get_thread_context returns None for assistant.user_message handlers when using custom authorize function #1368

import os, logging
from slack_bolt.async_app import AsyncApp, AsyncAssistant
from slack_bolt.authorization import AuthorizeResult
from slack_bolt.context.async_context import AsyncBoltContext
from slack_bolt.context.assistant.thread_context_store.default_async_store import (
    DefaultAsyncAssistantThreadContextStore,
)
from slack_sdk.web.async_client import AsyncWebClient

logging.basicConfig(level=logging.INFO)
log = logging.getLogger(__name__)

async def authorize(enterprise_id, team_id, user_id, client: AsyncWebClient) -> AuthorizeResult:
    # typical custom authorize: resolve identity, then set Authorization result
    auth = await client.auth_test(token=os.environ["SLACK_BOT_TOKEN"])
    return AuthorizeResult.from_auth_test_response(
        auth_test_response=auth, bot_token=os.environ["SLACK_BOT_TOKEN"]
    )

app = AsyncApp(authorize=authorize)
assistant = AsyncAssistant()
app.use(assistant)

@assistant.thread_started
async def started(
    say, get_thread_context, context: AsyncBoltContext,
):
     # This works (as long as you're coming from a DM or channel)
    tc = await get_thread_context()
    await say(
        ":wave: Hi! here's you're thread context: {tx}"
    )

@assistant.user_message
async def on_msg(
    say, context: AsyncBoltContext, get_thread_context,
):
    # Prove authorize() ran
    log.info(f"bot_user_id={context.bot_user_id}, channel={context.channel_id}, ts={context.thread_ts}")

    # 1) returns None (likely because context store was created pre-auth)
    tc_via_helper = await get_thread_context()
    log.info(f"get_thread_context() -> {tc_via_helper!r}")

    # 2) Fresh store built *now* (post-auth): returns context
    store = DefaultAsyncAssistantThreadContextStore(context)
    tc_via_store = await store.find(channel_id=context.channel_id, thread_ts=context.thread_ts)
    log.info(f"DefaultAsyncAssistantThreadContextStore.find(...) -> {tc_via_store!r}")

    await say(f"helper={tc_via_helper!r} | via_store={tc_via_store!r}")