Promos / New free tier
Hiro Stacks API
Free Stacks Blockchain API from October 30, with paid plans retired.
What you get
Free access to the Stacks Blockchain API, anonymously or with a free API key, with no monthly usage caps.
How to get it
Call the API without a key, or create a free key in the Hiro Platform.
What it requires
Nothing for anonymous use; a free Hiro Platform API key for higher limits.
The catch
It starts October 30, 2026, and final rate limits will be published in the API docs before then. The legacy x-hiro-api-key and x-partner headers stop working; use x-api-key.
From the official page · checked Oct 26, 2026
Details
Hiro is retiring all paid Stacks Blockchain API plans on October 30, 2026. From then, anyone can call the API anonymously with no signup or key, or use a free API key for higher limits. Hiro expects limits of 5 to 83+ requests per second depending on the operation, with no monthly caps.