Trunk works like git for a product's design

Decision

Trunk keeps a product's design the way git keeps code.

• Main is the approved design. Nobody edits main directly.
• An edit goes to your draft. Nobody creates a branch to start. Review names the draft and saves it as a new branch or into an open branch.
• Verify compares a branch with the captured site, or with any URL the person gives. It returns a match score.
• Merge puts a branch onto main. Only someone who can merge does it.
• A tag names a version of main, like a release. Every page, component, token and icon keeps its own history inside it.
• Sync. Every merge to main syncs every open branch and every draft. A conflict never stops a sync; it is marked and must be settled before that branch merges.
• Complete and Delta. A branch shows either main with its changes, or only its changes.
• A product starts from a URL (captured) or blank.
• After a capture, Trunk shows Analysis: scores, an AI analysis with ranked fixes, and detail. It only reports (2026-10-17-analysis-read-only).
• AI mode works in the editor on what is selected. Every AI change goes to the draft, never to main.

The rules are in branch-verify-merge. The editor around them is design-set, set by 2026-10-18-editor-redesign.

Why

• One shared file with autosave lets anyone break the design for everyone. A draft and a branch keep main safe until the change is checked.
• Verify answers "did my change drift from the real product?" with a number.
• The owner's flow, given on 2026-10-14, is the spec: capture or start blank, read Analysis, change it, verify, merge, tag.

Impact

• History is Versions: tags on main, history per thing, compare any two.
• Onboarding: Company → Plan → Setup → Capture → Analysis. See onboarding-steps.
• Access levels gain Can merge. See access-levels.
• The free month and Team: plans.

Status

Active.

Sources

• The owner's instructions in the sessions of 2026-10-14 and 2026-10-15.