# Request
## **Overview**
**Related Modules:**
[Samgr](samgr.md)
**Description:**
Defines a request.
You can use this structure to define the request that will be sent to a feature through the asynchronous function of [IUnknown](iunknown.md). [Request](request.md), which is data that is packed to send to a feature. If the data is not empty and the length is not 0, the system automatically releases the data.
## **Summary**
## Data Fields
## **Details**
## **Field Documentation**
## data
```
void* Request::data
```
**Description:**
Data content
## len
```
int16 Request::len
```
**Description:**
Data length
## msgId
```
int16 Request::msgId
```
**Description:**
Message ID
## msgValue
```
uint32 Request::msgValue
```
**Description:**
Message value, which is defined by developers