# Sending commands

All commands will use the JSON-RPC 2.0 protocol: [www.jsonrpc.org/specification](https://www.jsonrpc.org/specification)

There are two ways to send RNC commands:

> **Note:** The command JSON always travels in the string extra `BND_MESSAGE`, on both transports. It is not `method` and not `rnc_command`. A broadcast without that extra is discarded silently - no response is sent.

**Send command to activity**: This is the appropriate method if the receiving application must be put in the foreground when command is received.  
  
Pros:

- The receiving application will be brought to the foreground automatically

Cons:

- The sending application must be in the foreground when sending the command.

Example of usage:

*Java*

```java
String SEND_ACTION = "ACTION_RNC_BROADCAST";
String SEND_PACKAGE = "com.benomad.benav";
String SEND_CLASS = "com.benomad.benav.MainActivity";
String EXTRA_NAME = "BND_MESSAGE";

Intent i = new Intent(SEND_ACTION);
i.setPackage(SEND_PACKAGE);
i.setComponent(new ComponentName(SEND_PACKAGE, SEND_CLASS));
i.putExtra(EXTRA_NAME, "{\"jsonrpc\":\"2.0\",\"method\":\"getAppInfo\",\"id\":\"1\"}");
startActivity(i);
```

*Kotlin*

```kotlin
val SEND_ACTION = "ACTION_RNC_BROADCAST"
val SEND_PACKAGE = "com.benomad.benav"
val SEND_CLASS = "com.benomad.benav.MainActivity"
val EXTRA_NAME = "BND_MESSAGE"

val i = Intent(SEND_ACTION)
i.setPackage(SEND_PACKAGE)
i.component = ComponentName(SEND_PACKAGE, SEND_CLASS)
i.putExtra(
    EXTRA_NAME,
    "{\"jsonrpc\":\"2.0\",\"method\":\"getAppInfo\",\"id\":\"1\"}"
)
startActivity(i)
```

**Send command to service:** Use this method when the application must stay in the background while processing commands.

Pros:

- The sending application can be in the foreground or background while sending the command

Cons:

- The receiving application [can't be put in the foreground.](https://developer.android.com/guide/components/activities/background-starts)  
  This limitation can be bypassed by enabling "Allow display over other apps" in the receiving application's settings. On Android 10+, the receiving application must grant the [SYSTEM\_ALERT\_WINDOW permission.](https://developer.android.com/reference/android/Manifest.permission#SYSTEM_ALERT_WINDOW)

Example of usage

Example of usage:

*Java*

```java
String SEND_ACTION = "ACTION_RNC_BROADCAST";
String SEND_PACKAGE = "com.benomad.benav";
String SEND_CLASS = "com.benomad.move.rnc_domain.RNCBroadcastReceiver";
String EXTRA_NAME = "BND_MESSAGE";

Intent i = new Intent(SEND_ACTION);
i.setPackage(SEND_PACKAGE);
i.setComponent(new ComponentName(SEND_PACKAGE, SEND_CLASS));
i.putExtra(EXTRA_NAME, "{\"jsonrpc\":\"2.0\",\"method\":\"getAppInfo\",\"id\":\"1\"}");
sendBroadcast(i);
```

*Kotlin*

```kotlin
val SEND_ACTION = "ACTION_RNC_BROADCAST"
val SEND_PACKAGE = "com.benomad.benav"
val SEND_CLASS = "com.benomad.move.rnc_domain.RNCBroadcastReceiver"
val EXTRA_NAME = "BND_MESSAGE"

val i = Intent(SEND_ACTION)
i.setPackage(SEND_PACKAGE)
i.component = ComponentName(SEND_PACKAGE, SEND_CLASS)
i.putExtra(
    EXTRA_NAME,
    "{\"jsonrpc\":\"2.0\",\"method\":\"getAppInfo\",\"id\":\"1\"}"
)
sendBroadcast(i)
```

Commands responses