Microsoft 365 Developer Blog
A developer platform for building collaborative apps for hybrid work
Latest posts
Dev Proxy v1.0 with new features for building robust AI-powered apps
Introducing Dev Proxy v1.0, with new language model-specific testing capabilities to help developers build more reliable AI-powered applications by simulating real-world scenarios and tracking resource usage.
Build Smarter with the Microsoft 365 Agents Toolkit MCP Server
Bring your own agents into Microsoft 365 Copilot
Custom Engine Agents now generally available—build and integrate your own AI into the flow of work Microsoft 365 Copilot is redefining how people interact with AI—embedding it directly into the flow of work as the intuitive, natural interface for agents: the ‘UI for AI’ As Copilot becomes the interface for AI in the workplace, we’re seeing growing demand from customers who want to extend its capabilities with their own solutions. Many of our customers are looking to create custom agents—or have already built agents that operate outside the Microsoft 365 ecosystem—using fine-tuned models, custom logic, orchest...
Supercharge your EWS migration with AI and GitHub Copilot
We're announcing a new tutorial that helps developers migrate solutions from EWS to Microsoft Graph using AI and GitHub Copilot.
Microsoft 365 Copilot APIs: Unlocking enterprise knowledge for AI with the Retrieval API — Now in Public Preview
Read how the Retrieval API gives developers a secure, compliant and scalable way to integrate enterprise content into their AI workflows.
Dev Proxy v0.29 with refactored architecture, MCP server, and exposed LM prompts
Introducing Dev Proxy v0.29, with a major architectural overhaul, control over language model prompts, and improved diagnostics.
Deprecation of MS-APP-ACTS-AS header in Shifts Management Microsoft Graph APIs
In app-only access scenarios, Shifts Management Graph APIs previously required the MS-APP-ACTS-AS: userId header to indicate the user on whose behalf the application was acting. However, this conflicted with the Microsoft Graph permission model where there is no signed-in user for app-only access scenarios. To align Shifts Graph APIs with this model, the MS-APP-ACTS-AS header has now been deprecated. What Action You Need to Take If you don’t send the header today There is no impact. No changes are necessary. If you send the header today 1. Please remove the header. Example: Old: New: ...
Dev Proxy v0.28 with LLM usage and costs tracking
The latest version of Dev Proxy introduces a new ability to help you understand language models’ usage and costs in your applications, alongside many improvements to mocking, TypeSpec generation, and plugin flexibility.
Build like Microsoft: Developer agents in action
Take a deep dive into Athena, an AI-powered collaborative agent, to learn how it was built and how to create your own version of Athena right within Microsoft Teams.