how fusion coding works
Fusion builds and fixes. You approve and ship.
Point Fusion at a new task or an open pull request. Rival models from different labs compete, a blind jury picks the winner or fuses the best of each, and your own tests verify all of it. Don’t trust the result. Inspect the proof.
Every run happens in isolated git worktrees, on your own computer, shown live on the Fusion dashboard.
Your live code and your tests stay untouched until you approve the result.
the flow, end to end
build · a task goes in
You hand it a task
A goal, plus your repository.
goal: "add a rate limiter"repo: your-appreview · a pull request comes in
You point it at a PR
An open pull request that already exists.
pull request #69One Fusion engine, runs locally
same pipeline for build and review
- 1
Freeze the ask
The task or PR becomes a frozen brief with a Definition of Good. Nobody moves the goalposts after the race starts.
- 2
Fork the work
Rival agents from different labs take the brief into isolated git worktrees, blind to each other.
candidate/<model>/<run>candidate acandidate bcandidate c - 3
Let execution say no
Your build, tests, and lint grade every attempt against a clean baseline. The gate cannot be sweet-talked, and the polished failure leaves here.
- 4
Identity leaves the room
Blind judges score the survivors criterion by criterion. Every verdict is recorded with its reasoning, dissent included.
- 5
Fuse the best
An integrator grafts the jury’s flagged insights into the winning branch. Every line keeps its provenance.
- 6
Fresh eyes re-run everything
A second jury pass judges the fused result before versus after, and an independent QA pass re-runs the whole gate.
- 7
Print the proof
The Receipt: what ran, what passed, who agreed, who dissented, pinned to the exact commit. Portable, keepable, replayable.
- 8
Stop before ship
The prepared result reaches your pull request. A human merges, or nothing does.
build · a pull request goes out
A new PR, in GitHub
Opened on a clean branch, carrying the check it earned.
branch: fusion/<run>-rate-limiter✓ fusion/verifiedOpened for review. Not merged.
review · a fix comes back
A prepared fix on your PR
Fusion prepares the repair, re-verifies it against your gate, and posts it back: one grouped comment, one status check.
✓ verified fixWhen a fix cannot be proven, the finding is flagged for human judgment instead. Never stamped verified.
the proof
Every run leaves two proofs you can keep.
A Receipt of what competed and what passed, and a replay of the whole run you can watch back. Verified means the product proved it, not that someone said so.
Fusion never presses the button.
- never merges
- never ships
- never force-pushes
- never touches branch protections
It opens the door and steps back. You decide what gets merged, and you are the one who merges it.
today
Fusion starts from your terminal or the coding tool you already use. You watch it run on the dashboard. The prepared code goes to your own GitHub account.
on the roadmap
A hosted GitHub App where pull requests arrive automatically and the whole run lives in one web view.
Bring a task. Keep the receipt.
We’re onboarding design partners now. First runs happen on your repository, with your tests as the law.
get early access