refactor: remove redundant fatalError ref, use state directly in handleLeave

When Cal.com events appear in an aggregated ICS feed, the same event
gets two different UIDs (one from Cal.com, one from Google Calendar).
This caused duplicate meetings to be created for the same time slot.

Add time-window dedup check in create_upcoming_meetings_for_event:
after verifying no meeting exists for the calendar_event_id, also check
if a meeting already exists for the same room + start_date + end_date.

server/migrations/versions/3aa20b96d963_drop_use_celery_column.py

@@ -1,35 +0,0 @@
-"""drop_use_celery_column
-
-Revision ID: 3aa20b96d963
-Revises: e69f08ead8ea
-Create Date: 2026-02-05 10:12:44.065279
-
-"""
-
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "3aa20b96d963"
-down_revision: Union[str, None] = "e69f08ead8ea"
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    with op.batch_alter_table("room", schema=None) as batch_op:
-        batch_op.drop_column("use_celery")
-
-
-def downgrade() -> None:
-    with op.batch_alter_table("room", schema=None) as batch_op:
-        batch_op.add_column(
-            sa.Column(
-                "use_celery",
-                sa.Boolean(),
-                server_default=sa.text("false"),
-                nullable=False,
-            )
-        )

server/reflector/db/meetings.py

@@ -346,6 +346,27 @@ class MeetingController:
             return None
         return Meeting(**result)
 
+    async def get_by_room_and_time_window(
+        self, room: Room, start_date: datetime, end_date: datetime
+    ) -> Meeting | None:
+        """Check if a meeting already exists for this room with the same time window."""
+        query = (
+            meetings.select()
+            .where(
+                sa.and_(
+                    meetings.c.room_id == room.id,
+                    meetings.c.start_date == start_date,
+                    meetings.c.end_date == end_date,
+                    meetings.c.is_active,
+                )
+            )
+            .limit(1)
+        )
+        result = await get_database().fetch_one(query)
+        if not result:
+            return None
+        return Meeting(**result)
+
     async def update_meeting(self, meeting_id: str, **kwargs):
         query = meetings.update().where(meetings.c.id == meeting_id).values(**kwargs)
         await get_database().execute(query)

server/reflector/db/rooms.py

@@ -57,6 +57,12 @@ rooms = sqlalchemy.Table(
         sqlalchemy.String,
         nullable=False,
     ),
+    sqlalchemy.Column(
+        "use_celery",
+        sqlalchemy.Boolean,
+        nullable=False,
+        server_default=false(),
+    ),
     sqlalchemy.Column(
         "skip_consent",
         sqlalchemy.Boolean,
@@ -91,6 +97,7 @@ class Room(BaseModel):
     ics_last_sync: datetime | None = None
     ics_last_etag: str | None = None
     platform: Platform = Field(default_factory=lambda: settings.DEFAULT_VIDEO_PLATFORM)
+    use_celery: bool = False
     skip_consent: bool = False
 
 

server/reflector/services/transcript_process.py

@@ -15,10 +15,14 @@ from hatchet_sdk.clients.rest.exceptions import ApiException, NotFoundException
 from hatchet_sdk.clients.rest.models import V1TaskStatus
 
 from reflector.db.recordings import recordings_controller
+from reflector.db.rooms import rooms_controller
 from reflector.db.transcripts import Transcript, transcripts_controller
 from reflector.hatchet.client import HatchetClientManager
 from reflector.logger import logger
 from reflector.pipelines.main_file_pipeline import task_pipeline_file_process
+from reflector.pipelines.main_multitrack_pipeline import (
+    task_pipeline_multitrack_process,
+)
 from reflector.utils.string import NonEmptyString
 
