diff --git a/mujoco_warp/_src/collision_sdf.py b/mujoco_warp/_src/collision_sdf.py
index 0842421a0..1c43390c4 100644
--- a/mujoco_warp/_src/collision_sdf.py
+++ b/mujoco_warp/_src/collision_sdf.py
@@ -28,6 +28,7 @@
 from .types import vec5
 from .types import vec8
 from .types import vec8i
+from .types import vec_pluginattr
 from .util_misc import halton
 from .warp_util import event_scope
 
@@ -38,8 +39,8 @@
 class OptimizationParams:
   rel_mat: wp.mat33
   rel_pos: wp.vec3
-  attr1: wp.vec3
-  attr2: wp.vec3
+  attr1: vec_pluginattr
+  attr2: vec_pluginattr
 
 
 @wp.struct
@@ -81,14 +82,18 @@ def get_sdf_params(
   oct_aabb: wp.array2d(dtype=wp.vec3),
   oct_coeff: wp.array(dtype=vec8),
   plugin: wp.array(dtype=int),
-  plugin_attr: wp.array(dtype=wp.vec3f),
+  plugin_attr: wp.array(dtype=vec_pluginattr),
   # In:
   g_type: int,
   g_size: wp.vec3,
   plugin_id: int,
   mesh_id: int,
-) -> Tuple[wp.vec3, int, VolumeData, MeshData]:
-  attributes = g_size
+) -> Tuple[vec_pluginattr, int, VolumeData, MeshData]:
+  # default attributes from geom size, first 3 values copied
+  attributes = vec_pluginattr()
+  attributes[0] = g_size[0]
+  attributes[1] = g_size[1]
+  attributes[2] = g_size[2]
   plugin_index = -1
   volume_data = VolumeData()
 
@@ -211,13 +216,21 @@ def grad_ellipsoid(p: wp.vec3, size: wp.vec3) -> wp.vec3:
 
 
 @wp.func
-def user_sdf(p: wp.vec3, attr: wp.vec3, sdf_type: int) -> float:
+def user_sdf(p: wp.vec3, attr: vec_pluginattr, sdf_type: int) -> float:
+  """User-defined SDF function.
+
+  Access attributes via attr[i] where i is the attribute index (0 to _NPLUGINATTR-1).
+  """
   wp.printf("ERROR: user_sdf function must be implemented by user code\n")
   return 0.0
 
 
 @wp.func
-def user_sdf_grad(p: wp.vec3, attr: wp.vec3, sdf_type: int) -> wp.vec3:
+def user_sdf_grad(p: wp.vec3, attr: vec_pluginattr, sdf_type: int) -> wp.vec3:
+  """User-defined SDF gradient function.
+
+  Access attributes via attr[i] where i is the attribute index (0 to _NPLUGINATTR-1).
+  """
   wp.printf("ERROR: user_sdf_grad function must be implemented by user code\n")
   return wp.vec3(0.0)
 
@@ -355,15 +368,17 @@ def sample_volume_grad(xyz: wp.vec3, volume_data: VolumeData) -> wp.vec3:
 
 
 @wp.func
-def sdf(type: int, p: wp.vec3, attr: wp.vec3, sdf_type: int, volume_data: VolumeData, mesh_data: MeshData) -> float:
+def sdf(type: int, p: wp.vec3, attr: vec_pluginattr, sdf_type: int, volume_data: VolumeData, mesh_data: MeshData) -> float:
+  # extract first 3 elements as vec3 for primitive sdf functions
+  attr_vec3 = wp.vec3(attr[0], attr[1], attr[2])
   if type == GeomType.PLANE:
     return p[2]
   elif type == GeomType.SPHERE:
-    return sphere(p, attr)
+    return sphere(p, attr_vec3)
   elif type == GeomType.BOX:
-    return box(p, attr)
+    return box(p, attr_vec3)
   elif type == GeomType.ELLIPSOID:
-    return ellipsoid(p, attr)
+    return ellipsoid(p, attr_vec3)
   elif type == GeomType.MESH and mesh_data.valid:
     mesh_data.pnt = p
     mesh_data.vec = -wp.normalize(p)
@@ -404,16 +419,20 @@ def sdf(type: int, p: wp.vec3, attr: wp.vec3, sdf_type: int, volume_data: Volume
 
