| boolean | Returns **true** if the application is the default payment application; returns **false** otherwise.|
## HceService<sup>8+</sup>
Implements HCE, including receiving Application Protocol Data Units (APDUs) from the peer card reader and sending a response. Before using HCE-related APIs, check whether the device supports HCE. This API is used only for declaration and cannot be used currently.
### startHCE<sup>8+</sup>
startHCE(aidList: string[]): boolean
Starts HCE, including setting the application to be foreground preferred and dynamically registering the application identifier (AID) list. This API is used only for declaration and cannot be used currently.
> **NOTE**
> This API is supported since API version 8 and deprecated since API version 9. You are advised to use [start](#start9).
Starts HCE, including setting the application to be foreground preferred and dynamically registering the application identifier (AID) list. This API is used only for declaration and cannot be used currently.
| elementName | ElementName | Yes | Element name of a service capability.|
| aidList | string[] | Yes | AID list to register.|
**Error codes**
For details about the error codes, see [NFC Error Codes](../errorcodes/errorcode-nfc.md).
| ID| Error Message |
| ------- | -------|
| 3100301 | Card emulation running state is abnormal in service. |
### stopHCE<sup>8+</sup>
stopHCE(): boolean
Stops HCE, including removing the foreground preferred attribute and releasing the dynamically registered AID list. This API is used only for declaration and cannot be used currently.
> **NOTE**
> This API is supported since API version 8 and deprecated since API version 9. You are advised to use [stop](#stop).
Stops HCE, including removing the foreground preferred attribute and releasing the dynamically registered AID list. This API is used only for declaration and cannot be used currently.
| type | string | Yes | Event type to subscribe to. The value is **hceCmd**. |
| callback | AsyncCallback<number[]> | Yes | Callback invoked to return the APDU, which consists of hexadecimal numbers ranging from **0x00** to **0xFF**.|
### sendResponse<sup>8+</sup>
sendResponse(responseApdu: number[]): void;
Sends a response to the peer card reader. This API is used only for declaration and cannot be used currently.
> **NOTE**
> This API is supported since API version 8 and deprecated since API version 9. You are advised to use [transmit](#transmit9).
| responseApdu | number[] | Yes | Response APDU sent to the peer card reader. The value consists of hexadecimal numbers ranging from **0x00** to **0xFF**.|
### transmit<sup>9+</sup>
transmit(response: number[]): Promise\<void>;
Sends a response to the peer card reader. This API is used only for declaration and cannot be used currently.
| responseApdu | number[] | Yes | Response APDU sent to the peer card reader. The value consists of hexadecimal numbers ranging from **0x00** to **0xFF**.|
| responseApdu | number[] | Yes | Response APDU sent to the peer card reader. The value consists of hexadecimal numbers ranging from **0x00** to **0xFF**.|
| callback | AsyncCallback\<void> | Yes | Callback that returns no value.|
**Error codes**
For details about the error codes, see [NFC Error Codes](../errorcodes/errorcode-nfc.md).
| ID| Error Message |
| ------- | -------|
| 3100301 | Card emulation running state is abnormal in service. |