diff --git a/FirebaseAI.podspec b/FirebaseAI.podspec
index 0df48cf0a70..65fa42d28f6 100644
--- a/FirebaseAI.podspec
+++ b/FirebaseAI.podspec
@@ -63,7 +63,7 @@ Build AI-powered apps and features with the Gemini API using the Firebase AI SDK
       unit_tests_dir + 'Snippets/**/*.swift',
     ]
     unit_tests.resources = [
-      unit_tests_dir + 'vertexai-sdk-test-data/mock-responses/vertexai',
+      unit_tests_dir + 'vertexai-sdk-test-data/mock-responses',
       unit_tests_dir + 'Resources/**/*',
     ]
   end
diff --git a/FirebaseAI/Tests/Unit/ChatTests.swift b/FirebaseAI/Tests/Unit/ChatTests.swift
index 72dd14fa448..40373a47494 100644
--- a/FirebaseAI/Tests/Unit/ChatTests.swift
+++ b/FirebaseAI/Tests/Unit/ChatTests.swift
@@ -40,57 +40,58 @@ final class ChatTests: XCTestCase {
     let fileURL = try XCTUnwrap(bundle.url(
       forResource: "streaming-success-basic-reply-parts",
       withExtension: "txt",
-      subdirectory: "vertexai"
+      subdirectory: "mock-responses/vertexai"
     ))
 
     // Skip tests using MockURLProtocol on watchOS; unsupported in watchOS 2 and later, see
     // https://developer.apple.com/documentation/foundation/urlprotocol for details.
     #if os(watchOS)
       throw XCTSkip("Custom URL protocols are unsupported in watchOS 2 and later.")
-    #endif // os(watchOS)
-    MockURLProtocol.requestHandler = { request in
-      let response = HTTPURLResponse(
-        url: request.url!,
-        statusCode: 200,
-        httpVersion: nil,
-        headerFields: nil
-      )!
-      return (response, fileURL.lines)
-    }
+    #else // os(watchOS)
+      MockURLProtocol.requestHandler = { request in
+        let response = HTTPURLResponse(
+          url: request.url!,
+          statusCode: 200,
+          httpVersion: nil,
+          headerFields: nil
+        )!
+        return (response, fileURL.lines)
+      }
 
-    let app = FirebaseApp(instanceWithName: "testApp",
-                          options: FirebaseOptions(googleAppID: "ignore",
-                                                   gcmSenderID: "ignore"))
-    let model = GenerativeModel(
-      modelName: modelName,
-      modelResourceName: modelResourceName,
-      firebaseInfo: FirebaseInfo(
-        projectID: "my-project-id",
-        apiKey: "API_KEY",
-        firebaseAppID: "My app ID",
-        firebaseApp: app
-      ),
-      apiConfig: FirebaseAI.defaultVertexAIAPIConfig,
-      tools: nil,
-      requestOptions: RequestOptions(),
-      urlSession: urlSession
-    )
-    let chat = Chat(model: model, history: [])
-    let input = "Test input"
-    let stream = try chat.sendMessageStream(input)
+      let app = FirebaseApp(instanceWithName: "testApp",
+                            options: FirebaseOptions(googleAppID: "ignore",
+                                                     gcmSenderID: "ignore"))
+      let model = GenerativeModel(
+        modelName: modelName,
+        modelResourceName: modelResourceName,
+        firebaseInfo: FirebaseInfo(
+          projectID: "my-project-id",
+          apiKey: "API_KEY",
+          firebaseAppID: "My app ID",
+          firebaseApp: app
+        ),
+        apiConfig: FirebaseAI.defaultVertexAIAPIConfig,
+        tools: nil,
+        requestOptions: RequestOptions(),
+        urlSession: urlSession
+      )
+      let chat = Chat(model: model, history: [])
+      let input = "Test input"
+      let stream = try chat.sendMessageStream(input)
 
-    // Ensure the values are parsed correctly
-    for try await value in stream {
-      XCTAssertNotNil(value.text)
-    }
+      // Ensure the values are parsed correctly
+      for try await value in stream {
+        XCTAssertNotNil(value.text)
+      }
 
-    XCTAssertEqual(chat.history.count, 2)
-    let part = try XCTUnwrap(chat.history[0].parts[0])
-    let textPart = try XCTUnwrap(part as? TextPart)
-    XCTAssertEqual(textPart.text, input)
+      XCTAssertEqual(chat.history.count, 2)
+      let part = try XCTUnwrap(chat.history[0].parts[0])
+      let textPart = try XCTUnwrap(part as? TextPart)
+      XCTAssertEqual(textPart.text, input)
 
