Games (chess & draughts)

These packages split the two board games into per-concern layers (domain schemas, Effect services, React UI, rules engines) so chess-services and chess-ui — or draughts-rules and draughts-ui — can be tested and versioned independently. @repo/algorithms and the two @types/* shims are grouped here because they only exist to support this games code.

@repo/chess-domain

Schema-first domain types shared between the chess server and client: no UI, no I/O. Everything is effect Schema classes/unions, so decoded values are the only shapes the rest of the chess code is allowed to see.

• ChessError — tagged ChessError and its reason union (illegal move, not your turn, game not found, game over, join code not found, game already full, cannot join own game, not a participant)
• ChessGame — Side, Outcome, GameStatus, Variant, Move, GameState, and the GameEvent union (GameCreated, PlayerJoined, MoveMade, GameEnded)
• ChessId — branded GameId, PlayerId, JoinCode schemas
• ChessRpc — the OnlineRpc RpcGroup, Unauthorized error, and the GuestSession / GuestSessionMiddleware RPC middleware
• ChessSignal — SignalKind and SignalEvent schemas for WebRTC signaling
• ChessEvent — a small define/registered event-registry helper used to build the tagged events above

@repo/chess-services

Effect services that implement chess gameplay: the engine integration and the game/matchmaking logic, backed by @repo/db and @repo/realtime.

• EngineService — a Context.Service wrapping the stockfish UCI engine (via @repo/stockfish-types) for move analysis/best-move requests
• GameService — a Context.Service for creating, joining, and advancing chess games (row ⇄ GameState mapping, side resolution, event ids)
• detectOutcome / rulesForVariant (from rules-adapter) — adapts chess.js into the shared GameRules/MoveApplication shape and detects checkmate/stalemate/draw outcomes

@repo/chess-ui

React components and hooks for rendering a chess board and its game-end celebration, built on @repo/chess-domain types.

• Board — the chess board component
• isWin, outcomeLabel, type Outcome — outcome-to-label helpers
• fireConfetti, fireOutcomeConfetti — canvas-confetti wrappers
• useOutcomeConfetti — fires confetti on a win outcome
• useDialogCloseHandlers — shared close-handling for game-end dialogs

@repo/draughts-rules

Effect-based rules engines for draughts, covering three variants behind one DraughtsRules interface.

• rulesFor(variant) — picks the rules implementation for "international" | "english" | "russian"
• internationalRules — wraps @jortvl/draughts (via @repo/jortvl-draughts-types) as the authoritative rules oracle for international draughts
• englishRules, russianRules — hand-rolled rules implementations (handrolled.ts)
• board — squareToCell, squareToAlgebraic, algebraicToSquare, cellToSquare, buildFen, parsePosition square/FEN helpers
• variant — Variant, Player, Outcome, DraughtsMove schemas
• rules — the shared DraughtsRules / MoveResult types

@repo/draughts-ui

A single React board component for draughts, mirroring @repo/chess-ui's role for the chess game.

• DraughtsBoard, type DraughtsBoardProps — the draughts board component, built on @repo/draughts-rules types

@repo/algorithms

A standalone learning/reference package of Blind 75 algorithm solutions and generic data structures (TypeScript, with parallel Go/Kotlin/Python/Rust solutions); it isn't imported by the games code and isn't published as @repo/* (its package name is bare algorithms).

• Heap<T> — generic min/max heap backed by an array and a comparator
• ListNode, TreeNode, TrieNode — linked-list, binary-tree, and trie node types used across the solutions
• src/blind-75-solutions/typescript/** — the 65 Blind 75 solutions grouped by category (array, binary, dynamic-programming, graph, heap, interval, linked-list, matrix, strings, tree)

@repo/stockfish-types

A local @types/stockfish shim for the stockfish npm package, which ships no published types. Declares only the surface EngineService relies on.

• StockfishEngine — the UCI engine handle type (listener, sendCommand, terminate)
• initEngine(flavor?) — default export, initializes an engine instance

@repo/jortvl-draughts-types

A local @types/jortvl__draughts shim for @jortvl/draughts, which also ships no published types. Declares only the surface @repo/draughts-rules' international adapter uses.

• JortvlMove — one legal move (from, jumps, takes, to)
• Draughts — default-exported class: moves(), move(), fen(), turn(), gameOver()

See the packages overview and the architecture guide.