diff --git a/Tests/GoogleAITests/GenerationConfigTests.swift b/Tests/GoogleAITests/GenerationConfigTests.swift
new file mode 100644
index 0000000..e4dd7f7
--- /dev/null
+++ b/Tests/GoogleAITests/GenerationConfigTests.swift
@@ -0,0 +1,95 @@
+// Copyright 2024 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 Foundation
+import XCTest
+
+@testable import GoogleGenerativeAI
+
+@available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
+final class GenerationConfigTests: XCTestCase {
+  let encoder = JSONEncoder()
+
+  override func setUp() {
+    encoder.outputFormatting = .init(
+      arrayLiteral: .prettyPrinted, .sortedKeys, .withoutEscapingSlashes
+    )
+  }
+
+  // MARK: GenerationConfig Encoding
+
+  func testEncodeGenerationConfig_default() throws {
+    let generationConfig = GenerationConfig()
+
+    let jsonData = try encoder.encode(generationConfig)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+
+    }
+    """)
+  }
+
+  func testEncodeGenerationConfig_allOptions() throws {
+    let temperature: Float = 0.5
+    let topP: Float = 0.95
+    let topK = 40
+    let candidateCount = 2
+    let maxOutputTokens = 256
+    let stopSequences = ["END", "DONE"]
+    let responseMIMEType = "text/plain"
+    let generationConfig = GenerationConfig(
+      temperature: temperature,
+      topP: topP,
+      topK: topK,
+      candidateCount: candidateCount,
+      maxOutputTokens: maxOutputTokens,
+      stopSequences: stopSequences,
+      responseMIMEType: responseMIMEType
+    )
+
+    let jsonData = try encoder.encode(generationConfig)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+      "candidateCount" : \(candidateCount),
+      "maxOutputTokens" : \(maxOutputTokens),
+      "responseMIMEType" : "\(responseMIMEType)",
+      "stopSequences" : [
+        "END",
+        "DONE"
+      ],
+      "temperature" : \(temperature),
+      "topK" : \(topK),
+      "topP" : \(topP)
+    }
+    """)
+  }
+
+  func testEncodeGenerationConfig_responseMIMEType() throws {
+    let mimeType = "image/jpeg"
+    let generationConfig = GenerationConfig(responseMIMEType: mimeType)
+
+    let jsonData = try encoder.encode(generationConfig)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+      "responseMIMEType" : "\(mimeType)"
+    }
+    """)
+  }
+}
diff --git a/Tests/GoogleAITests/GoogleAITests.swift b/Tests/GoogleAITests/GoogleAITests.swift
index b4708af..ca4a822 100644
--- a/Tests/GoogleAITests/GoogleAITests.swift
+++ b/Tests/GoogleAITests/GoogleAITests.swift
@@ -28,7 +28,8 @@ final class GoogleGenerativeAITests: XCTestCase {
                                   topK: 16,
                                   candidateCount: 4,
                                   maxOutputTokens: 256,
-                                  stopSequences: ["..."])
+                                  stopSequences: ["..."],
+                                  responseMIMEType: "text/plain")
     let filters = [SafetySetting(harmCategory: .dangerousContent, threshold: .blockOnlyHigh)]
     let systemInstruction = ModelContent(role: "system", parts: [.text("Talk like a pirate.")])