-    let finalText = "1 2 3 4 5 6 7 8"
-    let assembledExpectation = ModelContent(role: "model", parts: finalText)
-    XCTAssertEqual(chat.history[1], assembledExpectation)
+      let finalText = "1 2 3 4 5 6 7 8"
+      let assembledExpectation = ModelContent(role: "model", parts: finalText)
+      XCTAssertEqual(chat.history[1], assembledExpectation)
+    #endif // os(watchOS)
   }
 }
diff --git a/FirebaseAI/Tests/Unit/Fakes/AppCheckInteropFake.swift b/FirebaseAI/Tests/Unit/Fakes/AppCheckInteropFake.swift
new file mode 100644
index 00000000000..62fc753ae68
--- /dev/null
+++ b/FirebaseAI/Tests/Unit/Fakes/AppCheckInteropFake.swift
@@ -0,0 +1,66 @@
+// Copyright 2025 Google LLC
+//
+// 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.
+
+import FirebaseAppCheckInterop
+import Foundation
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+class AppCheckInteropFake: NSObject, AppCheckInterop {
+  /// The placeholder token value returned when an error occurs
+  static let placeholderTokenValue = "placeholder-token"
+
+  var token: String
+  var error: Error?
+
+  private init(token: String, error: Error?) {
+    self.token = token
+    self.error = error
+  }
+
+  convenience init(token: String) {
+    self.init(token: token, error: nil)
+  }
+
+  convenience init(error: Error) {
+    self.init(token: AppCheckInteropFake.placeholderTokenValue, error: error)
+  }
+
+  func getToken(forcingRefresh: Bool) async -> any FIRAppCheckTokenResultInterop {
+    return AppCheckTokenResultInteropFake(token: token, error: error)
+  }
+
+  func tokenDidChangeNotificationName() -> String {
+    fatalError("\(#function) not implemented.")
+  }
+
+  func notificationTokenKey() -> String {
+    fatalError("\(#function) not implemented.")
+  }
+
+  func notificationAppNameKey() -> String {
+    fatalError("\(#function) not implemented.")
+  }
+
+  private class AppCheckTokenResultInteropFake: NSObject, FIRAppCheckTokenResultInterop {
+    var token: String
+    var error: Error?
+
+    init(token: String, error: Error?) {
+      self.token = token
+      self.error = error
+    }
+  }
+}
+
+struct AppCheckErrorFake: Error {}
diff --git a/FirebaseAI/Tests/Unit/GenerativeModelGoogleAITests.swift b/FirebaseAI/Tests/Unit/GenerativeModelGoogleAITests.swift
new file mode 100644
index 00000000000..130dc47b8b4
--- /dev/null
+++ b/FirebaseAI/Tests/Unit/GenerativeModelGoogleAITests.swift
@@ -0,0 +1,392 @@
+// Copyright 2025 Google LLC
+//
+// 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.
+
+import FirebaseAppCheckInterop
+import FirebaseAuthInterop
+import FirebaseCore
+import XCTest
+
+@testable import FirebaseAI
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+final class GenerativeModelGoogleAITests: XCTestCase {
+  let testPrompt = "What sorts of questions can I ask you?"
+  let safetyRatingsNegligible: [SafetyRating] = [
+    .init(
+      category: .sexuallyExplicit,
+      probability: .negligible,
+      probabilityScore: 0.0,
+      severity: SafetyRating.HarmSeverity(rawValue: "HARM_SEVERITY_UNSPECIFIED"),
+      severityScore: 0.0,
+      blocked: false
+    ),
+    .init(
+      category: .hateSpeech,
+      probability: .negligible,
+      probabilityScore: 0.0,
+      severity: SafetyRating.HarmSeverity(rawValue: "HARM_SEVERITY_UNSPECIFIED"),
+      severityScore: 0.0,
+      blocked: false
+    ),
+    .init(
+      category: .harassment,
+      probability: .negligible,
+      probabilityScore: 0.0,
+      severity: SafetyRating.HarmSeverity(rawValue: "HARM_SEVERITY_UNSPECIFIED"),
+      severityScore: 0.0,
+      blocked: false
+    ),
+    .init(
+      category: .dangerousContent,
+      probability: .negligible,
+      probabilityScore: 0.0,
+      severity: SafetyRating.HarmSeverity(rawValue: "HARM_SEVERITY_UNSPECIFIED"),
+      severityScore: 0.0,
+      blocked: false
+    ),
+  ].sorted()
+  let testModelName = "test-model"
+  let testModelResourceName = "projects/test-project-id/models/test-model"
+  let apiConfig = FirebaseAI.defaultVertexAIAPIConfig
+
+  let googleAISubdirectory = "mock-responses/googleai"
+
+  var urlSession: URLSession!
+  var model: GenerativeModel!
+
+  override func setUp() async throws {
+    let configuration = URLSessionConfiguration.default
+    configuration.protocolClasses = [MockURLProtocol.self]
+    urlSession = try XCTUnwrap(URLSession(configuration: configuration))
+    model = GenerativeModel(
+      modelName: testModelName,
+      modelResourceName: testModelResourceName,
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
+      apiConfig: apiConfig,
+      tools: nil,
+      requestOptions: RequestOptions(),
+      urlSession: urlSession
+    )
+  }
+
+  override func tearDown() {
+    MockURLProtocol.requestHandler = nil
+  }
+
+  // MARK: - Generate Content
+
+  func testGenerateContent_success_basicReplyLong() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-success-basic-reply-long",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    let response = try await model.generateContent(testPrompt)
+
+    XCTAssertEqual(response.candidates.count, 1)
+    let candidate = try XCTUnwrap(response.candidates.first)
+    let finishReason = try XCTUnwrap(candidate.finishReason)
+    XCTAssertEqual(finishReason, .stop)
+    XCTAssertEqual(candidate.safetyRatings.count, 4)
+    XCTAssertEqual(candidate.content.parts.count, 1)
+    let part = try XCTUnwrap(candidate.content.parts.first)
+    let partText = try XCTUnwrap(part as? TextPart).text
+    XCTAssertTrue(partText.hasPrefix("Making professional-quality"))
+    XCTAssertEqual(response.text, partText)
+    XCTAssertEqual(response.functionCalls, [])
+    XCTAssertEqual(response.inlineDataParts, [])
+  }
+
+  func testGenerateContent_success_basicReplyShort() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-success-basic-reply-short",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    let response = try await model.generateContent(testPrompt)
