NChess 0.0.1

NChess

NChess is pure C# chess core focused on correctness, clarity, and extensibility.
This is an early alpha release (v0.0.1-alpha) intended for engine development, analysis tools, and chess-related experiments.

Status

⚠️ Alpha

The public API is unstable and may change without notice.

Currently implemented:

• FEN load / save (round-trip safe)
• Legal move generation
• Move application and deterministic undo
• SAN and UCI notation
• PGN import / export (single game)
• Castling, en-passant, promotion
• Debug-friendly board representation

Project Structure

NChess
├─ NChess                // High-level Chess facade
├─ NChess.Console        // Console playground / scratchpad
├─ NChess.Core           // Core chess logic
│  ├─ Common             // Board, Position, Square, etc.
│  ├─ Engine             // Engine abstractions
│  │  └─ Classic         // Reference engine implementation
│  ├─ Fen                // FEN parsing and serialization
│  ├─ Moves              // Move, flags, undo
│  ├─ Notation           // SAN / UCI
│  └─ Pieces             // Piece, PieceType
└─ NChess.Core.Pgn       // PGN import / export

Quick Example

using NChess;

var chess = new Chess();

chess.TryMoveSan("e4", out _);
chess.TryMoveSan("e5", out _);
chess.TryMoveSan("Nf3", out _);

Console.WriteLine(chess.Fen);
Console.WriteLine(chess.ExportPgn());

Supported Formats

• FEN — load / save
• SAN — parse and format (with disambiguation)
• UCI — parse and format
• PGN — import / export (single game, no variations)

Design Goals

• Correctness first
• Deterministic move undo
• Engine-agnostic architecture
• Minimal allocations
• Easy debugging (ASCII board dump)

Non-Goals (for now)

• Strong evaluation or search
• Opening books or endgame tables
• PGN variations
• GUI
• Aggressive performance tuning

Target Framework

• Core library: .NET Standard 2.1
• Tests / tooling: modern .NET (net6+)

License

MIT (planned)

Version: 0.0.1-alpha
API stability: ❌ not guaranteed
Intended use: internal tools, experiments, learning, engine prototyping