From 700373dba3fe0016408acad140a4e559530f1613 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sun, 24 Mar 2024 13:10:24 +0200
Subject: [PATCH 01/26] Update humanoid_v5.py

---
 gymnasium/envs/mujoco/humanoid_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gymnasium/envs/mujoco/humanoid_v5.py b/gymnasium/envs/mujoco/humanoid_v5.py
index b6b324b47e..2b87c81f4c 100644
--- a/gymnasium/envs/mujoco/humanoid_v5.py
+++ b/gymnasium/envs/mujoco/humanoid_v5.py
@@ -38,7 +38,7 @@ class HumanoidEnv(MujocoEnv, utils.EzPickle):
     :name: humanoid
     ```
 
-    The action space is a `Box(-1, 1, (17,), float32)`. An action represents the torques applied at the hinge joints.
+    The action space is a `Box(-0.4, 0.4, (17,), float32)`. An action represents the torques applied at the hinge joints.
 
     | Num | Action                                                                             | Control Min | Control Max | Name (in corresponding XML file) | Joint | Type (Unit)  |
     | --- | ---------------------------------------------------------------------------------- | ----------- | ----------- | -------------------------------- | ----- | ------------ |

From e169b8fc8b5ae3f5006dfddeb856cebc3fdd927b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sun, 24 Mar 2024 13:14:53 +0200
Subject: [PATCH 02/26] Update humanoidstandup_v5.py

---
 gymnasium/envs/mujoco/humanoidstandup_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gymnasium/envs/mujoco/humanoidstandup_v5.py b/gymnasium/envs/mujoco/humanoidstandup_v5.py
index 8477ec0ca4..6666274f7a 100644
--- a/gymnasium/envs/mujoco/humanoidstandup_v5.py
+++ b/gymnasium/envs/mujoco/humanoidstandup_v5.py
@@ -32,7 +32,7 @@ class HumanoidStandupEnv(MujocoEnv, utils.EzPickle):
     :name: humanoid
     ```
 
-    The action space is a `Box(-1, 1, (17,), float32)`. An action represents the torques applied at the hinge joints.
+    The action space is a `Box(-0.4, 0.4, (17,), float32)`. An action represents the torques applied at the hinge joints.
 
     | Num | Action                                                                             | Control Min | Control Max | Name (in corresponding XML file) | Joint | Type (Unit)  |
     | --- | ---------------------------------------------------------------------------------- | ----------- | ----------- | -------------------------------- | ----- | ------------ |

From 2f656e3bd6deedd78440dc1805ace78a923ef42c Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 23 May 2024 09:41:36 +0300
Subject: [PATCH 03/26] Update mujoco_env.py

---
 gymnasium/envs/mujoco/mujoco_env.py | 199 ++++++++++++----------------
 1 file changed, 83 insertions(+), 116 deletions(-)

diff --git a/gymnasium/envs/mujoco/mujoco_env.py b/gymnasium/envs/mujoco/mujoco_env.py
index 5f2fa6396a..70a7aaf155 100644
--- a/gymnasium/envs/mujoco/mujoco_env.py
+++ b/gymnasium/envs/mujoco/mujoco_env.py
@@ -34,19 +34,22 @@ def expand_model_path(model_path: str) -> str:
     return fullpath
 
 
-class BaseMujocoEnv(gym.Env[NDArray[np.float64], NDArray[np.float32]]):
-    """Superclass for all MuJoCo environments."""
+class MujocoEnv(BaseMujocoEnv):
+    """Superclass for MuJoCo based environments."""
 
     def __init__(
         self,
-        model_path,
-        frame_skip,
+        model_path: str,
+        frame_skip: int,
         observation_space: Optional[Space],
         render_mode: Optional[str] = None,
         width: int = DEFAULT_SIZE,
         height: int = DEFAULT_SIZE,
         camera_id: Optional[int] = None,
         camera_name: Optional[str] = None,
+        default_camera_config: Optional[Dict[str, Union[float, int]]] = None,
+        max_geom: int = 1000,
+        visual_options: Dict[int, bool] = {},
     ):
         """Base abstract class for mujoco based environments.
 
@@ -59,6 +62,9 @@ def __init__(
             height: The height of the render window.
             camera_id: The camera ID used.
             camera_name: The name of the camera used (can not be used in conjunction with `camera_id`).
+            default_camera_config: configuration for rendering camera.
+            max_geom: max number of rendered geometries.
+            visual_options: render flag options.
 
