How agents edit safely

Handing your project to an autonomous editor raises a fair question: what stops it trampling your work? The mechanics are built for co-editing, and they’re worth understanding once.

You’re both editing the same live document

Your canvas and the agent read and write the same project document. The agent’s edits appear on your canvas as it makes them — and your edits appear in its next read.

• It can’t overwrite you. Every write carries the document version it was based on. If you changed something in the meantime, the write is rejected, the agent re-reads, re-applies its change on top of yours, and tries again. Merging is its job, not yours.
• Small, typed edits. For most changes the agent uses typed operations (“add this layer to that scene”) rather than rewriting the whole document — smaller edits, fewer surprises.
• It verifies as it goes. After each write it re-reads to confirm the structure it meant to create actually exists, and at milestones it renders real frames and inspects them before continuing.

You can see what it’s doing

• Presence — a connected agent shows up in the editor with a live status line of what it’s working on.
• Notes — it posts short notes to your activity feed when it finishes something or needs an answer.
• Draft marker — during multi-pass builds the composition carries a work-in-progress marker, cleared only when the agent’s final self-review passes. A build that’s still cooking looks like it.

It can put things on the workspace shelf

An agent works inside one project, but the material it finds or makes doesn’t have to stay there. Ask it to save something “to the workspace” — a brand typeface it pulled from your site’s @font-face rules, a logo it fetched, an image it generated — and it files it in the Library where every project can use it. It can also share something that already exists: “share that logo with the workspace.”

The default is deliberately the other way round. An agent working in a project files things in that project, because a screenshot for one scene on the shared shelf is clutter everyone else has to scroll past. Brand material is a decision, so it’s asked for rather than assumed — and because sharing is one-way, it’s the right default to be conservative about.

And nothing is special

The most important safety property is boring: everything the agent makes is ordinary scenes, layers, assets, and animations. There is no agent-only state — anything it did, you can undo, restyle, retime, or delete in the editor.

And every update is versioned: Mixture keeps snapshots of the document as you and the agent work — agent edits, your edits, autosaves — the twenty most recent per project. Your agent can already list them and restore one on request (“put it back to before you changed the titles”); doing that yourself from the editor is coming.