optional createdAt?: string;

optional model?: string;

optional signature?: string;

optional structuredOutput?: object;

optional data?: unknown;

optional errorMessage?: string;

optional partial?: unknown;

optional raw?: string;

optional reasoning?: string;

optional status?: "error" | "complete" | "streaming";

optional toolCallMetadata?: Record<string, unknown>;

optional toolResult?: object;

optional content?: ContentPart<unknown, unknown, unknown, unknown, unknown>[];

optional createdAt?: string;

optional id?: string;

optional uiResources?: UIResourcePart[];