A snippet manager for tmux only needs three things: somewhere to keep the snippets, a way to pick one, and a way to inject it.
Injection is the interesting constraint. send-keys types into the target pane
as if you had typed it, which means it composes with whatever shell, editor or
REPL happens to be focused — no integration per program.
The cost is that you cannot tell whether the paste landed somewhere sensible.
send-keys is fire-and-forget; a snippet dropped into a less pager is just
keystrokes to less.