 
 @wp.func
-def sdf_grad(type: int, p: wp.vec3, attr: wp.vec3, sdf_type: int, volume_data: VolumeData, mesh_data: MeshData) -> wp.vec3:
+def sdf_grad(
+  type: int, p: wp.vec3, attr: vec_pluginattr, sdf_type: int, volume_data: VolumeData, mesh_data: MeshData
+) -> wp.vec3:
+  # extract first 3 elements as vec3 for primitive sdf functions
+  attr_vec3 = wp.vec3(attr[0], attr[1], attr[2])
   if type == GeomType.PLANE:
     grad = wp.vec3(0.0, 0.0, 1.0)
     return grad
   elif type == GeomType.SPHERE:
     return grad_sphere(p)
   elif type == GeomType.BOX:
-    return grad_box(p, attr)
+    return grad_box(p, attr_vec3)
   elif type == GeomType.ELLIPSOID:
-    return grad_ellipsoid(p, attr)
+    return grad_ellipsoid(p, attr_vec3)
   elif type == GeomType.MESH and mesh_data.valid:
     mesh_data.pnt = p
     mesh_data.vec = -wp.normalize(p)
@@ -449,8 +468,8 @@ def clearance(
   type1: int,
   p1: wp.vec3,
   p2: wp.vec3,
-  s1: wp.vec3,
-  s2: wp.vec3,
+  s1: vec_pluginattr,
+  s2: vec_pluginattr,
   sdf_type1: int,
   sdf_type2: int,
   sfd_intersection: bool,
@@ -579,8 +598,8 @@ def gradient_descent(
   # In:
   type1: int,
   x0_initial: wp.vec3,
-  attr1: wp.vec3,
-  attr2: wp.vec3,
+  attr1: vec_pluginattr,
+  attr2: vec_pluginattr,
   pos1: wp.vec3,
   rot1: wp.mat33,
   pos2: wp.vec3,
@@ -659,7 +678,7 @@ def _sdf_narrowphase(
   pair_gap: wp.array2d(dtype=float),
   pair_friction: wp.array2d(dtype=vec5),
   plugin: wp.array(dtype=int),
-  plugin_attr: wp.array(dtype=wp.vec3f),
+  plugin_attr: wp.array(dtype=vec_pluginattr),
   geom_plugin_index: wp.array(dtype=int),
   # Data in:
   geom_xpos_in: wp.array2d(dtype=wp.vec3),
diff --git a/mujoco_warp/_src/io.py b/mujoco_warp/_src/io.py
index e2ed2d238..39d27db74 100644
--- a/mujoco_warp/_src/io.py
+++ b/mujoco_warp/_src/io.py
@@ -363,9 +363,11 @@ def geom_trid_index(i, j):
           current = []
       else:
         current.append(v)
-    # Pad with zeros if less than 3
-    attr_values += [0.0] * (3 - len(attr_values))
-    m.plugin_attr.append(attr_values[:3])
+    if len(attr_values) > types._NPLUGINATTR:
+      raise ValueError(f"Plugin has {len(attr_values)} attributes, which exceeds the maximum of {types._NPLUGINATTR}. ")
+    # pad with zeros to _NPLUGINATTR
+    attr_values += [0.0] * (types._NPLUGINATTR - len(attr_values))
+    m.plugin_attr.append(attr_values[: types._NPLUGINATTR])
 
   # equality constraint addresses
   m.eq_connect_adr = np.nonzero(mjm.eq_type == types.EqType.CONNECT)[0]
diff --git a/mujoco_warp/_src/sensor.py b/mujoco_warp/_src/sensor.py
index 431ad9d51..304b7cc0d 100644
--- a/mujoco_warp/_src/sensor.py
+++ b/mujoco_warp/_src/sensor.py
@@ -39,6 +39,7 @@
 from .types import vec6
 from .types import vec8
 from .types import vec8i
+from .types import vec_pluginattr
 from .util_misc import inside_geom
 from .warp_util import cache_kernel
 from .warp_util import event_scope
@@ -2106,7 +2107,7 @@ def _sensor_tactile(
   sensor_dim: wp.array(dtype=int),
   sensor_adr: wp.array(dtype=int),
   plugin: wp.array(dtype=int),
-  plugin_attr: wp.array(dtype=wp.vec3f),
+  plugin_attr: wp.array(dtype=vec_pluginattr),
   geom_plugin_index: wp.array(dtype=int),
   taxel_vertadr: wp.array(dtype=int),
   taxel_sensorid: wp.array(dtype=int),
diff --git a/mujoco_warp/_src/types.py b/mujoco_warp/_src/types.py
index 6ff16d703..d3540066c 100644
--- a/mujoco_warp/_src/types.py
+++ b/mujoco_warp/_src/types.py
@@ -32,6 +32,9 @@
 TILE_SIZE_JTDAJ_SPARSE = 16
 TILE_SIZE_JTDAJ_DENSE = 16
 
