Crypto APIs API Versioning
An additional feature in the Crypto APIs system allows us to generate new API versions of our endpoints each time backwards-incompatible changes have been made to them. Versions are generally titled with a date and "stable" versions are marked as such. You can try out new features and changes in our newer versions not marked as "stable". Our technical documentation lists all available API versions. To view a specific one, select it from the drop down menu. All requests use your account's API version, unless you override the API version with a header.
The request header that you should use to select a chosen API version: header: x-api-version