You can get a plain text log of a recorded session in several ways.

If you uploaded to asciinema server (e.g. asciinema.org) then you can click on Download and select txt format.

Or, with the CLI 3.0, you can either:

- convert existing cast file to plain text: asciinema convert demo.cast demo.txt

- record directly to plain text: asciinema rec demo.txt