         Raises:
             OSError: when the `model_path` does not exist.
@@ -93,48 +99,79 @@ def __init__(
         self.camera_name = camera_name
         self.camera_id = camera_id
 
+        from gymnasium.envs.mujoco.mujoco_rendering import MujocoRenderer
+
+        self.mujoco_renderer = MujocoRenderer(
+            self.model,
+            self.data,
+            default_camera_config,
+            self.width,
+            self.height,
+            max_geom,
+            camera_id,
+            camera_name,
+            visual_options,
+        )
+
     def _set_action_space(self):
         bounds = self.model.actuator_ctrlrange.copy().astype(np.float32)
         low, high = bounds.T
         self.action_space = spaces.Box(low=low, high=high, dtype=np.float32)
         return self.action_space
 
-    # methods to override:
-    # ----------------------------
-    def step(
-        self, action: NDArray[np.float32]
-    ) -> Tuple[NDArray[np.float64], np.float64, bool, bool, Dict[str, np.float64]]:
-        raise NotImplementedError
-
-    def reset_model(self) -> NDArray[np.float64]:
+    def _initialize_simulation(
+        self,
+    ) -> Tuple["mujoco.MjModel", "mujoco.MjData"]:
         """
-        Reset the robot degrees of freedom (qpos and qvel).
-        Implement this in each subclass.
+        Initialize MuJoCo simulation data structures `mjModel` and `mjData`.
         """
-        raise NotImplementedError
+        model = mujoco.MjModel.from_xml_path(self.fullpath)
+        # MjrContext will copy model.vis.global_.off* to con.off*
+        model.vis.global_.offwidth = self.width
+        model.vis.global_.offheight = self.height
+        data = mujoco.MjData(model)
+        return model, data
 
-    def _initialize_simulation(self) -> Tuple[Any, Any]:
-        """
-        Initialize MuJoCo simulation data structures mjModel and mjData.
+    def set_state(self, qpos, qvel):
+        """Set the joints position qpos and velocity qvel of the model.
+
+        Note: `qpos` and `qvel` is not the full physics state for all mujoco models/environments https://mujoco.readthedocs.io/en/stable/APIreference/APItypes.html#mjtstate
         """
-        raise NotImplementedError
+        assert qpos.shape == (self.model.nq,) and qvel.shape == (self.model.nv,)
+        self.data.qpos[:] = np.copy(qpos)
+        self.data.qvel[:] = np.copy(qvel)
+        if self.model.na == 0:
+            self.data.act[:] = None
+        mujoco.mj_forward(self.model, self.data)
 
-    def _step_mujoco_simulation(self, ctrl, n_frames) -> None:
+    def _step_mujoco_simulation(self, ctrl, n_frames):
         """
         Step over the MuJoCo simulation.
         """
-        raise NotImplementedError
+        self.data.ctrl[:] = ctrl
 
-    def render(self) -> Union[NDArray[np.float64], None]:
+        mujoco.mj_step(self.model, self.data, nstep=n_frames)
+
+        # As of MuJoCo 2.0, force-related quantities like cacc are not computed
+        # unless there's a force sensor in the model.
+        # See https://github.com/openai/gym/issues/1541
+        mujoco.mj_rnePostConstraint(self.model, self.data)
+
+    def render(self):
         """
         Render a frame from the MuJoCo simulation as specified by the render_mode.
         """
-        raise NotImplementedError
+        return self.mujoco_renderer.render(self.render_mode)
+
+    def close(self):
+        """Close rendering contexts processes."""
+        if self.mujoco_renderer is not None:
+            self.mujoco_renderer.close()
+
+    def get_body_com(self, body_name):
+        """Return the cartesian position of a body frame."""
+        return self.data.body(body_name).xpos
 
-    # -----------------------------
-    def _get_reset_info(self) -> Dict[str, float]:
-        """Function that generates the `info` that is returned during a `reset()`."""
-        return {}
 
     def reset(
         self,
@@ -168,99 +205,29 @@ def do_simulation(self, ctrl, n_frames) -> None:
             )
         self._step_mujoco_simulation(ctrl, n_frames)
 
-    def close(self):
-        """Close all processes like rendering contexts"""
-        raise NotImplementedError
-
-    def get_body_com(self, body_name) -> NDArray[np.float64]:
-        """Return the cartesian position of a body frame"""
-        raise NotImplementedError
-
     def state_vector(self) -> NDArray[np.float64]:
-        """Return the position and velocity joint states of the model"""
+        """Return the position and velocity joint states of the model.
+        
+        Note: `qpos` and `qvel` does not constitute the full physics state for all `mujoco` environments see https://mujoco.readthedocs.io/en/stable/computation/index.html#the-state.
+        """
         return np.concatenate([self.data.qpos.flat, self.data.qvel.flat])
 
