diff --git a/lucidia_llm/lucidia_core/model.py b/lucidia_llm/lucidia_core/model.py
new file mode 100644
index 0000000..bf1a464
--- /dev/null
+++ b/lucidia_llm/lucidia_core/model.py
@@ -0,0 +1,9 @@
+"""Lucidia model definition: simple decoder-only transformer skeleton."""
+
+class TransformerModel:
+    def __init__(self, config):
+        self.config = config
+
+    def forward(self, x):
+        """Forward pass placeholder."""
+        raise NotImplementedError("Model forward pass not implemented")