diff --git a/README.md b/README.md
index 8332c52..c9274b8 100644
--- a/README.md
+++ b/README.md
@@ -49,3 +49,6 @@ pip install git+https://mpxd.net/code/jan/masque.git@release
     - de-embedding
     - boolean ops
 * DOCS DOCS DOCS
+* Tests tests tests
+* check renderpather
+* pather and renderpather examples
diff --git a/examples/ellip_grating.py b/examples/ellip_grating.py
index 0c34cce..88cc936 100644
--- a/examples/ellip_grating.py
+++ b/examples/ellip_grating.py
@@ -3,28 +3,33 @@
 import numpy
 
 import masque
-import masque.file.klamath
+from masque.file import gdsii
 from masque import shapes
 
 
 def main():
     pat = masque.Pattern(name='ellip_grating')
-    for rmin in numpy.arange(10, 15, 0.5):
-        pat.shapes.append(shapes.Arc(
+    layer = (0, 0)
+    pat.shapes[layer].extend([
+        shapes.Arc(
             radii=(rmin, rmin),
             width=0.1,
             angles=(-numpy.pi/4, numpy.pi/4),
-            layer=(0, 0),
-        ))
+            )
+        for rmin in numpy.arange(10, 15, 0.5)]
+        )
 
-    pat.labels.append(masque.Label(string='grating centerline', offset=(1, 0), layer=(1, 2)))
+    pat.label(string='grating centerline', offset=(1, 0), layer=(1, 2))
 
     pat.scale_by(1000)
     pat.visualize()
-    pat2 = pat.copy()
-    pat2.name = 'grating2'
 
-    masque.file.klamath.writefile((pat, pat2), 'out.gds.gz', 1e-9, 1e-3)
+    lib = {
+        'ellip_grating': pat,
+        'grating2': pat.copy(),
+        }
+
+    gdsii.writefile(lib, 'out.gds.gz', meters_per_unit=1e-9, logical_units_per_unit=1e-3)
 
 
 if __name__ == '__main__':
diff --git a/examples/pic2mask.py b/examples/pic2mask.py
index 0f0d9a1..0e2516a 100644
--- a/examples/pic2mask.py
+++ b/examples/pic2mask.py
@@ -33,7 +33,9 @@ pyplot.show(block=False)
 # Create the layout from the contours
 #
 pat = Pattern()
-pat.shapes = [Polygon(vertices=vv) for vv in contours if len(vv) < 1_000]
+pat.shapes[(0, 0)].extend([
+    Polygon(vertices=vv) for vv in contours if len(vv) < 1_000
+    ])
 
 lib = {}
 lib['my_mask_name'] = pat
diff --git a/examples/test_rep.py b/examples/test_rep.py
index dbc6d72..5ed6a6a 100644
--- a/examples/test_rep.py
+++ b/examples/test_rep.py
@@ -16,8 +16,9 @@ def main():
 
     cell_name = 'ellip_grating'
     pat = masque.Pattern()
+
+    layer = (0, 0)
     for rmin in numpy.arange(10, 15, 0.5):
-        layer = (0, 0)
         pat.shapes[layer].append(Arc(
             radii=(rmin, rmin),
             width=0.1,
diff --git a/examples/tutorial/basic_shapes.py b/examples/tutorial/basic_shapes.py
index 8c9550b..f8e1eef 100644
--- a/examples/tutorial/basic_shapes.py
+++ b/examples/tutorial/basic_shapes.py
@@ -32,9 +32,10 @@ def hole(
     Returns:
         Pattern containing a circle.
     """
-    pat = Pattern(shapes=[
-        Circle(radius=radius, offset=(0, 0), layer=layer),
-        ])
+    pat = Pattern()
+    pat.shapes[layer].append(
+        Circle(radius=radius, offset=(0, 0))
+        )
     return pat
 
 
@@ -58,8 +59,9 @@ def triangle(
         (numpy.cos(   - pi / 6), numpy.sin(   - pi / 6)),
         ]) * radius
 
-    pat = Pattern(shapes=[
-        Polygon(offset=(0, 0), layer=layer, vertices=vertices),
+    pat = Pattern()
+    pat.shapes[layer].extend([
+        Polygon(offset=(0, 0), vertices=vertices),
         ])
     return pat
 
@@ -84,16 +86,18 @@ def smile(
     pat = Pattern()
 
     # Add all the shapes we want
-    pat.shapes += [
-        Circle(radius=radius, offset=(0, 0), layer=layer),   # Outer circle
-        Circle(radius=radius / 10, offset=(radius / 3, radius / 3), layer=secondary_layer),
-        Circle(radius=radius / 10, offset=(-radius / 3, radius / 3), layer=secondary_layer),
+    pat.shapes[layer] += [
+        Circle(radius=radius, offset=(0, 0)),   # Outer circle
+        ]
+
+    pat.shapes[secondary_layer] += [
+        Circle(radius=radius / 10, offset=(radius / 3, radius / 3)),
+        Circle(radius=radius / 10, offset=(-radius / 3, radius / 3)),
         Arc(
             radii=(radius * 2 / 3, radius * 2 / 3), # Underlying ellipse radii
             angles=(7 / 6 * pi, 11 / 6 * pi),        # Angles limiting the arc
             width=radius / 10,
             offset=(0, 0),
-            layer=secondary_layer,
             ),
         ]
 
diff --git a/examples/tutorial/devices.py b/examples/tutorial/devices.py
index b12fb6f..6211024 100644
--- a/examples/tutorial/devices.py
+++ b/examples/tutorial/devices.py
@@ -82,18 +82,18 @@ def perturbed_l3(
 
