Rate Limits

Understand API rate limits and how to handle them. Every request counts toward your plan’s hourly quota, and the API returns headers so you can track usage in real time.

For authentication setup, see Authentication.

Limits by Plan

Plan	Requests/hour	Posts/month	Blogs
Free	60	10 total	1
Starter ($9)	300	15	1
Creator ($29)	1,000	50	3
Scale ($79)	10,000	Unlimited	5
Enterprise ($199+)	10,000+	Unlimited	Unlimited

See Plans for full feature comparison.

Response Headers

Every API response includes rate limit headers:

X-RateLimit-Limit: 300
X-RateLimit-Remaining: 142
X-RateLimit-Reset: 1711324800

X-RateLimit-Limit — Your plan’s hourly limit
X-RateLimit-Remaining — Requests left in current window
X-RateLimit-Reset — Unix timestamp when the window resets

Reading headers in code

const res = await fetch('https://api.postlark.ai/v1/posts', {
  headers: { Authorization: 'Bearer pk_live_xxxxxxxxxxxx' },
});

const remaining = parseInt(res.headers.get('X-RateLimit-Remaining') ?? '0', 10);
const resetAt = parseInt(res.headers.get('X-RateLimit-Reset') ?? '0', 10);

if (remaining < 10) {
  const waitMs = (resetAt * 1000) - Date.now();
  console.log(`Low on quota. Resets in ${Math.ceil(waitMs / 1000)}s`);
}

When Exceeded

When you exceed your hourly limit, the API returns 429 Too Many Requests:

{
  "error": "rate_limit_exceeded",
  "message": "Rate limit exceeded. Limit: 60 requests/hour.",
  "retry_after": 1823
}

Wait retry_after seconds before retrying.

Post Packs (Starter+)

If you exceed your monthly post limit, you can purchase Post Packs as an add-on:

100 posts — $10 (no expiry)
300 posts — $25 (no expiry)

Monthly quota is consumed first, then packs. See Plans for pricing details and how to purchase.