Glossary
What is rate limiting?
Rate limiting is a site's or API's cap on how many requests a client can make in a time window, such as 10 form submissions an hour from one IP address. Going over usually returns HTTP 429 Too Many Requests or a block. Agents and automation should pace themselves to stay well inside limits.
How it's applied
- Per IP address, account, API key or session.
- Fixed windows (100 per hour) or sliding windows and token buckets.
- Stricter on sensitive actions: sign-ups, logins, form submissions.
The standard response is HTTP 429 Too Many Requests, sometimes with a Retry-After header saying when to try again.
For agents and automation
Spread actions out, honour Retry-After, and don't run parallel sessions against one site. For directory submissions, a few minutes between directories looks like a normal person working through a list and avoids tripping limits or bot protection.
Example
A script submits to 30 directories in two minutes; several block the IP for a day. An agent submitting one every three minutes over 90 minutes completes all 30 without a block.
Rate limits on APIs you use
AI model providers and other APIs rate-limit by requests and tokens per minute. Agents that call models or APIs in loops should handle 429 responses with backoff, waiting longer after each retry.
FAQ
What does error 429 mean?
Too many requests: you've hit a rate limit.
How long do rate limits last?
Depends on the site; Retry-After headers tell you when available.
Do rate limits apply to logged-in users?
Often per account as well as per IP.
What is exponential backoff?
Waiting longer after each failed retry, such as 1, 2, 4 and 8 seconds, to avoid hammering a limited service.