asciinema/asciinema

Asciinema is a command-line tool for recording and sharing terminal sessions. Instead of capturing a video file, it records what happens in your terminal as a lightweight text-based file in a format called asciicast (.cast). This makes the recordings highly compressible, potentially shrinking to 15% of the original size, and means they can be played back inside any terminal or embedded on a web page with a dedicated player. The key difference from screen recording software like video capture tools is that asciinema captures the actual text output of your terminal rather than pixels. This means the recording remains crisp and searchable at any size, and viewers can copy text from it. Key features include recording and local playback, live streaming (you can broadcast your terminal session in real-time to multiple viewers, either via a built-in HTTP server or through the asciinema.org hosting service), and publishing recordings online for easy sharing. The tool supports GNU/Linux, macOS, and FreeBSD. The basic commands are simple: run "asciinema rec demo.cast" to start recording, and "asciinema stream -l" to start a live stream over a local HTTP server. You would use asciinema when you want to show someone how to use a command-line tool, create documentation for a terminal workflow, share a debugging session, or demonstrate a process without recording a heavy video file. The current version (3.x) is written in Rust, an older version (2.x) written in Python also exists in the repository.