+
+    XCTAssertEqual(response.candidates.count, 1)
+    let candidate = try XCTUnwrap(response.candidates.first)
+    let finishReason = try XCTUnwrap(candidate.finishReason)
+    XCTAssertEqual(finishReason, .stop)
+    XCTAssertEqual(candidate.safetyRatings.sorted(), safetyRatingsNegligible)
+    XCTAssertEqual(candidate.content.parts.count, 1)
+    let part = try XCTUnwrap(candidate.content.parts.first)
+    let textPart = try XCTUnwrap(part as? TextPart)
+    XCTAssertTrue(textPart.text.hasPrefix("Google's headquarters"))
+    XCTAssertEqual(response.text, textPart.text)
+    XCTAssertEqual(response.functionCalls, [])
+    XCTAssertEqual(response.inlineDataParts, [])
+  }
+
+  func testGenerateContent_success_citations() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-success-citations",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    let response = try await model.generateContent(testPrompt)
+
+    XCTAssertEqual(response.candidates.count, 1)
+    let candidate = try XCTUnwrap(response.candidates.first)
+    XCTAssertEqual(candidate.content.parts.count, 1)
+    let text = try XCTUnwrap(response.text)
+    XCTAssertTrue(text.hasPrefix("Okay, let's break down quantum mechanics."))
+    let citationMetadata = try XCTUnwrap(candidate.citationMetadata)
+    XCTAssertEqual(citationMetadata.citations.count, 4)
+    let citationSource1 = try XCTUnwrap(citationMetadata.citations[0])
+    XCTAssertEqual(citationSource1.uri, "https://www.example.com/some-citation-1")
+    XCTAssertEqual(citationSource1.startIndex, 548)
+    XCTAssertEqual(citationSource1.endIndex, 690)
+    XCTAssertNil(citationSource1.title)
+    XCTAssertEqual(citationSource1.license, "mit")
+    XCTAssertNil(citationSource1.publicationDate)
+    let citationSource2 = try XCTUnwrap(citationMetadata.citations[1])
+    XCTAssertEqual(citationSource2.uri, "https://www.example.com/some-citation-1")
+    XCTAssertEqual(citationSource2.startIndex, 1240)
+    XCTAssertEqual(citationSource2.endIndex, 1407)
+    XCTAssertNil(citationSource2.title, "some-citation-2")
+    XCTAssertNil(citationSource2.license)
+    XCTAssertNil(citationSource2.publicationDate)
+    let citationSource3 = try XCTUnwrap(citationMetadata.citations[2])
+    XCTAssertEqual(citationSource3.startIndex, 1942)
+    XCTAssertEqual(citationSource3.endIndex, 2149)
+    XCTAssertNil(citationSource3.uri)
+    XCTAssertNil(citationSource3.license)
+    XCTAssertNil(citationSource3.title)
+    XCTAssertNil(citationSource3.publicationDate)
+    let citationSource4 = try XCTUnwrap(citationMetadata.citations[3])
+    XCTAssertEqual(citationSource4.startIndex, 2036)
+    XCTAssertEqual(citationSource4.endIndex, 2175)
+    XCTAssertNil(citationSource4.uri)
+    XCTAssertNil(citationSource4.license)
+    XCTAssertNil(citationSource4.title)
+    XCTAssertNil(citationSource4.publicationDate)
+  }
+
+  func testGenerateContent_usageMetadata() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-success-basic-reply-short",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    let response = try await model.generateContent(testPrompt)
+
+    let usageMetadata = try XCTUnwrap(response.usageMetadata)
+    XCTAssertEqual(usageMetadata.promptTokenCount, 7)
+    XCTAssertEqual(usageMetadata.promptTokensDetails.count, 1)
+    XCTAssertEqual(usageMetadata.promptTokensDetails[0].modality, .text)
+    XCTAssertEqual(usageMetadata.promptTokensDetails[0].tokenCount, 7)
+    XCTAssertEqual(usageMetadata.candidatesTokenCount, 22)
+    XCTAssertEqual(usageMetadata.candidatesTokensDetails.count, 1)
+    XCTAssertEqual(usageMetadata.candidatesTokensDetails[0].modality, .text)
+    XCTAssertEqual(usageMetadata.candidatesTokensDetails[0].tokenCount, 22)
+  }
+
+  func testGenerateContent_failure_invalidAPIKey() async throws {
+    let expectedStatusCode = 400
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-failure-api-key",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory,
+      statusCode: expectedStatusCode
+    )
+
+    do {
+      _ = try await model.generateContent(testPrompt)
+      XCTFail("Should throw GenerateContentError.internalError; no error thrown.")
+    } catch let GenerateContentError.internalError(error as BackendError) {
+      XCTAssertEqual(error.httpResponseCode, 400)
+      XCTAssertEqual(error.status, .invalidArgument)
+      XCTAssertEqual(error.message, "API key not valid. Please pass a valid API key.")
+      XCTAssertTrue(error.localizedDescription.contains(error.message))
+      XCTAssertTrue(error.localizedDescription.contains(error.status.rawValue))
+      XCTAssertTrue(error.localizedDescription.contains("\(error.httpResponseCode)"))
+      let nsError = error as NSError
+      XCTAssertEqual(nsError.domain, "\(Constants.baseErrorDomain).\(BackendError.self)")
+      XCTAssertEqual(nsError.code, error.httpResponseCode)
+      return
+    } catch {
+      XCTFail("Should throw GenerateContentError.internalError(RPCError); error thrown: \(error)")
+    }
+  }
+
+  func testGenerateContent_failure_finishReasonSafety() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-failure-finish-reason-safety",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    do {
+      _ = try await model.generateContent(testPrompt)
+      XCTFail("Should throw")
+    } catch let GenerateContentError.responseStoppedEarly(reason, response) {
+      XCTAssertEqual(reason, .safety)
+      XCTAssertEqual(response.text, "Safety error incoming in 5, 4, 3, 2...")
+    } catch {
+      XCTFail("Should throw a responseStoppedEarly")
+    }
+  }
+
+  func testGenerateContent_failure_unknownModel() async throws {
+    let expectedStatusCode = 404
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-failure-unknown-model",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory,
+      statusCode: 404
+    )
+
+    do {
+      _ = try await model.generateContent(testPrompt)
+      XCTFail("Should throw GenerateContentError.internalError; no error thrown.")
