Function withBackoff

packages/providers/src/retry.ts:309–341

(fn: () => Promise<T>, opts: BackoffOptions = {})

 * async op (e.g. `agent.prompt()` in the pi-agent-core path).
 */
export async function withBackoff<T>(fn: () => Promise<T>, opts: BackoffOptions = {}): Promise<T> {
  const maxRetries = opts.maxRetries ?? DEFAULT_MAX_RETRIES;
  const baseDelayMs = opts.baseDelayMs ?? DEFAULT_BASE_DELAY_MS;
  const classify = opts.classify ?? classifyError;
  const signal = opts.signal;

  let lastError: unknown;
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    if (signal?.aborted) {
      throw new CodesignError('Generation aborted by user', ERROR_CODES.PROVIDER_ABORTED);
    }
    try {
      return await fn();
    } catch (err) {
      lastError = err;
      const decision = classify(err);
      if (shouldStop(decision, attempt, maxRetries)) {
        if (decision.reason === 'aborted') {
          throw new CodesignError('Generation aborted by user', ERROR_CODES.PROVIDER_ABORTED, {
            cause: err,
          });
        }
        throw err;
      }
      const info = buildRetryInfo(attempt, maxRetries, decision, baseDelayMs);
      opts.onRetry?.(info);
      await sleepWithAbort(info.delayMs, signal);
    }
  }
  throw lastError instanceof Error
    ? lastError
    : new CodesignError('withBackoff exhausted', ERROR_CODES.PROVIDER_RETRY_EXHAUSTED);
}

export async function completeWithRetry(
  model: ModelRef,