Extend the API with a ProxyServer type.

api/src/main/java/com/velocitypowered/api/proxy/ProxyServer.java

@@ -0,0 +1,32 @@
+package com.velocitypowered.api.proxy;
+
+import javax.annotation.Nonnull;
+import java.util.Collection;
+import java.util.Optional;
+import java.util.UUID;
+
+/**
+ * Represents a Minecraft proxy server that follows the Velocity API.
+ */
+public interface ProxyServer {
+    /**
+     * Retrieves the player currently connected to this proxy by their Minecraft username.
+     * @param username the username
+     * @return an {@link Optional} with the player
+     */
+    Optional<Player> getPlayer(@Nonnull String username);
+
+    /**
+     * Retrieves the player currently connected to this proxy by their Minecraft UUID.
+     * @param uuid the UUID
+     * @return an {@link Optional} with the player
+     */
+    Optional<Player> getPlayer(@Nonnull UUID uuid);
+
+    /**
+     * Retrieves all players currently connected to this proxy. This call may or may not be a snapshot of all players
+     * online.
+     * @return the players online on this proxy
+     */
+    Collection<Player> getAllPlayers();
+}