feat: Add ChatCompletionsRequest object

core/src/main/java/com/google/adk/models/ChatCompletionsCommon.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2026 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
+ *
+ *      https://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 com.google.adk.models;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.Map;
+
+/** Shared models for Chat Completions Request and Response. */
+@JsonIgnoreProperties(ignoreUnknown = true)
+@JsonInclude(JsonInclude.Include.NON_NULL)
+final class ChatCompletionsCommon {
+
+  private ChatCompletionsCommon() {}
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class ToolCall {
+    public Integer index; // Applicable for response streaming, null in requests
+    public String id;
+    public String type;
+    public Function function;
+    public Custom custom;
+
+    @JsonProperty("extra_content")
+    public Map<String, Object> extraContent;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Function {
+    public String name;
+    public String arguments; // JSON string
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Custom {
+    public String input;
+    public String name;
+  }
+}

core/src/main/java/com/google/adk/models/ChatCompletionsRequest.java

@@ -0,0 +1,316 @@
+/*
+ * Copyright 2026 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
+ *
+ *      https://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 com.google.adk.models;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonValue;
+import java.util.List;
+import java.util.Map;
+
+/** Data Transfer Objects for Chat Completion API requests. */
+@JsonIgnoreProperties(ignoreUnknown = true)
+@JsonInclude(JsonInclude.Include.NON_NULL)
+final class ChatCompletionsRequest {
+
+  public List<Message> messages;
+  public String model;
+  public AudioParam audio;
+
+  @JsonProperty("frequency_penalty")
+  public Double frequencyPenalty;
+
+  @JsonProperty("logit_bias")
+  public Map<String, Double> logitBias;
+
+  public Boolean logprobs;
+
+  @JsonProperty("max_completion_tokens")
+  public Integer maxCompletionTokens;
+
+  @JsonProperty("max_tokens")
+  public Integer maxTokens;
+
+  public Map<String, String> metadata;
+  public List<String> modalities;
+  public Integer n;
+
+  @JsonProperty("parallel_tool_calls")
+  public Boolean parallelToolCalls;
+
+  public Prediction prediction;
+
+  @JsonProperty("presence_penalty")
+  public Double presencePenalty;
+
+  @JsonProperty("prompt_cache_key")
+  public String promptCacheKey;
+
+  @JsonProperty("prompt_cache_retention")
+  public String promptCacheRetention;
+
+  @JsonProperty("reasoning_effort")
+  public String reasoningEffort;
+
+  @JsonProperty("response_format")
+  public ResponseFormat responseFormat;
+
+  @JsonProperty("safety_identifier")
+  public String safetyIdentifier;
+
+  public Long seed;
+
+  @JsonProperty("service_tier")
+  public String serviceTier;
+
+  public Object stop; // Can be String or List<String>
+  public Boolean store;
+  public Boolean stream;
+
+  @JsonProperty("stream_options")
+  public StreamOptions streamOptions;
+
+  public Double temperature;
+
+  @JsonProperty("tool_choice")
+  public ToolChoice toolChoice;
+
+  public List<Tool> tools;
+
+  @JsonProperty("top_logprobs")
+  public Integer topLogprobs;
+
+  @JsonProperty("top_p")
+  public Double topP;
+
+  public String user;
+  public String verbosity;
+
+  @JsonProperty("web_search_options")
+  public WebSearchOptions webSearchOptions;
+
+  @JsonProperty("extra_body")
+  public Map<String, Object> extraBody;
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Message {
+    public String role;
+    public Object content; // Can be String or List<ContentPart>
+    public String name;
+
+    @JsonProperty("tool_calls")
+    public List<ChatCompletionsCommon.ToolCall> toolCalls;
+
+    @JsonProperty("function_call")
+    public FunctionCall functionCall; // Deprecated
+
+    @JsonProperty("tool_call_id")
+    public String toolCallId;
+
+    public Audio audio; // For assistant messages with audio
+    public String refusal;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class ContentPart {
+    public String type;
+    public String text;
+    public String refusal;
+
+    @JsonProperty("image_url")
+    public ImageUrl imageUrl;
+
+    @JsonProperty("input_audio")
+    public InputAudio inputAudio;
+
+    public File file;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class ImageUrl {
+    public String url;
+    public String detail;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class InputAudio {
+    public String data;
+    public String format;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class File {
+    @JsonProperty("file_data")
+    public String fileData;
+
+    @JsonProperty("file_id")
+    public String fileId;
+
+    public String filename;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class FunctionCall {
+    public String name;
+    public String arguments;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class AudioParam {
+    public String format;
+    public Object voice; // Can be String or Map
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Audio {
+    public String id;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Prediction {
+    public String type;
+    public Object content;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class StreamOptions {
+    @JsonProperty("include_obfuscation")
+    public Boolean includeObfuscation;
+
+    @JsonProperty("include_usage")
+    public Boolean includeUsage;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class Tool {
+    public String type;
+    public FunctionDefinition function;
+    public CustomTool custom;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class FunctionDefinition {
+    public String name;
+    public String description;
+    public Object parameters; // JSON Schema
+    public Boolean strict;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class CustomTool {
+    public String name;
+    public String description;
+    public Object format;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class WebSearchOptions {
+    @JsonProperty("search_context_size")
+    public String searchContextSize;
+
+    @JsonProperty("user_location")
+    public UserLocation userLocation;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class UserLocation {
+    public String type;
+    public ApproximateLocation approximate;
+  }
+
+  @JsonIgnoreProperties(ignoreUnknown = true)
+  @JsonInclude(JsonInclude.Include.NON_NULL)
+  static class ApproximateLocation {
+    public String city;
+    public String country;
+    public String region;
+    public String timezone;
+  }
+
+  interface ResponseFormat {}
+
+  static class ResponseFormatText implements ResponseFormat {
+    public String type = "text";
+  }
+
+  static class ResponseFormatJsonObject implements ResponseFormat {
+    public String type = "json_object";
+  }
+
+  static class ResponseFormatJsonSchema implements ResponseFormat {
+    public String type = "json_schema";
+
+    @JsonProperty("json_schema")
+    public JsonSchema jsonSchema;
+
+    static class JsonSchema {
+      public String name;
+      public String description;
+      public Object schema;
+      public Boolean strict;
+    }
+  }
+
+  interface ToolChoice {}
+
+  static class ToolChoiceMode implements ToolChoice {
+    private final String mode;
+
+    public ToolChoiceMode(String mode) {
+      this.mode = mode;
+    }
+
+    @JsonValue
+    public String getMode() {
+      return mode;
+    }
+  }
+
+  static class NamedToolChoice implements ToolChoice {
+    public String type = "function";
+    public FunctionName function;
+
+    static class FunctionName {
+      public String name;
+    }
+  }
+
+  static class NamedToolChoiceCustom implements ToolChoice {
+    public String type = "custom";
+    public CustomName custom;
+
+    static class CustomName {
+      public String name;
+    }
+  }
+}