+    } catch let GenerateContentError.internalError(underlying: rpcError as BackendError) {
+      XCTAssertEqual(rpcError.status, .notFound)
+      XCTAssertEqual(rpcError.httpResponseCode, expectedStatusCode)
+      XCTAssertTrue(rpcError.message.hasPrefix("models/gemini-5.0-flash is not found"))
+    } catch {
+      XCTFail("Should throw GenerateContentError.internalError; error thrown: \(error)")
+    }
+  }
+
+  // MARK: - Generate Content (Streaming)
+
+  func testGenerateContentStream_successBasicReplyLong() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "streaming-success-basic-reply-long",
+      withExtension: "txt",
+      subdirectory: googleAISubdirectory
+    )
+
+    var responses = 0
+    let stream = try model.generateContentStream("Hi")
+    for try await content in stream {
+      XCTAssertNotNil(content.text)
+      responses += 1
+    }
+
+    XCTAssertEqual(responses, 36)
+  }
+
+  func testGenerateContentStream_successBasicReplyShort() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "streaming-success-basic-reply-short",
+      withExtension: "txt",
+      subdirectory: googleAISubdirectory
+    )
+
+    var responses = 0
+    let stream = try model.generateContentStream("Hi")
+    for try await content in stream {
+      XCTAssertNotNil(content.text)
+      responses += 1
+    }
+
+    XCTAssertEqual(responses, 3)
+  }
+
+  func testGenerateContentStream_successWithCitations() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "streaming-success-citations",
+      withExtension: "txt",
+      subdirectory: googleAISubdirectory
+    )
+
+    let stream = try model.generateContentStream("Hi")
+    var citations = [Citation]()
+    var responses = [GenerateContentResponse]()
+    for try await content in stream {
+      responses.append(content)
+      XCTAssertNotNil(content.text)
+      let candidate = try XCTUnwrap(content.candidates.first)
+      if let sources = candidate.citationMetadata?.citations {
+        citations.append(contentsOf: sources)
+      }
+    }
+
+    let lastCandidate = try XCTUnwrap(responses.last?.candidates.first)
+    XCTAssertEqual(lastCandidate.finishReason, .stop)
+    XCTAssertEqual(citations.count, 1)
+    let citation = try XCTUnwrap(citations.first)
+    XCTAssertEqual(citation.startIndex, 111)
+    XCTAssertEqual(citation.endIndex, 236)
+    let citationURI = try XCTUnwrap(citation.uri)
+    XCTAssertTrue(citationURI.starts(with: "https://www."))
+    XCTAssertNil(citation.license)
+    XCTAssertNil(citation.title)
+    XCTAssertNil(citation.publicationDate)
+  }
+
+  func testGenerateContentStream_failureInvalidAPIKey() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "unary-failure-api-key",
+      withExtension: "json",
+      subdirectory: googleAISubdirectory
+    )
+
+    do {
+      let stream = try model.generateContentStream("Hi")
+      for try await _ in stream {
+        XCTFail("No content is there, this shouldn't happen.")
+      }
+    } catch let GenerateContentError.internalError(error as BackendError) {
+      XCTAssertEqual(error.httpResponseCode, 400)
+      XCTAssertEqual(error.status, .invalidArgument)
+      XCTAssertEqual(error.message, "API key not valid. Please pass a valid API key.")
+      XCTAssertTrue(error.localizedDescription.contains(error.message))
+      XCTAssertTrue(error.localizedDescription.contains(error.status.rawValue))
+      XCTAssertTrue(error.localizedDescription.contains("\(error.httpResponseCode)"))
+      let nsError = error as NSError
+      XCTAssertEqual(nsError.domain, "\(Constants.baseErrorDomain).\(BackendError.self)")
+      XCTAssertEqual(nsError.code, error.httpResponseCode)
+      return
+    }
+
+    XCTFail("Should have caught an error.")
+  }
+
+  func testGenerateContentStream_failureFinishRecitation() async throws {
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
+      forResource: "streaming-failure-recitation-no-content",
+      withExtension: "txt",
+      subdirectory: googleAISubdirectory
+    )
+
+    var responses = [GenerateContentResponse]()
+    do {
+      let stream = try model.generateContentStream("Hi")
+      for try await response in stream {
+        responses.append(response)
+      }
+      XCTFail("Expected a GenerateContentError.responseStoppedEarly error, but got no error.")
+    } catch let GenerateContentError.responseStoppedEarly(reason, response) {
+      XCTAssertEqual(reason, .recitation)
+      let candidate = try XCTUnwrap(response.candidates.first)
+      XCTAssertEqual(candidate.finishReason, reason)
+    } catch {
+      XCTFail("Expected a GenerateContentError.responseStoppedEarly error, but got error: \(error)")
+    }
+
+    XCTAssertEqual(responses.count, 8)
+    let firstResponse = try XCTUnwrap(responses.first)
+    XCTAssertEqual(firstResponse.text, "text1")
+    let lastResponse = try XCTUnwrap(responses.last)
+    XCTAssertEqual(lastResponse.text, "text8")
+  }
+}
diff --git a/FirebaseAI/Tests/Unit/GenerativeModelTests.swift b/FirebaseAI/Tests/Unit/GenerativeModelVertexAITests.swift
similarity index 84%
rename from FirebaseAI/Tests/Unit/GenerativeModelTests.swift
rename to FirebaseAI/Tests/Unit/GenerativeModelVertexAITests.swift
index 89bd8a13699..aa58238705c 100644
--- a/FirebaseAI/Tests/Unit/GenerativeModelTests.swift
+++ b/FirebaseAI/Tests/Unit/GenerativeModelVertexAITests.swift
@@ -20,7 +20,7 @@ import XCTest
 @testable import FirebaseAI
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-final class GenerativeModelTests: XCTestCase {
+final class GenerativeModelVertexAITests: XCTestCase {
   let testPrompt = "What sorts of questions can I ask you?"
   let safetyRatingsNegligible: [SafetyRating] = [
     .init(
@@ -61,7 +61,7 @@ final class GenerativeModelTests: XCTestCase {
     "projects/test-project-id/locations/test-location/publishers/google/models/test-model"
   let apiConfig = FirebaseAI.defaultVertexAIAPIConfig
 
