# Want
The **Want** module provides the basic communication component of the system.
> **NOTE**
>
> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Modules to Import
```
import Want from '@ohos.application.Want';
```
## Attributes
**System capability**: SystemCapability.Ability.AbilityBase
| Name | Readable/Writable| Type | Mandatory| Description |
| ----------- | -------- | -------------------- | ---- | ------------------------------------------------------------ |
| deviceId | Read only | string | No | ID of the device running the ability. |
| bundleName | Read only | string | No | Bundle name of the ability. If both **bundleName** and **abilityName** are specified in a **Want** object, the **Want** object can match a specific ability.|
| abilityName | Read only | string | No | Name of the ability. If both **package** and **abilityName** are specified in a **Want** object, the **Want** object can match a specific ability. The value of **abilityName** must be unique in an application.|
| uri | Read only | string | No | URI information to match. If **uri** is specified in a **Want** object, the **Want** object will match the specified URI information, including **scheme**, **schemeSpecificPart**, **authority**, and **path**.|
| type | Read only | string | No | MIME type, for example, **text/plain** or **image/***. |
| flags | Read only | number | No | How the **Want** object will be handled. By default, numbers are passed in. For details, see [flags](js-apis-featureAbility.md#flags).|
| action | Read only | string | No | Action option. |
| parameters | Read only | {[key: string]: any} | No | Want parameters in the form of custom key-value (KV) pairs. By default, the following keys are carried:
**ohos.aafwk.callerPid**: PID of the caller.
**ohos.aafwk.param.callerToken**: token of the caller.
**ohos.aafwk.param.callerUid**: UID of the caller. The **userId** parameter in the [Bundle](js-apis-Bundle.js) module can be used to obtain application and bundle information. |
| entities | Read only | Array\ | No | List of entities. |
| moduleName9+ | Read only | string | No | Module to which the ability belongs.|
**Example**
``` js
var want = {
"deviceId": "", // An empty deviceId indicates the local device.
"bundleName": "com.extreme.test",
"abilityName": "MainAbility",
"moduleName": "entry" // moduleName is optional.
};
this.context.startAbility(want, (error) => {
// Start an ability explicitly. The bundleName, abilityName, and moduleName parameters uniquely identify an ability.
console.log("error.code = " + error.code)
})
```