diff --git a/pyproject.toml b/pyproject.toml
index dda7fda7..ed4da7fc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ requires = [
   "pybind11",
   "cmake",
   "ninja",
-  "mujoco==3.2.6",
+  "mujoco==3.10.0",
   "pin==3.7.0",
 ]
 build-backend = "scikit_build_core.build"
@@ -36,7 +36,7 @@ dependencies = [
   "rpyc~=6.0.2",
   "pyarrow",
   "simplejpeg",
-  "mujoco==3.2.6",
+  "mujoco==3.10.0",
   "pin==3.7.0",
   # pin 3.7.0 currently resolves against older urdfdom/tinyxml SONAMEs at runtime
   "cmeel-urdfdom<5",
@@ -74,7 +74,7 @@ dev = [
   "cmake",
 ]
 build_deps = [
-  "mujoco==3.2.6",
+  "mujoco==3.10.0",
   "pin==3.7.0",
   "cmeel-urdfdom<5",
   "cmeel-tinyxml2<11",
@@ -86,7 +86,7 @@ skip = ["cp314*", "*-musllinux*"]
 # Install X11 headers needed to compile GLFW
 before-all = "yum install -y libXi-devel libXcursor-devel libXinerama-devel libXrandr-devel glfw-devel"
 # Exclude MuJoCo AND Pinocchio from being bundled.
-repair-wheel-command = "auditwheel repair -w {dest_dir} {wheel} --exclude libmujoco.so.3.2.6 --exclude libpinocchio_default.so.3.7.0 --exclude libpinocchio_parsers.so.3.7.0"
+repair-wheel-command = "auditwheel repair -w {dest_dir} {wheel} --exclude libmujoco.so.* --exclude libpinocchio_default.so.3.7.0 --exclude libpinocchio_parsers.so.3.7.0"
 
 [tool.scikit-build]
 build.verbose = true
diff --git a/python/rcs/sim/composer.py b/python/rcs/sim/composer.py
index 2a6ebe6e..c9e2bbb0 100644
--- a/python/rcs/sim/composer.py
+++ b/python/rcs/sim/composer.py
@@ -54,7 +54,7 @@ def _find_site(self, name: str) -> Optional[mujoco._specs.MjsSite]:
 
     def _find_body(self, name: str) -> Optional[mujoco._specs.MjsBody]:
         try:
-            return self.spec.find_body(name)
+            return self.spec.body(name)
         except ValueError:
             return None
 
@@ -104,7 +104,7 @@ def add_camera(
 
             camera_mount = mujoco.MjSpec().worldbody.add_body()
             camera_mount.name = "mount"
-            camera_mount = attachment_site.attach(camera_mount, f"{name}_", "")
+            camera_mount = attachment_site.attach_body(camera_mount, f"{name}_", "")
 
         self._apply_pose(camera_mount, pose)
 
@@ -137,6 +137,7 @@ def add_camera_xml(
         if root_body is None:
             msg = f"Camera MJCF '{xml_path}' must contain a root body."
             raise ValueError(msg)
+        root_body_name = root_body.name
 
         camera_names = [camera.name for camera in camera_spec.cameras]
         if len(camera_names) != 1 or camera_names[0] is None:
@@ -147,8 +148,8 @@ def add_camera_xml(
 
         if robot_prefix is None:
             attach_frame = self.spec.worldbody.add_frame()
-            attach_frame.attach(camera_spec, prefix, "")
-            attached_root_name = f"{prefix}{root_body.name}"
+            self.spec.attach(camera_spec, prefix=prefix, suffix="", frame=attach_frame)
+            attached_root_name = f"{prefix}{root_body_name}"
             attached_root = self._find_body(attached_root_name)
             if attached_root is None:
                 msg = f"Could not find camera root body '{attached_root_name}' after attachment."
@@ -161,7 +162,7 @@ def add_camera_xml(
                 msg = f"Attachment site '{site_name}' not found."
                 raise ValueError(msg)
 
-            attached_root = attachment_site.attach(root_body, prefix, "")
+            attached_root = attachment_site.attach_body(root_body, prefix=prefix, suffix="")
 
         self._apply_pose(attached_root, pose)
 
@@ -189,11 +190,11 @@ def add_robot(self, xml_path: str, prefix: str, pose: Pose | None = None) -> muj
 
         # 1. Use a frame to attach the child spec (most comprehensive)
         frame = self.spec.worldbody.add_frame()
-        frame.attach(child_spec, prefix, "")
+        self.spec.attach(child_spec, prefix=prefix, frame=frame)
 
         # 2. Identify the robot root body (it was prefixed)
         child_root_name = child_spec.worldbody.first_body().name
-        prefixed_root_name = f"{prefix}{child_root_name}"
+        prefixed_root_name = f"{child_root_name}"
 
         robot_root = self._find_body(prefixed_root_name)
         if not robot_root:
@@ -229,7 +230,7 @@ def add_gripper(
         self._resolve_asset_paths(gripper_spec, xml_path)
 
         gripper_root = gripper_spec.worldbody.first_body()
-        gripper_root = attachment_site.attach(gripper_root, gripper_prefix, "")
+        gripper_root = attachment_site.attach_body(gripper_root, gripper_prefix, "")
         self._apply_pose(gripper_root, pose)
         if gripper_prefix:
             self._gravcomp_prefixes.add(gripper_prefix)
@@ -261,7 +262,7 @@ def add_object_robot_frame(
             self.register_root_relative_replay_free_joints(self._prefixed_free_joint_names(object_spec, object_prefix))
 
         object_root = object_spec.worldbody.first_body()
-        object_root = attachment_site.attach(object_root, object_prefix, "")
+        object_root = attachment_site.attach_body(object_root, prefix=object_prefix, suffix="")
         self._apply_pose(object_root, pose)
         return object_root
 
@@ -285,16 +286,16 @@ def add_object_world_frame(
 
         # Load the child spec
         child_spec = mujoco.MjSpec.from_file(xml_path)
+        child_root_name = child_spec.worldbody.first_body().name
         self._resolve_asset_paths(child_spec, xml_path)
         if register_root_relative_replay_free_joints:
             self.register_root_relative_replay_free_joints(self._prefixed_free_joint_names(child_spec, object_prefix))
 
         # Attach using a frame
         frame = self.spec.worldbody.add_frame()
-        frame.attach(child_spec, object_prefix, "")
+        self.spec.attach(child_spec, prefix=object_prefix, suffix="", frame=frame)
 
         # Identify the root of the added object
-        child_root_name = child_spec.worldbody.first_body().name
         prefixed_root_name = f"{object_prefix}{child_root_name}"
         obj_root = self._find_body(prefixed_root_name)
         if not obj_root: