GitHub published an experimental preview on October 28, 2026 that lets Copilot Fusion add eligible local models to its smart routing and split tasks between local and cloud models. The same announcement states that routing decisions are still made in the cloud. A model running on a developer's machine and a coding session that needs no network at all are two separate things. The first is confirmed. The second has to be checked against a specific setup.

Copilot Fusion is GitHub Copilot's model routing and task coordination layer. Based on the request and the models available, it picks a model and feeds that model's output into the rest of the coding workflow. It answers which model handles a task. It does not move the whole workflow onto local hardware.

For anyone evaluating this feature, three questions carry the weight. Who chooses the model, which model performs inference, and what resources the tools touch while they run.…