feat(runner, api): allow limiting session events via GetSessionConfig in Runner and FastAPI endpoints

src/google/adk/cli/adk_web_server.py

@@ -74,6 +74,7 @@
 from ..memory.base_memory_service import BaseMemoryService
 from ..runners import Runner
 from ..sessions.base_session_service import BaseSessionService
+from ..sessions.base_session_service import GetSessionConfig
 from ..sessions.session import Session
 from ..utils.context_utils import Aclosing
 from .cli_eval import EVAL_SESSION_ID_PREFIX
@@ -164,6 +165,7 @@ class RunAgentRequest(common.BaseModel):
   new_message: types.Content
   streaming: bool = False
   state_delta: Optional[dict[str, Any]] = None
+  get_session_config: Optional[GetSessionConfig] = None
 
 
 class CreateSessionRequest(common.BaseModel):
@@ -1021,6 +1023,7 @@ async def run_agent(req: RunAgentRequest) -> list[Event]:
               session_id=req.session_id,
               new_message=req.new_message,
               state_delta=req.state_delta,
+              get_session_config=req.get_session_config,
           )
       ) as agen:
         events = [event async for event in agen]
@@ -1051,6 +1054,7 @@ async def event_generator():
                   new_message=req.new_message,
                   state_delta=req.state_delta,
                   run_config=RunConfig(streaming_mode=stream_mode),
+                  get_session_config=req.get_session_config,
               )
           ) as agen:
             async for event in agen:

src/google/adk/runners.py

@@ -47,6 +47,7 @@
 from .plugins.base_plugin import BasePlugin
 from .plugins.plugin_manager import PluginManager
 from .sessions.base_session_service import BaseSessionService
+from .sessions.base_session_service import GetSessionConfig
 from .sessions.in_memory_session_service import InMemorySessionService
 from .sessions.session import Session
 from .telemetry import tracer
@@ -125,6 +126,7 @@ def run(
       session_id: str,
       new_message: types.Content,
       run_config: RunConfig = RunConfig(),
+      get_session_config: Optional[GetSessionConfig] = None,
   ) -> Generator[Event, None, None]:
     """Runs the agent.
 
@@ -137,6 +139,8 @@ def run(
       session_id: The session ID of the session.
       new_message: A new message to append to the session.
       run_config: The run config for the agent.
+      get_session_config: Configuration for retrieving the session, allowing for
+        limiting the number of events returned.
 
     Yields:
       The events generated by the agent.
@@ -151,6 +155,7 @@ async def _invoke_run_async():
                 session_id=session_id,
                 new_message=new_message,
                 run_config=run_config,
+                get_session_config=get_session_config,
             )
         ) as agen:
           async for event in agen:
@@ -185,6 +190,7 @@ async def run_async(
       new_message: types.Content,
       state_delta: Optional[dict[str, Any]] = None,
       run_config: RunConfig = RunConfig(),
+      get_session_config: Optional[GetSessionConfig] = None,
   ) -> AsyncGenerator[Event, None]:
     """Main entry method to run the agent in this runner.
 
@@ -193,6 +199,8 @@ async def run_async(
       session_id: The session ID of the session.
       new_message: A new message to append to the session.
       run_config: The run config for the agent.
+      get_session_config: Configuration for retrieving the session, allowing for
+        limiting the number of events returned.
 
     Yields:
       The events generated by the agent.
@@ -203,7 +211,10 @@ async def _run_with_trace(
     ) -> AsyncGenerator[Event, None]:
       with tracer.start_as_current_span('invocation'):
         session = await self.session_service.get_session(
-            app_name=self.app_name, user_id=user_id, session_id=session_id
+            app_name=self.app_name,
+            user_id=user_id,
+            session_id=session_id,
+            config=get_session_config,
         )
         if not session:
           raise ValueError(f'Session not found: {session_id}')