 
@@ -177,7 +181,21 @@ async def dispatch_transcript_processing(
     Returns AsyncResult for Celery tasks, None for Hatchet workflows.
     """
     if isinstance(config, MultitrackProcessingConfig):
-        # Multitrack processing always uses Hatchet (no Celery fallback)
+        use_celery = False
+        if config.room_id:
+            room = await rooms_controller.get_by_id(config.room_id)
+            use_celery = room.use_celery if room else False
+
+        use_hatchet = not use_celery
+
+        if use_celery:
+            logger.info(
+                "Room uses legacy Celery processing",
+                room_id=config.room_id,
+                transcript_id=config.transcript_id,
+            )
+
+        if use_hatchet:
             # First check if we can replay (outside transaction since it's read-only)
             transcript = await transcripts_controller.get_by_id(config.transcript_id)
             if transcript and transcript.workflow_run_id and not force:
@@ -185,7 +203,9 @@ async def dispatch_transcript_processing(
                     transcript.workflow_run_id
                 )
                 if can_replay:
-                await HatchetClientManager.replay_workflow(transcript.workflow_run_id)
+                    await HatchetClientManager.replay_workflow(
+                        transcript.workflow_run_id
+                    )
                     logger.info(
                         "Replaying Hatchet workflow",
                         workflow_id=transcript.workflow_run_id,
@@ -213,7 +233,9 @@ async def dispatch_transcript_processing(
             # Force: cancel old workflow if exists
             if force and transcript and transcript.workflow_run_id:
                 try:
-                await HatchetClientManager.cancel_workflow(transcript.workflow_run_id)
+                    await HatchetClientManager.cancel_workflow(
+                        transcript.workflow_run_id
+                    )
                     logger.info(
                         "Cancelled old workflow (--force)",
                         workflow_id=transcript.workflow_run_id,
@@ -223,7 +245,9 @@ async def dispatch_transcript_processing(
                         "Old workflow already deleted (--force)",
                         workflow_id=transcript.workflow_run_id,
                     )
-            await transcripts_controller.update(transcript, {"workflow_run_id": None})
+                await transcripts_controller.update(
+                    transcript, {"workflow_run_id": None}
+                )
 
             # Re-fetch and check for concurrent dispatch (optimistic approach).
             # No database lock - worst case is duplicate dispatch, but Hatchet
@@ -269,6 +293,12 @@ async def dispatch_transcript_processing(
             logger.info("Hatchet workflow dispatched", workflow_id=workflow_id)
             return None
 
+        # Celery pipeline (durable workflows disabled)
+        return task_pipeline_multitrack_process.delay(
+            transcript_id=config.transcript_id,
+            bucket_name=config.bucket_name,
+            track_keys=config.track_keys,
+        )
     elif isinstance(config, FileProcessingConfig):
         return task_pipeline_file_process.delay(transcript_id=config.transcript_id)
     else:

server/reflector/settings.py

@@ -1,7 +1,7 @@
 from pydantic.types import PositiveInt
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
-from reflector.schemas.platform import DAILY_PLATFORM, Platform
+from reflector.schemas.platform import WHEREBY_PLATFORM, Platform
 from reflector.utils.string import NonEmptyString
 
 
@@ -155,7 +155,7 @@ class Settings(BaseSettings):
         None  # Webhook UUID for this environment. Not used by production code
     )
     # Platform Configuration
-    DEFAULT_VIDEO_PLATFORM: Platform = DAILY_PLATFORM
+    DEFAULT_VIDEO_PLATFORM: Platform = WHEREBY_PLATFORM
 
     # Zulip integration
     ZULIP_REALM: str | None = None

server/reflector/worker/ics_sync.py

@@ -5,7 +5,7 @@ from celery import shared_task
 from celery.utils.log import get_task_logger
 
 from reflector.asynctask import asynctask
-from reflector.db.calendar_events import calendar_events_controller
+from reflector.db.calendar_events import CalendarEvent, calendar_events_controller
 from reflector.db.meetings import meetings_controller
 from reflector.db.rooms import Room, rooms_controller
 from reflector.redis_cache import RedisAsyncLock
@@ -83,10 +83,9 @@ def _should_sync(room) -> bool:
     return time_since_sync.total_seconds() >= room.ics_fetch_interval
 
