# types.SetHookOptions.append

- **Module:** types
- **Package:** libtmux
- **Language:** TypeScript
- **Kind:** property
- **Source:** https://github.com/libtmux/libtmux-ts/blob/073b9d7dedad900bff6f5ec0ea47794e40225870/packages/libtmux/src/types.ts#L423
- **Page:** https://libtmux.org/en/ts/latest/reference/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.