Reliability

Throttle predictably and recover cleanly.

StateSet Voice protects tenant and platform resources with per-IP and per-tenant limits. Clients should read response headers, back off on 429, and treat call creation as a business operation.

Request API key Start building Endpoint guides Authentication Production readiness

Runtime APIBearer tenant keys

Admin APIx-admin-key

TelephonyTwilio signatures

SpecsOpenAPI 3.1

Headers

Header	Meaning
`X-RateLimit-Limit`	The request budget for the active limiter window.
`X-RateLimit-Remaining`	The remaining request budget after the current request.
`Retry-After`	Seconds to wait before retrying after a `429`.
`x-request-id`	Request correlation identifier to include in support and audit trails.

Retry behavior

async function requestWithBackoff(url, options, attempts = 4) {
  for (let attempt = 1; attempt <= attempts; attempt += 1) {
    const response = await fetch(url, options);
    if (response.status !== 429) return response;

    const retryAfter = Number(response.headers.get("retry-after") || "1");
    const jitter = Math.floor(Math.random() * 250);
    await new Promise((resolve) => setTimeout(resolve, retryAfter * 1000 + jitter));
  }

  throw new Error("StateSet Voice rate limit retry budget exhausted");
}

Operational guidance

Keep interactive admin tooling separate from batch or export jobs.
Use smaller pages and scheduled exports for call logs and voice sessions.
Alert on sustained 429 because it usually means a client loop or a traffic shift needs attention.