Cutloupe

Cutloupe is an MCP server with a live studio. Your agent (Claude Code, Antigravity, Codex, or any MCP client) edits a real timeline: cuts, titles, shapes, keyframes, captions, music. You watch each edit land in the studio and can edit alongside it. Before the agent calls the job done, the look tool renders the actual frames and returns them as an image, so the agent checks its own work instead of guessing.

When you are finished, export an MP4, or carry the timeline into DaVinci Resolve, Premiere Pro, CapCut or Remotion.

Why it exists

Agents can already write ffmpeg commands and Remotion code. What they cannot do is see the result. They hand back a file and hope the title is not sitting on the subtitle. Cutloupe gives the agent eyes on the same compositor that produces the export, and gives the person a live view of what the agent is doing so they can step in early.

Related MCP server: Lazynext MCP Server

What is in the box

Install

Requirements: Node 20 or newer, ffmpeg and ffprobe on your PATH, Chrome or Edge installed (used headless for rendering).

git clone https://github.com/bryankwandou/cutloupe
cd cutloupe
npm install
npm run build

Register the server with your agent.

Claude Code (run inside the cutloupe folder):

claude mcp add cutloupe -- node "$PWD/packages/mcp/bin/cutloupe.mjs"

Antigravity: Agent panel → MCP servers → Manage → View raw config, then add:

{
  "mcpServers": {
    "cutloupe": { "command": "node", "args": ["C:/path/to/cutloupe/packages/mcp/bin/cutloupe.mjs"] }
  }
}

Codex CLI (~/.codex/config.toml):

[mcp_servers.cutloupe]
command = "node"
args = ["C:/path/to/cutloupe/packages/mcp/bin/cutloupe.mjs"]

Then ask for something like: "Make a 20-second vertical teaser from intro.mp4 with bold captions and calm music, and check it before you export." The studio opens at http://127.0.0.1:4321 on the first edit.

To open only the studio, without an agent: node packages/mcp/bin/cutloupe.mjs studio.

The npm package is not published yet; install from GitHub for now.

Environment

Tools

Every edit, from the agent or from a person in the studio, goes through the same applyOp reducer and the same undo history. apply_ops applies a batch all at once or not at all.

Exports

Captions and music

extract_captions reads .srt/.vtt files, or the first subtitle stream in a video. If neither exists and Whisper (openai-whisper or whisper.cpp) is installed, it transcribes locally. Words get their own timings in every case.

The music library is six original tracks synthesized from code (packages/core/src/music.ts), released under CC0.

Edit ledger (Solana devnet)

Optional. With CUTLOUPE_KEYPAIR set, the ledger tool:

1. open_reel: creates a Reel account for the project (PDA ["reel", authority, reel_id]).

2. commit_cut: moves the reel head from the previous timeline hash to the new one. A stale prev is rejected (StaleHead).

3. seal_export: writes a Seal account (PDA ["seal", file_sha256]) for an exported file, only against the current head (NotHead otherwise). The seal records who edited (agent, person, both) and whether media or voice are synthetic.

Anyone can verify a file by hashing it; the website does this in the browser. Program ID G6kWfHR1X2tHFgwHvrc5soiXwUF4bYXprv7YMTJnx5eY. Transactions and checks are in docs/DEVNET.md.

Development

npm run build        # studio, server, site, core
npm test             # core unit tests (node --test)
npm run typecheck    # tsc --noEmit over every package
npm run smoke        # drives the real MCP server over stdio through every tool and export
npm run site         # serve site/ at http://127.0.0.1:4400
npm run walkthrough  # re-record the walkthrough video from the site and studio
CUTLOUPE_KEYPAIR=... npm run ledger:check   # devnet success and failure paths

Limits

• It does not generate footage. It edits and animates what you give it.

• Speech-to-text needs Whisper installed locally.

• The FCPXML, Premiere and CapCut exports pass structural tests, but have not yet been opened in Resolve, Premiere or CapCut on this release.

• MP4 export renders each frame in headless Chrome. An 8-second 1080p reel took 97 to 150 seconds on the test machine.

License

MIT. The music library is CC0.