Rayfin signals Microsoft’s push to make Fabric an AI app runtime
For enterprises embracing AI-assisted development, writing code is no longer the hardest part. Operationalizing it is. Microsoft is targeting that challenge with Rayfin, a new open-source SDK and CLI unveiled at Build 2026. “Rayfin turns backend development into a code-first workflow. Developers and coding agents can define a full application backend in code, including databases, business logic, APIs, identity, and access policies, and deploy it to Microsoft Fabric for a fully managed, enterprise-grade backend,” Shireesh Thota, CVP of databases at Microsoft, wrote in a blog post. In effect, Thota added, this approach cuts down the manual integration work and time typically required to connect backend systems once an application front-end is built. Explaining further, how Rayfin works, the top executive said that developers or coding agents working on their behalf define the entire backend using the SDK, and then that definition is deployed directly to Fabric using the CLI. Governance,