fix(model): apply thinkingBudget to OpenAI-compatible API request

agentscope-core/src/main/java/io/agentscope/core/formatter/openai/OpenAIChatFormatter.java

@@ -81,6 +81,13 @@ public void applyOptions(
             request.setReasoningEffort(reasoningEffort);
         }
 
+        // Apply thinking budget
+        Integer thinkingBudget =
+                getOptionOrDefault(options, defaultOptions, GenerateOptions::getThinkingBudget);
+        if (thinkingBudget != null) {
+            request.setThinkingBudget(thinkingBudget);
+        }
+
         // Apply top_p
         Double topP = getOptionOrDefault(options, defaultOptions, GenerateOptions::getTopP);
         if (topP != null) {

agentscope-core/src/main/java/io/agentscope/core/formatter/openai/dto/OpenAIRequest.java

@@ -128,6 +128,17 @@ public class OpenAIRequest {
     @JsonProperty("reasoning_effort")
     private String reasoningEffort;
 
+    /**
+     * Maximum tokens allocated for the model's internal thinking/reasoning process.
+     * Supported by OpenAI-compatible providers that expose a thinking budget parameter
+     * (e.g., Alibaba Cloud Bailian/DashScope Qwen3 series via {@code thinking_budget}).
+     * When set, the model is prevented from spending more than this many tokens on
+     * reasoning, leaving the remainder of {@code max_completion_tokens} for the
+     * visible response.
+     */
+    @JsonProperty("thinking_budget")
+    private Integer thinkingBudget;
+
     /**
      * Controls whether to allow parallel tool calls.
      * Set to false to disable parallel tool calling.
@@ -345,6 +356,14 @@ public void setReasoningEffort(String reasoningEffort) {
         this.reasoningEffort = reasoningEffort;
     }
 
+    public Integer getThinkingBudget() {
+        return thinkingBudget;
+    }
+
+    public void setThinkingBudget(Integer thinkingBudget) {
+        this.thinkingBudget = thinkingBudget;
+    }
+
     public Boolean getParallelToolCalls() {
         return parallelToolCalls;
     }
@@ -554,6 +573,11 @@ public Builder reasoningEffort(String reasoningEffort) {
             return this;
         }
 
+        public Builder thinkingBudget(Integer thinkingBudget) {
+            request.setThinkingBudget(thinkingBudget);
+            return this;
+        }
+
         public Builder parallelToolCalls(Boolean parallelToolCalls) {
             request.setParallelToolCalls(parallelToolCalls);
             return this;

agentscope-core/src/test/java/io/agentscope/core/formatter/openai/OpenAIChatFormatterTest.java

@@ -379,6 +379,64 @@ void testApplyToolsWithNullStrict() {
         }
     }
 
+    @Nested
+    @DisplayName("thinkingBudget Tests")
+    class ThinkingBudgetTests {
+
+        @Test
+        @DisplayName("Should apply thinkingBudget from GenerateOptions")
+        void testApplyThinkingBudget() {
+            OpenAIRequest request =
+                    OpenAIRequest.builder().model("qwen3.7-max").messages(List.of()).build();
+
+            GenerateOptions options = GenerateOptions.builder().thinkingBudget(4096).build();
+
+            formatter.applyOptions(request, options, null);
+
+            assertEquals(4096, request.getThinkingBudget());
+        }
+
+        @Test
+        @DisplayName("Should apply thinkingBudget from defaultOptions when options is null")
+        void testApplyThinkingBudgetFromDefault() {
+            OpenAIRequest request =
+                    OpenAIRequest.builder().model("qwen3.7-max").messages(List.of()).build();
+
+            GenerateOptions defaultOptions = GenerateOptions.builder().thinkingBudget(2048).build();
+
+            formatter.applyOptions(request, null, defaultOptions);
+
+            assertEquals(2048, request.getThinkingBudget());
+        }
+
+        @Test
+        @DisplayName("Options thinkingBudget should override defaultOptions")
+        void testThinkingBudgetOptionsOverridesDefault() {
+            OpenAIRequest request =
+                    OpenAIRequest.builder().model("qwen3.7-max").messages(List.of()).build();
+
+            GenerateOptions defaultOptions = GenerateOptions.builder().thinkingBudget(1000).build();
+            GenerateOptions options = GenerateOptions.builder().thinkingBudget(8000).build();
+
+            formatter.applyOptions(request, options, defaultOptions);
+
+            assertEquals(8000, request.getThinkingBudget());
+        }
+
+        @Test
+        @DisplayName("Should not set thinkingBudget when not specified")
+        void testThinkingBudgetNotSetWhenAbsent() {
+            OpenAIRequest request =
+                    OpenAIRequest.builder().model("gpt-4o").messages(List.of()).build();
+
+            GenerateOptions options = GenerateOptions.builder().temperature(0.7).build();
+
+            formatter.applyOptions(request, options, null);
+
+            assertNull(request.getThinkingBudget());
+        }
+    }
+
     @Nested
     @DisplayName("applyAdditionalBodyParams Tests")
     class ApplyAdditionalBodyParamsTests {