prevent any possible breaking changes

WilliamBergamin · Mar 17, 2026 · Mar 11, 2026 · Mar 12, 2026 · Mar 12, 2026 · Mar 13, 2026
commit 807e53b9bd44536902381fa6a87028140f916656
@@ -69,6 +69,7 @@
     IgnoringSelfEvents,
     CustomMiddleware,
     AttachingFunctionToken,
+    AttachingAgentKwargs,
 )
 from slack_bolt.middleware.assistant import Assistant
 from slack_bolt.middleware.message_listener_matches import MessageListenerMatches
@@ -132,6 +133,7 @@ def __init__(
         listener_executor: Optional[Executor] = None,
         # for AI Agents & Assistants
         assistant_thread_context_store: Optional[AssistantThreadContextStore] = None,
+        attaching_agent_kwargs_enabled: bool = True,
     ):
         """Bolt App that provides functionalities to register middleware/listeners.
 
@@ -352,6 +354,7 @@ def message_hello(message, say):
             listener_executor = ThreadPoolExecutor(max_workers=5)
 
         self._assistant_thread_context_store = assistant_thread_context_store
+        self._attaching_agent_kwargs_enabled = attaching_agent_kwargs_enabled
 
         self._process_before_response = process_before_response
         self._listener_runner = ThreadListenerRunner(
@@ -836,10 +839,13 @@ def ask_for_introduction(event, say):
             middleware: A list of lister middleware functions.
                 Only when all the middleware call `next()` method, the listener function can be invoked.
         """
+        middleware = list(middleware) if middleware else []
 
         def __call__(*args, **kwargs):
             functions = self._to_listener_functions(kwargs) if kwargs else list(args)
             primary_matcher = builtin_matchers.event(event, base_logger=self._base_logger)
+            if self._attaching_agent_kwargs_enabled:
+                middleware.insert(0, AttachingAgentKwargs(self._assistant_thread_context_store))
             return self._register_listener(list(functions), primary_matcher, matchers, middleware, True)
 
         return __call__
@@ -897,6 +903,8 @@ def __call__(*args, **kwargs):
             primary_matcher = builtin_matchers.message_event(
                 keyword=keyword, constraints=constraints, base_logger=self._base_logger
             )
+            if self._attaching_agent_kwargs_enabled:
+                middleware.insert(0, AttachingAgentKwargs(self._assistant_thread_context_store))
             middleware.insert(0, MessageListenerMatches(keyword))
             return self._register_listener(list(functions), primary_matcher, matchers, middleware, True)
 

@@ -86,6 +86,7 @@
     AsyncIgnoringSelfEvents,
     AsyncUrlVerification,
     AsyncAttachingFunctionToken,
+    AsyncAttachingAgentKwargs,
 )
 from slack_bolt.middleware.async_custom_middleware import (
     AsyncMiddleware,
@@ -141,6 +142,7 @@ def __init__(
         verification_token: Optional[str] = None,
         # for AI Agents & Assistants
         assistant_thread_context_store: Optional[AsyncAssistantThreadContextStore] = None,
+        attaching_agent_kwargs_enabled: bool = True,
     ):
         """Bolt App that provides functionalities to register middleware/listeners.
 
@@ -361,6 +363,7 @@ async def message_hello(message, say):  # async function
         self._async_listeners: List[AsyncListener] = []
 
         self._assistant_thread_context_store = assistant_thread_context_store
+        self._attaching_agent_kwargs_enabled = attaching_agent_kwargs_enabled
 
         self._process_before_response = process_before_response
         self._async_listener_runner = AsyncioListenerRunner(
@@ -864,10 +867,13 @@ async def ask_for_introduction(event, say):
             middleware: A list of lister middleware functions.
                 Only when all the middleware call `next()` method, the listener function can be invoked.
         """
+        middleware = list(middleware) if middleware else []
 
         def __call__(*args, **kwargs):
             functions = self._to_listener_functions(kwargs) if kwargs else list(args)
             primary_matcher = builtin_matchers.event(event, True, base_logger=self._base_logger)
+            if self._attaching_agent_kwargs_enabled:
+                middleware.insert(0, AsyncAttachingAgentKwargs(self._assistant_thread_context_store))
             return self._register_listener(list(functions), primary_matcher, matchers, middleware, True)
 
         return __call__
@@ -928,6 +934,8 @@ def __call__(*args, **kwargs):
                 asyncio=True,
                 base_logger=self._base_logger,
             )
+            if self._attaching_agent_kwargs_enabled:
+                middleware.insert(0, AsyncAttachingAgentKwargs(self._assistant_thread_context_store))
             middleware.insert(0, AsyncMessageListenerMatches(keyword))
             return self._register_listener(list(functions), primary_matcher, matchers, middleware, True)
 

