Microsoft just reframed what GitHub Copilot is supposed to be. On the Build keynote stage, Cassidy Williams walked through a brand-new GitHub Copilot desktop app that has very little to do with autocomplete and almost everything to do with orchestrating fleets of coding agents. Pair it with a new open-source SDK called Rayfin, and the pitch becomes clear: GitHub wants to be the place agents do the work, not just a sidebar that suggests the next line.

The shift is deliberate. The new app represents a move to bring agentic workflows into a native desktop experience, shifting the developer assistant from a reactive partner to a proactive orchestrator. This isn't about better autocomplete; it's about changing how you delegate complex, multi-step tasks.

One desktop, many agents, no stepping on toes

The headline interaction in the demo was deceptively simple. A release had a long list of blockers, and Cassidy selected all of them at once. The app kicked off a separate session for every issue. The trick that makes this safe is purely mechanical: each session runs in its own git worktree, which is a separate working copy of a code branch. Each agent gets its own little workspace, so multiple agents can work in parallel without stepping on each other.

From there, the app acts as a control plane. From a single My Work view, you can see work in motion across connected repositories: active sessions, issues, pull requests, and background automations. That matters because agentic development creates a new kind of operational sprawl, where one agent investigates a bug, another works through a backlog item, and another updates a pull request after review. Without a control plane, that quickly becomes hard to audit.

Canvases: where agents show their work

Chat alone is a thin interface for agents that are editing files, running tests, deploying services, and burning tokens in the background. The Copilot app introduces a second surface called canvases. A canvas might show a plan, pull request, browser session, terminal, deployment, dashboard, or workflow state. Agents update the canvas as they work, and developers can edit, reorder, approve, or redirect that work on the same surface. This is the beginning of agent experience (AX) in the Copilot app: interfaces where people and agents operate together.