Custom Engine Agents Coming to Microsoft 365 Apps: A Unified AI Ecosystem

Custom Engine Agents are going to be available in the Microsoft 365 apps (Word, Excel, PowerPoint, and OneNote) alongside the existing access to Copilot and declarative agents.

These are agents you build either in Copilot Studio (full) or other platforms outside of Microsoft 365 and can have different orchestration approaches and be plugged into other services in different ways.

Being able to access the same pool of agents everywhere makes a lot of sense and is a positive step forward. Although there is one class of agents (perhaps two with what was announce yesterday for OneDrive) that still behave a little differently - that's SharePoint Agents. So still a little more work to do here.

It continues to be exciting to see the degree to which Copilot services are now coming together in a clearly integrated ecosystem-wide plan giving all users more opportunity to get the best from these tools without having to worry too much about where they happen to be working.

First posted on Linkedin on 10/11/2025-> View Linkedin post here