-  let vertexSubdirectory = "vertexai"
+  let vertexSubdirectory = "mock-responses/vertexai"
 
   var urlSession: URLSession!
   var model: GenerativeModel!
@@ -73,7 +73,7 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
@@ -89,7 +89,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_basicReplyLong() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-long",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -108,11 +108,12 @@ final class GenerativeModelTests: XCTestCase {
     XCTAssertTrue(partText.hasPrefix("1. **Use Freshly Ground Coffee**:"))
     XCTAssertEqual(response.text, partText)
     XCTAssertEqual(response.functionCalls, [])
+    XCTAssertEqual(response.inlineDataParts, [])
   }
 
   func testGenerateContent_success_basicReplyShort() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -135,7 +136,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_basicReplyFullUsageMetadata() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-response-long-usage-metadata",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -160,7 +161,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_citations() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-citations",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -205,7 +206,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_quoteReply() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-quote-reply",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -256,7 +257,7 @@ final class GenerativeModelTests: XCTestCase {
       ),
     ]
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-unknown-enum-safety-ratings",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -271,7 +272,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_prefixedModelName() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -279,7 +280,7 @@ final class GenerativeModelTests: XCTestCase {
     let model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
@@ -291,7 +292,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_functionCall_emptyArguments() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-function-call-empty-arguments",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -314,7 +315,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_functionCall_noArguments() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-function-call-no-arguments",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -337,7 +338,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_functionCall_withArguments() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-function-call-with-arguments",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -364,7 +365,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_functionCall_parallelCalls() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-function-call-parallel-calls",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -381,7 +382,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_success_functionCall_mixedContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-function-call-mixed-content",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -403,14 +404,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(appCheck: AppCheckInteropFake(token: appCheckToken)),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        appCheck: AppCheckInteropFake(token: appCheckToken)
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -425,15 +428,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(appCheck: AppCheckInteropFake(token: appCheckToken),
-                                     privateAppID: true),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        appCheck: AppCheckInteropFake(token: appCheckToken), privateAppID: true
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -448,14 +452,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(appCheck: AppCheckInteropFake(error: AppCheckErrorFake())),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        appCheck: AppCheckInteropFake(error: AppCheckErrorFake())
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -470,14 +476,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(auth: AuthInteropFake(token: authToken)),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        auth: AuthInteropFake(token: authToken)
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -491,14 +499,14 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(auth: AuthInteropFake(token: nil)),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(auth: AuthInteropFake(token: nil)),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -512,14 +520,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(auth: AuthInteropFake(error: AuthErrorFake())),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        auth: AuthInteropFake(error: AuthErrorFake())
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -538,7 +548,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_usageMetadata() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -557,7 +567,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContent_failure_invalidAPIKey() async throws {
     let expectedStatusCode = 400
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-api-key",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -586,7 +596,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContent_failure_firebaseVertexAIAPINotEnabled() async throws {
     let expectedStatusCode = 403
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-firebasevertexai-api-not-enabled",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -610,7 +620,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_emptyContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-empty-content",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -634,7 +644,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_finishReasonSafety() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-finish-reason-safety",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -653,7 +663,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_finishReasonSafety_noContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-finish-reason-safety-no-content",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -673,7 +683,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContent_failure_imageRejected() async throws {
     let expectedStatusCode = 400
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-image-rejected",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -694,7 +704,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_promptBlockedSafety() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-prompt-blocked-safety",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -715,7 +725,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_promptBlockedSafetyWithMessage() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-prompt-blocked-safety-with-message",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -736,7 +746,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_unknownEnum_finishReason() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-unknown-enum-finish-reason",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -756,7 +766,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_unknownEnum_promptBlocked() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-unknown-enum-prompt-blocked",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -777,7 +787,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContent_failure_unknownModel() async throws {
     let expectedStatusCode = 404
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-unknown-model",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -797,7 +807,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testGenerateContent_failure_nonHTTPResponse() async throws {
-    MockURLProtocol.requestHandler = try nonHTTPRequestHandler()
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.nonHTTPRequestHandler()
 
