Microsoft launches Rayfin to let developers and agents build app backends on Fabric
Microsoft Corp. today introduced Rayfin, an open-source software development kit and command-line interface that lets developers and coding agents define an entire application backend in code and deploy it onto Microsoft Fabric.
Announced at Microsoft Build 2026, Rayfin targets a gap that has widened as artificial intelligence has made it trivial to spin up an app frontend. The backend, including data, identity and access policies, still requires teams to stitch together multiple services and governance and compliance often get added too late. Many teams hit enterprise requirements they never designed for and end up re-platforming to reach production.
With Rayfin, developers or the coding agents working on their behalf define data models, application programming interfaces, business logic, access policies and connections to existing data sources in one place. The definitions are strongly typed, so coding agents such as GitHub Copilot can read and modify them with the same reliability as a human. The CLI handles deployment to Fabric and stands up the databases, authentication, access policies and APIs, work that teams would otherwise wire together by hand.
