# types.EnvironmentValue

- **Module:** types
- **Package:** @libtmux/libtmux
- **Language:** TypeScript
- **Kind:** typealias
- **Source:** https://github.com/libtmux/libtmux-ts/blob/2cb93308200da38a26b59876618116850f110607/packages/libtmux/src/types.ts#L478
- **Page:** https://libtmux.org/reference/ts/types-environmentvalue/

A variable's state in a tmux environment.

`null` is tmux's `-NAME`: the variable is present and marked for removal from
the environment of any process tmux starts. Absent from the map is the third
state, and means tmux carries no entry at all.