 
-MEETING_DEFAULT_DURATION = timedelta(hours=1)
-
-
-async def create_upcoming_meetings_for_event(event, create_window, room: Room):
+async def create_upcoming_meetings_for_event(
+    event: CalendarEvent, create_window: datetime, room: Room
+):
     if event.start_time <= create_window:
         return
     existing_meeting = await meetings_controller.get_by_calendar_event(event.id, room)
@@ -94,6 +93,21 @@ async def create_upcoming_meetings_for_event(event, create_window, room: Room):
     if existing_meeting:
         return
 
+    # Prevent duplicate meetings from aggregated calendar feeds
+    # (e.g. same event appears with different UIDs from Cal.com and Google Calendar)
+    end_date = event.end_time
+    existing_by_time = await meetings_controller.get_by_room_and_time_window(
+        room, event.start_time, end_date
+    )
+    if existing_by_time:
+        logger.info(
+            "Skipping duplicate calendar event - meeting already exists for this time window",
+            room_id=room.id,
+            event_id=event.id,
+            existing_meeting_id=existing_by_time.id,
+        )
+        return
+
     logger.info(
         "Pre-creating meeting for calendar event",
         room_id=room.id,
@@ -102,8 +116,6 @@ async def create_upcoming_meetings_for_event(event, create_window, room: Room):
     )
 
     try:
-        end_date = event.end_time or (event.start_time + MEETING_DEFAULT_DURATION)
-
         client = create_platform_client(room.platform)
 
         meeting_data = await client.create_meeting(

server/reflector/worker/process.py

@@ -27,6 +27,9 @@ from reflector.db.transcripts import (
 from reflector.hatchet.client import HatchetClientManager
 from reflector.pipelines.main_file_pipeline import task_pipeline_file_process
 from reflector.pipelines.main_live_pipeline import asynctask
+from reflector.pipelines.main_multitrack_pipeline import (
+    task_pipeline_multitrack_process,
+)
 from reflector.pipelines.topic_processing import EmptyPipeline
 from reflector.processors import AudioFileWriterProcessor
 from reflector.processors.audio_waveform_processor import AudioWaveformProcessor
@@ -348,7 +351,17 @@ async def _process_multitrack_recording_inner(
             room_id=room.id,
         )
 
-    # Multitrack processing always uses Hatchet (no Celery fallback)
+    use_celery = room and room.use_celery
+    use_hatchet = not use_celery
+
+    if use_celery:
+        logger.info(
+            "Room uses legacy Celery processing",
+            room_id=room.id,
+            transcript_id=transcript.id,
+        )
+
+    if use_hatchet:
         workflow_id = await HatchetClientManager.start_workflow(
             workflow_name="DiarizationPipeline",
             input_data={
@@ -370,7 +383,17 @@ async def _process_multitrack_recording_inner(
             transcript_id=transcript.id,
         )
 
-    await transcripts_controller.update(transcript, {"workflow_run_id": workflow_id})
+        await transcripts_controller.update(
+            transcript, {"workflow_run_id": workflow_id}
+        )
+        return
+
+    # Celery pipeline (runs when durable workflows disabled)
+    task_pipeline_multitrack_process.delay(
+        transcript_id=transcript.id,
+        bucket_name=bucket_name,
+        track_keys=filter_cam_audio_tracks(track_keys),
+    )
 
 
 @shared_task
@@ -1049,7 +1072,10 @@ async def reprocess_failed_daily_recordings():
                 )
                 continue
 
