Agents

Today Microsoft unveiled the Microsoft Copilot harness in Foundry Agent Service. With the new harness (built on what was previously known as the GitHub Copilot SDK), Microsoft Foundry prompt agents can read and write files in the agent workspace, perform web searches, run shell commands in a sandboxed session, spawn subagents, and add standard agent skills (via a SKILL.md or the Foundry Skills Catalog).

I’ve been intrigued by the GitHub Copilot App ever since it first shipped at Build a few months ago. It offers a different way of working for me, and I’m getting more comfortable with it every day. One thing that held me back was its lack of support for repositories in WSL. That has now changed.

Microsoft Build is always packed with big announcements, but my favorite part is bringing those ideas back home and figuring out what actually helps teams ship better software. On June 20th, we did exactly that at Microsoft Build \\localhost:columbus.

Microsoft Build is a two-day event this year (after being three days in prior years). That’s in line with the overall smaller Build - fewer attendees, smaller venue, and fewer days. There was no day 2 keynote either. For me, day 2 was full of breakout sessions, a hands-on lab, and great conversations with Microsoft and GitHub employees.

I attended Microsoft Build in person on June 2, 2026. Below are my observations from day one. I’ll post a day-two update, as well as a wrap-up after the event.