+    # methods to override:
+    # ----------------------------
+    def step(
+        self, action: NDArray[np.float32]
+    ) -> Tuple[NDArray[np.float64], np.float64, bool, bool, Dict[str, np.float64]]:
+        raise NotImplementedError
 
-class MujocoEnv(BaseMujocoEnv):
-    """Superclass for MuJoCo environments."""
-
-    def __init__(
-        self,
-        model_path,
-        frame_skip,
-        observation_space: Optional[Space],
-        render_mode: Optional[str] = None,
-        width: int = DEFAULT_SIZE,
-        height: int = DEFAULT_SIZE,
-        camera_id: Optional[int] = None,
-        camera_name: Optional[str] = None,
-        default_camera_config: Optional[Dict[str, Union[float, int]]] = None,
-        max_geom: int = 1000,
-        visual_options: Dict[int, bool] = {},
-    ):
-        super().__init__(
-            model_path,
-            frame_skip,
-            observation_space,
-            render_mode,
-            width,
-            height,
-            camera_id,
-            camera_name,
-        )
-
-        from gymnasium.envs.mujoco.mujoco_rendering import MujocoRenderer
-
-        self.mujoco_renderer = MujocoRenderer(
-            self.model,
-            self.data,
-            default_camera_config,
-            self.width,
-            self.height,
-            max_geom,
-            camera_id,
-            camera_name,
-            visual_options,
-        )
-
-    def _initialize_simulation(
-        self,
-    ) -> Tuple["mujoco._structs.MjModel", "mujoco._structs.MjData"]:
-        model = mujoco.MjModel.from_xml_path(self.fullpath)
-        # MjrContext will copy model.vis.global_.off* to con.off*
-        model.vis.global_.offwidth = self.width
-        model.vis.global_.offheight = self.height
-        data = mujoco.MjData(model)
-        return model, data
-
-    def set_state(self, qpos, qvel):
-        """Set the joints position qpos and velocity qvel of the model.
-
-        Note: `qpos` and `qvel` is not the full physics state for all mujoco models/environments https://mujoco.readthedocs.io/en/stable/APIreference/APItypes.html#mjtstate
+    def reset_model(self) -> NDArray[np.float64]:
         """
-        assert qpos.shape == (self.model.nq,) and qvel.shape == (self.model.nv,)
-        self.data.qpos[:] = np.copy(qpos)
-        self.data.qvel[:] = np.copy(qvel)
-        if self.model.na == 0:
-            self.data.act[:] = None
-        mujoco.mj_forward(self.model, self.data)
-
-    def _step_mujoco_simulation(self, ctrl, n_frames):
-        self.data.ctrl[:] = ctrl
-
-        mujoco.mj_step(self.model, self.data, nstep=n_frames)
-
-        # As of MuJoCo 2.0, force-related quantities like cacc are not computed
-        # unless there's a force sensor in the model.
-        # See https://github.com/openai/gym/issues/1541
-        mujoco.mj_rnePostConstraint(self.model, self.data)
-
-    def render(self):
-        return self.mujoco_renderer.render(self.render_mode)
+        Reset the robot degrees of freedom (qpos and qvel).
+        Implement this in each environment subclass.
+        """
+        raise NotImplementedError
 
-    def close(self):
-        if self.mujoco_renderer is not None:
-            self.mujoco_renderer.close()
+    def _get_reset_info(self) -> Dict[str, float]:
+        """Function that generates the `info` that is returned during a `reset()`."""
+        return {}
 
-    def get_body_com(self, body_name):
-        return self.data.body(body_name).xpos
+    # -----------------------------

From 13f67fe44cc3ff0f3874f2059e102691e6e07868 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 23 May 2024 09:42:59 +0300
Subject: [PATCH 04/26] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index afba1da473..c7a5fb0c01 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -600,10 +600,7 @@ def test_model_object_count(version: str):
         else:
             assert env.model.nbvh == 18
         assert env.model.njnt == 11
-        if version == "v4":
-            assert env.model.ngeom == 21
-        else:
-            assert env.model.ngeom == 20
+        assert env.model.ngeom == 21
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From 93d8a0cd5ec2b931111982b9cc36f3ffbde39626 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sat, 1 Jun 2024 08:40:16 +0000
Subject: [PATCH 05/26] `pre-commit`