+# maximum number of plugin attributes
+_NPLUGINATTR = 128
+
 
 # TODO(team): add check that all wp.launch_tiled 'block_dim' settings are configurable
 @dataclasses.dataclass
@@ -600,6 +603,10 @@ class vec11f(wp.types.vector(length=11, dtype=float)):
   pass
 
 
+class vec_pluginattr(wp.types.vector(length=_NPLUGINATTR, dtype=float)):
+  pass
+
+
 class mat23f(wp.types.matrix(shape=(2, 3), dtype=float)):
   pass
 
@@ -617,6 +624,7 @@ class mat63f(wp.types.matrix(shape=(6, 3), dtype=float)):
 vec8 = vec8f
 vec10 = vec10f
 vec11 = vec11f
+vec128 = vec_pluginattr
 mat23 = mat23f
 mat43 = mat43f
 mat63 = mat63f
@@ -999,7 +1007,7 @@ class Model:
     sensor_adr: address in sensor array                      (nsensor,)
     sensor_cutoff: cutoff for real and positive; 0: ignore   (nsensor,)
     plugin: globally registered plugin slot number           (nplugin,)
-    plugin_attr: config attributes of geom plugin            (nplugin, 3)
+    plugin_attr: config attributes of geom plugin            (nplugin, _NPLUGINATTR)
     M_rownnz: number of non-zeros in each row of qM          (nv,)
     M_rowadr: index of each row in qM                        (nv,)
     M_colind: column indices of non-zeros in qM              (nM,)
@@ -1347,7 +1355,7 @@ class Model:
   sensor_adr: array("nsensor", int)
   sensor_cutoff: array("nsensor", float)
   plugin: array("nplugin", int)
-  plugin_attr: array("nplugin", wp.vec3f)
+  plugin_attr: array("nplugin", vec_pluginattr)
   M_rownnz: array("nv", int)
   M_rowadr: array("nv", int)
   M_colind: array("nC", int)
diff --git a/mujoco_warp/test_data/collision_sdf/bolt.py b/mujoco_warp/test_data/collision_sdf/bolt.py
index 07a99a1e0..9b80926f7 100644
--- a/mujoco_warp/test_data/collision_sdf/bolt.py
+++ b/mujoco_warp/test_data/collision_sdf/bolt.py
@@ -1,5 +1,7 @@
 import warp as wp
 
+from mujoco_warp._src.types import vec_pluginattr
+
 
 @wp.func
 def Fract(x: float) -> float:
@@ -22,7 +24,7 @@ def Intersection(a: float, b: float) -> float:
 
 
 @wp.func
-def bolt(p: wp.vec3, attr: wp.vec3) -> float:
+def bolt(p: wp.vec3, attr: vec_pluginattr) -> float:
   screw = 12.0
   radius = wp.sqrt(p[0] * p[0] + p[1] * p[1]) - attr[0]
   sqrt12 = wp.sqrt(2.0) / 2.0
@@ -52,7 +54,7 @@ def bolt(p: wp.vec3, attr: wp.vec3) -> float:
 
 
 @wp.func
-def bolt_sdf_grad(p: wp.vec3, attr: wp.vec3) -> wp.vec3:
+def bolt_sdf_grad(p: wp.vec3, attr: vec_pluginattr) -> wp.vec3:
   grad = wp.vec3()
   eps = 1e-6
   f_original = bolt(p, attr)
diff --git a/mujoco_warp/test_data/collision_sdf/gear.py b/mujoco_warp/test_data/collision_sdf/gear.py
index c505f2644..bc4ea227d 100644
--- a/mujoco_warp/test_data/collision_sdf/gear.py
+++ b/mujoco_warp/test_data/collision_sdf/gear.py
@@ -1,5 +1,7 @@
 import warp as wp
 
+from mujoco_warp._src.types import vec_pluginattr
+
 
 @wp.func
 def Subtraction(a: float, b: float) -> float:
@@ -44,7 +46,7 @@ def mod(x: float, y: float) -> float:
 
 
 @wp.func
-def distance2D(p: wp.vec3, attributes: wp.vec3) -> float:
+def distance2D(p: wp.vec3, attributes: vec_pluginattr) -> float:
   # see https://www.shadertoy.com/view/3lG3WR
   D = 2.8
   N = 25.0
@@ -120,13 +122,13 @@ def distance2D(p: wp.vec3, attributes: wp.vec3) -> float:
 
 
 @wp.func
-def gear(p: wp.vec3, attr: wp.vec3) -> float:
+def gear(p: wp.vec3, attr: vec_pluginattr) -> float:
   thickness = 0.2
   return extrusion(p, distance2D(p, attr), thickness / 2.0)
 
