Copilot Fusion routes one task through one or more models

Copilot Fusion is generally available in VS Code, the Copilot app, Copilot CLI and JetBrains IDEs. Standard, High and Max effort can use a single model, a cascade that escalates after a quality check, or a draft–critique–revision loop. GitHub reports a score of 60 for Fusion Max in the Artificial Analysis Coding Agent Index, within two points of Claude Code with Opus 5.5 Max, at about half the average API cost and 40% less task time. Those are vendor-reported results from one benchmark. Run the same repository tasks under Fusion and your current fixed model, then compare accepted patches, wall time and billed model calls before changing the default. ²

Relevant to: Copilot teams considering automatic model selection and multi-model review.