     var responseError: Error?
     var content: GenerateContentResponse?
@@ -821,7 +831,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testGenerateContent_failure_invalidResponse() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-failure-invalid-response",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -852,7 +862,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContent_failure_malformedContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-malformed-content",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -885,7 +895,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testGenerateContentMissingSafetyRatings() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-success-missing-safety-ratings",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -900,7 +910,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContent_requestOptions_customTimeout() async throws {
     let expectedTimeout = 150.0
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-basic-reply-short",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -910,7 +920,7 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: requestOptions,
@@ -926,7 +936,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failureInvalidAPIKey() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-api-key",
         withExtension: "json",
         subdirectory: vertexSubdirectory
@@ -956,7 +966,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContentStream_failure_vertexAIInFirebaseAPINotEnabled() async throws {
     let expectedStatusCode = 403
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-failure-firebasevertexai-api-not-enabled",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -982,7 +992,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failureEmptyContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-empty-content",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1003,7 +1013,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failureFinishReasonSafety() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-finish-reason-safety",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1027,7 +1037,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failurePromptBlockedSafety() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-prompt-blocked-safety",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1050,7 +1060,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failurePromptBlockedSafetyWithMessage() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-prompt-blocked-safety-with-message",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1073,7 +1083,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_failureUnknownFinishEnum() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-unknown-finish-enum",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1095,7 +1105,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_successBasicReplyLong() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-long",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1113,7 +1123,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_successBasicReplyShort() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-short",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1131,7 +1141,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_successUnknownSafetyEnum() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-unknown-safety-enum",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1160,7 +1170,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_successWithCitations() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-citations",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1215,14 +1225,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(appCheck: AppCheckInteropFake(token: appCheckToken)),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        appCheck: AppCheckInteropFake(token: appCheckToken)
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-short",
         withExtension: "txt",
         subdirectory: vertexSubdirectory,
@@ -1237,14 +1249,16 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(appCheck: AppCheckInteropFake(error: AppCheckErrorFake())),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(
+        appCheck: AppCheckInteropFake(error: AppCheckErrorFake())
+      ),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: RequestOptions(),
       urlSession: urlSession
     )
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-short",
         withExtension: "txt",
         subdirectory: vertexSubdirectory,
@@ -1257,7 +1271,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_usageMetadata() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-short",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1283,7 +1297,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testGenerateContentStream_errorMidStream() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "streaming-failure-error-mid-stream",
       withExtension: "txt",
       subdirectory: vertexSubdirectory
@@ -1309,7 +1323,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testGenerateContentStream_nonHTTPResponse() async throws {
-    MockURLProtocol.requestHandler = try nonHTTPRequestHandler()
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.nonHTTPRequestHandler()
 
     let stream = try model.generateContentStream("Hi")
     do {
@@ -1326,7 +1340,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_invalidResponse() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-invalid-json",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1351,7 +1365,7 @@ final class GenerativeModelTests: XCTestCase {
 
   func testGenerateContentStream_malformedContent() async throws {
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-failure-malformed-content",
         withExtension: "txt",
         subdirectory: vertexSubdirectory
@@ -1378,7 +1392,7 @@ final class GenerativeModelTests: XCTestCase {
   func testGenerateContentStream_requestOptions_customTimeout() async throws {
     let expectedTimeout = 150.0
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "streaming-success-basic-reply-short",
         withExtension: "txt",
         subdirectory: vertexSubdirectory,
@@ -1388,7 +1402,7 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: requestOptions,
@@ -1408,7 +1422,7 @@ final class GenerativeModelTests: XCTestCase {
   // MARK: - Count Tokens
 
   func testCountTokens_succeeds() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-success-total-tokens",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -1421,7 +1435,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testCountTokens_succeeds_detailed() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-success-detailed-token-response",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -1439,7 +1453,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testCountTokens_succeeds_allOptions() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-success-total-tokens",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -1465,7 +1479,7 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       generationConfig: generationConfig,
       tools: [Tool(functionDeclarations: [sumFunction])],
@@ -1481,7 +1495,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testCountTokens_succeeds_noBillableCharacters() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-success-no-billable-characters",
       withExtension: "json",
       subdirectory: vertexSubdirectory
@@ -1494,7 +1508,7 @@ final class GenerativeModelTests: XCTestCase {
   }
 
   func testCountTokens_modelNotFound() async throws {
-    MockURLProtocol.requestHandler = try httpRequestHandler(
+    MockURLProtocol.requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
       forResource: "unary-failure-model-not-found", withExtension: "json",
       subdirectory: vertexSubdirectory,
       statusCode: 404
@@ -1516,7 +1530,7 @@ final class GenerativeModelTests: XCTestCase {
   func testCountTokens_requestOptions_customTimeout() async throws {
     let expectedTimeout = 150.0
     MockURLProtocol
-      .requestHandler = try httpRequestHandler(
+      .requestHandler = try GenerativeModelTestUtil.httpRequestHandler(
         forResource: "unary-success-total-tokens",
         withExtension: "json",
         subdirectory: vertexSubdirectory,
@@ -1526,7 +1540,7 @@ final class GenerativeModelTests: XCTestCase {
     model = GenerativeModel(
       modelName: testModelName,
       modelResourceName: testModelResourceName,
-      firebaseInfo: testFirebaseInfo(),
+      firebaseInfo: GenerativeModelTestUtil.testFirebaseInfo(),
       apiConfig: apiConfig,
       tools: nil,
       requestOptions: requestOptions,
@@ -1537,157 +1551,8 @@ final class GenerativeModelTests: XCTestCase {
 
