diff --git a/doc/changelog.rst b/doc/changelog.rst
index c175ccd3..6e813d81 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -17,7 +17,7 @@ General
 MJX
 ^^^
 - Added ``mocap_pos`` and ``mocap_quat`` in kinematics.
-- Added support for :ref:`spatial tendons <tendon-spatial>` with external sphere and cylinder wrapping.
+- Added support for :ref:`spatial tendons <tendon-spatial>` with pulleys and external sphere and cylinder wrapping.
 
 Bug fixes
 ^^^^^^^^^
diff --git a/doc/mjx.rst b/doc/mjx.rst
index 8322b62d..270e8ca9 100644
--- a/doc/mjx.rst
+++ b/doc/mjx.rst
@@ -196,7 +196,7 @@ The following features are **fully supported** in MJX:
    * - :ref:`Actuator Bias <mjtBias>`
      - ``NONE``, ``AFFINE``
    * - :ref:`Tendon Wrapping <mjtWrap>`
-     - ``JOINT``, ``SITE``
+     - ``JOINT``, ``SITE``, ``PULLEY``
    * - :ref:`Geom <mjtGeom>`
      - ``PLANE``, ``HFIELD``, ``SPHERE``, ``CAPSULE``, ``BOX``, ``MESH`` are fully implemented. ``ELLIPSOID`` and
        ``CYLINDER`` are implemented but only collide with other primitives, note that ``BOX`` is implemented as a mesh.
@@ -247,7 +247,7 @@ The following features are **in development** and coming soon:
    * - :ref:`Actuator Bias <mjtBias>`
      - ``MUSCLE``
    * - :ref:`Tendon Wrapping <mjtWrap>`
-     - ``PULLEY``, ``SPHERE``, ``CYLINDER``
+     - ``SPHERE``, ``CYLINDER``
    * - Fluid Model
      - :ref:`flEllipsoid`
    * - :ref:`Tendons <tendon>`
diff --git a/mjx/mujoco/mjx/_src/smooth.py b/mjx/mujoco/mjx/_src/smooth.py
index 27b32510..6eb8491b 100644
--- a/mjx/mujoco/mjx/_src/smooth.py
+++ b/mjx/mujoco/mjx/_src/smooth.py
@@ -713,6 +713,21 @@ def tendon(m: Model, d: Data) -> Data:
   adr_moment_jnt = np.repeat(tendon_id_jnt, tendon_num_jnt)
   dofadr_moment_jnt = m.jnt_dofadr[wrap_objid_jnt]
 
+  # process pulleys
+  (wrap_id_pulley,) = np.nonzero(m.wrap_type == WrapType.PULLEY)
+  nwrap_pulley = wrap_id_pulley.size
+
+  tendon_wrapnum_pulley = np.array([
+      sum((wrap_id_pulley >= adr) & (wrap_id_pulley < adr + num))
+      for adr, num in zip(m.tendon_adr, m.tendon_num)
+  ])
+
+  divisor = np.ones(m.nwrap)
+  for adr, num in zip(m.tendon_adr, m.tendon_num):
+    for id_pulley in wrap_id_pulley:
+      if adr <= id_pulley < adr + num:
+        divisor[id_pulley : adr + num] = m.wrap_prm[id_pulley]
+
   # process spatial tendon sites
   (wrap_id_site,) = np.nonzero(m.wrap_type == WrapType.SITE)
   nwrap_site = wrap_id_site.size
@@ -720,7 +735,6 @@ def tendon(m: Model, d: Data) -> Data:
   # find consecutive sites, skipping tendon transitions
   (pair_id,) = np.nonzero(np.diff(wrap_id_site) == 1)
   wrap_id_site_pair = np.setdiff1d(wrap_id_site[pair_id], m.tendon_adr[1:] - 1)
-
   wrap_objid_site0 = m.wrap_objid[wrap_id_site_pair]
   wrap_objid_site1 = m.wrap_objid[wrap_id_site_pair + 1]
 
@@ -746,6 +760,11 @@ def tendon(m: Model, d: Data) -> Data:
       m.site_bodyid[wrap_objid_site1],
   )
 
+  if wrap_id_site_pair.size:
+    divisor_site_pair = divisor[wrap_id_site_pair]
+    lengths_site /= divisor_site_pair
+    moments_site /= divisor_site_pair[:, None]
+
   tendon_nsite = np.array([
       sum((wrap_id_site_pair >= adr) & (wrap_id_site_pair < adr + num))
       for adr, num in zip(m.tendon_adr, m.tendon_num)
@@ -848,6 +867,11 @@ def tendon(m: Model, d: Data) -> Data:
       moments_sitegeom + moments_geomgeom + moments_geomsite,
   )
 
