ChatCompletionMessage

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/ChatCompletionMessage",
  "title": "ChatCompletionMessage",
  "type": "object",
  "required": [
    "role"
  ],
  "description": "A message in the conversation. Supports roles: `system`, `user`, `assistant`, and `tool`.",
  "properties": {
    "role": {
      "type": "string",
      "enum": [
        "system",
        "user",
        "assistant",
        "tool"
      ],
      "description": "The role of the message author: `system` (instructions), `user` (input), `assistant` (model response), or `tool` (tool result)."
    },
    "content": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "array",
          "items": {
            "anyOf": [
              {
                "$ref": "#/components/schemas/ChatCompletionContentPartTextParam"
              },
              {
                "$ref": "#/components/schemas/ChatCompletionContentPartImageParam"
              },
              {
                "$ref": "#/components/schemas/ChatCompletionContentPartInputAudioParam"
              }
            ]
          }
        }
      ],
      "description": "The message content. Can be a string or an array of content parts (text, image, audio) for multimodal inputs."
    },
    "name": {
      "type": "string",
      "description": "An optional name for the participant. Useful for distinguishing between multiple users or assistants."
    },
    "tool_calls": {
      "type": "array",
      "items": {
        "$ref": "#/components/schemas/ChatCompletionMessageToolCallParam"
      },
      "description": "Tool calls generated by the model (for assistant messages)."
    },
    "tool_call_id": {
      "type": "string",
      "description": "The ID of the tool call this message responds to (required for tool messages)."
    }
  }
}