Microsoft’s new Windows Copilot Runtime aims to appeal to AI developers

Microsoft yesterday launched a line of Copilot Plus PCs that include new AI features built right into Windows 11. Behind the scenes, the company now has more than 40 AI models running on Windows 11 thanks to a new Windows Copilot Runtime that will also allow developers to use these templates for their applications.

Today at Microsoft Build, the company is providing much more detail on how exactly this Windows Copilot Runtime works. The runtime includes a library of APIs that developers can leverage for their own applications, with AI frameworks and toolchains designed to allow developers to deliver their own models on-device on Windows.

“The Windows Copilot library includes ready-to-use AI APIs such as Studio Effects, Live Captions Translations, OCR, Recall with User Activity and Phi Silica, which will be available to developers in June,” says Pavan Davuluri, head of Windows and Surface.

Developers will be able to use the Windows Copilot library to integrate things like Studio effects, filters, portrait blur, and other features into their apps. Meta adds Windows Studio effects to WhatsApp, so you’ll benefit from features like background blur and eye contact during video calls. Even live captions and the new AI-powered translation feature can be used by developers with little to no code.

Microsoft introduced its Recall AI feature yesterday, allowing Copilot Plus PCs to document and store everything you do on your PC so you can recall memories and search a timeline. All of this is powered by a new Windows Semantic Index that stores this data locally, and Microsoft plans to allow developers to create something similar.

“We will make this functionality available to developers with the Vector Embeddings API so that they can create their own vector store and RAG within their applications and with their application data,” says Davuluri.

Developers will also be able to enhance Windows’ new Reminder feature by adding contextual information to their apps that will populate the database that powers this feature. “This integration helps users pick up where they left off in your app, improving app engagement and the seamless flow of users between Windows and your app,” says Davuluri.

All of these improvements in Windows for developers are the very first building blocks for more AI-driven applications on top of its new Arm-powered systems and NPUs coming soon from AMD and Intel . As Microsoft builds the platform for developers to create AI applications for Windows, it is now counting on this as an important part of the next decade of Windows development. On stage at Build today, Davuluri stood in front of a slide that read “Windows is the most open platform for AI,” signaling how important this moment is for Microsoft.