@@ -17,6 +17,7 @@
 from .ssl_check import SslCheck
 from .url_verification import UrlVerification
 from .attaching_function_token import AttachingFunctionToken
+from .attaching_agent_kwargs import AttachingAgentKwargs
 
 builtin_middleware_classes = [
     SslCheck,
@@ -41,5 +42,6 @@
     "SslCheck",
     "UrlVerification",
     "AttachingFunctionToken",
+    "AttachingAgentKwargs",
     "builtin_middleware_classes",
 ]
@@ -7,7 +7,7 @@
 from slack_bolt.context.assistant.thread_context_store.store import AssistantThreadContextStore
 from slack_bolt.listener_matcher.builtins import build_listener_matcher
 
-from slack_bolt.middleware.assistant.attaching_assistant_kwargs import AttachingAssistantKwargs
+from slack_bolt.middleware.attaching_agent_kwargs import AttachingAgentKwargs
 from slack_bolt.request.request import BoltRequest
 from slack_bolt.response.response import BoltResponse
 from slack_bolt.listener_matcher import CustomListenerMatcher
@@ -272,7 +272,7 @@ def build_listener(
             return listener_or_functions
         elif isinstance(listener_or_functions, list):
             middleware = middleware if middleware else []
-            middleware.insert(0, AttachingAssistantKwargs(self.thread_context_store))
+            middleware.insert(0, AttachingAgentKwargs(self.thread_context_store))
             functions = listener_or_functions
             ack_function = functions.pop(0)
 

@@ -8,7 +8,7 @@
 
 from slack_bolt.listener.asyncio_runner import AsyncioListenerRunner
 from slack_bolt.listener_matcher.builtins import build_listener_matcher
-from slack_bolt.middleware.assistant.async_attaching_assistant_kwargs import AsyncAttachingAssistantKwargs
+from slack_bolt.middleware.attaching_agent_kwargs.async_attaching_agent_kwargs import AsyncAttachingAgentKwargs
 from slack_bolt.request.async_request import AsyncBoltRequest
 from slack_bolt.response import BoltResponse
 from slack_bolt.error import BoltError
@@ -301,7 +301,7 @@ def build_listener(
             return listener_or_functions
         elif isinstance(listener_or_functions, list):
             middleware = middleware if middleware else []
-            middleware.insert(0, AsyncAttachingAssistantKwargs(self.thread_context_store))
+            middleware.insert(0, AsyncAttachingAgentKwargs(self.thread_context_store))
             functions = listener_or_functions
             ack_function = functions.pop(0)
 

diff --git a/slack_bolt/middleware/assistant/attaching_assistant_kwargs.py b/slack_bolt/middleware/assistant/attaching_assistant_kwargs.py
@@ -10,6 +10,7 @@
     AsyncMessageListenerMatches,
 )
 from .attaching_function_token.async_attaching_function_token import AsyncAttachingFunctionToken
+from .attaching_agent_kwargs.async_attaching_agent_kwargs import AsyncAttachingAgentKwargs
 
 __all__ = [
     "AsyncIgnoringSelfEvents",
@@ -18,4 +19,5 @@
     "AsyncUrlVerification",
     "AsyncMessageListenerMatches",
     "AsyncAttachingFunctionToken",
+    "AsyncAttachingAgentKwargs",
 ]
@@ -0,0 +1,5 @@
+from .attaching_agent_kwargs import AttachingAgentKwargs
+
+__all__ = [
+    "AttachingAgentKwargs",
+]
@@ -4,15 +4,15 @@
 from slack_bolt.context.assistant.thread_context_store.async_store import AsyncAssistantThreadContextStore
 from slack_bolt.middleware.async_middleware import AsyncMiddleware
 from slack_bolt.request.async_request import AsyncBoltRequest
-from slack_bolt.request.payload_utils import to_event
+from slack_bolt.request.payload_utils import is_assistant_event, to_event
 from slack_bolt.response import BoltResponse
 
 
-class AsyncAttachingAssistantKwargs(AsyncMiddleware):
+class AsyncAttachingAgentKwargs(AsyncMiddleware):
 
     thread_context_store: Optional[AsyncAssistantThreadContextStore]
 
-    def __init__(self, thread_context_store: Optional[AsyncAssistantThreadContextStore]):
+    def __init__(self, thread_context_store: Optional[AsyncAssistantThreadContextStore] = None):
         self.thread_context_store = thread_context_store
 