     # Build L3 cavity, using references to the provided hole pattern
     pat = Pattern()
-    pat.refs += [
-        Ref(hole, scale=r, offset=(lattice_constant * x,
-                                   lattice_constant * y))
+    pat.refs[hole] += [
+        Ref(scale=r, offset=(lattice_constant * x,
+                             lattice_constant * y))
         for x, y, r in xyr]
 
     # Add rectangular undercut aids
     min_xy, max_xy = pat.get_bounds_nonempty(hole_lib)
     trench_dx = max_xy[0] - min_xy[0]
 
-    pat.shapes += [
-        Polygon.rect(ymin=max_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width, layer=trench_layer),
-        Polygon.rect(ymax=min_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width, layer=trench_layer),
+    pat.shapes[trench_layer] += [
+        Polygon.rect(ymin=max_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width),
+        Polygon.rect(ymax=min_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width),
         ]
 
     # Ports are at outer extents of the device (with y=0)
@@ -131,9 +131,9 @@ def waveguide(
 
     # Build the pattern
     pat = Pattern()
-    pat.refs += [
-        Ref(hole, offset=(lattice_constant * x,
-                          lattice_constant * y))
+    pat.refs[hole] += [
+        Ref(offset=(lattice_constant * x,
+                    lattice_constant * y))
         for x, y in xy]
 
     # Ports are at outer edges, with y=0
@@ -170,9 +170,9 @@ def bend(
 
     # Build the pattern
     pat= Pattern()
-    pat.refs += [
-        Ref(hole, offset=(lattice_constant * x,
-                          lattice_constant * y))
+    pat.refs[hole] += [
+        Ref(offset=(lattice_constant * x,
+                    lattice_constant * y))
         for x, y in xy]
 
     # Figure out port locations.
@@ -209,9 +209,9 @@ def y_splitter(
 
     # Build pattern
     pat = Pattern()
-    pat.refs += [
-        Ref(hole, offset=(lattice_constant * x,
-                          lattice_constant * y))
+    pat.refs[hole] += [
+        Ref(offset=(lattice_constant * x,
+                    lattice_constant * y))
         for x, y in xy]
 
     # Determine port locations
@@ -248,30 +248,30 @@ def main(interactive: bool = True) -> None:
 
     # Turn our dict of devices into a Library -- useful for getting abstracts
     lib = Library(devices)
-    abv = lib.abstract_view()     # lets us use abv[cell] instead of lib.abstract(cell)
 
     #
     # Build a circuit
     #
-    circ = Builder(library=lib)
+    # Create a builder, and add the circuit to our library as "my_circuit"
+    circ = Builder(library=lib, name='my_circuit')
 
     # Start by placing a waveguide. Call its ports "in" and "signal".
-    circ.place(abv['wg10'], offset=(0, 0), port_map={'left': 'in', 'right': 'signal'})
+    circ.place('wg10', offset=(0, 0), port_map={'left': 'in', 'right': 'signal'})
 
     # Extend the signal path by attaching the "left" port of a waveguide.
     #   Since there is only one other port ("right") on the waveguide we
     # are attaching (wg10), it automatically inherits the name "signal".
-    circ.plug(abv['wg10'], {'signal': 'left'})
+    circ.plug('wg10', {'signal': 'left'})
 
     # Attach a y-splitter to the signal path.
     #   Since the y-splitter has 3 ports total, we can't auto-inherit the
     # port name, so we have to specify what we want to name the unattached
     # ports. We can call them "signal1" and "signal2".
-    circ.plug(abv['ysplit'], {'signal': 'in'}, {'top': 'signal1', 'bot': 'signal2'})
+    circ.plug('ysplit', {'signal': 'in'}, {'top': 'signal1', 'bot': 'signal2'})
 
     # Add a waveguide to both signal ports, inheriting their names.
-    circ.plug(abv['wg05'], {'signal1': 'left'})
-    circ.plug(abv['wg05'], {'signal2': 'left'})
+    circ.plug('wg05', {'signal1': 'left'})
+    circ.plug('wg05', {'signal2': 'left'})
 
     # Add a bend to both ports.
     #   Our bend's ports "left" and "right" refer to the original counterclockwise
@@ -280,22 +280,22 @@ def main(interactive: bool = True) -> None:
     # to "signal2" to bend counterclockwise.
     #   We could also use `mirrored=(True, False)` to mirror one of the devices
     # and then use same device port on both paths.
-    circ.plug(abv['bend0'], {'signal1': 'right'})
-    circ.plug(abv['bend0'], {'signal2': 'left'})
+    circ.plug('bend0', {'signal1': 'right'})
+    circ.plug('bend0', {'signal2': 'left'})
 
