> ## Documentation Index
> Fetch the complete documentation index at: https://docs.towns.com/llms.txt
> Use this file to discover all available pages before exploring further.

# useTowns

Hook to get an observable from the sync agent.

An alternative of our premade hooks, allowing the creation of custom abstractions.

## Imports

```ts theme={null}
import { useTowns } from '@towns-protocol/react-sdk'
```

## Definition

```ts theme={null}
function useTowns<T>(
  selector: (sync: SyncSelector) => Observable<T>,
  config?: ObservableConfig.FromData<T>,
): ObservableValue<T extends PersistedModel<infer UnwrappedData> ? UnwrappedData : T>
```

**Source:** [useTowns](https://github.com/towns-protocol/towns/blob/main/packages/react-sdk/src/useTowns.ts)

## Parameters

### selector

* **Type:** `(sync: SyncSelector) => Observable<T>`

A selector function to get a observable from the sync agent.

### config

* **Type:** `ObservableConfig.FromData<T>`
* **Optional**

Configuration options for the observable.

#### config.fireImmediately

* **Type:** `boolean`
* **Optional**

Trigger the update immediately, without waiting for the first update.

#### config.onError

* **Type:** `(error: Error) => void`
* **Optional**

Callback function to be called when an error occurs.

#### config.onUpdate

* **Type:** `(data: Data) => void`
* **Optional**

Callback function to be called when the data is updated.

## Return Type

The data from the selected observable.

```ts theme={null}
ObservableValue<T extends PersistedModel<infer UnwrappedData> ? UnwrappedData : T>
```