KeyRace

Create a room, share the id, everyone types the same paragraph and watches the leaderboard move. A Turborepo monorepo — Vite + React + TanStack Router on the client, a socket.io server holding the game state.

The server owns the game

A Game instance per room, held in a Map on the server.

• Clients emit what they typed, not a score. The server splits the paragraph and the submission and counts matching words by position, so there’s no number to lie about.
• Every state change fans out over the room channel — player-joined, player-score, game-started, game-finished. The client is a renderer.
• Only the host can start a round, and starting twice is rejected rather than silently reshuffling everyone mid-race.
• A round is a fixed 60-second timer; at the end the server picks the winner and broadcasts it.

Room lifecycle is the part that’s easy to skip

The interesting case isn’t the happy path, it’s people leaving.

• If the host disconnects, the first remaining player is promoted and a new-host event goes out — the room keeps working instead of stranding everyone in a lobby nobody can start.
• If the room empties, the Game is deleted from the map, so a long-running server doesn’t accumulate abandoned rooms.
• Explicit leave, socket disconnect and beforeunload all route through the same handler, so a closed tab is treated exactly like a clicked button.

Degrading instead of failing

Paragraphs come from a third-party text API, with a local generator behind it that builds one from a seed string. A dead API downgrades the text rather than the game — the round still starts.

Where it stopped

The client’s socket URL is hard-coded to localhost, so the server was never deployed and the hosted client can’t reach one. Archived at that point: the game logic is the part worth keeping, and it holds up.