Main branch
Also called main, master, Default branch, Trunk
The branch everyone treats as the real version of the project. Work happens elsewhere and joins it when it is ready. The name is only a convention: many older projects call it master.
An agent working on main is one bad commit away from breaking what everyone depends on. Don't assume your tools protect it. Claude Code's auto mode, as of November 2026, allows pushes to the default branch (sending your commits to a shared server, coming shortly) unless your own rules or the server stop them.
Say it to your agent
“Never commit directly to main. If git status says you are on main, stop, run git switch -c with a name for this task, and carry on there.”