Running it

On your machine, on your files.

Byline is a local application. The book is a directory on your disk and the history is a git repository you own. There is no MAH7 service holding the manuscript and no upload step. Back it up to any remote you already use, or to none.

Models

Hosted or local, your choice per work.

Byline talks to hosted models and to models running on your own hardware. Which one wrote a given turn is recorded in the commit, so switching provider does not blur the record. Tokens and cost are accounted per work as you go.

Honest about the state of it

In beta, and used daily on real manuscripts.
Single author per repository today. Review comes back through DOCX rather than through shared accounts.
Export beyond markdown and HTML needs pandoc installed.
It runs on your network. There is no hosted version to sign up for.