Deprecate Gemini 3.x tuning parameters

FirebaseAI/AGENTS.md

@@ -20,7 +20,7 @@ This directory contains the main source code for the FirebaseAI library.
 - **`GenerateContentError.swift`**: Defines the public `GenerateContentError` enum, representing errors that can occur when generating content.
 - **`GenerateContentRequest.swift`**: Defines the `GenerateContentRequest` struct, representing a request to generate content from the model.
 - **`GenerateContentResponse.swift`**: Represents the model's response to a generate content request, including usage metadata, candidates, and prompt feedback.
-- **`GenerationConfig.swift`**: Defines the `GenerationConfig` struct for configuring model parameters (e.g., temperature, topP).
+- **`GenerationConfig.swift`**: Defines the `GenerationConfig` struct for configuring model parameters (e.g., maxOutputTokens).
 - **`GenerativeAIRequest.swift`**: Defines the `GenerativeAIRequest` protocol for requests sent to the generative AI backend.
 - **`GenerativeAIService.swift`**: Responsible for making requests to the generative AI backend, handling authentication, URL construction, and response parsing.
 - **`GenerativeModel.swift`**: Defines the `GenerativeModel` class, representing a remote multimodal model. It provides methods for generating content and starting chats.

FirebaseAI/CHANGELOG.md

@@ -1,3 +1,8 @@
+# Unreleased
+- [changed] Deprecated model tuning parameters (`temperature`, `topP`, `topK`, `candidateCount`,
+  `presencePenalty`, and `frequencyPenalty`) in `GenerationConfig` and `LiveGenerationConfig` as
+  they are unsupported in Gemini 3.x and later models.
+
 # 12.19.0
 - [feature] **Public Preview**: Added `GeminiLanguageModel`, allowing Gemini
   models to be used with Apple's Foundation Models framework. See the

FirebaseAI/Sources/GenerationConfig.swift

@@ -73,67 +73,9 @@ public struct GenerationConfig: Sendable, Equatable {
   /// for more details.
   ///
   /// - Parameters:
-  ///   - temperature:Controls the randomness of the language model's output. Higher values (for
-  ///     example, 1.0) make the text more random and creative, while lower values (for example,
-  ///     0.1) make it more focused and deterministic.
-  ///
-  ///     > Note: A temperature of 0 means that the highest probability tokens are always selected.
-  ///     > In this case, responses for a given prompt are mostly deterministic, but a small amount
-  ///     > of variation is still possible.
-  ///
-  ///     > Important: The range of supported temperature values depends on the model; see the
-  ///     > [documentation](https://firebase.google.com/docs/vertex-ai/model-parameters?platform=ios#temperature)
-  ///     > for more details.
-  ///   - topP: Controls diversity of generated text. Higher values (e.g., 0.9) produce more diverse
-  ///     text, while lower values (e.g., 0.5) make the output more focused.
-  ///
-  ///     The supported range is 0.0 to 1.0.
-  ///
-  ///     > Important: The default `topP` value depends on the model; see the
-  ///     > [documentation](https://firebase.google.com/docs/vertex-ai/model-parameters?platform=ios#top-p)
-  ///     > for more details.
-  ///   - topK: Limits the number of highest probability words the model considers when generating
-  ///     text. For example, a topK of 40 means only the 40 most likely words are considered for the
-  ///     next token. A higher value increases diversity, while a lower value makes the output more
-  ///     deterministic.
-  ///
-  ///     The supported range is 1 to 40.
-  ///
-  ///     > Important: Support for `topK` and the default value depends on the model; see the
-  ///     [documentation](https://firebase.google.com/docs/vertex-ai/model-parameters?platform=ios#top-k)
-  ///     for more details.
-  ///   - candidateCount: The number of response variations to return; defaults to 1 if not set.
-  ///     Support for multiple candidates depends on the model; see the
-  ///     [Cloud documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/inference#generationconfig)
-  ///     for more details.
   ///   - maxOutputTokens: Maximum number of tokens that can be generated in the response.
   ///     See the configure model parameters [documentation](https://firebase.google.com/docs/vertex-ai/model-parameters?platform=ios#max-output-tokens)
   ///     for more details.
-  ///   - presencePenalty: Controls the likelihood of repeating the same words or phrases already
-  ///     generated in the text. Higher values increase the penalty of repetition, resulting in more
-  ///     diverse output.
-  ///
-  ///     > Note: While both `presencePenalty` and `frequencyPenalty` discourage repetition,
-  ///     > `presencePenalty` applies the same penalty regardless of how many times the word/phrase
-  ///     > has already appeared, whereas `frequencyPenalty` increases the penalty for *each*
-  ///     > repetition of a word/phrase.
-  ///
-  ///     > Important: The range of supported `presencePenalty` values depends on the model; see the
-  ///     > [Cloud documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/inference#generationconfig)
-  ///     > for more details
-  ///   - frequencyPenalty: Controls the likelihood of repeating words or phrases, with the penalty
-  ///     increasing for each repetition. Higher values increase the penalty of repetition,
-  ///     resulting in more diverse output.
-  ///
-  ///     > Note: While both `frequencyPenalty` and `presencePenalty` discourage repetition,
-  ///     > `frequencyPenalty` increases the penalty for *each* repetition of a word/phrase, whereas
-  ///     > `presencePenalty` applies the same penalty regardless of how many times the word/phrase
-  ///     > has already appeared.
-  ///
-  ///     > Important: The range of supported `frequencyPenalty` values depends on the model; see
-  ///     > the
-  ///     > [Cloud documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/inference#generationconfig)
-  ///     > for more details
   ///   - stopSequences: A set of up to 5 `String`s that will stop output generation. If specified,
   ///     the API will stop at the first appearance of a stop sequence. The stop sequence will not
   ///     be included as part of the response. See the
@@ -174,6 +116,11 @@ public struct GenerationConfig: Sendable, Equatable {
   ///     > that it is not subject to any SLA or deprecation policy and could change in
   ///     > backwards-incompatible ways.
   ///   - imageConfig: Configuration options for generating images.
+  @available(
+    *,
+    deprecated,
+    message: "candidateCount, temperature, topP, topK, presencePenalty, and frequencyPenalty are unsupported in Gemini 3.x and later models."
+  )
   public init(temperature: Float? = nil, topP: Float? = nil, topK: Int? = nil,
               candidateCount: Int? = nil, maxOutputTokens: Int? = nil,
               presencePenalty: Float? = nil, frequencyPenalty: Float? = nil,
@@ -200,6 +147,80 @@ public struct GenerationConfig: Sendable, Equatable {
     self.speechConfig = speechConfig?.speechConfig
   }
 