---
 gymnasium/envs/mujoco/mujoco_env.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/gymnasium/envs/mujoco/mujoco_env.py b/gymnasium/envs/mujoco/mujoco_env.py
index 70a7aaf155..2f3e530503 100644
--- a/gymnasium/envs/mujoco/mujoco_env.py
+++ b/gymnasium/envs/mujoco/mujoco_env.py
@@ -1,5 +1,5 @@
 from os import path
-from typing import Any, Dict, Optional, Tuple, Union
+from typing import Dict, Optional, Tuple, Union
 
 import numpy as np
 from numpy.typing import NDArray
@@ -34,7 +34,7 @@ def expand_model_path(model_path: str) -> str:
     return fullpath
 
 
-class MujocoEnv(BaseMujocoEnv):
+class MujocoEnv(gym.Env):
     """Superclass for MuJoCo based environments."""
 
     def __init__(
@@ -172,7 +172,6 @@ def get_body_com(self, body_name):
         """Return the cartesian position of a body frame."""
         return self.data.body(body_name).xpos
 
-
     def reset(
         self,
         *,
@@ -207,7 +206,7 @@ def do_simulation(self, ctrl, n_frames) -> None:
 
     def state_vector(self) -> NDArray[np.float64]:
         """Return the position and velocity joint states of the model.
-        
+
         Note: `qpos` and `qvel` does not constitute the full physics state for all `mujoco` environments see https://mujoco.readthedocs.io/en/stable/computation/index.html#the-state.
         """
         return np.concatenate([self.data.qpos.flat, self.data.qvel.flat])

From 5ca94b43b89f67cf72970fe15a3c9d5de5c073b3 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sat, 1 Jun 2024 11:48:11 +0300
Subject: [PATCH 06/26] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 50 ++++++++++++++---------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index c7a5fb0c01..bf9c639e4a 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -6,7 +6,7 @@
 import pytest
 
 import gymnasium as gym
-from gymnasium.envs.mujoco.mujoco_env import BaseMujocoEnv, MujocoEnv
+from gymnasium.envs.mujoco.mujoco_env import MujocoEnv
 from gymnasium.envs.mujoco.mujoco_py_env import BaseMujocoPyEnv
 from gymnasium.envs.mujoco.utils import check_mujoco_reset_state
 from gymnasium.error import Error
@@ -90,7 +90,7 @@ def test_verify_info_y_position(env_id: str):
 def test_verify_info_x_velocity(env_name: str, version: str):
     """Asserts that the environment `info['x_velocity']` is properly assigned."""
     env = gym.make(f"{env_name}-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_x = env.data.qpos[0]
@@ -107,7 +107,7 @@ def test_verify_info_x_velocity(env_name: str, version: str):
 def test_verify_info_y_velocity(env_id: str):
     """Asserts that the environment `info['y_velocity']` is properly assigned."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_y = env.data.qpos[1]
@@ -123,7 +123,7 @@ def test_verify_info_y_velocity(env_id: str):
 def test_verify_info_xy_velocity_xpos(env_id: str):
     """Asserts that the environment `info['x/y_velocity']` is properly assigned, for the ant environment which uses kinmatics for the velocity."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_xy = env.get_body_com("torso")[:2].copy()
@@ -146,7 +146,7 @@ def mass_center(model, data):
         return (np.sum(mass * xpos, axis=0) / np.sum(mass))[0:2].copy()
 
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_xy = mass_center(env.model, env.data)
@@ -178,7 +178,7 @@ def mass_center(model, data):
 def test_verify_reward_survive(env_name: str, version: str):
     """Assert that `reward_survive` is 0 on `terminal` states and not 0 on non-`terminal` states."""
     env = gym.make(f"{env_name}-{version}", reset_noise_scale=0).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset(seed=0)
     env.action_space.seed(1)
 
@@ -361,7 +361,7 @@ def test_ant_com(version: str):
     """Verify the kinmatic behaviour of the ant."""
     # `env` contains `data : MjData` and `model : MjModel`
     env = gym.make(f"Ant-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()  # randomly initlizies the `data.qpos` and `data.qvel`, calls mujoco.mj_forward(env.model, env.data)
 