     XCTAssertEqual(response.totalTokens, 6)
   }
-
-  // MARK: - Helpers
-
-  private func testFirebaseInfo(appCheck: AppCheckInterop? = nil,
-                                auth: AuthInterop? = nil,
-                                privateAppID: Bool = false) -> FirebaseInfo {
-    let app = FirebaseApp(instanceWithName: "testApp",
-                          options: FirebaseOptions(googleAppID: "ignore",
-                                                   gcmSenderID: "ignore"))
-    app.isDataCollectionDefaultEnabled = !privateAppID
-    return FirebaseInfo(
-      appCheck: appCheck,
-      auth: auth,
-      projectID: "my-project-id",
-      apiKey: "API_KEY",
-      firebaseAppID: "My app ID",
-      firebaseApp: app
-    )
-  }
-
-  private func nonHTTPRequestHandler() throws -> ((URLRequest) -> (
-    URLResponse,
-    AsyncLineSequence<URL.AsyncBytes>?
-  )) {
-    // Skip tests using MockURLProtocol on watchOS; unsupported in watchOS 2 and later, see
-    // https://developer.apple.com/documentation/foundation/urlprotocol for details.
-    #if os(watchOS)
-      throw XCTSkip("Custom URL protocols are unsupported in watchOS 2 and later.")
-    #endif // os(watchOS)
-    return { request in
-      // This is *not* an HTTPURLResponse
-      let response = URLResponse(
-        url: request.url!,
-        mimeType: nil,
-        expectedContentLength: 0,
-        textEncodingName: nil
-      )
-      return (response, nil)
-    }
-  }
-
-  private func httpRequestHandler(forResource name: String,
-                                  withExtension ext: String,
-                                  subdirectory subpath: String,
-                                  statusCode: Int = 200,
-                                  timeout: TimeInterval = RequestOptions().timeout,
-                                  appCheckToken: String? = nil,
-                                  authToken: String? = nil,
-                                  dataCollection: Bool = true) throws -> ((URLRequest) throws -> (
-    URLResponse,
-    AsyncLineSequence<URL.AsyncBytes>?
-  )) {
-    // Skip tests using MockURLProtocol on watchOS; unsupported in watchOS 2 and later, see
-    // https://developer.apple.com/documentation/foundation/urlprotocol for details.
-    #if os(watchOS)
-      throw XCTSkip("Custom URL protocols are unsupported in watchOS 2 and later.")
-    #endif // os(watchOS)
-    let bundle = BundleTestUtil.bundle()
-    let fileURL = try XCTUnwrap(
-      bundle.url(forResource: name, withExtension: ext, subdirectory: subpath)
-    )
-    return { request in
-      let requestURL = try XCTUnwrap(request.url)
-      XCTAssertEqual(requestURL.path.occurrenceCount(of: "models/"), 1)
-      XCTAssertEqual(request.timeoutInterval, timeout)
-      let apiClientTags = try XCTUnwrap(request.value(forHTTPHeaderField: "x-goog-api-client"))
-        .components(separatedBy: " ")
-      XCTAssert(apiClientTags.contains(GenerativeAIService.languageTag))
-      XCTAssert(apiClientTags.contains(GenerativeAIService.firebaseVersionTag))
-      XCTAssertEqual(request.value(forHTTPHeaderField: "X-Firebase-AppCheck"), appCheckToken)
-
-      let firebaseAppID = request.value(forHTTPHeaderField: "X-Firebase-AppId")
-      let appVersion = request.value(forHTTPHeaderField: "X-Firebase-AppVersion")
-      let expectedAppVersion =
-        try? XCTUnwrap(Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String)
-      XCTAssertEqual(firebaseAppID, dataCollection ? "My app ID" : nil)
-      XCTAssertEqual(appVersion, dataCollection ? expectedAppVersion : nil)
-
-      if let authToken {
-        XCTAssertEqual(request.value(forHTTPHeaderField: "Authorization"), "Firebase \(authToken)")
-      } else {
-        XCTAssertNil(request.value(forHTTPHeaderField: "Authorization"))
-      }
-      let response = try XCTUnwrap(HTTPURLResponse(
-        url: requestURL,
-        statusCode: statusCode,
-        httpVersion: nil,
-        headerFields: nil
-      ))
-      return (response, fileURL.lines)
-    }
-  }
-}
-
-private extension String {
-  /// Returns the number of occurrences of `substring` in the `String`.
-  func occurrenceCount(of substring: String) -> Int {
-    return components(separatedBy: substring).count - 1
-  }
 }
 
