# ✅ Project Status Report ## Multiplayer Tic-Tac-Toe Platform **To:** CTO & Technical Interview Panel **Date:** November 28, 2025 **Version:** v0.2.0 --- ## **1. Objective** Design and implement a lightweight, scalable, server-authoritative multiplayer game system using **Nakama + Go plugins **, supporting authentication, matchmaking, authoritative gameplay, leaderboards, and a functional UI — deployable to Google Cloud for demonstration. --- ## **2. Current Completion Summary** | Requirement | Status | |----------------------------------------------|--------------------------| | Install Nakama + PostgreSQL | ✅ Completed | | Custom Go server plugins | ✅ Completed | | Server-authoritative Tic-Tac-Toe | ✅ Completed | | Real-time WebSocket communication | ✅ Completed | | Device-based authentication | ✅ Completed | | JWT-based session management | ✅ Completed | | Match creation & joining | ✅ Completed | | **Matchmaking queue support** | ✅ Completed | | **Game state validation & turn enforcement** | ✅ Completed | | **Leaderboard system** | ✅ Completed | | **UI Game Client** | 🟡 Partially Implemented | | Google Cloud deployment | 🟡 Not Started | ✅ **Backend is fully authoritative and complete** 🟡 **UI functional but missing polish, UX, and failure handling** --- ## **3. Core Technical Architecture** * **Backend Framework:** Nakama 3.x * **Business Logic:** Custom Go runtime module * **Frontend:** React + Vite + Nakama JS * **Database:** PostgreSQL 14 * **Transport:** WebSockets (real-time) * **Authentication:** Device-ID based auth → JWT session returned * **State Management:** Fully server-authoritative * **Build & Deployment:** Docker-based --- ## **4. Authentication** ### Backend * Device authentication, auto-account creation * JWT returned and used for RT connections ### UI * Generates a device UUID and authenticates via `client.authenticateDevice()` * Stores and manages session state in React context --- ## **5. Game Server Logic (Go)** Significant enhancements made: ### **✔ Initial State Broadcast** * When the second player joins, the server immediately sends the full authoritative state. ### **✔ Complete Turn + Move Validation** Rejects: * out-of-bounds moves * occupied cells * wrong player's turn * invalid payloads ### **✔ Forfeit Handling** * When a user disconnects or leaves, match ends in `forfeit` * Final state broadcast to remaining player ### **✔ Authoritative State Updates** * Only broadcasts when state actually changes * Robust structured logging Result: **Absolute server authority, zero trust in client.** --- ## **6. Real-Time Networking** Communication validated end-to-end: * `match_create` * `match_join` * `matchmaker_add` / `matchmaker_matched` * `match_data_send` for moves (OpCode 1) * Server broadcasts state (OpCode 2) Python simulators and UI both confirm: * move ordering * correct enforcement of turn rules * correct state sync * stable WebSocket behavior --- ## **7. Matchmaking System (Go + UI)** ### **Backend (Go)** * Implements `MatchmakerMatched` hook * Ensures both players: * have valid `mode` * match modes * exactly two players * Creates authoritative matches server-side * RPC `leave_matchmaking` added ### **UI** * Integrates matchmaking: mode selection → queue → ticket → matched → auto-join * Uses Nakama JS `socket.addMatchmaker()` **Status:** Fully functional end-to-end --- ## **8. Leaderboard System (Go + UI)** ### **Backend (Go)** * Leaderboard auto-created on startup * On win: * winner identified * username resolved * score incremented (+1 win) * metadata logged ### **UI** * Implements leaderboard view using `client.listLeaderboardRecords()` * Read-only UI display works ### **Remaining** * UI sorting, layout, styling * No leaderboard write actions needed from UI --- ## **9. UI Implementation Status (React + Vite)** ### **What Is Implemented** - ✔ Authentication flow (device auth) - ✔ WebSocket session handling - ✔ Matchmaking (classic/blitz modes) - ✔ Automatic match join - ✔ Move sending (OpCode 1) - ✔ State updates (OpCode 2) - ✔ Board rendering and interactive cells - ✔ End-of-game messaging - ✔ Leaderboard display ### **Partially Implemented** - 🟡 Match mode UI selection wired but not visually emphasized - 🟡 Context handles all RT states but missing error handling ### **Not Implemented / Missing** - 🔴 Reconnect flow (UI does not recover session after WS drop) - 🔴 No error UI for: matchmaking failure, move rejection, disconnects - 🔴 No UI for leaving match or returning to lobby - 🔴 No rematch button / flow - 🔴 No transitions, animations, or mobile layout - 🔴 No global app shell (Routing, Home Screen, etc.) **Summary:** UI is *functional* and capable of playing full authoritative games, but lacks UX polish and failure handling. --- ## **10. Testing & Validation** ### Backend * Extensive scenario tests: draws, wins, illegal moves, disconnects * Matchmaking simulation across N clients ### UI * Verified: * matchmaking * game correctness * leaderboard retrieval * state sync * Missing: * stress testing * reconnection scenarios * mobile layout testing --- ## **11. Google Cloud Deployment** Planned architecture remains: | Component | GCP Service | |---------------|-------------------------------| | Nakama server | Compute Engine VM (Docker) | | PostgreSQL | Cloud SQL (shared tier) | | Game UI | Cloud Run or Firebase Hosting | | Networking | Static IP + HTTPS | | Auth secrets | Secret Manager (optional) | Estimated setup time: **6–8 hours** --- ## **12. Risks & Considerations** | Risk | Mitigation | |--------------------------------|--------------------------------| | UI lacks error/reconnect logic | Add retry + reconnection flows | | No rematch or lobby UX | Add match lifecycle UI | | No mobile layout | Add responsive CSS | | Cloud deployment pending | Prioritize after UI polish | | Matchmaking UX is minimal | Add feedback, loading states | None of these affect core backend stability. --- ## **13. Next Steps** ### **UI Tasks** 1. Add reconnect + error-handling UI 2. Create lobby → gameplay → results, flow 3. Add rematch capability 4. Add responsive + polished UI 5. Add loading indicators & animations Estimated remaining effort: **6 to 8 hours** --- ## **Executive Summary** ### Issues faced Several unexpected integration challenges during UI setup contributed to the additional day of work. These included: - Aligning the UI’s matchmaking flow with the new authoritative Go-based matchmaking logic. - Handling Nakama JS WebSocket behaviors, especially around session timing, matchmaker ticket handling, and match join events. - Ensuring OpCode handling and server-produced state updates matched the server’s authoritative model. - Resolving environment-related issues (Vite dev server, Node version mismatches, and WebSocket URL configuration). - Debugging cross-origin and connection-reset issues during early WebSocket initialization. These challenges required deeper synchronization between the backend and frontend layers, resulting in an additional **+1 day** of engineering time. ### Project Progress The system now features a fully authoritative backend with matchmaking, gameplay logic, and leaderboards implemented completely in Go. The UI is functional and integrates correctly with all backend systems, supporting end-to-end matchmaking and gameplay. Key remaining work involves UI polish, recovery/error handling, and deployment setup. No major architectural risks remain. **The project is now fully playable, technically solid, and ready for final UI enhancements and cloud deployment.**