     x_position_before = env.data.qpos[0]
@@ -382,7 +382,7 @@ def test_ant_com(version: str):
 def test_set_state(version: str):
     """Simple Test to verify that `mujocoEnv.set_state()` works correctly."""
     env = gym.make(f"Hopper-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
     new_qpos = np.array(
         [0.00136962, 1.24769787, -0.00459026, -0.00483472, 0.0031327, 0.00412756]
@@ -405,7 +405,7 @@ def test_set_state(version: str):
 def test_distance_from_origin_info(env_id: str):
     """Verify that `info"distance_from_origin"` is correct."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     _, _, _, _, info = env.step(env.action_space.sample())
@@ -487,7 +487,7 @@ def test_reset_info(env_name: str, version: str):
 def test_inverted_double_pendulum_max_height(version: str):
     """Verify the max height of Inverted Double Pendulum."""
     env = gym.make(f"InvertedDoublePendulum-{version}", reset_noise_scale=0).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     y = env.data.site_xpos[0][2]
@@ -498,7 +498,7 @@ def test_inverted_double_pendulum_max_height(version: str):
 def test_inverted_double_pendulum_max_height_old(version: str):
     """Verify the max height of Inverted Double Pendulum (v4 does not have `reset_noise_scale` argument)."""
     env = gym.make(f"InvertedDoublePendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.set_state(env.init_qpos, env.init_qvel)
 
     y = env.data.site_xpos[0][2]
@@ -510,7 +510,7 @@ def test_inverted_double_pendulum_max_height_old(version: str):
 def test_model_object_count(version: str):
     """Verify that all the objects of the model are loaded, mostly useful for using non-mujoco simulator."""
     env = gym.make(f"Ant-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 15
     assert env.model.nv == 14
     assert env.model.nu == 8
@@ -521,7 +521,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"HalfCheetah-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 9
     assert env.model.nv == 9
     assert env.model.nu == 6
@@ -532,7 +532,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Hopper-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 6
     assert env.model.nv == 6
     assert env.model.nu == 3
@@ -543,7 +543,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Humanoid-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 24
     assert env.model.nv == 23
     assert env.model.nu == 17
@@ -554,7 +554,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 2
 
     env = gym.make(f"HumanoidStandup-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 24
     assert env.model.nv == 23
     assert env.model.nu == 17
@@ -565,7 +565,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 2
 
     env = gym.make(f"InvertedDoublePendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 3
     assert env.model.nv == 3
     assert env.model.nu == 1
@@ -576,7 +576,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"InvertedPendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 2
     assert env.model.nv == 2
     assert env.model.nu == 1
@@ -588,7 +588,7 @@ def test_model_object_count(version: str):
 
     if not (version == "v4" and mujoco.__version__ >= "3.0.0"):
         env = gym.make(f"Pusher-{version}").unwrapped
-        assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+        assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
         assert env.model.nq == 11
         assert env.model.nv == 11
         assert env.model.nu == 7
@@ -604,7 +604,7 @@ def test_model_object_count(version: str):
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 4
     assert env.model.nv == 4
     assert env.model.nu == 2
@@ -616,7 +616,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Swimmer-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 5
     assert env.model.nv == 5
     assert env.model.nu == 2
@@ -628,7 +628,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Walker2d-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 9
     assert env.model.nv == 9
     assert env.model.nu == 6
@@ -666,8 +666,8 @@ def test_dt():
     env_b = gym.make(
         "Ant-v5", include_cfrc_ext_in_observation=False, frame_skip=1
     ).unwrapped
-    assert isinstance(env_a, BaseMujocoEnv)
-    assert isinstance(env_b, BaseMujocoEnv)
+    assert isinstance(env_a, MujocoEnv)
+    assert isinstance(env_b, MujocoEnv)
     env_b.model.opt.timestep = 0.05
 
     assert env_a.dt == env_b.dt
@@ -702,7 +702,7 @@ def test_dt():
 )
 def test_reset_noise_scale(env_id):
     """Checks that when `reset_noise_scale=0` we have deterministic initialization."""
-    env: BaseMujocoEnv = gym.make(env_id, reset_noise_scale=0).unwrapped
+    env = gym.make(env_id, reset_noise_scale=0).unwrapped
     env.reset()
 
     assert np.all(env.data.qpos == env.init_qpos)

From 52c04fb4aae4cb70ff034cccc1e88b73d03b9c04 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 08:10:16 +0000
Subject: [PATCH 07/26] Trigger Build


From 0df947382e613972cfdc59f1478a8995dd4f495b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 11:25:03 +0300
Subject: [PATCH 08/26] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index bf9c639e4a..e3ce08b119 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -600,7 +600,10 @@ def test_model_object_count(version: str):
         else:
             assert env.model.nbvh == 18
         assert env.model.njnt == 11
-        assert env.model.ngeom == 21
+        if version == "v4":
+            assert env.model.ngeom == 21
+        else:
+            assert env.model.ngeom == 20        
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From e8943b65de0db2d877170a660c1bb595e00da5fe Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 09:21:29 +0000
Subject: [PATCH 09/26] `pre-commit`

