# Strict Mode

To enable strict mode, simply pass in `strict: true` when creating a Vuex store:

``` js
const store = new Vuex.Store({
  // ...
  strict: true
})
```

In strict mode, whenever Vuex state is mutated outside of mutation handlers, an error will be thrown. This ensures that all state mutations can be explicitly tracked by debugging tools.

### Development vs. Production

**Do not enable strict mode when deploying for production!** Strict mode runs a deep watch on the state tree for detecting inappropriate mutations - make sure to turn it off in production to avoid the performance cost.

Similar to plugins, we can let the build tools handle that:

``` js
const store = new Vuex.Store({
  // ...
  strict: process.env.NODE_ENV !== 'production'
})
```