 
 @wp.func
-def gear_sdf_grad(p: wp.vec3, attr: wp.vec3) -> wp.vec3:
+def gear_sdf_grad(p: wp.vec3, attr: vec_pluginattr) -> wp.vec3:
   grad = wp.vec3()
   eps = 1e-6
   f_original = gear(p, attr)
diff --git a/mujoco_warp/test_data/collision_sdf/nut.py b/mujoco_warp/test_data/collision_sdf/nut.py
index 47b8cc736..452842ae0 100644
--- a/mujoco_warp/test_data/collision_sdf/nut.py
+++ b/mujoco_warp/test_data/collision_sdf/nut.py
@@ -1,5 +1,7 @@
 import warp as wp
 
+from mujoco_warp._src.types import vec_pluginattr
+
 
 @wp.func
 def Fract(x: float) -> float:
@@ -22,7 +24,7 @@ def Intersection(a: float, b: float) -> float:
 
 
 @wp.func
-def nut(p: wp.vec3, attr: wp.vec3) -> float:
+def nut(p: wp.vec3, attr: vec_pluginattr) -> float:
   screw = 12.0
   radius2 = wp.sqrt(p[0] * p[0] + p[1] * p[1]) - attr[0]
   sqrt12 = wp.sqrt(2.0) / 2.0
@@ -47,7 +49,7 @@ def nut(p: wp.vec3, attr: wp.vec3) -> float:
 
 
 @wp.func
-def nut_sdf_grad(p: wp.vec3, attr: wp.vec3) -> wp.vec3:
+def nut_sdf_grad(p: wp.vec3, attr: vec_pluginattr) -> wp.vec3:
   grad = wp.vec3()
   eps = 1e-6
   f_original = nut(p, attr)
diff --git a/mujoco_warp/test_data/collision_sdf/torus.py b/mujoco_warp/test_data/collision_sdf/torus.py
index 2cc05e892..cfd514731 100644
--- a/mujoco_warp/test_data/collision_sdf/torus.py
+++ b/mujoco_warp/test_data/collision_sdf/torus.py
@@ -2,9 +2,11 @@
 
 import warp as wp
 
+from mujoco_warp._src.types import vec_pluginattr
+
 
 @wp.func
-def torus(p: wp.vec3, attr: wp.vec3) -> wp.float32:
+def torus(p: wp.vec3, attr: vec_pluginattr) -> wp.float32:
   major_radius = attr[0]
   minor_radius = attr[1]
 
@@ -14,7 +16,7 @@ def torus(p: wp.vec3, attr: wp.vec3) -> wp.float32:
 
 
 @wp.func
-def torus_sdf_grad(p: wp.vec3, attr: wp.vec3) -> wp.vec3:
+def torus_sdf_grad(p: wp.vec3, attr: vec_pluginattr) -> wp.vec3:
   grad = wp.vec3()
   major_radius = attr[0]
   minor_val = attr[1]
diff --git a/mujoco_warp/test_data/collision_sdf/utils.py b/mujoco_warp/test_data/collision_sdf/utils.py
index 741e7c9ed..b9759971a 100644
--- a/mujoco_warp/test_data/collision_sdf/utils.py
+++ b/mujoco_warp/test_data/collision_sdf/utils.py
@@ -20,6 +20,8 @@
 import mujoco
 import warp as wp
 
+from mujoco_warp._src.types import vec_pluginattr
+
 from .bolt import bolt
 from .bolt import bolt_sdf_grad
 from .gear import gear
@@ -81,7 +83,7 @@ def register_sdf_plugins(mjwarp) -> Dict[str, int]:
       sdf_types[SDFType.GEAR] = int(m.plugin[i])
 
   @wp.func
-  def user_sdf(p: wp.vec3, attr: wp.vec3, sdf_type: int) -> float:
+  def user_sdf(p: wp.vec3, attr: vec_pluginattr, sdf_type: int) -> float:
     result = 0.0
     if sdf_type == wp.static(sdf_types[SDFType.NUT]):
       result = nut(p, attr)
@@ -94,7 +96,7 @@ def user_sdf(p: wp.vec3, attr: wp.vec3, sdf_type: int) -> float:
     return result
 
   @wp.func
-  def user_sdf_grad(p: wp.vec3, attr: wp.vec3, sdf_type: int) -> wp.vec3:
+  def user_sdf_grad(p: wp.vec3, attr: vec_pluginattr, sdf_type: int) -> wp.vec3:
     if sdf_type == wp.static(sdf_types[SDFType.NUT]):
       return nut_sdf_grad(p, attr)
     elif sdf_type == wp.static(sdf_types[SDFType.BOLT]):