     async def async_process(
@@ -24,15 +24,16 @@ async def async_process(
     ) -> Optional[BoltResponse]:
         event = to_event(req.body)
         if event is not None:
-            assistant = AsyncAssistantUtilities(
-                payload=event,
-                context=req.context,
-                thread_context_store=self.thread_context_store,
-            )
-            req.context["say"] = assistant.say
-            req.context["set_status"] = assistant.set_status
-            req.context["set_title"] = assistant.set_title
-            req.context["set_suggested_prompts"] = assistant.set_suggested_prompts
-            req.context["get_thread_context"] = assistant.get_thread_context
-            req.context["save_thread_context"] = assistant.save_thread_context
+            if is_assistant_event(req.body):
+                assistant = AsyncAssistantUtilities(
+                    payload=event,
+                    context=req.context,
+                    thread_context_store=self.thread_context_store,
+                )
+                req.context["say"] = assistant.say
+                req.context["set_status"] = assistant.set_status
+                req.context["set_title"] = assistant.set_title
+                req.context["set_suggested_prompts"] = assistant.set_suggested_prompts
+                req.context["get_thread_context"] = assistant.get_thread_context
+                req.context["save_thread_context"] = assistant.save_thread_context
         return await next()
@@ -0,0 +1,33 @@
+from typing import Optional, Callable
+
+from slack_bolt.context.assistant.assistant_utilities import AssistantUtilities
+from slack_bolt.context.assistant.thread_context_store.store import AssistantThreadContextStore
+from slack_bolt.middleware import Middleware
+from slack_bolt.request.payload_utils import is_assistant_event, to_event
+from slack_bolt.request.request import BoltRequest
+from slack_bolt.response.response import BoltResponse
+
+
+class AttachingAgentKwargs(Middleware):
+
+    thread_context_store: Optional[AssistantThreadContextStore]
+
+    def __init__(self, thread_context_store: Optional[AssistantThreadContextStore] = None):
+        self.thread_context_store = thread_context_store
+
+    def process(self, *, req: BoltRequest, resp: BoltResponse, next: Callable[[], BoltResponse]) -> Optional[BoltResponse]:
+        event = to_event(req.body)
+        if event is not None:
+            if is_assistant_event(req.body):
+                assistant = AssistantUtilities(
+                    payload=event,
+                    context=req.context,
+                    thread_context_store=self.thread_context_store,
+                )
+                req.context["say"] = assistant.say
+                req.context["set_status"] = assistant.set_status
+                req.context["set_title"] = assistant.set_title
+                req.context["set_suggested_prompts"] = assistant.set_suggested_prompts
+                req.context["get_thread_context"] = assistant.get_thread_context
+                req.context["save_thread_context"] = assistant.save_thread_context
+        return next()
@@ -166,6 +166,80 @@ def handle_user_message(say: Say, set_status: SetStatus, context: BoltContext):
         assert_target_called()
         assert state["middleware_called"] is True
 
+    def test_assistant_events_without_assistant_middleware(self):
+        app = App(client=self.web_client)
+
+        state = {"called": False}
+
+        def assert_target_called():
+            count = 0
+            while state["called"] is False and count < 20:
+                sleep(0.1)
+                count += 1
+            assert state["called"] is True
+            state["called"] = False
+
+        @app.event("assistant_thread_started")
+        def start_thread(say: Say, set_suggested_prompts: SetSuggestedPrompts, set_status: SetStatus, context: BoltContext):
+            assert context.channel_id == "D111"
+            assert context.thread_ts == "1726133698.626339"
+            assert say.thread_ts == context.thread_ts
+            assert set_status is not None
+            assert set_suggested_prompts is not None
+            assert context.get("set_title") is not None
+            assert context.get("get_thread_context") is not None
+            assert context.get("save_thread_context") is not None
+            say("Hi, how can I help you today?")
+            state["called"] = True
+
+        @app.event("message")
+        def handle_message(say: Say, context: BoltContext, body: dict):
+            if context.get("set_status") is not None:
+                assert say.thread_ts == context.thread_ts
+                state["called"] = True
+
+        request = BoltRequest(body=thread_started_event_body, mode="socket_mode")
+        response = app.dispatch(request)
+        assert response.status == 200
+        assert_target_called()
+
+        request = BoltRequest(body=user_message_event_body, mode="socket_mode")
+        response = app.dispatch(request)
+        assert response.status == 200
+        assert_target_called()
+
+        # Non-assistant events should not get kwargs injected
+        request = BoltRequest(body=channel_user_message_event_body, mode="socket_mode")
+        response = app.dispatch(request)
+        assert response.status == 200
+
+    def test_assistant_events_kwargs_disabled(self):
+        app = App(client=self.web_client, attaching_agent_kwargs_enabled=False)
+
+        state = {"called": False}
+
+        def assert_target_called():
+            count = 0
+            while state["called"] is False and count < 20:
+                sleep(0.1)
+                count += 1
+            assert state["called"] is True
+            state["called"] = False
+
+        @app.event("assistant_thread_started")
+        def start_thread(context: BoltContext):
+            assert context.get("set_status") is None
+            assert context.get("set_title") is None
+            assert context.get("set_suggested_prompts") is None
+            assert context.get("get_thread_context") is None
+            assert context.get("save_thread_context") is None
+            state["called"] = True
+
+        request = BoltRequest(body=thread_started_event_body, mode="socket_mode")
+        response = app.dispatch(request)
+        assert response.status == 200
+        assert_target_called()
+
     def test_assistant_threads_custom_middleware_can_short_circuit(self):
         app = App(client=self.web_client)
         assistant = Assistant()