1.0 Published on 13 Mar 2015 by Marcin Kulik

I’m very happy to announce the release of asciinema 1.0, which brings many long-awaited features and settles the ground for even more awesome features and improvements coming in the future.

See CHANGELOG for a detailed list of changes, continue reading for highlights of this important release.

Idle time optimization

Did you ever wish you had more powerful machine because this software compilation you’re recording takes long time? Or maybe you wanted to pause the recording process, plan your next steps, and then resume recording? If you said “yes!” to any of the above then you may like asciinema’s new option.

asciinema rec command learned new option: --max-wait. It allows limiting idle time, by replacing long pauses (terminal inactivity) with shorter ones.

You use it like this:

asciinema rec --max-wait=2

This starts recording session in which all pauses longer than 2 seconds are replaced with exactly 2 second ones.

An asciicast is worth a thousand words, so let’s compare recording with and without --max-wait. First, let’s look at the result of recording with plain asciinema rec:

Now, let’s look at the result of recording the same thing, this time with asciinema rec --max-wait=2:

Using this new option will make you look like you always know what to do next, you’re confident, and last but not least - you own a super computer that can compile the biggest project in a matter of seconds. How cool is that?

Local workflow

Another improvement to asciinema rec is its ability to save the recording to a local file.

asciinema rec demo.json

This saves the session to demo.json file. Now, you can replay it directly in your terminal:

asciinema play demo.json

Finally, if you’re happy about it and you want to share it on asciinema.org just run:

asciinema upload demo.json

Let’s see it in action:

If you don’t need to keep your recording local and just want to record and upload in one step, you can still asciinema rec without a filename.

New, simple asciicast format

Due to the fact that previous versions of asciinema recorder didn’t allow saving recordings locally, there was no stable and documented “asciicast format”.

This changes with 1.0. The file produced with asciinema rec <filename> is a simple JSON file with a strict set of attributes. The format is versioned to allow future extensions while preserving backwards compatibility. See asciicast file format version 1.

If you know how to deal with ansi escape sequences you can manually edit your recordings with a text editor, or build a tool that can post-process them.

Configuration file

There are several new options that can be set in ~/.asciinema/config file. See README for a description of all of them.

Here’s an example of setting --max-wait permanently, so you don’t need to pass it manually on each invocation of asciinema rec:

maxwait = 2


All available installation methods can be found on installation page.

Note: not all native packages may be updated yet. If you want to make sure you’re getting the latest version of asciinema download a binary for you platform here.

The future

The changes introduced in this release, in addition to being valuable by themselves, enable even more awesomeness in the future. For example, the upcoming ability to self host (yes!) your recordings (without depending on asciinema.org) wouldn’t be possible without having a way to record to a file with a well defined format.

I hope you’ll enjoy the future. Meanwhile, enjoy asciinema 1.0!

Did you like it? Feel free to send me an email with your feedback to . Thanks!