Just One — web edition

A web version of the cooperative party game Just One, built for playing with friends while you're together on a call. One player guesses a mystery word; everyone else secretly writes a one-word clue — but identical clues cancel out and are never shown.

• Aspire 13.4 orchestration, Blazor Server UI on .NET 10 — no JS framework
• Rooms are joined with a 4-letter code (or a shared link); state is in-memory only and rooms expire after an hour of inactivity
• Standard rules: 13 cards per game, guesser picks a number 1–5, duplicate clues auto-cancel (case/accent-insensitive) plus tap-to-cancel for variants, exact guesses auto-score, near-misses go to an accept/reject vote, a wrong guess burns the next card too
• 3–12 players; refreshing the page rejoins your seat (identity lives in localStorage); mid-game joiners spectate until the next game; the host can skip stuck players or rounds

Screenshots

Create or join	Lobby	Pick a number

Write a clue	Check for duplicates	Guess

Close enough?	Round result	Game over

Run it

dotnet run --project src/JustOne.AppHost     # with the Aspire dashboard
# or, standalone (same app, fixed ports):
dotnet run --project src/JustOne.Web         # http://localhost:5201

The web app always listens on http://localhost:5201 (launch profile), under both the AppHost and standalone runs.

Host for friends via dev tunnels

The AppHost includes Aspire's native dev tunnels integration (Aspire.Hosting.DevTunnels): a tunnel resource fronts the game's http endpoint with anonymous access enabled, so dotnet run --project src/JustOne.AppHost is all it takes — the public https://….devtunnels.ms URL appears on the tunnel resource in the Aspire dashboard. Share that URL (or URL + room code) with your friends.

One-time setup: install the devtunnel CLI and run devtunnel user login. If the CLI is missing the tunnel resource reports it in the dashboard and the game still runs locally on port 5201.

Notes:

• The tunnel exposes the http endpoint; dev tunnels terminate TLS at the edge, and the app deliberately does not redirect to its local https endpoint.
• WebSockets (Blazor's circuit transport) work through dev tunnels out of the box.
• Guests may see a one-time anonymous-access interstitial on first visit — just continue.
• Don't want the tunnel on a given run? Comment out the AddDevTunnel block in src/JustOne.AppHost/AppHost.cs, or run the web project standalone.

Project layout

src/JustOne.AppHost          Aspire app host (run this)
src/JustOne.ServiceDefaults  OpenTelemetry / health checks / service discovery defaults
src/JustOne.Core             Pure game engine — rules state machine, no ASP.NET deps
src/JustOne.Web              Blazor Server app: rooms, real-time fan-out, UI
tests/JustOne.Core.Tests     TUnit tests for the engine

How real-time works: a singleton RoomManager holds each room behind a lock (RoomHandle); every mutation raises a Changed event and each player's Blazor circuit re-renders from an immutable per-viewer snapshot (RoomView). Information hiding happens in the snapshot, so the guesser's browser never receives the mystery word or unrevealed clues.

Tests

dotnet run --project tests/JustOne.Core.Tests   # TUnit / Microsoft.Testing.Platform
# `dotnet test` works too

Manual smoke script (multi-browser)

1. Open three browser windows (use private windows so each gets its own identity), create a room as the host, join with the other two.
2. Start the game, pick a number, submit Café and cafe as clues → both get struck through in review; reveal → guesser sees no clues; pass.
3. Next round: distinct clues, tap one to cancel/uncancel it, reveal, guess the word with different casing → auto-scores.
4. Wrong guess → reject in the judgment step → two cards gone.
5. Refresh a window mid-round → same seat; join with a fourth window mid-game → spectator until the next game.