+  if wrap_id_geom.size:
+    divisor_geom = divisor[wrap_id_geom]
+    lengths_geom /= divisor_geom
+    moments_geom /= divisor_geom[:, None]
+
   # construct number of site-geom-site instances per tendon
   tendon_ngeom = np.array([
       sum((wrap_id_geom >= adr) & (wrap_id_geom < adr + num))
@@ -886,12 +910,16 @@ def tendon(m: Model, d: Data) -> Data:
   ten_moment = ten_moment.at[tendon_id_geom].add(moment_geom)
 
   # construct wrap addresses
+  wrap_adr_pulley = []
   wrap_adr_site = []
   wrap_adr_geom = []
 
   count = 0
   for wrap_type in m.wrap_type:
-    if wrap_type == WrapType.SITE:
+    if wrap_type == WrapType.PULLEY:
+      wrap_adr_pulley.append(count)
+      count += 1
+    elif wrap_type == WrapType.SITE:
       wrap_adr_site.append(count)
       count += 1
     elif wrap_type in (WrapType.SPHERE, WrapType.CYLINDER):
@@ -899,11 +927,12 @@ def tendon(m: Model, d: Data) -> Data:
       wrap_adr_geom.append(count + 1)
       count += 2
 
+  wrap_adr_pulley = np.array(wrap_adr_pulley).astype(int)
   wrap_adr_site = np.array(wrap_adr_site).astype(int)
   wrap_adr_geom = np.array(wrap_adr_geom).astype(int)
-  wrap_adr_sitegeom = np.concatenate([wrap_adr_site, wrap_adr_geom])
+  wrap_adr = np.concatenate([wrap_adr_pulley, wrap_adr_site, wrap_adr_geom])
 
-  ten_wrapnum = jp.array(tendon_wrapnum_site)
+  ten_wrapnum = jp.array(tendon_wrapnum_pulley + tendon_wrapnum_site)
   ten_wrapnum = ten_wrapnum.at[tendon_id_geom].add(tendon_wrapnum_geom)
 
   ten_wrapadr = jp.concatenate([jp.array([0]), jp.cumsum(ten_wrapnum)[:-1]])
@@ -912,9 +941,7 @@ def tendon(m: Model, d: Data) -> Data:
   xpos_geom = jp.hstack([geom_pnt0, geom_pnt1]).reshape((-1, 3))
 
   # sort objects, moving no wrap geoms to bottom rows
-  nwrap_sitegeom = wrap_adr_sitegeom.size
-  wrap_adr_sitegeom_sort = np.argsort(wrap_adr_sitegeom)
-
+  wrap_adr_sort = np.argsort(wrap_adr)
   skipped = (
       jp.zeros(count, dtype=bool)
       .at[wrap_adr_geom]
@@ -922,17 +949,20 @@ def tendon(m: Model, d: Data) -> Data:
   )
   sort = jp.argsort(skipped)
 
-  wrap_xpos = jp.concatenate([xpos_site, xpos_geom])[wrap_adr_sitegeom_sort]
   wrap_xpos = jp.concatenate(
-      [wrap_xpos[sort], jp.zeros((2 * m.nwrap - nwrap_sitegeom, 3))]
+      [jp.zeros((nwrap_pulley, 3)), xpos_site, xpos_geom]
+  )[wrap_adr_sort]
+  wrap_xpos = jp.concatenate(
+      [wrap_xpos[sort], jp.zeros((2 * m.nwrap - count, 3))]
   ).reshape((m.nwrap, 6))
 
   wrap_obj = jp.concatenate([
+      -2 * jp.ones(nwrap_pulley, dtype=int),
       -1 * jp.ones(nwrap_site, dtype=int),
       jp.repeat(wrap_objid_geom_skip, 2).reshape(-1),
-  ])[wrap_adr_sitegeom_sort]
+  ])[wrap_adr_sort]
   wrap_obj = jp.concatenate(
-      [wrap_obj[sort], jp.zeros(2 * m.nwrap - nwrap_sitegeom, dtype=int)]
+      [wrap_obj[sort], jp.zeros(2 * m.nwrap - count, dtype=int)]
   ).reshape((m.nwrap, 2))
 
