chore: Update create_session endpoint to use Request message as post body

Also deprecate create_session_with_id which is not very RESTful. PiperOrigin-RevId: 802357718

Author: DeanChensj

src/google/adk/cli/adk_web_server.py

@@ -166,6 +166,23 @@ class RunAgentRequest(common.BaseModel):
  state_delta: Optional[dict[str, Any]] = None
 
 
+class CreateSessionRequest(common.BaseModel):
+ session_id: Optional[str] = Field(
+ default=None,
+ description=(
+ "The ID of the session to create. If not provided, a random session"
+ " ID will be generated."
+ ),
+ )
+ state: Optional[dict[str, Any]] = Field(
+ default=None, description="The initial state of the session."
+ )
+ events: Optional[list[Event]] = Field(
+ default=None,
+ description="A list of events to initialize the session with.",
+ )
+
+
 class AddSessionToEvalSetRequest(common.BaseModel):
  eval_id: str
  session_id: str
@@ -452,6 +469,10 @@ async def list_sessions(app_name: str, user_id: str) -> list[Session]:
  if not session.id.startswith(EVAL_SESSION_ID_PREFIX)
  ]
 
+ @deprecated(
+ "Please use create_session instead. This will be removed in future"
+ " releases."
+ )
  @app.post(
  "/apps/{app_name}/users/{user_id}/sessions/{session_id}",
  response_model_exclude_none=True,
@@ -484,18 +505,24 @@ async def create_session_with_id(
  async def create_session(
  app_name: str,
  user_id: str,
- state: Optional[dict[str, Any]] = None,
- events: Optional[list[Event]] = None,
+ req: Optional[CreateSessionRequest] = None,
  ) -> Session:
+ if not req:
+ return await self.session_service.create_session(
+ app_name=app_name, user_id=user_id
+ )
+
  session = await self.session_service.create_session(
- app_name=app_name, user_id=user_id, state=state
+ app_name=app_name,
+ user_id=user_id,
+ state=req.state,
+ session_id=req.session_id,
  )
 
- if events:
- for event in events:
+ if req.events:
+ for event in req.events:
  await self.session_service.append_event(session=session, event=event)
 
- logger.info("New session created")
  return session
 
  @app.delete("/apps/{app_name}/users/{user_id}/sessions/{session_id}")