Authentication

All API requests require a Bearer token in the Authorization header.

API Key

Authorization: Bearer pk_live_xxxxxxxxxxxx

Generate keys in Dashboard → Settings → API Keys. Each key is bound to a specific blog.

Rate Limits

Plan	Requests/hour
Free	60
Starter	300
Creator	1,000
Scale	10,000
Enterprise	10,000+

Rate limit headers are included in every response:

X-RateLimit-Limit: 300
X-RateLimit-Remaining: 299
X-RateLimit-Reset: 1711324800

When exceeded, you’ll receive a 429 response with retry_after seconds.

Error Format

All errors follow a consistent format:

{
  "error": "not_found",
  "message": "Post not found"
}

Status	Error Code	Description
400	bad_request	Invalid input
401	unauthorized	Missing or invalid API key
403	forbidden	Plan upgrade required (includes upgrade_url)
404	not_found	Resource not found
409	conflict	Duplicate resource (slug, domain)
429	rate_limit_exceeded	Rate limit hit (includes retry_after)
500	internal_error	Server error

Base URL

https://api.postlark.ai/v1

Interactive docs: api.postlark.ai/docs