Java SDK — Realtime

Realtime

Reliable WebSocket (TCP) plus an optional UDP fast lane — 1 TCP + 1 UDP per player

Realtime.getToken

public static TokenResponse getToken(
    Client client,
    String playerToken
) throws IOException

Retrieves a realtime authentication token for WebSocket connections.

Realtime.connect

public boolean connect(
    String realtimeToken
)

Connects to the realtime WebSocket server using the provided token.

Realtime.send

public void send(
    ERoomTargetPlayer target,
    String command,
    Object data,
    int[] targetIds
)

Sends a message to the specified players via WebSocket.

Realtime.connectUdp

public boolean connectUdp(
    Integer udpPort
)

Binds one UDP endpoint alongside the WebSocket (max 1 TCP + 1 UDP per player). Datagrams authenticate with the server-issued connection id. Null port = the udp_port announced by the server.

Realtime.sendUnreliable

public void sendUnreliable(
    ERoomTargetPlayer target,
    String command,
    Object data,
    int[] targetIds
)

Sends over the bound UDP channel — unordered, unacknowledged, latest-wins via seq. Ideal for 20-60Hz movement/state streams. Falls back to the WebSocket when UDP isn't bound.

Prediction helpers

Prediction.PredictionBuffer<S, I> — nextSeq() / record() / reconcile()
Prediction.SnapshotBuffer<S> — add(t, state, seq) / sample(renderTime, lerp)

Client-side movement prediction: record each input with its seq, adopt authoritative state on arrival, replay unacked inputs. SnapshotBuffer interpolates remote entities ~100ms in the past. In rooms/realtime/Prediction.java.

Realtime.disconnect

public void disconnect()

Disconnects from the server and cleans up both channels.