A free key, after the demo
The free plan is for people building something. Start with the public demo key, which works right now with no sign-up, and request your own key once you have a working integration.
The demo key is published in the documentation, with every variable and example. It has the same data and the same limits as a free key, but it is public, and we change it from time to time without notice: fine for testing, not something to build a product on.
When your integration works with the demo key, request a permanent free key for it. Free keys are issued by email, typically within 24 hours, and there is no guarantee that a key will be issued.
The Starter and Pro plans are issued immediately, on the page, the moment a subscription starts. See the plans.