API

The developer API is fairly simple and straight-forward, so I'll leave you with some basic documentation and some examples.

Maven

To include the plugin into your Maven project, just use the repository and link below.

<repositories>
  <repository>
    <id>egg82-nexus</id>
    <url>https://nexus.egg82.me/repository/maven-releases/</url>
  </repository>
</repositories>

<dependencies>
  <dependency>
    <groupId>me.egg82</groupId>
    <artifactId>antivpn-api</artifactId>
    <version>LATEST-VERSION</version>
    <scope>provided</scope>
  </dependency>
</dependencies>

Link to the latest version is available here.
Javadocs are available from the same repository, so IDEs should be able to pick those up automatically.

Gradle

repositories {
    maven {
        url 'https://nexus.egg82.me/repository/maven-releases/'
    }
}

dependencies {
    compileOnly 'me.egg82:antivpn-api:LATEST-VERSION'
}

Link to the latest version is available here.
Javadocs are available from the same repository, so IDEs should be able to pick those up automatically.

Examples

Get the API instance.

VPNAPI api = VPNAPIProvider.getInstance();

IP manager

IPManager ipManager = VPNAPIProvider.getInstance().getIPManager();

// Get consensus value for an IP, using Anti-VPN's cache
ipManager.consensus(player.getAddress(), true).whenCompleteAsync((val, ex) -> {
  if (ex != null) {
    ex.printStackTrace();
    return;
  }
  if (val != null && val >= ipManager.getMinConsensusValue()) {
    // Do something
  }
});

// Get consensus value for an IP, using Anti-VPN's cache
// Note: This stalls the executing thread until the result is fetched
try {
  Double val = ipManager.consensus(player.getAddress(), true).get();
  return ipManager.consensus(val != null && val >= ipManager.getMinConsensusValue();
} catch (InterruptedException ignored) {
  Thread.currentThread().interrupt();
} catch (ExecutionException | CancellationException ex) {
  ex.printStackTrace();
}

// Get cascade value for an IP, using Anti-VPN's cache
ipManager.cascade(player.getAddress(), true).whenCompleteAsync((val, ex) -> {
  if (ex != null) {
    ex.printStackTrace();
    return;
  }
  if (Boolean.TRUE.equals(val)) {
    // Do something
  }
});

// Get cascade value for an IP, using Anti-VPN's cache
// Note: This stalls the executing thread until the result is fetched
try {
  return Boolean.TRUE.equals(ipManager.cascade(player.getAddress(), true).get());
} catch (InterruptedException ignored) {
  Thread.currentThread().interrupt();
} catch (ExecutionException | CancellationException ex) {
  ex.printStackTrace();
}

// Kick a player and/or run configured commands for VPN usage
if (!ipManager.kickForVpn(player.getName(), player.getUniqueId(), player.getAddress())) {
  logger.warn("Could not kick player/run commands for VPN usage.");
}

Player manager

PlayerManager playerManager = VPNAPIProvider.getInstance().getPlayerManager();

// Get MCLeaks result for a player, using Anti-VPN's cache
playerManager.checkMcLeaks(player.getUniqueId(), true).whenCompleteAsync((val, ex) -> {
  if (ex != null) {
    ex.printStackTrace();
    return;
  }
  if (Boolean.TRUE.equals(val)) {
    // Do something
  }
});

// Get MCLeaks result for a player, using Anti-VPN's cache
// Note: This stalls the executing thread until the result is fetched
try {
  return Boolean.TRUE.equals(playerManager.checkMcLeaks(player.getUniqueId(), true).get());
} catch (InterruptedException ignored) {
  Thread.currentThread().interrupt();
} catch (ExecutionException | CancellationException ex) {
  ex.printStackTrace();
}

// Kick a player and/or run configured commands for MCLeaks usage
if (!playerManager.kickForMcLeaks(player.getName(), player.getUniqueId(), player.getAddress())) {
  logger.warn("Could not kick player/run commands for MCLeaks usage.");
}

Source manager

SourceManager sourceManager = VPNAPIProvider.getInstance().getSourceManager();

// Try a specific source for a result
Source<GetIPIntelModel> getIpIntel = sourceManager.getSource("getipintel", GetIPIntelModel.class);
try {
  return Boolean.TRUE.equals(getIpIntel.getResult(player.getAddress()).join());
} catch (InterruptedException ignored) {
  Thread.currentThread().interrupt();
} catch (ExecutionException | CancellationException ex) {
  ex.printStackTrace();
}

// Get a raw response from a specific source
Source<GetIPIntelModel> getIpIntel = sourceManager.getSource("getipintel", GetIPIntelModel.class);
try {
  return getIpIntel.getRawResponse(player.getAddress()).get();
} catch (InterruptedException ignored) {
  Thread.currentThread().interrupt();
} catch (ExecutionException | CancellationException ex) {
  ex.printStackTrace();
}

// Add your own source (yes, this affects Anti-VPN commands and behavior as well)
if (!sourceManager.registerSource(mySource)) {
  logger.error("Could not register custom source.");
}

// Remove a source (yes, this affects Anti-VPN commands and behavior as well)
if (!sourceManager.deregisterSource(source)) {
  logger.error("Could not deregister source.");
}

// Get a list of all available sources
return sourceManager.getSources();

Event bus

MBassador<VPNEvent> eventBus = VPNAPIProvider.getInstance().getEventBus();

// Implement listener for various events
@Listener(references = References.Strong)
class SimpleListener {
    @Handler
    public void handle(SourceRegisterEvent file){
      // do something synchronously
    }
    @Handler(delivery = Invoke.Asynchronously)
    public void expensiveOperation(APIReloadEvent file){
      // do something asynchronously
    }
}

eventBus.subscribe(new SimpleListener());

More documentation on the Mbassador event bus here.