder().build();
+        } else if (isGpt5) {
+            // GPT-5 supports temperature but not topP
+            return ChatRequestParameters.builder()
+                    .temperature(customChatModel.getTemperature())
+                    .build();
         } else {
             return ChatRequestParameters.builder()
                     .temperature(customChatModel.getTemperature())

src/test/java/com/devoxx/genie/chatmodel/cloud/openai/OpenAiChatModelFactoryTest.java

@@ -9,10 +9,12 @@
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.testFramework.ServiceContainerUtil;
 import dev.langchain4j.model.chat.ChatModel;
+import dev.langchain4j.model.chat.request.ChatRequestParameters;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import java.lang.reflect.Method;
 import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -67,6 +69,60 @@ void getModels() {
         assertThat(models).size().isGreaterThan(7);
     }
 
+    @Test
+    void createChatModel_gpt5_omitsTopP() throws Exception {
+        OpenAIChatModelFactory factory = new OpenAIChatModelFactory();
+
+        Method method = OpenAIChatModelFactory.class.getDeclaredMethod("createChatContextParameters", CustomChatModel.class);
+        method.setAccessible(true);
+
+        CustomChatModel customChatModel = new CustomChatModel();
+        customChatModel.setModelName("gpt-5");
+        customChatModel.setTemperature(0.7);
+        customChatModel.setTopP(0.9);
+
+        ChatRequestParameters params = (ChatRequestParameters) method.invoke(factory, customChatModel);
+
+        assertThat(params.temperature()).isEqualTo(0.7);
+        assertThat(params.topP()).isNull();
+    }
+
+    @Test
+    void createChatModel_o1_omitsTemperatureAndTopP() throws Exception {
+        OpenAIChatModelFactory factory = new OpenAIChatModelFactory();
+
+        Method method = OpenAIChatModelFactory.class.getDeclaredMethod("createChatContextParameters", CustomChatModel.class);
+        method.setAccessible(true);
+
+        CustomChatModel customChatModel = new CustomChatModel();
+        customChatModel.setModelName("o1");
+        customChatModel.setTemperature(0.7);
+        customChatModel.setTopP(0.9);
+
+        ChatRequestParameters params = (ChatRequestParameters) method.invoke(factory, customChatModel);
+
+        assertThat(params.temperature()).isNull();
+        assertThat(params.topP()).isNull();
+    }
+
+    @Test
+    void createChatModel_gpt4_includesTopP() throws Exception {
+        OpenAIChatModelFactory factory = new OpenAIChatModelFactory();
+
+        Method method = OpenAIChatModelFactory.class.getDeclaredMethod("createChatContextParameters", CustomChatModel.class);
+        method.setAccessible(true);
+
+        CustomChatModel customChatModel = new CustomChatModel();
+        customChatModel.setModelName("gpt-4o");
+        customChatModel.setTemperature(0.7);
+        customChatModel.setTopP(0.9);
+
+        ChatRequestParameters params = (ChatRequestParameters) method.invoke(factory, customChatModel);
+
+        assertThat(params.temperature()).isEqualTo(0.7);
+        assertThat(params.topP()).isEqualTo(0.9);
+    }
+
     private static LanguageModel model(String modelName) {
         return LanguageModel.builder()
             .provider(ModelProvider.OpenAI)