Fix: store agent on app object, access via current_app

Global module variable was unreliable across import boundaries. Storing
the compiled agent on app.main_agent and reading it via current_app is
the idiomatic Quart pattern and guaranteed to reflect the initialized value.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -103,7 +103,7 @@ async def lifespan():
     async with aiosqlite.connect(checkpoint_path) as conn:
         checkpointer = AsyncSqliteSaver(conn)
         await checkpointer.setup()
-        build_agent(checkpointer)
+        app.main_agent = build_agent(checkpointer)
         logging.info(f"Agent checkpointer ready at {checkpoint_path}")
 
         watcher_task = None

blueprints/conversation/__init__.py

@@ -6,7 +6,7 @@ import re
 import time
 import uuid
 
-from quart import Blueprint, jsonify, make_response, request
+from quart import Blueprint, current_app, jsonify, make_response, request
 from quart_jwt_extended import (
     get_jwt_identity,
     jwt_refresh_token_required,
@@ -21,7 +21,6 @@ from utils.s3_client import generate_presigned_url as s3_presigned_url
 from utils.s3_client import get_image as s3_get_image
 from utils.s3_client import upload_image as s3_upload_image
 
-from . import agents as _agents
 from .logic import (
     add_message_to_conversation,
     persist_agent_tool_messages,
@@ -152,7 +151,7 @@ async def query():
             }
         }
 
-        response = await _agents.main_agent.ainvoke(payload, config=agent_config)
+        response = await current_app.main_agent.ainvoke(payload, config=agent_config)
         message = extract_agent_text(response.get("messages", [])[-1].content)
         await persist_agent_tool_messages(
             conversation, user, response.get("messages", [])
@@ -301,7 +300,7 @@ async def stream_query():
             )
 
         try:
-            aiter = _agents.main_agent.astream_events(
+            aiter = current_app.main_agent.astream_events(
                 payload, version="v2", config=agent_config
             ).__aiter__()
             while True:

blueprints/conversation/agents.py

@@ -1230,18 +1230,11 @@ if google_gmail_enabled:
     tools.extend([gmail_search_emails, gmail_get_email])
 
 
-# main_agent is compiled lazily by build_agent() once the checkpointer is
-# ready (the async SQLite connection must be created inside the event loop).
-main_agent = None
-
-
 def build_agent(checkpointer=None):
-    """Compile the LangGraph agent, optionally with a checkpointer."""
-    global main_agent
-    main_agent = create_react_agent(
+    """Compile and return the LangGraph agent."""
+    return create_react_agent(
         model=model_with_fallback,
         tools=tools,
         prompt=SIMBA_SYSTEM_PROMPT,
         checkpointer=checkpointer,
     )
-    return main_agent

blueprints/imessage/__init__.py

@@ -16,7 +16,7 @@ from blueprints.conversation.logic import (
     persist_agent_tool_messages,
 )
 from blueprints.conversation.models import Conversation, ConversationMessage
-import blueprints.conversation.agents as _conv_agents
+from quart import current_app
 from utils.strip_markdown import extract_agent_text, strip_markdown
 
 imessage_blueprint = Blueprint("imessage_api", __name__, url_prefix="/api/imessage")
@@ -351,7 +351,7 @@ async def _process_and_reply(
             }
         }
         logger.info(f"Invoking LangChain agent for conversation {conversation.id}")
-        response = await _conv_agents.main_agent.ainvoke(
+        response = await current_app.main_agent.ainvoke(
             {"messages": [{"role": "user", "content": user_content}]},
             config=agent_config,
         )

blueprints/whatsapp/__init__.py

@@ -13,7 +13,7 @@ from blueprints.conversation.logic import (
     add_message_to_conversation,
     persist_agent_tool_messages,
 )
-import blueprints.conversation.agents as _conv_agents
+from quart import current_app
 from utils.strip_markdown import extract_agent_text
 
 whatsapp_blueprint = Blueprint("whatsapp_api", __name__, url_prefix="/api/whatsapp")
@@ -185,7 +185,7 @@ async def webhook():
             }
         }
         logger.info(f"Invoking LangChain agent for conversation {conversation.id}")
-        response = await _conv_agents.main_agent.ainvoke(
+        response = await current_app.main_agent.ainvoke(
             {"messages": [{"role": "user", "content": body}]},
             config=agent_config,
         )