Credits APIs are now publicly available for merchants & tech partners.

Previously, credits could only be applied manually in the portal or automatically through Rewards flows, which limited ways you could reward and engage your customers. With the Credit Account and Credit Adjustment endpoints, you can now issue, track, and manage credits programmatically to power custom experiences (for example, rewarding reviews, shares, or other engagement), and partners can integrate credit-based incentives into their tools.  

Note: Apps using these endpoints can only be installed on stores that have access to Rewards.

Developer documentation and API references are available here.