   return d.replace(
diff --git a/mjx/mujoco/mjx/_src/smooth_test.py b/mjx/mujoco/mjx/_src/smooth_test.py
index 9892e740..46f1fa2e 100644
--- a/mjx/mujoco/mjx/_src/smooth_test.py
+++ b/mjx/mujoco/mjx/_src/smooth_test.py
@@ -240,9 +240,14 @@ class TendonTest(parameterized.TestCase):
       'tendon/fixed.xml',
       'tendon/fixed_site.xml',
       'tendon/fixed_site_wrap.xml',
+      'tendon/pulley_fixed_site_wrap.xml',
+      'tendon/pulley_site.xml',
+      'tendon/pulley_site_wrap.xml',
+      'tendon/pulley_wrap.xml',
       'tendon/no_tendon.xml',
       'tendon/site.xml',
       'tendon/site_wrap.xml',
+      'tendon/tendon.xml',
       'tendon/wrap_sidesite.xml',
   )
   def test_tendon(self, filename):
diff --git a/mjx/mujoco/mjx/_src/types.py b/mjx/mujoco/mjx/_src/types.py
index a9ba040b..b0be4743 100644
--- a/mjx/mujoco/mjx/_src/types.py
+++ b/mjx/mujoco/mjx/_src/types.py
@@ -197,15 +197,16 @@ class WrapType(enum.IntEnum):
 
   Members:
     JOINT: constant moment arm
+    PULLEY: pulley used to split tendon
     SITE: pass through site
     SPHERE: wrap around sphere
     CYLINDER: wrap around (infinite) cylinder
   """
   JOINT = mujoco.mjtWrap.mjWRAP_JOINT
+  PULLEY = mujoco.mjtWrap.mjWRAP_PULLEY
   SITE = mujoco.mjtWrap.mjWRAP_SITE
   SPHERE = mujoco.mjtWrap.mjWRAP_SPHERE
   CYLINDER = mujoco.mjtWrap.mjWRAP_CYLINDER
-  # unsupported: NONE, PULLEY
 
