API Rate Limiting Explained: 429 Errors

Rate limiting caps how many requests a client can make in a time window. It protects the service from overload and abuse, and it protects you from runaway scripts.

How limits work in the SyllHost API

The limit is set per account and applies per key. The default is 60 requests per minute.
Over the limit you receive 429 rate_limited and a Retry-After header with the seconds to wait.
Repeated invalid keys from one IP are blocked for a while.
You can read your limit with GET /account (rate_limit_per_minute).

What a 429 looks like

HTTP/1.1 429 Too Many Requests
Retry-After: 23
{"error": {"code": "rate_limited", "message": "Too many requests."}}

How to stay within limits

Cache catalogue data. Plans and domain prices change rarely. Cache /products and /domains/tlds for minutes or hours.
Avoid polling in tight loops. Poll a pending service every 30 to 60 seconds, not every second.
Use pagination properly. Request per_page=100 instead of many small pages.
Queue background work and process it at a steady rate.
Respect Retry-After. Sleep for that many seconds before retrying.

Simple handling in code

if r.status_code == 429:
    time.sleep(int(r.headers.get("Retry-After", 5)))
    # then retry the same request (same Idempotency-Key if it was an order)

Need a higher limit?

If your integration legitimately needs more, contact us. Limits are configurable per account.

Why limits exist

Without limits, one faulty script can send thousands of requests a minute and slow the service for everyone. Limits also stop credential-guessing attacks. They are a safety net for you as much as for the provider: a bug in your loop is stopped before it does real damage.

A polite client

Spread requests evenly instead of bursts.
Use a queue with a worker that sleeps between calls.
Stop immediately on 401 or 403 instead of hammering the API.
Add jitter to retries so many workers do not retry at the same second.

Estimating your needs

Count requests per customer action. A checkout might use one domain check, one order and a couple of polls, around 5 to 10 calls. With a limit of 60 per minute you can handle several customers per minute comfortably. Only large batch jobs need a higher limit or throttling.

FAQ

Does a 429 charge me?

No. A rate-limited request is rejected before any action is taken.

Are limits per IP or per key?

Per key. Failed authentication attempts are additionally throttled per IP.

Build with our API: read the Reseller API reference and the step-by-step guide. API access is enabled per account, so contact us to request it.

API Rate Limiting Explained: 429 Errors and How to Handle Them