seam

Command-line tool for Seam Video — a flowing video editor where edits are defined as JSON (.seam files). Instead of absolute timecodes, clips are defined by their source ranges; everything shifts automatically when you add, remove, or reorder.

This package is self-contained: it bundles the Seam core, renderer (headless WebGPU compositing via Dawn), and the Electron preview app. Native rendering dependencies (WebGPU/Dawn, Skia canvas, ffmpeg-free mux via mediabunny) install as prebuilt binaries.

Install

npm install -g @seam-media/cli

Requires Node.js >= 22.

Usage

Usage: seam [options] [command]

Commands:
  render [options] <file>   Render a .seam file to mp4
  preview <file>            Open an Electron preview of a .seam file
  resolve [options] <file>  Print the resolved timeline JSON for a .seam file
  help [command]            display help for command

Render

seam render test.seam

Validates the .seam file and renders it to test.mp4. Output dimensions come from the root composition's contentWidth/contentHeight, or override with --width/--height. Quality presets (--quality) range very-low → very-high.

Preview

seam preview test.seam

Opens a live-updating Electron preview that reloads on file changes.

Resolve

seam resolve test.seam

Prints the resolved timeline JSON (temporal + spatial layout) to stdout, or to a file with -o.

License

MIT — see LICENSE.