 
 class TrnType(enum.IntEnum):
diff --git a/mjx/mujoco/mjx/test_data/tendon/pulley_fixed_site_wrap.xml b/mjx/mujoco/mjx/test_data/tendon/pulley_fixed_site_wrap.xml
new file mode 100644
index 00000000..a3e553cd
--- /dev/null
+++ b/mjx/mujoco/mjx/test_data/tendon/pulley_fixed_site_wrap.xml
@@ -0,0 +1,103 @@
+<mujoco model="pulley_fixed_site_wrap">
+  <option>
+    <flag contact="disable" gravity="disable"/>
+  </option>
+  <worldbody>
+    <body>
+      <joint name="joint0" type="hinge" axis="0 1 0"/>
+      <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+      <site name="site0" pos="0.25 0 0.1" size="0.025"/>
+      <geom name="sphere0" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+      <body pos="0.5 0 0">
+        <joint name="joint1" type="hinge" axis="0 1 0"/>
+        <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+        <site name="site1" pos="0.25 0 0.1" size="0.025"/>
+        <geom name="sphere1" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+        <body pos="0.5 0 0">
+          <joint name="joint2" type="hinge" axis="0 1 0"/>
+          <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+          <site name="site2" pos="0.25 0 0.1" size="0.025"/>
+          <geom name="cylinder2" type="cylinder" contype="0" conaffinity="0" pos="0.5 0 0.25" euler="90 0 0" size="0.085 0.1"/>
+          <geom name="sphere2" type="sphere" contype="0" conaffinity="0" pos="0.5 0 0.25" size="0.085"/>
+          <body pos="0.5 0 0">
+            <joint name="joint3" type="hinge" axis="0 1 0"/>
+            <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+            <site name="site3" pos="0.25 0 0.1" size="0.025"/>
+          </body>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+  <tendon>
+    <spatial width="0.0125">
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="0.2"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <fixed>
+      <joint joint="joint0" coef=".1"/>
+      <joint joint="joint1" coef=".2"/>
+      <joint joint="joint2" coef=".3"/>
+    </fixed>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <pulley divisor="7"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="4"/>
+      <site site="site0"/>
+      <site site="site2"/>
+      <site site="site3"/>
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+  </tendon>
+</mujoco>
diff --git a/mjx/mujoco/mjx/test_data/tendon/pulley_site.xml b/mjx/mujoco/mjx/test_data/tendon/pulley_site.xml
new file mode 100644
index 00000000..6ae3e137
--- /dev/null
+++ b/mjx/mujoco/mjx/test_data/tendon/pulley_site.xml
@@ -0,0 +1,84 @@
+<mujoco model="pulley_site">
+  <option>
+    <flag contact="disable" gravity="disable"/>
+  </option>
+  <worldbody>
+    <body>
+      <joint name="joint0" type="hinge" axis="0 1 0"/>
+      <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+      <site name="site0" pos="0.25 0 0.1" size="0.025"/>
+      <geom name="sphere0" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+      <body pos="0.5 0 0">
+        <joint name="joint1" type="hinge" axis="0 1 0"/>
+        <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+        <site name="site1" pos="0.25 0 0.1" size="0.025"/>
+        <geom name="sphere1" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+        <body pos="0.5 0 0">
+          <joint name="joint2" type="hinge" axis="0 1 0"/>
+          <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+          <site name="site2" pos="0.25 0 0.1" size="0.025"/>
+          <geom name="cylinder2" type="cylinder" contype="0" conaffinity="0" pos="0.5 0 0.25" euler="90 0 0" size="0.085 0.1"/>
+          <geom name="sphere2" type="sphere" contype="0" conaffinity="0" pos="0.5 0 0.25" size="0.085"/>
+          <body pos="0.5 0 0">
+            <joint name="joint3" type="hinge" axis="0 1 0"/>
+            <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+            <site name="site3" pos="0.25 0 0.1" size="0.025"/>
+          </body>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+  <tendon>
+    <spatial width="0.0125">
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="0.2"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <pulley divisor="7"/>
+      <site site="site2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <site site="site0"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="4"/>
+      <site site="site0"/>
+      <site site="site2"/>
+      <site site="site3"/>
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+  </tendon>
+</mujoco>
diff --git a/mjx/mujoco/mjx/test_data/tendon/pulley_site_wrap.xml b/mjx/mujoco/mjx/test_data/tendon/pulley_site_wrap.xml
new file mode 100644
index 00000000..6621b6fa
--- /dev/null
+++ b/mjx/mujoco/mjx/test_data/tendon/pulley_site_wrap.xml
@@ -0,0 +1,98 @@
+<mujoco model="pulley_site_wrap">
+  <option>
+    <flag contact="disable" gravity="disable"/>
+  </option>
+  <worldbody>
+    <body>
+      <joint name="joint0" type="hinge" axis="0 1 0"/>
+      <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+      <site name="site0" pos="0.25 0 0.1" size="0.025"/>
+      <geom name="sphere0" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+      <body pos="0.5 0 0">
+        <joint name="joint1" type="hinge" axis="0 1 0"/>
+        <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+        <site name="site1" pos="0.25 0 0.1" size="0.025"/>
+        <geom name="sphere1" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+        <body pos="0.5 0 0">
+          <joint name="joint2" type="hinge" axis="0 1 0"/>
