FableCut is a zero-dependency, browser-native non-linear video editor designed for AI agent control. It exposes its entire timeline as a JSON document, enabling programmatic editing via APIs (MCP/REST) or direct manipulation, while offering a live-reloading UI for real-time feedback. This approach allows AI agents to drive video editing workflows efficiently and facilitates concurrent human-AI collaboration.

How It Works

FableCut operates as a single-page application within a Chromium-based browser, powered by a minimal Node.js server. Its core innovation lies in representing the complete video project—media, clips, tracks, effects, and keyframes—as a single project.json file. This JSON interface allows any process capable of generating JSON to edit video. Changes are reflected in the UI almost instantly (~150ms) via server-sent events, enabling seamless interaction between the user interface, direct file edits, and AI agents.

Quick Start & Requirements

• Install: Clone the repository, navigate to the directory, and run node server.js. The editor will be accessible at http://localhost:7777.
• Requirements: Node.js 18+ and a Chromium-based browser are mandatory. ffmpeg installed and available on the system PATH is optional but recommended for faster export and upload remuxing. AI background removal models are downloaded from a CDN on first use.
• LAN Access: To use FableCut from another device on your local network, run HOST=0.0.0.0 FABLECUT_ALLOWED_HOSTS=<your-ip> node server.js.
• Documentation: Agent interaction details, schema, and recipes are available in CLAUDE.md.

Highlighted Details

• Supports 4 video and 3 audio tracks with standard NLE editing features like drag, trim, split, snap, multi-select, and undo/redo.
• Includes advanced features such as beat and cue markers, real-time audio waveforms, aspect ratio presets, and safe-area guides.
• Offers a comprehensive suite of visual effects, including 12 filter presets, adjustment layers, full color grading controls, blend modes, per-edge cropping, corner radius, flip, and chroma key.
• Features in-browser AI background removal (person cut-out) powered by MediaPipe.
• Enables keyframe animation on approximately 25 properties with easing, speed ramps, camera shake, and RGB split effects.
• Provides 17 built-in transitions, including fades, slides, wipes, zoom, glitch, and whip-pan.
• Supports kinetic captions with advanced font control (system, custom, Google Fonts) and styling options like gradient fills and neon glow.
• Allows authoring and rendering of CSS @keyframes-animated SVG clips for overlays and graphics.
• Includes a reference video analysis tool (analyze.js) to extract edit blueprints (shots, beats, BPM, music) for rebuilding edits with user footage.
• Implements conflict-safe concurrent editing using a revision counter to prevent data loss between UI and agent modifications.

Maintenance & Community

No specific details regarding maintainers, community channels (e.g., Discord, Slack), or roadmap were provided in the README.

Licensing & Compatibility

FableCut is released under the MIT License, permitting commercial use and integration into closed-source projects.

Limitations & Caveats

Optimal export performance and upload remuxing rely on an optional ffmpeg installation. The server binds to 127.0.0.1 by default in recent versions (v1.3.1+), requiring explicit configuration for network access. AI background removal requires an initial CDN download.