+  /// Creates a new `GenerationConfig` value without deprecated tuning parameters.
+  ///
+  /// See the
+  /// [Configure model parameters](https://firebase.google.com/docs/vertex-ai/model-parameters)
+  /// guide and the
+  /// [Cloud documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/inference#generationconfig)
+  /// for more details.
+  ///
+  /// - Parameters:
+  ///   - maxOutputTokens: Maximum number of tokens that can be generated in the response.
+  ///     See the configure model parameters [documentation](https://firebase.google.com/docs/vertex-ai/model-parameters?platform=ios#max-output-tokens)
+  ///     for more details.
+  ///   - stopSequences: A set of up to 5 `String`s that will stop output generation. If specified,
+  ///     the API will stop at the first appearance of a stop sequence. The stop sequence will not
+  ///     be included as part of the response. See the
+  ///     [Cloud documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/inference#generationconfig)
+  ///     for more details.
+  ///   - responseMIMEType: Output response MIME type of the generated candidate text.
+  ///
+  ///     Supported MIME types:
+  ///     - `text/plain`: Text output; the default behavior if unspecified.
+  ///     - `application/json`: JSON response in the candidates.
+  ///     - `text/x.enum`: For classification tasks, output an enum value as defined in the
+  ///       `responseSchema`.
+  ///   - responseSchema: Output schema of the generated candidate text. If set, a compatible
+  ///     `responseMIMEType` must also be set.
+  ///
+  ///     Compatible MIME types:
+  ///     - `application/json`: Schema for JSON response.
+  ///
+  ///     Refer to the
+  ///     [Generate structured
+  ///     output](https://firebase.google.com/docs/vertex-ai/structured-output?platform=ios) guide
+  ///     for more details.
+  ///   - responseModalities: The data types (modalities) that may be returned in model responses.
+  ///
+  ///     See the [multimodal
+  ///     responses](https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal-response-generation)
+  ///     documentation for more details.
+  ///
+  ///     > Warning: Specifying response modalities is a **Public Preview** feature, which means
+  ///     > that it is not subject to any SLA or deprecation policy and could change in
+  ///     > backwards-incompatible ways.
+  ///   - thinkingConfig: Configuration for controlling the "thinking" behavior of compatible Gemini
+  ///     models; see ``ThinkingConfig`` for more details.
+  ///   - speechConfig: Configuration for controlling the voice of the model during conversation;
+  ///     see ``SpeechConfig`` for more details.
+  ///
+  ///     > Warning: Specifying a speech configuration is a **Public Preview** feature, which means
+  ///     > that it is not subject to any SLA or deprecation policy and could change in
+  ///     > backwards-incompatible ways.
+  ///   - imageConfig: Configuration options for generating images.
+  public init(maxOutputTokens: Int? = nil,
+              stopSequences: [String]? = nil, responseMIMEType: String? = nil,
+              responseSchema: Schema? = nil, responseModalities: [ResponseModality]? = nil,
+              thinkingConfig: ThinkingConfig? = nil, imageConfig: ImageConfig? = nil,
+              speechConfig: SpeechConfig? = nil) {
+    temperature = nil
+    topP = nil
+    topK = nil
+    candidateCount = nil
+    self.maxOutputTokens = maxOutputTokens
+    presencePenalty = nil
+    frequencyPenalty = nil
+    self.stopSequences = stopSequences
+    self.responseMIMEType = responseMIMEType
+    self.responseSchema = responseSchema
+    responseJSONSchema = nil
+    self.responseModalities = responseModalities
+    self.thinkingConfig = thinkingConfig
+    self.imageConfig = imageConfig
+    self.speechConfig = speechConfig?.speechConfig
+  }
+
   init(temperature: Float? = nil, topP: Float? = nil, topK: Int? = nil, candidateCount: Int? = nil,
        maxOutputTokens: Int? = nil, presencePenalty: Float? = nil, frequencyPenalty: Float? = nil,
        stopSequences: [String]? = nil, responseMIMEType: String, responseJSONSchema: JSONObject,