UCI engine: python -m chess_nnue.uci

README.md

@@ -197,6 +197,7 @@ print(move, info)   # e.g. d2d4 {'depth': 6, 'nodes': ..., 'score': ..., 'ms': .
 ```
 
 - Browser board: `python -m chess_nnue.ui` (http://127.0.0.1:7863): drag or click to move, promotion picker, eval bar, take back, flip.
+- UCI engine (any chess GUI or harness, e.g. Cute Chess, Arena, python-chess): `python -m chess_nnue.uci` from `reasoning_harness/`.
 - Lichess bot: `chess_nnue/lichess_bot.py` is a [lichess-bot](https://github.com/lichess-bot-devs/lichess-bot) "homemade" engine.
 
 ## Run the benchmarks

chess_nnue/uci.py

@@ -0,0 +1,78 @@
+"""depth 5 as a UCI engine, so any chess GUI or harness can run it.
+
+    python -m chess_nnue.uci [--weights PATH]      (run from reasoning_harness/)
+
+Supports: uci, isready, ucinewgame, position (startpos/fen + moves), go
+(movetime / wtime btime winc binc / depth), quit.
+shortcut: search runs synchronously, so "stop" is ignored until the move is found
+(the search always ends at its deadline); add a search thread if a GUI needs ponder/infinite.
+"""
+import argparse
+import sys
+from pathlib import Path
+
+import chess
+
+from .engine import Engine, MATE
+from .net import NNUE
+
+DEFAULT = Path(__file__).parent.parent / "artifacts" / "chess_nnue" / "chess.nnue"
+
+
+def budget_ms(board, args):
+    """Same clock rule as the benchmarks: a 20th of the clock plus most of the increment."""
+    opt = dict(zip(args[::2], args[1::2]))
+    if "movetime" in opt:
+        return max(10, int(opt["movetime"]) - 20)
+    side = "w" if board.turn == chess.WHITE else "b"
+    if side + "time" in opt:
+        clock, inc = int(opt[side + "time"]), int(opt.get(side + "inc", 0))
+        return max(10, min(clock / 20 + inc * 0.75, clock / 2 - 50))
+    return 1000
+
+
+def main(argv=None, inp=sys.stdin, out=sys.stdout):
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--weights", default=str(DEFAULT))
+    a = ap.parse_args(argv)
+    nnue = NNUE(a.weights)
+    engine, board = Engine(nnue), chess.Board()
+
+    def say(line):
+        out.write(line + "\n")
+        out.flush()
+
+    for line in inp:
+        parts = line.split()
+        if not parts:
+            continue
+        cmd, args = parts[0], parts[1:]
+        if cmd == "uci":
+            say("id name depth 5")
+            say("id author Kedhareswer")
+            say("uciok")
+        elif cmd == "isready":
+            say("readyok")
+        elif cmd == "ucinewgame":
+            engine = Engine(nnue)
+        elif cmd == "position":
+            if args[0] == "startpos":
+                board, rest = chess.Board(), args[1:]
+            else:
+                end = args.index("moves") if "moves" in args else len(args)
+                board, rest = chess.Board(" ".join(args[1:end])), args[end:]
+            for u in rest[1:]:
+                board.push_uci(u)
+        elif cmd == "go":
+            opt = dict(zip(args[::2], args[1::2]))
+            move, info = engine.search(board, budget_ms(board, args), int(opt.get("depth", 64)))
+            s = info["score"]
+            score = f"mate {(MATE - abs(s) + 1) // 2 * (1 if s > 0 else -1)}" if abs(s) >= MATE - 100 else f"cp {s}"
+            say(f"info depth {info['depth']} nodes {info['nodes']} time {int(info['ms'])} score {score}")
+            say(f"bestmove {move.uci()}")
+        elif cmd == "quit":
+            break
+
+
+if __name__ == "__main__":
+    main()

chess_nnue/ui.html

@@ -62,6 +62,7 @@
   .card { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; }
   h1 { font-size: 18px; margin: 0; letter-spacing: -.01em; }
   .sub { color: var(--muted); font-size: 13px; margin: 2px 0 0; }
+  .sub a { color: var(--accent); }
   .player { display: flex; align-items: center; gap: 10px; padding: 6px 0; }
   .player + .player { border-top: 1px solid var(--line); }
   .swatch { width: 14px; height: 14px; border-radius: 3px; border: 1px solid var(--line); flex: none; }
@@ -106,6 +107,7 @@
     <div class="card c-about">
       <h1>depth 5</h1>
       <p class="sub">A 4.8 MB neural network plus alpha-beta search, running on CPU. Drag a piece or click it, then click a square.</p>
+      <p class="sub"><a href="https://llm-chess-agentic.vercel.app" target="_blank" rel="noopener">Play it against LLMs in LLM Chess Arena</a> · <a href="https://huggingface.co/Kedhareswer/depth-5" target="_blank" rel="noopener">model and benchmarks</a></p>
     </div>
     <div class="card c-players" aria-live="polite">
       <div class="player" id="p-engine"><span class="swatch"></span><span class="name">depth 5</span><span class="meta" id="eng-meta"></span><span class="dots" aria-label="thinking"><i></i><i></i><i></i></span></div>

tests/test_chess_nnue.py

@@ -115,6 +115,23 @@ class NNUETests(unittest.TestCase):
         b = chess.Board("r1bqkb1r/ppp2p2/2n2n1p/4p1p1/P5P1/5P1N/1PPBP2P/RN1QKB1R w KQkq - 2 8")
         self.assertNotEqual(Engine(PST_Eval(), "plain").search(b, 1500)[0], chess.Move.from_uci("h3g5"))
 
+    def test_uci_engine_plays_legal_moves(self):
+        import sys
+        import chess.engine
+        root = Path(__file__).parent.parent
+        uci = chess.engine.SimpleEngine.popen_uci([sys.executable, "-m", "chess_nnue.uci", "--weights", str(self.path)], cwd=root)
+        try:
+            self.assertEqual(uci.id["name"], "depth 5")
+            board = chess.Board()
+            for _ in range(6):
+                move = uci.play(board, chess.engine.Limit(time=0.2)).move
+                self.assertIn(move, board.legal_moves)
+                board.push(move)
+            mate = chess.Board("6k1/5ppp/8/8/8/8/8/R5K1 w - - 0 1")
+            self.assertEqual(uci.play(mate, chess.engine.Limit(white_clock=5, black_clock=5)).move, chess.Move.from_uci("a1a8"))
+        finally:
+            uci.quit()
+
     def test_finds_mate_in_one(self):
         b = chess.Board("6k1/5ppp/8/8/8/8/8/R5K1 w - - 0 1")
         for eng in (Engine(self.nn), Engine(PST_Eval(), "plain")):