Quick Start

Betamax currently supports macOS and Linux. Windows is not supported because the upstream libghostty-vt-sys native build does not support Windows.

Install

cargo install betamax --locked

GIF, PNG, screenshot, and state JSON outputs are written in process. MP4 and WebM output require ffmpeg on PATH:

# macOS
brew install ffmpeg

# Debian/Ubuntu
sudo apt-get update
sudo apt-get install ffmpeg

Create A Tape

betamax new demo.tape

The starter tape includes a compact command summary and writes demo.gif by default. Render it with:

betamax run demo.tape

Append an extra output from the CLI without editing the tape:

betamax run demo.tape --output target/demo.png

The output path is appended as another Output command. It does not replace outputs already in the tape.

Validate Tapes

Validate one tape or a group of tapes without rendering:

betamax validate demo.tape
betamax validate "examples/*.tape"

Validation parses syntax and enforces command ordering. It does not start a shell, load a theme, run Require checks, or write output files. Use betamax run for a full execution check.

List Themes

betamax themes
betamax themes --json
betamax themes --markdown

Use the exact theme name with Set Theme "...". See Themes And Styling for lookup behavior, layout settings, and frame decoration.

Repository Examples

Clone the repository to render the checked-in examples:

git clone https://github.com/joshka/betamax
cd betamax
pnpm install
scripts/render-examples.sh

Rendered outputs are written under examples/output and copied to target/betamax-examples for local inspection. The Examples page explains what each tape demonstrates. The Tape Reference documents every command and setting.