fix: preserve field aliases during Block serialization with include_secrets (#21306)

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: alex.s <alex.s@prefect.io>
Co-authored-by: alex.s <ajstreed1@gmail.com>

Author: devin-ai-integration[bot]

src/prefect/blocks/core.py

@@ -428,21 +428,28 @@ def ser_model(
         if (ctx := info.context) and ctx.get("include_secrets") is True:
             # Add serialization mode to context so handle_secret_render knows how to process nested models
             ctx["serialization_mode"] = info.mode
+            ctx["by_alias"] = info.by_alias
 
-            for field_name in type(self).model_fields:
+            for field_name, field_info in type(self).model_fields.items():
                 field_value = getattr(self, field_name)
 
-                # In JSON mode, skip fields that don't contain secrets
+                # Determine the correct key in the serialized dict,
+                # respecting alias settings to avoid creating duplicate
+                # entries (e.g. both "schema" and "schema_" for a field
+                # defined as `schema_: str = Field(alias="schema")`).
+                alias = field_info.serialization_alias or field_info.alias
+                if info.by_alias and alias:
+                    key = alias
+                else:
+                    key = field_name
+
+                # Skip fields that don't contain secrets
                 # as they're already properly serialized by the handler
-                if (
-                    info.mode == "json"
-                    and field_name in jsonable_self
-                    and not self._field_has_secrets(field_name)
-                ):
+                if key in jsonable_self and not self._field_has_secrets(field_name):
                     continue
 
                 # For all other fields, use visit_collection with handle_secret_render
-                jsonable_self[field_name] = visit_collection(
+                jsonable_self[key] = visit_collection(
                     expr=field_value,
                     visit_fn=partial(handle_secret_render, context=ctx),
                     return_data=True,

src/prefect/utilities/pydantic.py

@@ -350,21 +350,27 @@ def handle_secret_render(value: object, context: dict[str, Any]) -> object:
     elif isinstance(value, BaseModel):
         # Pass the serialization mode if available in context
         mode = context.get("serialization_mode", "python")
+        by_alias = context.get("by_alias", False)
         if mode == "json":
             # For JSON mode with nested models, we need to recursively process fields
             # because regular Pydantic models don't understand include_secrets
 
-            json_data = value.model_dump(mode="json")
-            for field_name in type(value).model_fields:
+            json_data = value.model_dump(mode="json", by_alias=by_alias)
+            for field_name, field_info in type(value).model_fields.items():
                 field_value = getattr(value, field_name)
-                json_data[field_name] = visit_collection(
+                alias = field_info.serialization_alias or field_info.alias
+                if by_alias and alias:
+                    key = alias
+                else:
+                    key = field_name
+                json_data[key] = visit_collection(
                     expr=field_value,
                     visit_fn=partial(handle_secret_render, context=context),
                     return_data=True,
                 )
             return json_data
         else:
-            return value.model_dump(context=context)
+            return value.model_dump(by_alias=by_alias, context=context)
     return value