diff --git a/trinity/common/workflows/__init__.py b/trinity/common/workflows/__init__.py
index ea7390b4a4..ad38cb935c 100644
--- a/trinity/common/workflows/__init__.py
+++ b/trinity/common/workflows/__init__.py
@@ -48,6 +48,8 @@
         # on-policy distillation workflows
         "on_policy_distill_workflow": "trinity.common.workflows.on_policy_distill_workflow.OnPolicyDistillWorkflow",
         "on_policy_distill_math_workflow": "trinity.common.workflows.on_policy_distill_workflow.OnPolicyDistillMathWorkflow",
+        # custom workflows
+        "sudoku_workflow": "trinity.common.workflows.sudoku_workflow.SudokuWorkflow",
     },
 )
 
diff --git a/trinity/common/workflows/sudoku_generator.py b/trinity/common/workflows/sudoku_generator.py
new file mode 100644
index 0000000000..bcca7e12cc
--- /dev/null
+++ b/trinity/common/workflows/sudoku_generator.py
@@ -0,0 +1,75 @@
+import random
+
+
+class SudokuGenerator:
+    """
+    Sudoku puzzle generator inspired by standard backtracking-based generators.
+
+    - Generates a fresh solved Sudoku board using backtracking
+    - Removes cells based on difficulty (number of empty cells)
+    - Avoids relying on a single canonical solution
+    """
+
+    def generate(self, difficulty="medium"):
+        holes_map = {
+            "easy": 30,
+            "medium": 40,
+            "hard": 50,
+        }
+        holes = holes_map.get(difficulty, 40)
+
+        board = [[0 for _ in range(9)] for _ in range(9)]
+        self._fill_board(board)
+
+        solution = [row[:] for row in board]
+        self._remove_cells(board, holes)
+
+        return board, solution
+
+    def _fill_board(self, board):
+        empty = self._find_empty(board)
+        if not empty:
+            return True
+
+        r, c = empty
+        nums = list(range(1, 10))
+        random.shuffle(nums)
+
+        for v in nums:
+            if self._is_valid(board, r, c, v):
+                board[r][c] = v
+                if self._fill_board(board):
+                    return True
+                board[r][c] = 0
+
+        return False
+
+    def _find_empty(self, board):
+        for i in range(9):
+            for j in range(9):
+                if board[i][j] == 0:
+                    return i, j
+        return None
+
+    def _is_valid(self, board, r, c, v):
+        if v in board[r]:
+            return False
+
+        if v in [board[i][c] for i in range(9)]:
+            return False
+
+        br, bc = (r // 3) * 3, (c // 3) * 3
+        for i in range(br, br + 3):
+            for j in range(bc, bc + 3):
+                if board[i][j] == v:
+                    return False
+
+        return True
+
+    def _remove_cells(self, board, holes):
+        cells = [(i, j) for i in range(9) for j in range(9)]
+        random.shuffle(cells)
+
+        for i in range(min(holes, 81)):
+            r, c = cells[i]
+            board[r][c] = 0
diff --git a/trinity/common/workflows/sudoku_judge.py b/trinity/common/workflows/sudoku_judge.py
new file mode 100644
index 0000000000..9fee423710
--- /dev/null
+++ b/trinity/common/workflows/sudoku_judge.py
@@ -0,0 +1,43 @@
+class SudokuJudge:
+    """
+    Judge Sudoku board state.
