789 Sudoku

Use to start a playable Sudoku game inside ChatGPT. Call this tool when the user explicitly asks to play Sudoku, asks for a logic puzzle, asks for a brain-training or cognitive game, or otherwise indicates that they want an interactive Sudoku board rendered in chat. The tool accepts a difficulty level of easy, medium, or hard and returns a fresh valid Sudoku puzzle for that difficulty. The returned structured content contains the initial board state, which the widget uses to render the puzzle and track the player's progress. The widget is the correct experience when the user wants to interact with a board, fill cells, or play a complete game without leaving the conversation. Do not use this tool for plain-text explanations of Sudoku rules, textual puzzle walkthroughs, or requests that explicitly forbid widget or tool usage. Do not call it when the user only wants discussion about focus, brain training, or general games without asking to start one. If the user does want to begin playing, this tool is the authoritative way to launch the in-chat Sudoku board.