     # We add some waveguides and a cavity to "signal1".
-    circ.plug(abv['wg10'], {'signal1': 'left'})
-    circ.plug(abv['l3cav'], {'signal1': 'input'})
-    circ.plug(abv['wg10'], {'signal1': 'left'})
+    circ.plug('wg10', {'signal1': 'left'})
+    circ.plug('l3cav', {'signal1': 'input'})
+    circ.plug('wg10', {'signal1': 'left'})
 
     # "signal2" just gets a single of equivalent length
-    circ.plug(abv['wg28'], {'signal2': 'left'})
+    circ.plug('wg28', {'signal2': 'left'})
 
     # Now we bend both waveguides back towards each other
-    circ.plug(abv['bend0'], {'signal1': 'right'})
-    circ.plug(abv['bend0'], {'signal2': 'left'})
-    circ.plug(abv['wg05'], {'signal1': 'left'})
-    circ.plug(abv['wg05'], {'signal2': 'left'})
+    circ.plug('bend0', {'signal1': 'right'})
+    circ.plug('bend0', {'signal2': 'left'})
+    circ.plug('wg05', {'signal1': 'left'})
+    circ.plug('wg05', {'signal2': 'left'})
 
     # To join the waveguides, we attach a second y-junction.
     #   We plug "signal1" into the "bot" port, and "signal2" into the "top" port.
@@ -303,19 +303,16 @@ def main(interactive: bool = True) -> None:
     #   This operation would raise an exception if the ports did not line up
     # correctly (i.e. they required different rotations or translations of the
     # y-junction device).
-    circ.plug(abv['ysplit'], {'signal1': 'bot', 'signal2': 'top'}, {'in': 'signal_out'})
+    circ.plug('ysplit', {'signal1': 'bot', 'signal2': 'top'}, {'in': 'signal_out'})
 
     # Finally, add some more waveguide to "signal_out".
-    circ.plug(abv['wg10'], {'signal_out': 'left'})
+    circ.plug('wg10', {'signal_out': 'left'})
 
     # We can also add text labels for our circuit's ports.
     #   They will appear at the uppermost hierarchy level, while the individual
     # device ports will appear further down, in their respective cells.
     ports_to_data(circ.pattern)
 
-    # Add the pattern into our library
-    lib['my_circuit'] = circ.pattern
-
     # Check if we forgot to include any patterns... ooops!
     if dangling := lib.dangling_refs():
         print('Warning: The following patterns are referenced, but not present in the'
diff --git a/examples/tutorial/library.py b/examples/tutorial/library.py
index fe31265..5c8dfd0 100644
--- a/examples/tutorial/library.py
+++ b/examples/tutorial/library.py
@@ -1,4 +1,4 @@
-from typing import Sequence, Callable
+from typing import Sequence, Callable, Any
 from pprint import pformat
 
 import numpy
@@ -38,7 +38,7 @@ def main() -> None:
     #
 
     lib['triangle'] = lambda: basic_shapes.triangle(devices.RADIUS)
-    opts = dict(
+    opts: dict[str, Any] = dict(
         lattice_constant = devices.LATTICE_CONSTANT,
         hole = 'triangle',
         )
@@ -73,9 +73,7 @@ def main() -> None:
     circ2.plug('tri_wg10', {'output': 'left'})
 
     # Add the circuit to the device library.
-    #  It has already been generated, so we can use `set_const` as a shorthand for
-    #       `lib['mixed_wg_cav'] = lambda: circ2.pattern`
-    lib.set_const('mixed_wg_cav', circ2.pattern)
+    lib['mixed_wg_cav'] = circ2.pattern
 
 
     #
@@ -87,7 +85,7 @@ def main() -> None:
 
     # ... that lets us continue from where we left off.
     circ3.plug('tri_bend0', {'input': 'right'})
-    circ3.plug('tri_bend0', {'input': 'left'}, mirrored=(True, False)) # mirror since no tri y-symmetry
+    circ3.plug('tri_bend0', {'input': 'left'}, mirrored=True) # mirror since no tri y-symmetry
     circ3.plug('tri_bend0', {'input': 'right'})
     circ3.plug('bend0', {'output': 'left'})
     circ3.plug('bend0', {'output': 'left'})
@@ -96,7 +94,7 @@ def main() -> None:
     circ3.plug('tri_wg28', {'input': 'right'})
     circ3.plug('tri_wg10', {'input': 'right', 'output': 'left'})
 
-    lib.set_const('loop_segment', circ3.pattern)
+    lib['loop_segment'] = circ3.pattern
 
     #
     # Write all devices into a GDS file
@@ -128,7 +126,6 @@ if __name__ == '__main__':
 #                name = port_map.get(name, name)
 #            if name is None:
 #                continue
-#            self.pattern.labels += [
-#                Label(string=name, offset=self.ports[name].offset, layer=layer)]
+#            self.pattern.label(string=name, offset=self.ports[name].offset, layer=label_layer)
 #        return self
 #