feat(files): fix expires_after API shape (#3604)

This was just quite incorrect. See source here:
https://platform.openai.com/docs/api-reference/files/create

llama_stack/apis/files/files.py

@@ -111,9 +111,7 @@ class Files(Protocol):
         self,
         file: Annotated[UploadFile, File()],
         purpose: Annotated[OpenAIFilePurpose, Form()],
-        expires_after_anchor: Annotated[str | None, Form(alias="expires_after[anchor]")] = None,
-        expires_after_seconds: Annotated[int | None, Form(alias="expires_after[seconds]")] = None,
-        # TODO: expires_after is producing strange openapi spec, params are showing up as a required w/ oneOf being null
+        expires_after: Annotated[ExpiresAfter | None, Form()] = None,
     ) -> OpenAIFileObject:
         """
         Upload a file that can be used across various endpoints.
@@ -121,10 +119,11 @@ class Files(Protocol):
         The file upload should be a multipart form request with:
         - file: The File object (not file name) to be uploaded.
         - purpose: The intended purpose of the uploaded file.
-        - expires_after: Optional form values describing expiration for the file. Expected expires_after[anchor] = "created_at", expires_after[seconds] = {integer}. Seconds must be between 3600 and 2592000 (1 hour to 30 days).
+        - expires_after: Optional form values describing expiration for the file.
 
         :param file: The uploaded file object containing content and metadata (filename, content_type, etc.).
         :param purpose: The intended purpose of the uploaded file (e.g., "assistants", "fine-tune").
+        :param expires_after: Optional form values describing expiration for the file.
         :returns: An OpenAIFileObject representing the uploaded file.
         """
         ...

llama_stack/providers/inline/files/localfs/files.py

@@ -14,6 +14,7 @@ from fastapi import File, Form, Response, UploadFile
 from llama_stack.apis.common.errors import ResourceNotFoundError
 from llama_stack.apis.common.responses import Order
 from llama_stack.apis.files import (
+    ExpiresAfter,
     Files,
     ListOpenAIFileResponse,
     OpenAIFileDeleteResponse,
@@ -86,14 +87,13 @@ class LocalfsFilesImpl(Files):
         self,
         file: Annotated[UploadFile, File()],
         purpose: Annotated[OpenAIFilePurpose, Form()],
-        expires_after_anchor: Annotated[str | None, Form(alias="expires_after[anchor]")] = None,
-        expires_after_seconds: Annotated[int | None, Form(alias="expires_after[seconds]")] = None,
+        expires_after: Annotated[ExpiresAfter | None, Form()] = None,
     ) -> OpenAIFileObject:
         """Upload a file that can be used across various endpoints."""
         if not self.sql_store:
             raise RuntimeError("Files provider not initialized")
 
-        if expires_after_anchor is not None or expires_after_seconds is not None:
+        if expires_after is not None:
             raise NotImplementedError("File expiration is not supported by this provider")
 
         file_id = self._generate_file_id()

llama_stack/providers/remote/files/s3/files.py

@@ -195,8 +195,7 @@ class S3FilesImpl(Files):
         self,
         file: Annotated[UploadFile, File()],
         purpose: Annotated[OpenAIFilePurpose, Form()],
-        expires_after_anchor: Annotated[str | None, Form(alias="expires_after[anchor]")] = None,
-        expires_after_seconds: Annotated[int | None, Form(alias="expires_after[seconds]")] = None,
+        expires_after: Annotated[ExpiresAfter | None, Form()] = None,
     ) -> OpenAIFileObject:
         file_id = f"file-{uuid.uuid4().hex}"
 
@@ -204,14 +203,6 @@ class S3FilesImpl(Files):
 
         created_at = self._now()
 
-        expires_after = None
-        if expires_after_anchor is not None or expires_after_seconds is not None:
-            # we use ExpiresAfter to validate input
-            expires_after = ExpiresAfter(
-                anchor=expires_after_anchor,  # type: ignore[arg-type]
-                seconds=expires_after_seconds,  # type: ignore[arg-type]
-            )
-
         # the default is no expiration.
         # to implement no expiration we set an expiration beyond the max.
         # we'll hide this fact from users when returning the file object.

llama_stack/strong_typing/inspection.py

@@ -567,6 +567,22 @@ def get_class_properties(typ: type) -> Iterable[Tuple[str, type | str]]:
 
     if is_dataclass_type(typ):
         return ((field.name, field.type) for field in dataclasses.fields(typ))
+    elif hasattr(typ, "model_fields"):
+        # Pydantic BaseModel - use model_fields to exclude ClassVar and other non-field attributes
+        # Reconstruct Annotated type if discriminator exists to preserve metadata
+        from typing import Annotated, Any, cast
+        from pydantic.fields import FieldInfo
+
+        def get_field_type(name: str, field: Any) -> type | str:
+            # If field has discriminator, wrap in Annotated to preserve it for schema generation
+            if field.discriminator:
+                field_info = FieldInfo(annotation=None, discriminator=field.discriminator)
+                # Annotated returns _AnnotatedAlias which isn't a type but is valid here
+                return Annotated[field.annotation, field_info]  # type: ignore[return-value]
+            # field.annotation can be Union types, Annotated, etc. which aren't type but are valid
+            return field.annotation  # type: ignore[return-value,no-any-return]
+
+        return ((name, get_field_type(name, field)) for name, field in typ.model_fields.items())
     else:
         resolved_hints = get_resolved_hints(typ)
         return resolved_hints.items()

llama_stack/strong_typing/schema.py

@@ -92,7 +92,12 @@ def get_class_property_docstrings(
     :returns: A dictionary mapping property names to descriptions.
     """
 
-    result = {}
+    result: Dict[str, str] = {}
+    # Only try to get MRO if data_type is actually a class
+    # Special types like Literal, Union, etc. don't have MRO
+    if not inspect.isclass(data_type):
+        return result
+
     for base in inspect.getmro(data_type):
         docstr = docstring.parse_type(base)
         for param in docstr.params.values():