Ensure all entities rebuild with forward references before starting the server (#149)

Author: simba-git

src/enrichmcp/app.py

@@ -88,6 +88,11 @@ def __init__(
         # Register built-in resources
         self._register_builtin_resources()
 
+    def rebuild_models(self) -> None:
+        """Rebuild all registered models to resolve forward references."""
+        for entity_cls in self.entities.values():
+            entity_cls.model_rebuild()
+
     def data_model_tool_name(self) -> str:
         """Return the name of the built-in data model exploration tool."""
 
@@ -516,6 +521,10 @@ def run(
                 f"Define resolvers with @Entity.relationship.resolver"
             )
 
+        # Resolve any forward references now that all entities are registered
+        for entity_cls in self.entities.values():
+            entity_cls.model_rebuild()
+
         # Forward transport options to FastMCP
         if transport is not None:
             options.setdefault("transport", transport)

src/enrichmcp/relationship.py

@@ -106,7 +106,12 @@ def decorator(func: Callable[..., Any]) -> Callable[..., Any]:
                     name=resource_name,
                     description=resource_description,
                 )
-                return self.app._register_tool_def(func, tool_def)
+                try:
+                    return self.app._register_tool_def(func, tool_def)
+                except Exception:
+                    if hasattr(self.app, "rebuild_models"):
+                        self.app.rebuild_models()
+                    return self.app._register_tool_def(func, tool_def)
 
             return func