diff --git a/agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java b/agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java
index 2de490fa0..3622ded47 100644
--- a/agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java
+++ b/agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java
@@ -136,6 +136,7 @@ public class ReActAgent extends StructuredOutputCapableAgent {
     private final String sysPrompt;
     private final Model model;
     private final int maxIters;
+    private final GenerateOptions generateOptions;
     private final ExecutionConfig modelExecutionConfig;
     private final ExecutionConfig toolExecutionConfig;
     private final PlanNotebook planNotebook;
@@ -157,6 +158,7 @@ private ReActAgent(Builder builder, Toolkit agentToolkit) {
         this.sysPrompt = builder.sysPrompt;
         this.model = builder.model;
         this.maxIters = builder.maxIters;
+        this.generateOptions = builder.generateOptions;
         this.modelExecutionConfig = builder.modelExecutionConfig;
         this.toolExecutionConfig = builder.toolExecutionConfig;
         this.planNotebook = builder.planNotebook;
@@ -786,11 +788,14 @@ private List<ToolUseBlock> extractPendingToolCalls() {
 
     @Override
     protected GenerateOptions buildGenerateOptions() {
-        GenerateOptions.Builder builder = GenerateOptions.builder();
-        if (modelExecutionConfig != null) {
-            builder.executionConfig(modelExecutionConfig);
-        }
-        return builder.build();
+        // Build options with modelExecutionConfig (timeout, retry, etc.)
+        GenerateOptions executionOptions =
+                modelExecutionConfig != null
+                        ? GenerateOptions.builder().executionConfig(modelExecutionConfig).build()
+                        : null;
+        // Merge: user's generateOptions (temperature, topP, maxTokens, etc.) as base,
+        // executionOptions overrides executionConfig
+        return GenerateOptions.mergeOptions(executionOptions, generateOptions);
     }
 
     // ==================== Hook Notification Methods ====================
@@ -807,7 +812,8 @@ private <T extends HookEvent> Mono<T> notifyHooks(T event) {
     }
 
     private Mono<PreReasoningEvent> notifyPreReasoningEvent(List<Msg> msgs) {
-        return notifyHooks(new PreReasoningEvent(this, model.getModelName(), null, msgs));
+        return notifyHooks(
+                new PreReasoningEvent(this, model.getModelName(), buildGenerateOptions(), msgs));
     }
 
     private Mono<PostReasoningEvent> notifyPostReasoning(Msg msg) {
@@ -977,6 +983,7 @@ public static class Builder {
         private Toolkit toolkit = new Toolkit();
         private Memory memory = new InMemoryMemory();
         private int maxIters = 10;
+        private GenerateOptions generateOptions;
         private ExecutionConfig modelExecutionConfig;
         private ExecutionConfig toolExecutionConfig;
         private final Set<Hook> hooks = new LinkedHashSet<>();
@@ -1124,6 +1131,22 @@ public Builder enableMetaTool(boolean enableMetaTool) {
             return this;
         }
 
+        /**
+         * Sets the generation options for model API calls.
+         *
+         * <p>This configuration includes generation parameters such as temperature, topP,
+         * maxTokens, etc. When set, these options will be passed to the model and recorded
+         * in trace spans (e.g., gen_ai.request.temperature for OpenTelemetry).
+         *
+         * @param generateOptions The generation options (temperature, topP, maxTokens, etc.)
+         * @return This builder instance for method chaining
+         * @see GenerateOptions
+         */
+        public Builder generateOptions(GenerateOptions generateOptions) {
+            this.generateOptions = generateOptions;
+            return this;
+        }
+
         /**
          * Sets the execution configuration for model API calls.
          *
diff --git a/agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentTest.java b/agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentTest.java
index 46536c692..433b4a262 100644
--- a/agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentTest.java
+++ b/agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentTest.java
@@ -36,6 +36,7 @@
 import io.agentscope.core.message.ToolUseBlock;
 import io.agentscope.core.model.ChatResponse;
 import io.agentscope.core.model.ChatUsage;
+import io.agentscope.core.model.GenerateOptions;
 import io.agentscope.core.tool.Toolkit;
 import io.agentscope.core.util.JsonUtils;
 import java.time.Duration;
@@ -101,6 +102,34 @@ void testInitialization() {
         assertTrue(agent.getMemory().getMessages().isEmpty(), "Memory should be empty initially");
     }
 
+    @Test
+    @DisplayName("Should pass generateOptions (temperature, topP, maxTokens) to model for tracing")
+    void testGenerateOptionsPassedToModel() {
+        GenerateOptions options =
+                GenerateOptions.builder().temperature(0.7).topP(0.9).maxTokens(1000).build();
+
+        ReActAgent agentWithOptions =
+                ReActAgent.builder()
+                        .name(TestConstants.TEST_REACT_AGENT_NAME)
+                        .sysPrompt(TestConstants.DEFAULT_SYS_PROMPT)
+                        .model(mockModel)
+                        .toolkit(mockToolkit)
+                        .memory(memory)
+                        .generateOptions(options)
+                        .build();
+
+        Msg userMsg = TestUtils.createUserMessage("User", TestConstants.TEST_USER_INPUT);
+        agentWithOptions
+                .call(userMsg)
+                .block(Duration.ofMillis(TestConstants.DEFAULT_TEST_TIMEOUT_MS));
+
+        GenerateOptions lastOptions = mockModel.getLastOptions();
+        assertNotNull(lastOptions, "Model should receive GenerateOptions");
+        assertEquals(0.7, lastOptions.getTemperature(), "Temperature should be passed to model");
+        assertEquals(0.9, lastOptions.getTopP(), "TopP should be passed to model");
+        assertEquals(1000, lastOptions.getMaxTokens(), "MaxTokens should be passed to model");
+    }
+
     @Test
     @DisplayName("Should generate simple text response")
     void testSimpleReply() {