Rate limits
Per-key request limits and the headers that describe them.
Mercel rate-limits requests per API key. Limits are independent — exceeding a limit on one key does not affect other keys.
Default limits
| Credential | Limit |
|---|---|
API key (mercel_sk_…) | 300 requests / minute |
Personal access token (mercel_pat_…) | 120 requests / minute |
Throttled responses
When you exceed the limit, the API returns 429 Too Many Requests:
{
"error": {
"code": "RATE_LIMITED",
"message": "Rate limit exceeded",
"details": { "retryAfterMs": 1000 }
}
}The throttled response includes these headers:
| Header | Description |
|---|---|
Retry-After | Seconds to wait before retrying. |
RateLimit-Reset | Seconds until the window resets (mirrors Retry-After). |
RateLimit-Remaining | Always 0 on a 429. |
Clients should back off and retry; do not treat 429 as a permanent failure.