[Home](./index.md) > [@empathyco/x-components](./x-components.md) > [XInjectKey](./x-components.xinjectkey.md) ## XInjectKey interface Type of the key passed to `provide` and `inject` to be type-safe. With this type you can declare the type of the injected value directly in the injection key. **Signature:** ```typescript export interface XInjectKey extends String ``` **Extends:** String ## Example `const myKey: XInjectKey = 'myFilter';` `inject(myKey)`