+    - Checks row validity
+    - Checks column validity
+    - Checks 3x3 block validity
+    """
+
+    @staticmethod
+    def is_valid(board):
+        # Check rows
+        for row in board:
+            nums = [v for v in row if v != 0]
+            if len(nums) != len(set(nums)):
+                return False
+
+        # Check columns
+        for col in range(9):
+            nums = []
+            for row in range(9):
+                v = board[row][col]
+                if v != 0:
+                    nums.append(v)
+            if len(nums) != len(set(nums)):
+                return False
+
+        # Check 3x3 sub-grids
+        for br in range(0, 9, 3):
+            for bc in range(0, 9, 3):
+                nums = []
+                for r in range(br, br + 3):
+                    for c in range(bc, bc + 3):
+                        v = board[r][c]
+                        if v != 0:
+                            nums.append(v)
+                if len(nums) != len(set(nums)):
+                    return False
+
+        return True
+
+    @staticmethod
+    def is_solved(board, solution):
+        return board == solution
diff --git a/trinity/common/workflows/sudoku_workflow.py b/trinity/common/workflows/sudoku_workflow.py
new file mode 100644
index 0000000000..e65604ca30
--- /dev/null
+++ b/trinity/common/workflows/sudoku_workflow.py
@@ -0,0 +1,159 @@
+from trinity.common.experience import Experience
+from trinity.common.workflows.workflow import Workflow
+
+from .sudoku_generator import SudokuGenerator
+from .sudoku_judge import SudokuJudge
+
+
+class SudokuWorkflow(Workflow):
+    can_reset = True
+
+    def __init__(self, task, model, auxiliary_models=None):
+        super().__init__(task=task, model=model, auxiliary_models=auxiliary_models)
+
+        if "puzzle" in task.raw_task and "solution" in task.raw_task:
+            self.board = [row[:] for row in task.raw_task["puzzle"]]
+            self.solution = [row[:] for row in task.raw_task["solution"]]
+        else:
+            generator = SudokuGenerator()
+            self.board, self.solution = generator.generate()
+
+        self.judge = SudokuJudge()
+        self.max_steps = 20
+        self.max_moves_per_step = 5
+
+        self.current_step = 0
+        self.last_board = None
+        self.last_action = None
+
+    def reset(self, task):
+        self.board = [row[:] for row in task.raw_task["puzzle"]]
+        self.solution = [row[:] for row in task.raw_task["solution"]]
+        self.current_step = 0
+        self.last_board = None
+        self.last_action = None
+
+    def render_board(self):
+        return "\n".join(" ".join(str(v) for v in row) for row in self.board)
+
+    def _build_prompt(self):
+        prompt = (
+            "You are playing a Sudoku game.\n\n"
+            "Rules:\n"
+            "- The board is 9x9.\n"
+            "- 0 means empty.\n"
+            "- Numbers 1–9 must appear exactly once in every row, column, and 3x3 block.\n"
+            "- You may only fill empty cells.\n\n"
+            "Task:\n"
+            "- In each step, output ONE OR MORE valid moves.\n"
+            f"- You may output up to {self.max_moves_per_step} moves per step.\n\n"
+            "Output format (STRICT):\n"
+            "row col value\n"
+            "row col value\n\n"
+            "Example:\n"
+            "0 2 4\n"
+            "1 3 5\n\n"
+            f"Current step: {self.current_step}\n"
+            f"Remaining steps: {self.max_steps - self.current_step}\n\n"
+            f"Current board:\n{self.render_board()}\n"
+        )
+
+        if self.last_board is not None and self.board == self.last_board:
+            prompt += (
+                "\nYour previous response was invalid or had no effect. "
+                "Please follow the rules and output format strictly."
+            )
+
+        return prompt
+
+    def parse_action(self, text):
+        lines = text.strip().splitlines()
+        actions = []
+
+        for line in lines:
+            line = line.strip()
+            if not line:
+                continue
+            parts = line.split()
+            if len(parts) != 3:
+                return None
+            try:
+                r, c, v = map(int, parts)
+            except ValueError:
+                return None
+            if not (0 <= r <= 8 and 0 <= c <= 8 and 1 <= v <= 9):
+                return None
+            actions.append((r, c, v))
+
+        if not actions or len(actions) > self.max_moves_per_step:
+            return None
+
+        return actions
+
+    def run(self):
+        experiences = []
+
+        for _ in range(self.max_steps):
+            prompt = self._build_prompt()
+            responses = self.model.chat([{"role": "user", "content": prompt}])
+            resp = responses[0]
+
+            self.last_board = [row[:] for row in self.board]
+
+            actions = self.parse_action(resp.response_text)
+            if actions is None:
+                experiences.append(
+                    Experience(
+                        tokens=resp.tokens,
+                        prompt_length=resp.prompt_length,
+                        reward=-1.0,
+                        logprobs=resp.logprobs,
+                    )
+                )
+                break
+
+            board_changed = False
+            invalid_move = False
+
+            for r, c, v in actions:
+                if self.board[r][c] != 0:
+                    invalid_move = True
+                    break
+                self.board[r][c] = v
+                board_changed = True
+
+            if invalid_move or not board_changed or not self.judge.is_valid(self.board):
+                experiences.append(
+                    Experience(
+                        tokens=resp.tokens,
+                        prompt_length=resp.prompt_length,
+                        reward=-1.0,
+                        logprobs=resp.logprobs,
+                    )
+                )
+                break
+
+            if self.judge.is_solved(self.board, self.solution):
+                experiences.append(
+                    Experience(
+                        tokens=resp.tokens,
+                        prompt_length=resp.prompt_length,
+                        reward=1.0,
+                        logprobs=resp.logprobs,
+                    )
+                )
+                break
+
+            experiences.append(
+                Experience(
+                    tokens=resp.tokens,
+                    prompt_length=resp.prompt_length,
+                    reward=0.0,
+                    logprobs=resp.logprobs,
+                )
+            )
+
+            self.last_action = actions
+            self.current_step += 1
+
+        return experiences