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Asciinema: making movies at the command-line
In open-source circles there are many situations, such as bug reports, demos, and tutorials, when one might want to provide a play-by-play of a session in one's terminal. The asciinema project provides a set of tools to do just that. Its tools let users record, edit, and share terminal sessions in a text-based format that has quite a few advantages compared to making and sharing videos of terminal sessions. For example, it is easy to use, offers the ability to search text from recorded sessions, and allows users to copy and paste directly from the recording.
History
Marcin Kulik started the project in 2011; it was originally called "ascii.io" and then renamed to asciinema and published to the Python Package Index (PyPI) in 2013. The asciinema project now consists of several parts: a command-line interface (CLI) recorder and player, a web player, the asciicast file format for recordings, the agg utility to create animated GIFs, and the asciinema virtual terminal (avt) used by the project's other components.
Each project has its own license; the asciinema CLI and agg are available under the GPLv3, while the other components are Apache 2.0-licensed. The project's components have undergone a number of changes and rewrites in the past 13 years. Version 3.0 of the CLI, released in September 2025, featured a complete rewrite in Rust, as well as an updated (v3) file format.
The project provides hosting for recordings on asciinema.org for users who don't mind storing them with a third party. The terms of service seem fairly standard for an open-source project that provides content hosting. LWN readers can explore some of the published recordings to get a sense of how others are using the tools. I should note that the project seems to have done a good job keeping recordings online: I have recordings from 2017 that are still available.
The server software is open-source too, of course, for those who prefer to self host. It is written in Elixir and uses the Phoenix Framework; the server is available under the Apache 2.0 license. The most recent server release, v20251114 from November 2025, included new search features and stricter validation of uploaded asciicast files.