provide sampler by name

modules/api/processing.py

@@ -42,7 +42,8 @@ class PydanticModelGenerator:
     def __init__(
         self,
         model_name: str = None,
-        class_instance = None
+        class_instance = None,
+        additional_fields = None,
     ):
         def field_type_generator(k, v):
             # field_type = str if not overrides.get(k) else overrides[k]["type"]
@@ -70,6 +71,13 @@ class PydanticModelGenerator:
             )
             for (k,v) in self._class_data.items() if k not in API_NOT_ALLOWED
         ]
+        
+        for fields in additional_fields:
+            self._model_def.append(ModelDef(
+                field=underscore(fields["key"]), 
+                field_alias=fields["key"], 
+                field_type=fields["type"],
+                field_value=fields["default"]))
 
     def generate_model(self):
         """
@@ -84,4 +92,8 @@ class PydanticModelGenerator:
         DynamicModel.__config__.allow_mutation = True
         return DynamicModel
     
-StableDiffusionProcessingAPI = PydanticModelGenerator("StableDiffusionProcessingTxt2Img", StableDiffusionProcessingTxt2Img).generate_model()
+StableDiffusionProcessingAPI = PydanticModelGenerator(
+    "StableDiffusionProcessingTxt2Img", 
+    StableDiffusionProcessingTxt2Img,
+    [{"key": "sampler_index", "type": str, "default": "k_euler_a"}]
+).generate_model()