call AgentInitializedEvent hooks synchronously

Author: pgrayy

src/strands/agent/agent.py

@@ -365,7 +365,7 @@ def __init__(
             for hook in hooks:
                 self.hooks.add_hook(hook)
 
-        run_async(lambda: self.hooks.invoke_callbacks_async(AgentInitializedEvent(agent=self)))
+        self.hooks.invoke_callbacks(AgentInitializedEvent(agent=self))
 
     @property
     def tool(self) -> ToolCaller:

src/strands/hooks/registry.py

@@ -9,7 +9,6 @@
 
 import inspect
 import logging
-import warnings
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Awaitable, Generator, Generic, Protocol, Type, TypeVar
 
@@ -171,6 +170,9 @@ def my_handler(event: StartRequestEvent):
             registry.add_callback(StartRequestEvent, my_handler)
             ```
         """
+        if event_type.__name__ == "AgentInitializedEvent" and inspect.iscoroutinefunction(callback):
+            raise ValueError("AgentInitializedEvent can only be registered with a synchronous callback")
+
         callbacks = self._registered_callbacks.setdefault(event_type, [])
         callbacks.append(callback)
 
@@ -268,11 +270,7 @@ def invoke_callbacks(self, event: TInvokeEvent) -> tuple[TInvokeEvent, list[Inte
             registry.invoke_callbacks(event)
             ```
         """
-        warnings.warn(
-            "invoke_callbacks is deprecated and replaced by invoke_callbacks_async", DeprecationWarning, stacklevel=2
-        )
-
-        callbacks = self.get_callbacks_for(event)
+        callbacks = list(self.get_callbacks_for(event))
         interrupts: dict[str, Interrupt] = {}
 
         if any(inspect.iscoroutinefunction(callback) for callback in callbacks):

tests/strands/hooks/test_registry.py

@@ -3,7 +3,7 @@
 import pytest
 
 from strands.agent.interrupt import InterruptState
-from strands.hooks import AgentInitializedEvent, BeforeToolCallEvent, HookRegistry
+from strands.hooks import AgentInitializedEvent, BeforeInvocationEvent, BeforeToolCallEvent, HookRegistry
 from strands.interrupt import Interrupt
 
 
@@ -19,6 +19,13 @@ def agent():
     return instance
 
 
+def test_hook_registry_add_callback_agent_init_coroutine(registry):
+    callback = unittest.mock.AsyncMock()
+
+    with pytest.raises(ValueError, match=r"AgentInitializedEvent can only be registered with a synchronous callback"):
+        registry.add_callback(AgentInitializedEvent, callback)
+
+
 @pytest.mark.asyncio
 async def test_hook_registry_invoke_callbacks_async_interrupt(registry, agent):
     event = BeforeToolCallEvent(
@@ -77,7 +84,7 @@ async def test_hook_registry_invoke_callbacks_async_interrupt_name_clash(registr
 
 def test_hook_registry_invoke_callbacks_coroutine(registry, agent):
     callback = unittest.mock.AsyncMock()
-    registry.add_callback(AgentInitializedEvent, callback)
+    registry.add_callback(BeforeInvocationEvent, callback)
 
     with pytest.raises(RuntimeError, match=r"use invoke_callbacks_async to invoke async callback"):
-        registry.invoke_callbacks(AgentInitializedEvent(agent=agent))
+        registry.invoke_callbacks(BeforeInvocationEvent(agent=agent))

tests_integ/hooks/test_events.py

@@ -30,7 +30,6 @@ def register_hooks(self, registry):
             registry.add_callback(AfterToolCallEvent, self.after_tool_call)
             registry.add_callback(AfterToolCallEvent, self.after_tool_call_async)
             registry.add_callback(AgentInitializedEvent, self.agent_initialized)
-            registry.add_callback(AgentInitializedEvent, self.agent_initialized_async)
             registry.add_callback(BeforeInvocationEvent, self.before_invocation)
             registry.add_callback(BeforeInvocationEvent, self.before_invocation_async)
             registry.add_callback(BeforeModelCallEvent, self.before_model_call)
@@ -111,7 +110,6 @@ def test_events(agent, callback_names):
     tru_callback_names = callback_names
     exp_callback_names = [
         "agent_initialized",
-        "agent_initialized_async",
         "before_invocation",
         "before_invocation_async",
         "message_added",