+          <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+          <site name="site2" pos="0.25 0 0.1" size="0.025"/>
+          <geom name="cylinder2" type="cylinder" contype="0" conaffinity="0" pos="0.5 0 0.25" euler="90 0 0" size="0.085 0.1"/>
+          <geom name="sphere2" type="sphere" contype="0" conaffinity="0" pos="0.5 0 0.25" size="0.085"/>
+          <body pos="0.5 0 0">
+            <joint name="joint3" type="hinge" axis="0 1 0"/>
+            <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+            <site name="site3" pos="0.25 0 0.1" size="0.025"/>
+          </body>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+  <tendon>
+    <spatial width="0.0125">
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="0.2"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <pulley divisor="7"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="4"/>
+      <site site="site0"/>
+      <site site="site2"/>
+      <site site="site3"/>
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <site site="site1"/>
+      <site site="site2"/>
+      <site site="site3"/>
+    </spatial>
+  </tendon>
+</mujoco>
diff --git a/mjx/mujoco/mjx/test_data/tendon/pulley_wrap.xml b/mjx/mujoco/mjx/test_data/tendon/pulley_wrap.xml
new file mode 100644
index 00000000..c9929d6e
--- /dev/null
+++ b/mjx/mujoco/mjx/test_data/tendon/pulley_wrap.xml
@@ -0,0 +1,78 @@
+<mujoco model="pulley_wrap">
+  <option>
+    <flag contact="disable" gravity="disable"/>
+  </option>
+  <worldbody>
+    <body>
+      <joint name="joint0" type="hinge" axis="0 1 0"/>
+      <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+      <site name="site0" pos="0.25 0 0.1" size="0.025"/>
+      <geom name="sphere0" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+      <body pos="0.5 0 0">
+        <joint name="joint1" type="hinge" axis="0 1 0"/>
+        <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+        <site name="site1" pos="0.25 0 0.1" size="0.025"/>
+        <geom name="sphere1" type="sphere" pos="0.5 0 0.125" size="0.085"/>
+        <body pos="0.5 0 0">
+          <joint name="joint2" type="hinge" axis="0 1 0"/>
+          <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+          <site name="site2" pos="0.25 0 0.1" size="0.025"/>
+          <geom name="cylinder2" type="cylinder" contype="0" conaffinity="0" pos="0.5 0 0.25" euler="90 0 0" size="0.085 0.1"/>
+          <geom name="sphere2" type="sphere" contype="0" conaffinity="0" pos="0.5 0 0.25" size="0.085"/>
+          <body pos="0.5 0 0">
+            <joint name="joint3" type="hinge" axis="0 1 0"/>
+            <geom type="capsule" size="0.05 0.5" fromto="0 0 0 0.5 0 0"/>
+            <site name="site3" pos="0.25 0 0.1" size="0.025"/>
+          </body>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+  <tendon>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <pulley divisor="3"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <pulley divisor="7"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+      <pulley divisor="2"/>
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site1"/>
+      <geom geom="sphere1"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+    <spatial width="0.0125">
+      <site site="site0"/>
+      <geom geom="sphere0"/>
+      <site site="site2"/>
+      <geom geom="cylinder2"/>
+      <site site="site3"/>
+    </spatial>
+  </tendon>
+</mujoco>
diff --git a/mjx/mujoco/mjx/test_data/tendon/tendon.xml b/mjx/mujoco/mjx/test_data/tendon/tendon.xml
new file mode 100644
index 00000000..ab1c4227
--- /dev/null
+++ b/mjx/mujoco/mjx/test_data/tendon/tendon.xml
@@ -0,0 +1,66 @@
+<mujoco model="tendon">
+  <default>
+    <joint axis="0 1 0" range="0 60" limited="true"/>
+    <geom type="capsule" size=".01" rgba=".9 .7 .1 1"/>
+    <site rgba=".9 .9 .9 1"/>
+    <default class="visual_cylinder">
+      <geom type="cylinder" fromto="0 .015 0  0 -.015 0" size=".02" rgba=".3 .9 .3 .4"/>
+    </default>
+  </default>
+
+  <worldbody>
+    <light pos="0 0 1"/>
+    <body name="weight" pos="-.03 0 .175">
+      <joint axis="0 0 1" pos="0 0 .025" type="slide"/>
+      <geom type="cylinder" size=".03 .025" density="5000" rgba=".2 .2 .5 1"/>
+      <site name="s1" pos="0 0 .025"/>
+    </body>
+
+    <site name="s2" pos="-.03 0 .33"/>
+
+    <body pos="0 0 .3">
+      <joint/>
+      <geom name="g1" class="visual_cylinder"/>
+      <geom fromto="0 0 0  .1 0 0"/>
+      <site name="s3" pos=".02 0 .03"/>
+
+      <body pos=".1 0 0">
+        <joint/>
+        <geom name="g2" class="visual_cylinder"/>
+        <geom fromto="0 0 0  .1 0 0"/>
+        <site name="s4" pos=".03 0 .01"/>
+        <site name="s5" pos=".05 0 .02"/>
+        <site name="side2" pos="0 0 .03"/>
+
+        <body pos=".1 0 0">
+          <joint/>
+          <geom name="g3" class="visual_cylinder"/>
+          <geom fromto="0 0 0  .1 0 0"/>
+          <site name="s6" pos=".03 0 .01"/>
+          <site name="side3" pos="0 0 .03"/>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+
+  <tendon>
+    <spatial range="0 .33" limited="true" width=".002" rgba=".95 .3 .3 1">
+      <site site="s1"/>
+      <site site="s2"/>
+      <geom geom="g1"/>
+      <site site="s3"/>
+
+      <pulley divisor="2"/>
+      <site site="s3"/>
+      <geom geom="g2" sidesite="side2"/>
+      <site site="s4"/>
+
+      <pulley divisor="2"/>
+      <site site="s3"/>
+      <geom geom="g2" sidesite="side2"/>
+      <site site="s5"/>
+      <geom geom="g3" sidesite="side3"/>
+      <site site="s6"/>
+    </spatial>
+  </tendon>
+</mujoco>