More idiomatic REST API (#765)

# What does this PR do?

This PR changes our API to follow more idiomatic REST API approaches of
having paths being resources and methods indicating the action being
performed.

Changes made to generator:
1) removed the prefix check of "get" as its not required and is actually
needed for other method types too
2) removed _ check on path since variables can have "_"



## Test Plan

LLAMA_STACK_BASE_URL=http://localhost:5000 pytest -v
tests/client-sdk/agents/test_agents.py

llama_stack/distribution/server/server.py

@@ -14,16 +14,13 @@ import signal
 import sys
 import traceback
 import warnings
-
 from contextlib import asynccontextmanager
-
 from importlib.metadata import version as parse_version
 from pathlib import Path
-from typing import Any, Union
+from typing import Any, List, Union
 
 import yaml
-
-from fastapi import Body, FastAPI, HTTPException, Request
+from fastapi import Body, FastAPI, HTTPException, Path as FastapiPath, Request
 from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse, StreamingResponse
 from pydantic import BaseModel, ValidationError
@@ -31,7 +28,6 @@ from termcolor import cprint
 from typing_extensions import Annotated
 
 from llama_stack.distribution.datatypes import StackRunConfig
-
 from llama_stack.distribution.distribution import builtin_automatically_routed_apis
 from llama_stack.distribution.request_headers import set_request_provider_data
 from llama_stack.distribution.resolver import InvalidProviderError
@@ -41,13 +37,11 @@ from llama_stack.distribution.stack import (
     replace_env_vars,
     validate_env_pair,
 )
-
 from llama_stack.providers.datatypes import Api
 from llama_stack.providers.inline.telemetry.meta_reference.config import TelemetryConfig
 from llama_stack.providers.inline.telemetry.meta_reference.telemetry import (
     TelemetryAdapter,
 )
-
 from llama_stack.providers.utils.telemetry.tracing import (
     end_trace,
     setup_logger,
@@ -56,7 +50,6 @@ from llama_stack.providers.utils.telemetry.tracing import (
 
 from .endpoints import get_all_api_endpoints
 
-
 REPO_ROOT = Path(__file__).parent.parent.parent.parent
 
 
@@ -178,7 +171,7 @@ async def sse_generator(event_gen):
         )
 
 
-def create_dynamic_typed_route(func: Any, method: str):
+def create_dynamic_typed_route(func: Any, method: str, route: str):
     async def endpoint(request: Request, **kwargs):
         set_request_provider_data(request.headers)
 
@@ -196,6 +189,7 @@ def create_dynamic_typed_route(func: Any, method: str):
             raise translate_exception(e) from e
 
     sig = inspect.signature(func)
+
     new_params = [
         inspect.Parameter(
             "request", inspect.Parameter.POSITIONAL_OR_KEYWORD, annotation=Request
@@ -203,12 +197,21 @@ def create_dynamic_typed_route(func: Any, method: str):
     ]
     new_params.extend(sig.parameters.values())
 
+    path_params = extract_path_params(route)
     if method == "post":
-        # make sure every parameter is annotated with Body() so FASTAPI doesn't
-        # do anything too intelligent and ask for some parameters in the query
-        # and some in the body
+        # Annotate parameters that are in the path with Path(...) and others with Body(...)
         new_params = [new_params[0]] + [
-            param.replace(annotation=Annotated[param.annotation, Body(..., embed=True)])
+            (
+                param.replace(
+                    annotation=Annotated[
+                        param.annotation, FastapiPath(..., title=param.name)
+                    ]
+                )
+                if param.name in path_params
+                else param.replace(
+                    annotation=Annotated[param.annotation, Body(..., embed=True)]
+                )
+            )
             for param in new_params[1:]
         ]
 
@@ -386,6 +389,7 @@ def main():
                     create_dynamic_typed_route(
                         impl_method,
                         endpoint.method,
+                        endpoint.route,
                     )
                 )
 
@@ -409,5 +413,13 @@ def main():
     uvicorn.run(app, host=listen_host, port=args.port)
 
 
+def extract_path_params(route: str) -> List[str]:
+    segments = route.split("/")
+    params = [
+        seg[1:-1] for seg in segments if seg.startswith("{") and seg.endswith("}")
+    ]
+    return params
+
+
 if __name__ == "__main__":
     main()