-            # Multitrack reprocessing always uses Hatchet (no Celery fallback)
+            use_celery = room and room.use_celery
+            use_hatchet = not use_celery
+
+            if use_hatchet:
                 if not transcript:
                     logger.warning(
                         "No transcript for Hatchet reprocessing, skipping",
@@ -1086,6 +1112,26 @@ async def reprocess_failed_daily_recordings():
                     room_name=meeting.room_name,
                     track_count=len(recording.track_keys),
                 )
+            else:
+                logger.info(
+                    "Queueing Daily recording for Celery reprocessing",
+                    recording_id=recording.id,
+                    room_name=meeting.room_name,
+                    track_count=len(recording.track_keys),
+                    transcript_status=transcript.status if transcript else None,
+                )
+
+                # For reprocessing, pass actual recording time (though it's ignored - see _process_multitrack_recording_inner)
+                # Reprocessing uses recording.meeting_id directly instead of time-based matching
+                recording_start_ts = int(recording.recorded_at.timestamp())
+
+                process_multitrack_recording.delay(
+                    bucket_name=bucket_name,
+                    daily_room_name=meeting.room_name,
+                    recording_id=recording.id,
+                    track_keys=recording.track_keys,
+                    recording_start_ts=recording_start_ts,
+                )
 
             reprocessed_count += 1
 

server/tests/conftest.py

@@ -4,7 +4,7 @@ from unittest.mock import patch
 
 import pytest
 
-from reflector.schemas.platform import DAILY_PLATFORM, WHEREBY_PLATFORM
+from reflector.schemas.platform import WHEREBY_PLATFORM
 
 
 @pytest.fixture(scope="session", autouse=True)
@@ -14,7 +14,6 @@ def register_mock_platform():
     from reflector.video_platforms.registry import register_platform
 
     register_platform(WHEREBY_PLATFORM, MockPlatformClient)
-    register_platform(DAILY_PLATFORM, MockPlatformClient)
     yield
 
 

