I’ll share some comments based on my understanding/searching
About the teletype package. Does the distant collaborator have the file in local ?
The file is only on the host’s file system but a guest can save a copy of the file locally if they want if you do a
How does it works precisely ?
The blog post has an “Implementation Details” section that might be helpful and you can always view the source as well:
Can I share an all directory that my collaborator can explore and edit as he wants ? Or is it just one file ?
As of Teletype 3.0, you can now work on multiple files together:
So you can’t directly share a directory or project, but you can open multiple files that are shared with guests. See this comment for more details on the changes:
Can he then download my files for example execute it on his side ?
Guests can save the host’s files locally like I mentioned above but I’m not sure what you mean about executing on the guest side? If you save the file locally you can do whatever you’d like with the file.