When T3 Code starts a thread in a new worktree, Git checks out tracked files only. Untracked
local files — .env files, credentials, machine-specific config — stay behind in the original
checkout.
To copy those files into each new worktree automatically, add a .worktreeinclude file to the
repository root. List one pattern per line, using the same syntax as .gitignore:
# copied into every new worktree
.env
.env.local
secrets/
When a worktree is created, every untracked file in the original checkout that matches a pattern
is copied into the same location in the worktree. Patterns follow .gitignore rules: a bare name
like .env matches at any depth, a leading / anchors it to the repository root, and a trailing
/ matches a whole directory.
The copy finishes before the project setup script runs, so a setup script can rely on the files being there. A file that fails to copy never blocks the worktree: T3 Code logs a warning and the thread starts normally.