feat: Add url field to PaginatedResponse and populate it using route path

Resolves: https://github.com/meta-llama/llama-stack/issues/1847
Changes:
- responses.py: added optional `url` field to PaginatedResponse
- server.py: automatically populate the URL field with route path

docs/_static/llama-stack-spec.html

@@ -10711,6 +10711,10 @@
                     "has_more": {
                         "type": "boolean",
                         "description": "Whether there are more items available after this set"
+                    },
+                    "url": {
+                        "type": "string",
+                        "description": "The URL for accessing this list"
                     }
                 },
                 "additionalProperties": false,

docs/_static/llama-stack-spec.yaml

@@ -7511,6 +7511,9 @@ components:
           type: boolean
           description: >-
             Whether there are more items available after this set
+        url:
+          type: string
+          description: The URL for accessing this list
       additionalProperties: false
       required:
         - data

llama_stack/apis/common/responses.py

@@ -23,7 +23,9 @@ class PaginatedResponse(BaseModel):
 
     :param data: The list of items for the current page
     :param has_more: Whether there are more items available after this set
+    :param url: The URL for accessing this list
     """
 
     data: list[dict[str, Any]]
     has_more: bool
+    url: str | None = None

llama_stack/distribution/server/server.py

@@ -30,6 +30,7 @@ from fastapi.responses import JSONResponse, StreamingResponse
 from openai import BadRequestError
 from pydantic import BaseModel, ValidationError
 
+from llama_stack.apis.common.responses import PaginatedResponse
 from llama_stack.distribution.datatypes import AuthenticationRequiredError, LoggingConfig, StackRunConfig
 from llama_stack.distribution.distribution import builtin_automatically_routed_apis
 from llama_stack.distribution.request_headers import PROVIDER_DATA_VAR, User, request_provider_data_context
@@ -230,7 +231,10 @@ def create_dynamic_typed_route(func: Any, method: str, route: str) -> Callable:
                     return StreamingResponse(gen, media_type="text/event-stream")
                 else:
                     value = func(**kwargs)
-                    return await maybe_await(value)
+                    result = await maybe_await(value)
+                    if isinstance(result, PaginatedResponse) and result.url is None:
+                        result.url = route
+                    return result
             except Exception as e:
                 logger.exception(f"Error executing endpoint {route=} {method=}")
                 raise translate_exception(e) from e