diff --git a/src/fiddledyn/serializer.py b/src/fiddledyn/serializer.py
index d9337e8..8ab53db 100644
--- a/src/fiddledyn/serializer.py
+++ b/src/fiddledyn/serializer.py
@@ -80,6 +80,17 @@ def _serialize_recursive(cfg: Any, ctx: SerializationContext) -> Any:
     return [_serialize_recursive(x, ctx) for x in cfg]
   if isinstance(cfg, dict):
     return {k: _serialize_recursive(v, ctx) for k, v in cfg.items()}
+  if (
+    inspect.isfunction(cfg)
+    or inspect.isbuiltin(cfg)
+    or inspect.ismethod(cfg)
+    or inspect.isclass(cfg)
+  ):
+    # For builtin functions and methods with module/name, store as a resolvable reference
+    if hasattr(cfg, "__module__") and hasattr(cfg, "__name__"):
+      # Store module path and function name so it can be resolved later
+      # return fdl.Config(f'{value.__module__}.{value.__name__}')
+      return {"_target_": f"{cfg.__module__}.{cfg.__name__}", "_call_": False}
   if not isinstance(cfg, (run.Config, run.Partial, fdl.Config, fdl.Partial)):
     return cfg
 
@@ -106,6 +117,9 @@ def _serialize_recursive(cfg: Any, ctx: SerializationContext) -> Any:
   if current_id is not None:
     output["_id_"] = current_id
 
+  if isinstance(cfg, (run.Partial, fdl.Partial)):
+    output["_partial_"] = True
+
   # Handle _call_: False if this was a raw object reference that we serialized?
   # NOTE: Currently Fiddle configs don't store "_call_" state.
   # If the object is a Config, it implies _call_=True.