# control.Event.SubscriptionChanged.index

- **Module:** control.Event
- **Package:** libtmux
- **Language:** Rust
- **Kind:** attribute
- **Source:** https://github.com/libtmux/libtmux-rs/blob/84de9258a07d10bdd5f6da01b016a9ae06fe1210/crates/libtmux/src/control.rs#L251
- **Page:** https://libtmux.org/en/rs/latest/reference/control-event-subscriptionchanged-index/

```rs
index: Option<u32>
```

That window's index, when the subscription names one.