FableCut

A browser video editor that AI agents can drive.

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https://github.com/user-attachments/assets/2430b854-168b-4a9a-af2e-489e5efa7543

FableCut is a Premiere-style non-linear video editor that runs entirely in your browser — and exposes its whole timeline as one JSON document. Edit it by hand, from the UI, or let an AI agent (Claude Code, Claude Desktop, or anything that speaks MCP/REST) cut your video for you while you watch the timeline update live.

Zero npm dependencies. One node server.js. That's it.

Why it's interesting

Most "AI video" tools hide the edit behind an API. FableCut flips that: the project file is the interface. project.json describes media, clips, tracks, effects, keyframes and transitions — any process that can write JSON can edit video, and the open browser UI hot-reloads within ~150 ms via server-sent events. A human and an agent can work on the same timeline at the same time.

Features

Editing

• Video + audio tracks (default 3+4; add more with +V / +A in the track header; right-click an empty header → Remove track), drag/trim/split/snap, undo/redo
• Settings (cog in the top bar) — optional prefs stored in this browser via localStorage. Enable Link timeline and Project bin selection so picking a timeline clip highlights its media in Project, and clicking a Project item selects every timeline clip that uses it (off by default).
• Video + audio tracks (default 3+4), drag/trim/split/snap, undo/redo
  • +V / +A in the track header add a video or audio lane (up to 16 each)
  • Right-click an empty track header → Remove track (disabled if the lane has clips, or if it would leave you with zero video/audio tracks)
  • Track header S solos that lane (mutes all others); click again to restore the previous mute state. Using the mute toggle while soloed exits solo.
  • Track targeting — click a track's name to target / untarget it (lit = targeted). Split, insert, ripple, close gap and jump-to-cut touch targeted tracks only; the eye / speaker toggle is output-only (hide from preview and export) and no longer blocks edits. A selected clip is edited wherever it sits.
  • Track lock — the padlock in the track header. Nothing on a locked track can be moved, trimmed, split or deleted, and ripples leave it in place while the other tracks shift — lock the music bed and re-cut the picture freely.
• Clip lock, disable and unlink — right-click a clip (or use the toggles at the top of the inspector): Lock pins it like a locked track; Disable (⇧E) keeps it on the timeline but hides it from preview and export; Unlink (Ctrl/Cmd+L) splits a video from its audio so they move separately, and Link re-joins them once they line up again. Agents see locks too: fablecut_patch_project refuses to edit locked clips unless the op says force: true.
  • Dropping a video with more audio channels than A-tracks adds the missing lanes automatically (up to 16) and toasts how many were added; each channel becomes a linked stem on its own A-track
• Direct manipulation on the monitor — click a clip or title on the preview to move, resize (corner handles), or rotate (top handle, Shift-snap) it directly
• **Timeline multi-s