# API rate limits

> How many requests the Acme API accepts, and how to handle a 429 response.

- **600 requests per minute** per API key
- **20 concurrent requests** per workspace

Every response includes these headers:

```text
X-RateLimit-Limit: 600
X-RateLimit-Remaining: 412
X-RateLimit-Reset: 1735689600
```

Over the limit you get **HTTP 429** with a `Retry-After` header in seconds. Wait that long, then retry; don't retry in a tight loop.

---
Source: https://acme.kbshelf.com/a/api-rate-limits/ · Updated 2026-11-02