fix(core): Make HTTP version configurable

Author: guanxuc

agentscope-core/src/main/java/io/agentscope/core/model/transport/HttpTransportConfig.java

@@ -41,6 +41,7 @@ public class HttpTransportConfig {
     private final Duration keepAliveDuration;
     private final boolean ignoreSsl;
     private final ProxyConfig proxyConfig;
+    private final HttpVersion httpVersion;
 
     private HttpTransportConfig(Builder builder) {
         this.connectTimeout = builder.connectTimeout;
@@ -50,6 +51,7 @@ private HttpTransportConfig(Builder builder) {
         this.keepAliveDuration = builder.keepAliveDuration;
         this.ignoreSsl = builder.ignoreSsl;
         this.proxyConfig = builder.proxyConfig;
+        this.httpVersion = builder.httpVersion;
     }
 
     /**
@@ -119,6 +121,15 @@ public ProxyConfig getProxyConfig() {
         return proxyConfig;
     }
 
+    /**
+     * Get the HTTP version.
+     *
+     * @return the HTTP version
+     */
+    public HttpVersion getHttpVersion() {
+        return httpVersion;
+    }
+
     /**
      * Create a new builder for HttpTransportConfig.
      *
@@ -148,6 +159,7 @@ public static class Builder {
         private Duration keepAliveDuration = Duration.ofMinutes(5);
         private boolean ignoreSsl = false;
         private ProxyConfig proxyConfig = null;
+        private HttpVersion httpVersion = HttpVersion.HTTP_2;
 
         /**
          * Set the connect timeout.
@@ -232,6 +244,17 @@ public Builder proxy(ProxyConfig proxyConfig) {
             return this;
         }
 
+        /**
+         * Set the HTTP version to use.
+         *
+         * @param httpVersion the HTTP version
+         * @return this builder
+         */
+        public Builder httpVersion(HttpVersion httpVersion) {
+            this.httpVersion = httpVersion;
+            return this;
+        }
+
         /**
          * Build the HttpTransportConfig.
          *

agentscope-core/src/main/java/io/agentscope/core/model/transport/HttpVersion.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.core.model.transport;
+
+import java.net.http.HttpClient;
+
+/**
+ * HTTP version.
+ */
+public enum HttpVersion {
+
+    /**
+     * HTTP version 1.1
+     */
+    HTTP_1_1,
+
+    /**
+     * HTTP version 2
+     */
+    HTTP_2;
+
+    public HttpClient.Version toJdkHttpVersion() {
+        return switch (this) {
+            case HTTP_1_1 -> HttpClient.Version.HTTP_1_1;
+            case HTTP_2 -> HttpClient.Version.HTTP_2;
+        };
+    }
+}

agentscope-core/src/main/java/io/agentscope/core/model/transport/JdkHttpTransport.java

@@ -27,7 +27,6 @@
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpClient.Redirect;
-import java.net.http.HttpClient.Version;
 import java.net.http.HttpResponse.BodyHandlers;
 import java.nio.charset.StandardCharsets;
 import java.security.KeyManagementException;
@@ -111,7 +110,7 @@ public JdkHttpTransport(HttpClient client, HttpTransportConfig config) {
     private static HttpClient buildClient(HttpTransportConfig config) {
         HttpClient.Builder builder =
                 HttpClient.newBuilder()
-                        .version(Version.HTTP_2)
+                        .version(config.getHttpVersion().toJdkHttpVersion())
                         .followRedirects(Redirect.NORMAL)
                         .connectTimeout(config.getConnectTimeout());
 

agentscope-core/src/test/java/io/agentscope/core/model/transport/JdkHttpTransportTest.java

@@ -18,6 +18,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -1047,4 +1048,19 @@ void testStreamNdJsonFormatWithoutHeaderDefaultsToSse() {
                         "{\"id\":\"2\",\"text\":\"World\"}") // This is sent before [DONE] marker
                 .verifyComplete();
     }
+
+    @Test
+    void testHttpVersionConfig() {
+        HttpTransportConfig defaults = HttpTransportConfig.defaults();
+        HttpTransportConfig config =
+                HttpTransportConfig.builder().httpVersion(HttpVersion.HTTP_1_1).build();
+        JdkHttpTransport jdkHttpTransport = JdkHttpTransport.builder().config(defaults).build();
+        JdkHttpTransport jdkHttpTransport2 = JdkHttpTransport.builder().config(config).build();
+        assertSame(HttpVersion.HTTP_2, defaults.getHttpVersion());
+        assertEquals(HttpClient.Version.HTTP_2, defaults.getHttpVersion().toJdkHttpVersion());
+        assertSame(HttpVersion.HTTP_1_1, config.getHttpVersion());
+        assertEquals(HttpClient.Version.HTTP_1_1, config.getHttpVersion().toJdkHttpVersion());
+        assertNotNull(jdkHttpTransport);
+        assertNotNull(jdkHttpTransport2);
+    }
 }