---
 tests/envs/mujoco/test_mujoco_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index e3ce08b119..c7277d10b7 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -603,7 +603,7 @@ def test_model_object_count(version: str):
         if version == "v4":
             assert env.model.ngeom == 21
         else:
-            assert env.model.ngeom == 20        
+            assert env.model.ngeom == 20
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From 63177ceba425bbecce43b063784025fb72fd4ff3 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:15:52 +0300
Subject: [PATCH 10/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 7ded820638..823726c7b2 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -10,10 +10,10 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         numpy-version: ['>=1.21,<2.0', '>=2.0']
         exclude:
-          - python-version: '3.8'  # numpy>=2.0 requires Python>=3.9
+          - python-version: '3.9'  # numpy>=2.0 requires Python>=3.9
             numpy-version: '>=2.0'
     steps:
       - uses: actions/checkout@v4
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v4
       - run: |
            docker build -f bin/necessary-py.Dockerfile \
-             --build-arg PYTHON_VERSION='3.10' \
+             --build-arg PYTHON_VERSION='3.13' \
              --tag gymnasium-necessary-docker .
       - name: Run tests
         run: |

From 6115ccc3a096c4799e6fa598578a3537e51291e4 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:17:13 +0300
Subject: [PATCH 11/26] Update pyproject.toml

---
 pyproject.toml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 61d5221ec5..e83807c340 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,7 +13,7 @@ authors = [{ name = "Farama Foundation", email = "contact@farama.org" }]
 license = { text = "MIT License" }
 keywords = ["Reinforcement Learning", "game", "RL", "AI", "gymnasium"]
 classifiers = [
-    "Development Status :: 4 - Beta",  # change to `5 - Production/Stable` when ready
+    "Development Status :: 5 - Production/Stable",
     "License :: OSI Approved :: MIT License",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.8",
@@ -21,6 +21,7 @@ classifiers = [
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.15",
     'Intended Audience :: Science/Research',
     'Topic :: Scientific/Engineering :: Artificial Intelligence',
 ]

From 7fc3ffe7f484db5269e7f7586fee0288c5111d39 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:18:54 +0300
Subject: [PATCH 12/26] Update pyproject.toml

---
 pyproject.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index e83807c340..365c67a845 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ classifiers = [
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
-    "Programming Language :: Python :: 3.15",
+    "Programming Language :: Python :: 3.13",
     'Intended Audience :: Science/Research',
     'Topic :: Scientific/Engineering :: Artificial Intelligence',
 ]

From aeb1aab1013404b54991c37f1dfc8a3007107f3e Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:19:06 +0300
Subject: [PATCH 13/26] Update pyproject.toml

---
 pyproject.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 365c67a845..784f1bd216 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,6 @@ classifiers = [
     "Development Status :: 5 - Production/Stable",
     "License :: OSI Approved :: MIT License",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",

From 5451d84cdcec4d9acdffb5df35376172d159f4c6 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 16:21:33 +0300
Subject: [PATCH 14/26] Update README.md

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index ff2d9bb9b3..6c6cc9be7d 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ To install the base Gymnasium library, use `pip install gymnasium`
 
 This does not include dependencies for all families of environments (there's a massive number, and some can be problematic to install on certain systems). You can install these dependencies for one family like `pip install "gymnasium[atari]"` or use `pip install "gymnasium[all]"` to install all dependencies.
 
-We support and test for Python 3.8, 3.9, 3.10, 3.11 and 3.12 on Linux and macOS. We will accept PRs related to Windows, but do not officially support it.
+We support and test for Linux and macOS. We will accept PRs related to Windows, but do not officially support it.
 
 ## API
 

From ceb897a58bcd9aa8b034615120e9a5c54c913f77 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Tue, 1 Oct 2024 15:38:59 +0300
Subject: [PATCH 15/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 823726c7b2..888eb1e7da 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v4
       - run: |
            docker build -f bin/necessary-py.Dockerfile \
-             --build-arg PYTHON_VERSION='3.13' \
+             --build-arg PYTHON_VERSION='3.12' \
              --tag gymnasium-necessary-docker .
       - name: Run tests
         run: |

From be728b1108cc7767cb61842764e599af9a9d2a4b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 2 Oct 2024 12:37:42 +0300
Subject: [PATCH 16/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 888eb1e7da..823726c7b2 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v4
       - run: |
            docker build -f bin/necessary-py.Dockerfile \
-             --build-arg PYTHON_VERSION='3.12' \
+             --build-arg PYTHON_VERSION='3.13' \
              --tag gymnasium-necessary-docker .
       - name: Run tests
         run: |

