# addValueProvider()

Adds custom value providers to a component.

## Signature

`addValueProvider(String key, Object valueProvider)`

## Parameters

***key*:** Type: `String`. Key to identify the value provider. Used in expressions in markup.

***valueProvider*:** Type: `Object`. The object to request data from. Must implement `get(expression)`, can implement `set(key,value)`.

**See Also**

- [Value Providers](/docs/platform/aura-platform/guide/expr-source.md)