server/tests/test_ics_dedup.py

@@ -0,0 +1,190 @@
+from datetime import datetime, timedelta, timezone
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from reflector.db import get_database
+from reflector.db.calendar_events import CalendarEvent, calendar_events_controller
+from reflector.db.meetings import meetings
+from reflector.db.rooms import rooms_controller
+from reflector.worker.ics_sync import create_upcoming_meetings_for_event
+
+
+@pytest.mark.asyncio
+async def test_duplicate_calendar_event_does_not_create_duplicate_meeting():
+    """When an aggregated ICS feed contains the same event with different UIDs
+    (e.g. Cal.com UID + Google Calendar UUID), only one meeting should be created."""
+
+    room = await rooms_controller.add(
+        name="dedup-test-room",
+        user_id="test-user",
+        zulip_auto_post=False,
+        zulip_stream="",
+        zulip_topic="",
+        is_locked=False,
+        room_mode="normal",
+        recording_type="cloud",
+        recording_trigger="automatic-2nd-participant",
+        is_shared=False,
+        ics_url="https://calendar.example.com/dedup.ics",
+        ics_enabled=True,
+    )
+
+    now = datetime.now(timezone.utc)
+    start_time = now + timedelta(hours=1)
+    end_time = now + timedelta(hours=2)
+
+    # Create first calendar event (Cal.com UID)
+    event1 = await calendar_events_controller.upsert(
+        CalendarEvent(
+            room_id=room.id,
+            ics_uid="abc123@Cal.com",
+            title="Team Standup",
+            start_time=start_time,
+            end_time=end_time,
+        )
+    )
+
+    # create_window must be before start_time for the function to proceed
+    create_window = now - timedelta(minutes=6)
+
+    # Create meeting for event1
+    with patch(
+        "reflector.worker.ics_sync.create_platform_client"
+    ) as mock_platform_factory:
+        mock_client = AsyncMock()
+
+        async def mock_create_meeting_1(room_name_prefix, *, end_date, room):
+            return AsyncMock(
+                meeting_id="meeting-1",
+                room_name="dedup-test-room-abc",
+                room_url="https://mock.video/dedup-test-room-abc",
+                host_room_url="https://mock.video/dedup-test-room-abc?host=true",
+            )
+
+        mock_client.create_meeting = mock_create_meeting_1
+        mock_client.upload_logo = AsyncMock()
+        mock_platform_factory.return_value = mock_client
+
+        await create_upcoming_meetings_for_event(event1, create_window, room)
+
+    # Verify meeting was created
+    results = await get_database().fetch_all(
+        meetings.select().where(meetings.c.room_id == room.id)
+    )
+    assert len(results) == 1, f"Expected 1 meeting, got {len(results)}"
+
+    # Create second calendar event with different UID but same time window (Google Calendar UUID)
+    event2 = await calendar_events_controller.upsert(
+        CalendarEvent(
+            room_id=room.id,
+            ics_uid="550e8400-e29b-41d4-a716-446655440000",
+            title="Team Standup",
+            start_time=start_time,
+            end_time=end_time,
+        )
+    )
+
+    # Try to create meeting for event2 - should be skipped due to dedup
+    with patch(
+        "reflector.worker.ics_sync.create_platform_client"
+    ) as mock_platform_factory:
+        mock_client = AsyncMock()
+        create_meeting_called = False
+
+        async def mock_create_meeting_2(room_name_prefix, *, end_date, room):
+            nonlocal create_meeting_called
+            create_meeting_called = True
+
+        mock_client.create_meeting = mock_create_meeting_2
+        mock_client.upload_logo = AsyncMock()
+        mock_platform_factory.return_value = mock_client
+
+        await create_upcoming_meetings_for_event(event2, create_window, room)
+
+        # Platform client should NOT have been called for the duplicate
+        assert (
+            not create_meeting_called
+        ), "create_meeting should not be called for duplicate"
+
+    # Verify still only 1 meeting
+    results = await get_database().fetch_all(
+        meetings.select().where(meetings.c.room_id == room.id)
+    )
+    assert len(results) == 1, f"Expected 1 meeting after dedup, got {len(results)}"
+
+
+@pytest.mark.asyncio
+async def test_different_time_windows_create_separate_meetings():
+    """Events at different times should create separate meetings, even if titles match."""
+
+    room = await rooms_controller.add(
+        name="dedup-diff-time-room",
+        user_id="test-user",
+        zulip_auto_post=False,
+        zulip_stream="",
+        zulip_topic="",
+        is_locked=False,
+        room_mode="normal",
+        recording_type="cloud",
+        recording_trigger="automatic-2nd-participant",
+        is_shared=False,
+        ics_url="https://calendar.example.com/dedup2.ics",
+        ics_enabled=True,
+    )
+
+    now = datetime.now(timezone.utc)
+    create_window = now - timedelta(minutes=6)
+
+    # Event 1: 1-2pm
+    event1 = await calendar_events_controller.upsert(
+        CalendarEvent(
+            room_id=room.id,
+            ics_uid="event-morning@Cal.com",
+            title="Team Standup",
+            start_time=now + timedelta(hours=1),
+            end_time=now + timedelta(hours=2),
+        )
+    )
+
+    # Event 2: 3-4pm (different time)
+    event2 = await calendar_events_controller.upsert(
+        CalendarEvent(
+            room_id=room.id,
+            ics_uid="event-afternoon@Cal.com",
+            title="Team Standup",
+            start_time=now + timedelta(hours=3),
+            end_time=now + timedelta(hours=4),
+        )
+    )
+
+    with patch(
+        "reflector.worker.ics_sync.create_platform_client"
+    ) as mock_platform_factory:
+        mock_client = AsyncMock()
+
+        call_count = 0
+
+        async def mock_create_meeting(room_name_prefix, *, end_date, room):
+            nonlocal call_count
+            call_count += 1
+            return AsyncMock(
+                meeting_id=f"meeting-{call_count}",
+                room_name=f"dedup-diff-time-room-{call_count}",
+                room_url=f"https://mock.video/dedup-diff-time-room-{call_count}",
+                host_room_url=f"https://mock.video/dedup-diff-time-room-{call_count}?host=true",
+            )
+
+        mock_client.create_meeting = mock_create_meeting
+        mock_client.upload_logo = AsyncMock()
+        mock_platform_factory.return_value = mock_client
+
+        await create_upcoming_meetings_for_event(event1, create_window, room)
+        await create_upcoming_meetings_for_event(event2, create_window, room)
+
+    results = await get_database().fetch_all(
+        meetings.select().where(meetings.c.room_id == room.id)
+    )
+    assert (
+        len(results) == 2
+    ), f"Expected 2 meetings for different times, got {len(results)}"

