Class LoggingContentGenerator

packages/core/src/core/loggingContentGenerator.ts:48–191

 * A decorator that wraps a ContentGenerator to add logging to API calls.
 */
export class LoggingContentGenerator implements ContentGenerator {
  constructor(
    private readonly wrapped: ContentGenerator,
    private readonly config: Config,
  ) {}

  private logApiRequest(
    contents: Content[],
    model: string,
    promptId: string,
  ): void {
    const requestText = JSON.stringify(contents);
    logApiRequest(
      this.config,
      new ApiRequestEvent(model, promptId, requestText),
    );
  }

  private _logApiResponse(
    durationMs: number,
    prompt_id: string,
    usageMetadata?: GenerateContentResponseUsageMetadata,
    responseText?: string,
  ): void {
    logApiResponse(
      this.config,
      new ApiResponseEvent(
        this.config.getModel(),
        durationMs,
        prompt_id,
        this.config.getContentGeneratorConfig()?.authType,
        usageMetadata,
        responseText,
      ),
    );
  }

  private _logApiError(
    durationMs: number,
    error: unknown,
    prompt_id: string,
  ): void {
    const errorMessage = error instanceof Error ? error.message : String(error);
    const errorType = error instanceof Error ? error.name : 'unknown';

    logApiError(
      this.config,
      new ApiErrorEvent(
        this.config.getModel(),
        errorMessage,
        durationMs,
        prompt_id,
        this.config.getContentGeneratorConfig()?.authType,
        errorType,
        isStructuredError(error)
          ? (error as StructuredError).status
          : undefined,
      ),