As we grow, we're constantly refining our API by adding new capabilities and sometimes by removing or replacing features that aren't working as well as we'd like. To make these changes easier to follow, we've created a new mailing list, available on Google Groups. Going forward, we'll send updates to this mailing list any time we add or change something in the Stripe API.
Whenever we change our API, we make every effort to ensure we won't cause problems for any of our existing users. One of the main ways we maintain backwards compatibility is by marking accounts with specific flags that tell our API to return an older version of a particular response, or enable an older set of input parameters. New users immediately get the new behavior, and we can work with our existing users over time to upgrade their Stripe integrations.
This same system works with Stripe Connect, to ensure that an application accessing many Stripe accounts can still work with a consistent API, even if the individual accounts use a different set of flags when talking to Stripe on their own. If you aren't using Stripe Connect, but you are still working with code used across multiple Stripe accounts (e.g. a Stripe API library), you may need different code for some accounts. If so, it is especially important to sign up for this new list to be updated about changes.