server/tests/test_transcripts_process.py

@@ -1,6 +1,6 @@
 import asyncio
 import time
-from unittest.mock import AsyncMock, patch
+from unittest.mock import patch
 
 import pytest
 from httpx import ASGITransport, AsyncClient
@@ -142,17 +142,17 @@ async def test_whereby_recording_uses_file_pipeline(client):
             "reflector.services.transcript_process.task_pipeline_file_process"
         ) as mock_file_pipeline,
         patch(
-            "reflector.services.transcript_process.HatchetClientManager"
-        ) as mock_hatchet,
+            "reflector.services.transcript_process.task_pipeline_multitrack_process"
+        ) as mock_multitrack_pipeline,
     ):
         response = await client.post(f"/transcripts/{transcript.id}/process")
 
         assert response.status_code == 200
         assert response.json()["status"] == "ok"
 
-        # Whereby recordings should use file pipeline, not Hatchet
+        # Whereby recordings should use file pipeline
         mock_file_pipeline.delay.assert_called_once_with(transcript_id=transcript.id)
-        mock_hatchet.start_workflow.assert_not_called()
+        mock_multitrack_pipeline.delay.assert_not_called()
 
 
 @pytest.mark.usefixtures("setup_database")
@@ -177,6 +177,8 @@ async def test_dailyco_recording_uses_multitrack_pipeline(client):
         recording_trigger="automatic-2nd-participant",
         is_shared=False,
     )
+    # Force Celery backend for test
+    await rooms_controller.update(room, {"use_celery": True})
 
     transcript = await transcripts_controller.add(
         "",
@@ -211,23 +213,18 @@ async def test_dailyco_recording_uses_multitrack_pipeline(client):
             "reflector.services.transcript_process.task_pipeline_file_process"
         ) as mock_file_pipeline,
         patch(
-            "reflector.services.transcript_process.HatchetClientManager"
-        ) as mock_hatchet,
+            "reflector.services.transcript_process.task_pipeline_multitrack_process"
+        ) as mock_multitrack_pipeline,
     ):
-        mock_hatchet.start_workflow = AsyncMock(return_value="test-workflow-id")
-
         response = await client.post(f"/transcripts/{transcript.id}/process")
 
         assert response.status_code == 200
         assert response.json()["status"] == "ok"
 
-        # Daily.co multitrack recordings should use Hatchet workflow
-        mock_hatchet.start_workflow.assert_called_once()
-        call_kwargs = mock_hatchet.start_workflow.call_args.kwargs
-        assert call_kwargs["workflow_name"] == "DiarizationPipeline"
-        assert call_kwargs["input_data"]["transcript_id"] == transcript.id
-        assert call_kwargs["input_data"]["bucket_name"] == "daily-bucket"
-        assert call_kwargs["input_data"]["tracks"] == [
-            {"s3_key": k} for k in track_keys
-        ]
+        # Daily.co multitrack recordings should use multitrack pipeline
+        mock_multitrack_pipeline.delay.assert_called_once_with(
+            transcript_id=transcript.id,
+            bucket_name="daily-bucket",
+            track_keys=track_keys,
+        )
         mock_file_pipeline.delay.assert_not_called()

www/app/[roomName]/components/DailyRoom.tsx

@@ -8,7 +8,7 @@ import {
   useRef,
   useState,
 } from "react";
-import { Box, Spinner, Center, Text } from "@chakra-ui/react";
+import { Box, Spinner, Center, Text, Button, VStack } from "@chakra-ui/react";
 import { useRouter, useParams } from "next/navigation";
 import DailyIframe, {
   DailyCall,
@@ -16,10 +16,13 @@ import DailyIframe, {
   DailyCustomTrayButton,
   DailyCustomTrayButtons,
   DailyEventObjectCustomButtonClick,
+  DailyEventObjectFatalError,
+  DailyFatalErrorType,
   DailyFactoryOptions,
   DailyParticipantsObject,
 } from "@daily-co/daily-js";
 import type { components } from "../../reflector-api";
+import { printApiError, ApiError } from "../../api/_error";
 import { useAuth } from "../../lib/AuthProvider";
 import { useConsentDialog } from "../../lib/consent";
 import {
@@ -45,6 +48,63 @@ const RAW_TRACKS_NAMESPACE = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";
 const RECORDING_START_DELAY_MS = 2000;
 const RECORDING_START_MAX_RETRIES = 5;
 