From b3092cc44b4f3dba19d80646481c48bd140ada70 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 2 Oct 2024 12:41:16 +0300
Subject: [PATCH 17/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 823726c7b2..4304166b32 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13-rc']
         numpy-version: ['>=1.21,<2.0', '>=2.0']
         exclude:
           - python-version: '3.9'  # numpy>=2.0 requires Python>=3.9
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v4
       - run: |
            docker build -f bin/necessary-py.Dockerfile \
-             --build-arg PYTHON_VERSION='3.13' \
+             --build-arg PYTHON_VERSION='3.12' \
              --tag gymnasium-necessary-docker .
       - name: Run tests
         run: |

From 0be7f34c393284d00d5d11969289c474d99778f2 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Tue, 8 Oct 2024 02:27:56 +0300
Subject: [PATCH 18/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 4304166b32..888eb1e7da 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13-rc']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         numpy-version: ['>=1.21,<2.0', '>=2.0']
         exclude:
           - python-version: '3.9'  # numpy>=2.0 requires Python>=3.9

From e6f4109d10327335b94b2c497f6d3a40a7c30962 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 23 Oct 2024 14:39:11 +0300
Subject: [PATCH 19/26] Update pyproject.toml

---
 pyproject.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index dd9fd7b146..d6ecb2e4ea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ build-backend = "setuptools.build_meta"
 name = "gymnasium"
 description = "A standard API for reinforcement learning and a diverse set of reference environments (formerly Gym)."
 readme = "README.md"
-requires-python = ">= 3.8"
+requires-python = ">= 3.9"
 authors = [{ name = "Farama Foundation", email = "contact@farama.org" }]
 license = { text = "MIT License" }
 keywords = ["Reinforcement Learning", "game", "RL", "AI", "gymnasium"]

From 299055616423bf29620ef5d4bccc925336f14925 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 23 Oct 2024 14:39:59 +0300
Subject: [PATCH 20/26] Update .pre-commit-config.yaml

---
 .pre-commit-config.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 58954ef886..44fcf4bf94 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -38,7 +38,7 @@ repos:
     rev: v3.17.0
     hooks:
       - id: pyupgrade
-        args: ["--py38-plus"]
+        args: ["--py39-plus"]
   - repo: https://github.com/PyCQA/isort
     rev: 5.13.2
     hooks:

From dfa349b5ad317a8e6b1bc773eca16bad7ed1318d Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 4 Dec 2024 00:02:41 +0200
Subject: [PATCH 21/26] Update README.md

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 56aabde589..92ad7e1fd2 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
     <img src="https://raw.githubusercontent.com/Farama-Foundation/Gymnasium/main/gymnasium-text.png" width="500px"/>
 </p>
 
-Gymnasium is an open source Python library for developing and comparing reinforcement learning algorithms by providing a standard API to communicate between learning algorithms and environments, as well as a standard set of environments compliant with that API. This is a fork of OpenAI's [Gym](https://github.com/openai/gym) library by its maintainers (OpenAI handed over maintenance a few years ago to an outside team), and is where future maintenance will occur going forward.
+Gymnasium is an open source Python library for developing and comparing reinforcement learning algorithms by providing a standard API to communicate between learning algorithms and environments, as well as a standard set of environments compliant with that API. This is a fork of OpenAI's [Gym](https://github.com/openai/gym) library by its maintainers (OpenAI handed over maintenance a few years ago to an outside team), and is where future maintenance will occur going forward. 
 
 The documentation website is at [gymnasium.farama.org](https://gymnasium.farama.org), and we have a public discord server (which we also use to coordinate development work) that you can join here: https://discord.gg/bnJ6kubTg6
 

From 37240a9bc0984490ee7982b2a0a956de848412df Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 4 Dec 2024 00:02:50 +0200
Subject: [PATCH 22/26] Update README.md

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 92ad7e1fd2..56aabde589 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
     <img src="https://raw.githubusercontent.com/Farama-Foundation/Gymnasium/main/gymnasium-text.png" width="500px"/>
 </p>
 
-Gymnasium is an open source Python library for developing and comparing reinforcement learning algorithms by providing a standard API to communicate between learning algorithms and environments, as well as a standard set of environments compliant with that API. This is a fork of OpenAI's [Gym](https://github.com/openai/gym) library by its maintainers (OpenAI handed over maintenance a few years ago to an outside team), and is where future maintenance will occur going forward. 
+Gymnasium is an open source Python library for developing and comparing reinforcement learning algorithms by providing a standard API to communicate between learning algorithms and environments, as well as a standard set of environments compliant with that API. This is a fork of OpenAI's [Gym](https://github.com/openai/gym) library by its maintainers (OpenAI handed over maintenance a few years ago to an outside team), and is where future maintenance will occur going forward.
 
