Multiplayer

Gully Studio online games use a server-authoritative setup: FishNet for netcode, headless Linux dedicated servers that run the simulation, and Nakama as the backend for accounts, matchmaking, leaderboards and storage. Everything runs on Gully infrastructure.

Unity client ──Gully ID token──▶ Nakama (custom auth)  ── session, matchmaker ticket
     │                              │
     │                              └── match found: server address + join token
     ▼
FishNet client ──UDP──▶ dedicated server (StandaloneLinux64, headless)
                              │
                              └── reports results to Nakama (leaderboards, storage)
                                  and to Gully Chain (quests, scores) when needed

#Netcode: FishNet

The studio template's Packages/manifest.json ships Netcode for GameObjects and Unity Transport as defaults. The FPS foundation swaps to FishNet: server-authoritative, client-side prediction and lag compensation suited to a shooter. A project picks one netcode and removes the other; do not ship both.

Rules for either:

• The server owns game state: health, hits, scores, inventory changes. Clients send inputs, not results.
• Anything that grants value (a quest completion, a reward, a purchase) is decided on the server.
• Network prefabs are listed under Assets/_Project/Netcode/.

#Dedicated servers

Servers are the same Unity project built for StandaloneLinux64 as a headless server build. The template's CI already builds the Linux target (see Release and CI).

Run a server without graphics:

./Game.x86_64 -batchmode -nographics -logFile -

• Strip client-only code and assets from server builds with scripting defines and #if UNITY_SERVER.
• One process per match; the orchestrator starts and stops them.
• Servers bind to the box's private network; players reach them through the UDP proxy, never through an open port on every process.

#Backend: Nakama

The backend is the Gully Labs fork of Heroic Labs Nakama, gully-labs/nakama (opens in a new tab) (Apache-2.0).

Players never get a raw Nakama account without a verified Gully ID behind it. See Gully ID for what the server checks.

#Fleet and matchmaking at scale

For more than a handful of servers, Gully Labs keeps forks of the standard open-source pieces:

Nakama's built-in matchmaker is enough to start; Open Match and Agones come in when the fleet needs them.

#Where it runs

All studio services run on Gully-operated boxes under the same rules as every Gully product:

• only Gully containers on Gully boxes;
• service ports bound to localhost or the private Docker network, with Caddy as the only public HTTP entry point;
• game UDP traffic through the proxy, not through ports opened per process;
• secrets (Nakama server key, database passwords, signer keys) live in each service's environment on the box, never in a repo or a client build.

#On-chain pieces in a multiplayer game

• Achievements: Gully Quests. The player completes them from their own account; the server can tell the client when a quest is ready.
• Scores: the server decides the score; on-chain submission goes through an attestation, as with Gully Arcade.
• Items and purchases: Payments, granted by the server from verified Gully Pay webhooks.