diff --git a/amber/src/test/scala/org/apache/texera/web/resource/aiassistant/AiAssistantManagerSpec.scala b/amber/src/test/scala/org/apache/texera/web/resource/aiassistant/AiAssistantManagerSpec.scala
new file mode 100644
index 00000000000..a14b5a4b11b
--- /dev/null
+++ b/amber/src/test/scala/org/apache/texera/web/resource/aiassistant/AiAssistantManagerSpec.scala
@@ -0,0 +1,102 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.texera.web.resource.aiassistant
+
+import com.sun.net.httpserver.{HttpExchange, HttpHandler, HttpServer}
+import org.scalatest.PrivateMethodTester
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+import java.net.InetSocketAddress
+import java.util.concurrent.atomic.AtomicReference
+
+class AiAssistantManagerSpec extends AnyFlatSpec with Matchers with PrivateMethodTester {
+
+  private val initOpenAI = PrivateMethod[String](Symbol("initOpenAI"))
+
+  private def initializeOpenAI(): String = AiAssistantManager invokePrivate initOpenAI()
+
+  private def withAssistantConfiguration[T](
+      accountKey: String,
+      sharedUrl: String
+  )(test: => T): T = {
+    val originalAccountKey = AiAssistantManager.accountKey
+    val originalSharedUrl = AiAssistantManager.sharedUrl
+    AiAssistantManager.accountKey = accountKey
+    AiAssistantManager.sharedUrl = sharedUrl
+    try {
+      test
+    } finally {
+      AiAssistantManager.accountKey = originalAccountKey
+      AiAssistantManager.sharedUrl = originalSharedUrl
+    }
+  }
+
+  private def withModelsServer(statusCode: Int)(
+      test: (String, AtomicReference[String], AtomicReference[String]) => Unit
+  ): Unit = {
+    val requestMethod = new AtomicReference[String]()
+    val authorization = new AtomicReference[String]()
+    val server = HttpServer.create(new InetSocketAddress("127.0.0.1", 0), 0)
+    server.createContext(
+      "/models",
+      new HttpHandler {
+        override def handle(exchange: HttpExchange): Unit = {
+          requestMethod.set(exchange.getRequestMethod)
+          authorization.set(exchange.getRequestHeaders.getFirst("Authorization"))
+          exchange.sendResponseHeaders(statusCode, -1)
+          exchange.close()
+        }
+      }
+    )
+    server.start()
+    try {
+      val serverUrl = s"http://127.0.0.1:${server.getAddress.getPort}"
+      test(serverUrl, requestMethod, authorization)
+    } finally {
+      server.stop(0)
+    }
+  }
+
+  "initOpenAI" should "accept a successful models response with a normalized bearer key" in {
+    withModelsServer(200) { (serverUrl, requestMethod, authorization) =>
+      withAssistantConfiguration("  \"test-key\"  ", serverUrl) {
+        initializeOpenAI() shouldBe "OpenAI"
+      }
+
+      requestMethod.get() shouldBe "GET"
+      authorization.get() shouldBe "Bearer test-key"
+    }
+  }
+
+  it should "reject a non-successful models response" in {
+    withModelsServer(503) { (serverUrl, _, _) =>
+      withAssistantConfiguration("test-key", serverUrl) {
+        initializeOpenAI() shouldBe "NoAiAssistant"
+      }
+    }
+  }
+
+  it should "fall back when the configured service URL is malformed" in {
+    withAssistantConfiguration("test-key", "not a valid URL") {
+      initializeOpenAI() shouldBe "NoAiAssistant"
+    }
+  }
+}