Module 7 · FusionVerified 2 Nov 2026
Copilot Fusion
Fusion is not another model. It is a way of coordinating models so one answer gets drafted, challenged and refined before you see it.
- 1
Draft
A first model produces an initial answer or plan.
- 2
Critique
Another model looks for bugs, gaps and wrong assumptions.
- 3
Revise
The draft is improved using that feedback.
- 4
Deliver
You see one final answer, not the back-and-forth.
| Single model | Copilot Fusion | |
|---|---|---|
| Speed | Fastest | Slower, several passes |
| AI credits | Lowest | Noticeably higher |
| Best for | Routine and quick tasks | High-value, well-scoped work |
| Error catching | One pass | Built-in second opinion |
Preview and availability
Fusion is an early-access feature. Availability, tiers and pricing can change and depend on your plan and VS Code setup, so check your model picker and the official page below.
Do
- ✓ Migrations with tests that define done
- ✓ Security-sensitive reviews, then verify the findings
- ✓ Architecture decisions that are expensive to reverse
- ✓ Give it acceptance criteria up front
Don't
- ✗ Renames, formatting or small edits
- ✗ Open-ended exploration with no goal
- ✗ Treat its output as a guarantee
- ✗ Leave it on by default
Rule of thumb: if a wrong answer would cost you more than an hour, an extra review pass is usually worth it. If you would spot the mistake in seconds, use a single model.