diff --git a/netlists/lcm.json b/netlists/lcm.json
new file mode 100644
index 00000000..85177dd6
--- /dev/null
+++ b/netlists/lcm.json
@@ -0,0 +1,5 @@
+{
+  "cell": "lcm",
+  "devices": [],
+  "nets": []
+}
diff --git a/src/glayout/__init__.py b/src/glayout/__init__.py
index 6e0c7e80..89ea1f2d 100644
--- a/src/glayout/__init__.py
+++ b/src/glayout/__init__.py
@@ -31,7 +31,12 @@ def activate(self):
     ihp130 = None
 
 # Primitive components
-from .primitives.via_gen import via_stack, via_array
+try:
+    from .primitives.via_gen import via_stack, via_array
+except ModuleNotFoundError:
+    # Allow JSON-only workflows (dataset analysis / netlisting)
+    via_stack = None
+    via_array = None
 from .primitives.fet import nmos, pmos, multiplier
 from .primitives.guardring import tapring
 from .primitives.mimcap import mimcap, mimcap_array
diff --git a/src/glayout/blocks/lcm.py b/src/glayout/blocks/lcm.py
new file mode 100644
index 00000000..33efd56b
--- /dev/null
+++ b/src/glayout/blocks/lcm.py
@@ -0,0 +1,23 @@
+from glayout.util.netlist_json import write_netlist_json
+
+
+def lcm(...):
+    ...
+
+netlist_dict = {
+    "block": "lcm",
+    "devices": [
+        {
+            "name": "M1",
+            "type": "nmos",
+            "connections": {"D": "out", "G": "in", "S": "vss", "B": "vss"}
+        }
+    ]
+}
+
+write_netlist_json(
+    netlist_dict,
+    "netlists/lcm.json"
+)
+
+    return comp
diff --git a/src/glayout/util/netlist_json.py b/src/glayout/util/netlist_json.py
new file mode 100644
index 00000000..54a6beec
--- /dev/null
+++ b/src/glayout/util/netlist_json.py
@@ -0,0 +1,12 @@
+import json
+from pathlib import Path
+
+def write_netlist_json(netlist: dict, path: str):
+    path = Path(path)
+    path.parent.mkdir(parents=True, exist_ok=True)
+    with open(path, "w") as f:
+        json.dump(netlist, f, indent=2)
+
+def read_netlist_json(path: str) -> dict:
+    with open(path, "r") as f:
+        return json.load(f)