 The documentation website is at [gymnasium.farama.org](https://gymnasium.farama.org), and we have a public discord server (which we also use to coordinate development work) that you can join here: https://discord.gg/bnJ6kubTg6
 

From 4254d956b897d87a8686f4c33b9943bd79f3349e Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 19 Dec 2024 18:21:40 +0200
Subject: [PATCH 23/26] Update run-pytest.yml

---
 .github/workflows/run-pytest.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
index 888eb1e7da..de93aba043 100644
--- a/.github/workflows/run-pytest.yml
+++ b/.github/workflows/run-pytest.yml
@@ -8,7 +8,7 @@ jobs:
   build-all:
     runs-on: ubuntu-latest
     strategy:
-      fail-fast: true
+      fail-fast: false
       matrix:
         python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         numpy-version: ['>=1.21,<2.0', '>=2.0']

From a657582a87121b8f0920f98c629176604b824c3b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 19 Dec 2024 19:56:35 +0200
Subject: [PATCH 24/26] testing upgrading cython

---
 pyproject.toml | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index a8003e92c9..2ee945d93d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,8 +39,8 @@ atari = ["ale_py >=0.9"]
 box2d = ["box2d-py ==2.3.5", "pygame >=2.1.3", "swig ==4.*"]
 classic-control = ["pygame >=2.1.3"]
 classic_control = ["pygame >=2.1.3"]  # kept for backward compatibility
-mujoco-py = ["mujoco-py >=2.1,<2.2", "cython<3"]
-mujoco_py = ["mujoco-py >=2.1,<2.2", "cython<3"]  # kept for backward compatibility
+mujoco-py = ["mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"]
+mujoco_py = ["mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"]  # kept for backward compatibility
 mujoco = ["mujoco >=2.1.5", "imageio >=2.14.1"]
 toy-text = ["pygame >=2.1.3"]
 toy_text = ["pygame >=2.1.3"]  # kept for backward compatibility
@@ -59,8 +59,7 @@ all = [
     # classic-control
     "pygame >=2.1.3",
     # mujoco-py
-    "mujoco-py >=2.1,<2.2",
-    "cython <3",
+    "mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"
     # mujoco
     "mujoco >=2.1.5",
     "imageio >=2.14.1",

From 1d9e9a8cc48c2c7289e8973c4a749ac5da15bd5b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 19 Dec 2024 19:59:38 +0200
Subject: [PATCH 25/26] testing upgrading cython

---
 pyproject.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 2ee945d93d..f5c35abb8b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -59,7 +59,7 @@ all = [
     # classic-control
     "pygame >=2.1.3",
     # mujoco-py
-    "mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"
+    "mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git",
     # mujoco
     "mujoco >=2.1.5",
     "imageio >=2.14.1",

From bf71195e2deb58cb063aef501b692fa034e4e96c Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 19 Dec 2024 20:10:25 +0200
Subject: [PATCH 26/26] Update pyproject.toml

---
 pyproject.toml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index f5c35abb8b..bada529713 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,8 +39,8 @@ atari = ["ale_py >=0.9"]
 box2d = ["box2d-py ==2.3.5", "pygame >=2.1.3", "swig ==4.*"]
 classic-control = ["pygame >=2.1.3"]
 classic_control = ["pygame >=2.1.3"]  # kept for backward compatibility
-mujoco-py = ["mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"]
-mujoco_py = ["mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git"]  # kept for backward compatibility
+mujoco-py = ["mujoco-py >=2.1,<2.2", "cython<3"]
+mujoco_py = ["mujoco-py >=2.1,<2.2", "cython<3"]  # kept for backward compatibility
 mujoco = ["mujoco >=2.1.5", "imageio >=2.14.1"]
 toy-text = ["pygame >=2.1.3"]
 toy_text = ["pygame >=2.1.3"]  # kept for backward compatibility
@@ -59,7 +59,7 @@ all = [
     # classic-control
     "pygame >=2.1.3",
     # mujoco-py
-    "mujoco-py@git+https://github.com/Kallinteris-Andreas/mujoco-py.git",
+    "mujoco-py >=2.1,<2.2", "cython<3",
     # mujoco
     "mujoco >=2.1.5",
     "imageio >=2.14.1",