Developers

Handling errors

Retry what is safe to retry, and nothing else.

Branch on error.code, not on the message: codes are stable, messages may be reworded. Retry only codes marked retryable, with exponential backoff, and honor Retry-After when present.

JavaScript

const RETRYABLE = new Set([
  "RATE_LIMITED", "INTERNAL_ERROR", "UPSTREAM_UNAVAILABLE",
  "UPSTREAM_RATE_LIMITED", "SERVICE_UNAVAILABLE",
])

async function withRetry(fn, attempts = 4) {
  for (let i = 0; ; i++) {
    try {
      return await fn()
    } catch (err) {
      if (!RETRYABLE.has(err.code) || i >= attempts - 1) throw err
      const wait = err.retryAfter ? err.retryAfter * 1000 : 500 * 2 ** i
      await new Promise((r) => setTimeout(r, wait + Math.random() * 250))
    }
  }
}

See the full list in Errors.