# types.SetHookOptions.append

- **Module:** types.SetHookOptions
- **Package:** @libtmux/libtmux
- **Language:** TypeScript
- **Kind:** property
- **Source:** https://github.com/libtmux/libtmux-ts/blob/2cb93308200da38a26b59876618116850f110607/packages/libtmux/src/types.ts#L353
- **Page:** https://libtmux.org/reference/ts/types-sethookoptions-append/

Add to the commands this hook already holds, tmux's `-a`.

A hook is a list, and without this each write replaces the whole list. It
is what builds the several commands `showHooks` reports, and the reason a
hook read back can hold more than was last written to it.