Short, copy-pasteable answers to the questions that come up porting a Unity Netcode project onto ClutchCall. Each assumes the com.clutchcall.transport package is installed and a NetworkManager is in the scene. For the full surface see SDK methods.

​
How do I install the package?

Add it via Package Manager → Add package from git URL: 
https://github.com/clutchcall/core-sdk.git?path=unity/com.clutchcall.transport

​
How do I swap UnityTransport for ClutchCall?

Remove the UnityTransport component from the NetworkManager and add ClutchCallTransport, then point Netcode at it. 
var nm = GetComponent<NetworkManager>();
nm.NetworkConfig.NetworkTransport = nm.GetComponent<ClutchCallTransport>();

​
How do I configure the relay + token in code?

Set the inspector fields from C# before starting the session. 
var t = nm.GetComponent<ClutchCallTransport>();
t.RelayHost = "relay.clutchcall.dev";
t.Token     = await FetchRoomTokenAsync("duel-42", "alice");
t.RoomId    = "duel-42";

​
How do I start a host vs a client?

Host/server vs client is chosen by Netcode, not the transport — the same calls you used with UTP. 
nm.StartHost();    // authority: opens the room's authority namespace
// or
nm.StartClient();  // joins: announces a discovery namespace to the host

​
How do I send on the unreliable (datagram) lane?

Pick Unreliable delivery for high-frequency, latest-wins traffic. It rides a single QUIC datagram — no head-of-line blocking, no retransmit. 
// In a NetworkBehaviour RPC:
[Rpc(SendTo.Server, Delivery = RpcDelivery.Unreliable)]
void SubmitInputRpc(InputPayload input) { /* ... */ }

​
How do I send a reliable, must-arrive message?

Use Reliable* delivery for spawns, despawns, and control RPCs. It rides a MoQT subgroup stream — ordered and guaranteed. 
[Rpc(SendTo.ClientsAndHost, Delivery = RpcDelivery.Reliable)]
void AnnounceWinnerRpc(ulong clientId) { /* ... */ }

​
How do I read the current RTT to a peer?

GetCurrentRtt returns the QUIC transport’s smoothed RTT in milliseconds. 
var transport = nm.GetComponent<ClutchCallTransport>();
double rttMs = transport.GetCurrentRtt(clientId);

​
How big can an unreliable payload be?

Query the live max datagram size and keep latest-wins deltas under it; spill anything larger onto a reliable RPC. 
int maxBytes = nm.GetComponent<ClutchCallTransport>().MaxPayloadSize();
if (snapshot.Length <= maxBytes) SendUnreliable(snapshot);
else                             SendReliableChunked(snapshot);

​
How do I react to players joining and leaving?

Use Netcode’s standard callbacks — peer join/leave is surfaced through them, not a transport-specific event. 
nm.OnClientConnectedCallback  += id => roster.Add(id);
nm.OnClientDisconnectCallback += id => roster.Remove(id);

​
How do I mint a room-scoped token?

Mint a short-lived token from your control-plane API and hand it to the transport — don’t bake a static secret into the build. 
async Task<string> FetchRoomTokenAsync(string room, string player) {
    var resp = await http.PostAsJsonAsync(
        "https://api.clutchcall.dev/rooms/token",
        new { room, player });
    return (await resp.Content.ReadFromJsonAsync<TokenResp>()).Token;
}

​
How do I run a headless dedicated server?

Build a dedicated-server (or headless) player and start the host on launch. Editor batch mode does not drive Netcode — you need a built player. 
void Start() {
    if (Application.isBatchMode) {
        nm.GetComponent<ClutchCallTransport>().RoomId = Args.Get("room");
        nm.StartServer();
    }
}

​
How do I run the ECS racing sample over ClutchCall?

Open the ECS-Network-Racing-Sample, swap UnityTransport for ClutchCallTransport on its NetworkManager, set the relay host + token, and build a player. The full walkthrough is in Recipes.

​
How do I pin the relay’s TLS certificate?

Set the certificate hash in the inspector (or in code) for environments that pin instead of relying on the public trust store. 
nm.GetComponent<ClutchCallTransport>().ServerCertificateHash = pinnedHash;

​
How do I handle a dropped connection?

The QUIC session reconnects under the hood. Watch OnTransportFailure for the unrecoverable case and re-enter matchmaking. 
nm.OnTransportFailure += () => {
    Debug.LogWarning("transport failed; returning to lobby");
    SceneManager.LoadScene("Lobby");
};

SDK methods

The component, inspector fields, and UTP surface.

Recipes

Worked end-to-end examples.