cm-render reference (20260106)

February 15, 2026 · View on GitHub

Render the final MP4 using Remotion from visuals + timestamps + audio.

Synopsis

cm render [options]

Inputs

--input: visuals JSON from cm visuals
--audio: audio WAV from cm audio
--timestamps: timestamps JSON from cm audio (default timestamps.json)
--audio-mix: optional mix plan from cm audio

Outputs

Video MP4 at --output (default video.mp4)

Options

-i, --input <path>: input visuals JSON file (required)
--audio <path>: audio file path (required)
--audio-mix <path>: audio mix plan JSON file (optional)
--timestamps <path>: timestamps JSON file (default: timestamps.json)
-o, --output <path>: output video file path (default: video.mp4)
--template <idOrPath>: render template id or path to template.json
--allow-template-code: allow executing Remotion code templates (dangerous)
--template-deps <auto|prompt|never>: code-template dependency install mode
--template-pm <npm|pnpm|yarn>: code-template package manager
--orientation <type>: portrait|landscape|square (default: portrait)
--fps <fps>: frames per second (default: 30)
--hook <idOrPath>: hook intro clip id, local path, or URL
--hook-library <id>: hook library id (defaults to config)
--hooks-dir <path>: root directory for hook libraries (defaults to config)
--download-hook: download hook clip from the selected library if missing (default: false)
--mock: use mock renderer (writes a placeholder MP4)
--download-assets: download remote visuals into the bundle (default: true)
--no-download-assets: stream remote visuals directly (no download)
--preflight: validate inputs and exit without rendering

Global options

-v, --verbose: enable verbose logging
--json: print a schema-versioned JSON envelope to stdout
--offline: disable on-demand downloads
-y, --yes: allow safe auto-downloads where supported

Exit codes

0: success
1: failure
2: invalid arguments / missing files / invalid JSON

Examples

cm render -i out/visuals.json --audio out/audio.wav --timestamps out/timestamps.json -o out/video.mp4
cm render -i visuals.json --audio audio.wav --orientation portrait --fps 30
cm render -i visuals.json --audio audio.wav --audio-mix audio.mix.json --timestamps timestamps.json -o video.mp4

# Render a code template (opt-in required)
cm render -i visuals.json --audio audio.wav --timestamps timestamps.json \
  --template remotion-tiktok --allow-template-code -o out/video.mp4

Notes

Local visuals with source: "user-footage" are copied into the render bundle for reliable playback.
Use --download-assets (default) to cache remote stock footage inside the bundle.
Local clips are validated before render (file size + optional ffprobe); install ffprobe for deeper checks and clearer errors.
Code templates execute arbitrary JS/TS during bundling/rendering and are denied by default (require --allow-template-code).