-@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-class AppCheckInteropFake: NSObject, AppCheckInterop {
-  /// The placeholder token value returned when an error occurs
-  static let placeholderTokenValue = "placeholder-token"
-
-  var token: String
-  var error: Error?
-
-  private init(token: String, error: Error?) {
-    self.token = token
-    self.error = error
-  }
-
-  convenience init(token: String) {
-    self.init(token: token, error: nil)
-  }
-
-  convenience init(error: Error) {
-    self.init(token: AppCheckInteropFake.placeholderTokenValue, error: error)
-  }
-
-  func getToken(forcingRefresh: Bool) async -> any FIRAppCheckTokenResultInterop {
-    return AppCheckTokenResultInteropFake(token: token, error: error)
-  }
-
-  func tokenDidChangeNotificationName() -> String {
-    fatalError("\(#function) not implemented.")
-  }
-
-  func notificationTokenKey() -> String {
-    fatalError("\(#function) not implemented.")
-  }
-
-  func notificationAppNameKey() -> String {
-    fatalError("\(#function) not implemented.")
-  }
-
-  private class AppCheckTokenResultInteropFake: NSObject, FIRAppCheckTokenResultInterop {
-    var token: String
-    var error: Error?
-
-    init(token: String, error: Error?) {
-      self.token = token
-      self.error = error
-    }
-  }
-}
-
-struct AppCheckErrorFake: Error {}
-
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
 extension SafetyRating: Swift.Comparable {
   public static func < (lhs: SafetyRating, rhs: SafetyRating) -> Bool {
diff --git a/FirebaseAI/Tests/Unit/TestUtilities/GenerativeModelTestUtil.swift b/FirebaseAI/Tests/Unit/TestUtilities/GenerativeModelTestUtil.swift
new file mode 100644
index 00000000000..9b00f0b0c87
--- /dev/null
+++ b/FirebaseAI/Tests/Unit/TestUtilities/GenerativeModelTestUtil.swift
@@ -0,0 +1,127 @@
+// Copyright 2025 Google LLC
+//
+// 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.
+
+import FirebaseAppCheckInterop
+import FirebaseAuthInterop
+import FirebaseCore
+import Foundation
+import XCTest
+
+@testable import FirebaseAI
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+enum GenerativeModelTestUtil {
+  /// Returns an HTTP request handler
+  static func httpRequestHandler(forResource name: String,
+                                 withExtension ext: String,
+                                 subdirectory subpath: String,
+                                 statusCode: Int = 200,
+                                 timeout: TimeInterval = RequestOptions().timeout,
+                                 appCheckToken: String? = nil,
+                                 authToken: String? = nil,
+                                 dataCollection: Bool = true) throws -> ((URLRequest) throws -> (
+    URLResponse,
+    AsyncLineSequence<URL.AsyncBytes>?
+  )) {
+    // Skip tests using MockURLProtocol on watchOS; unsupported in watchOS 2 and later, see
+    // https://developer.apple.com/documentation/foundation/urlprotocol for details.
+    #if os(watchOS)
+      throw XCTSkip("Custom URL protocols are unsupported in watchOS 2 and later.")
+    #else // os(watchOS)
+      let bundle = BundleTestUtil.bundle()
+      let fileURL = try XCTUnwrap(
+        bundle.url(forResource: name, withExtension: ext, subdirectory: subpath)
+      )
+      return { request in
+        let requestURL = try XCTUnwrap(request.url)
+        XCTAssertEqual(requestURL.path.occurrenceCount(of: "models/"), 1)
+        XCTAssertEqual(request.timeoutInterval, timeout)
+        let apiClientTags = try XCTUnwrap(request.value(forHTTPHeaderField: "x-goog-api-client"))
+          .components(separatedBy: " ")
+        XCTAssert(apiClientTags.contains(GenerativeAIService.languageTag))
+        XCTAssert(apiClientTags.contains(GenerativeAIService.firebaseVersionTag))
+        XCTAssertEqual(request.value(forHTTPHeaderField: "X-Firebase-AppCheck"), appCheckToken)
+
+        let firebaseAppID = request.value(forHTTPHeaderField: "X-Firebase-AppId")
+        let appVersion = request.value(forHTTPHeaderField: "X-Firebase-AppVersion")
+        let expectedAppVersion =
+          try? XCTUnwrap(Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String)
+        XCTAssertEqual(firebaseAppID, dataCollection ? "My app ID" : nil)
+        XCTAssertEqual(appVersion, dataCollection ? expectedAppVersion : nil)
+
+        if let authToken {
+          XCTAssertEqual(
+            request.value(forHTTPHeaderField: "Authorization"),
+            "Firebase \(authToken)"
+          )
+        } else {
+          XCTAssertNil(request.value(forHTTPHeaderField: "Authorization"))
+        }
+        let response = try XCTUnwrap(HTTPURLResponse(
+          url: requestURL,
+          statusCode: statusCode,
+          httpVersion: nil,
+          headerFields: nil
+        ))
+        return (response, fileURL.lines)
+      }
+    #endif // os(watchOS)
+  }
+
+  static func nonHTTPRequestHandler() throws -> ((URLRequest) -> (
+    URLResponse,
+    AsyncLineSequence<URL.AsyncBytes>?
+  )) {
+    // Skip tests using MockURLProtocol on watchOS; unsupported in watchOS 2 and later, see
+    // https://developer.apple.com/documentation/foundation/urlprotocol for details.
+    #if os(watchOS)
+      throw XCTSkip("Custom URL protocols are unsupported in watchOS 2 and later.")
+    #else // os(watchOS)
+      return { request in
+        // This is *not* an HTTPURLResponse
+        let response = URLResponse(
+          url: request.url!,
+          mimeType: nil,
+          expectedContentLength: 0,
+          textEncodingName: nil
+        )
+        return (response, nil)
+      }
+    #endif // os(watchOS)
+  }
+
+  static func testFirebaseInfo(appCheck: AppCheckInterop? = nil,
+                               auth: AuthInterop? = nil,
+                               privateAppID: Bool = false) -> FirebaseInfo {
+    let app = FirebaseApp(instanceWithName: "testApp",
+                          options: FirebaseOptions(googleAppID: "ignore",
+                                                   gcmSenderID: "ignore"))
+    app.isDataCollectionDefaultEnabled = !privateAppID
+    return FirebaseInfo(
+      appCheck: appCheck,
+      auth: auth,
+      projectID: "my-project-id",
+      apiKey: "API_KEY",
+      firebaseAppID: "My app ID",
+      firebaseApp: app
+    )
+  }
+}
+
+private extension String {
+  /// Returns the number of occurrences of `substring` in the `String`.
+  func occurrenceCount(of substring: String) -> Int {
+    return components(separatedBy: substring).count - 1
+  }
+}
diff --git a/Package.swift b/Package.swift
index 1fa0ccc82a6..c121735282e 100644
--- a/Package.swift
+++ b/Package.swift
@@ -208,7 +208,7 @@ let package = Package(
       ],
       path: "FirebaseAI/Tests/Unit",
       resources: [
-        .copy("vertexai-sdk-test-data/mock-responses/vertexai"),
+        .copy("vertexai-sdk-test-data/mock-responses"),
         .process("Resources"),
       ],
       cSettings: [