io.github.libtmux.PaneCommand.PaneCommand.typed

Typed at the pane's own interactive shell rather than a fresh one, so the command sees the environment a person set up there — a virtualenv, a loaded module, a directory someone changed into. The leading space asks bash (HISTCONTROL=ignorespace) and zsh (HIST_IGNORE_SPACE) to keep the plumbing out of the history; a shell set to neither records it. Builtins are called as \\trap, \\eval and \\exit so an alias of the same name cannot take them over.

The line begins with that space; strip it to have the shell record the line like any other.