+const FATAL_ERROR_MESSAGES: Partial<
+  Record<DailyFatalErrorType, { message: string; rejoinable?: boolean }>
+> = {
+  "connection-error": {
+    message: "Connection lost. Please check your network.",
+    rejoinable: true,
+  },
+  "exp-room": { message: "The meeting time has ended." },
+  "exp-token": { message: "Your session has expired.", rejoinable: true },
+  ejected: { message: "You were removed from this meeting." },
+  "meeting-full": { message: "This meeting is full." },
+  "not-allowed": { message: "You are not allowed to join this meeting." },
+  "nbf-room": { message: "This meeting hasn't started yet." },
+  "nbf-token": { message: "This meeting hasn't started yet." },
+  "no-room": { message: "This room does not exist." },
+  "end-of-life": { message: "This meeting room is no longer available." },
+};
+
+function FatalErrorScreen({
+  error,
+  roomName,
+}: {
+  error: FatalError;
+  roomName: string;
+}) {
+  const router = useRouter();
+  const info =
+    error.type !== "unknown" ? FATAL_ERROR_MESSAGES[error.type] : undefined;
+  const message = info?.message ?? `Something went wrong: ${error.message}`;
+  const rejoinable = info?.rejoinable ?? false;
+
+  return (
+    <Center width="100vw" height="100vh">
+      <VStack gap={4}>
+        <Text color="red.500">{message}</Text>
+        {rejoinable ? (
+          <>
+            <Button onClick={() => window.location.reload()}>
+              Try Rejoining
+            </Button>
+            <Button
+              variant="outline"
+              onClick={() => router.push(`/${roomName}`)}
+            >
+              Leave
+            </Button>
+          </>
+        ) : (
+          <Button onClick={() => router.push(`/${roomName}`)}>
+            Back to Room
+          </Button>
+        )}
+      </VStack>
+    </Center>
+  );
+}
+
 type Meeting = components["schemas"]["Meeting"];
 type Room = components["schemas"]["RoomDetails"];
 
@@ -82,6 +142,8 @@ const USE_FRAME_INIT_STATE = {
   joined: false as boolean,
 } as const;
 
+type FatalError = { type: DailyFatalErrorType | "unknown"; message: string };
+
 // Daily js and not Daily react used right now because daily-js allows for prebuild interface vs. -react is customizable but has no nice defaults
 const useFrame = (
   container: HTMLDivElement | null,
@@ -89,6 +151,7 @@ const useFrame = (
     onLeftMeeting: () => void;
     onCustomButtonClick: (ev: DailyEventObjectCustomButtonClick) => void;
     onJoinMeeting: () => void;
+    onError: (ev: DailyEventObjectFatalError) => void;
   },
 ) => {
   const [{ frame, joined }, setState] = useState(USE_FRAME_INIT_STATE);
@@ -134,6 +197,7 @@ const useFrame = (
     if (!frame) return;
     frame.on("left-meeting", cbs.onLeftMeeting);
     frame.on("custom-button-click", cbs.onCustomButtonClick);
+    frame.on("error", cbs.onError);
     const joinCb = () => {
       if (!frame) {
         console.error("frame is null in joined-meeting callback");
@@ -145,6 +209,7 @@ const useFrame = (
     return () => {
       frame.off("left-meeting", cbs.onLeftMeeting);
       frame.off("custom-button-click", cbs.onCustomButtonClick);
+      frame.off("error", cbs.onError);
       frame.off("joined-meeting", joinCb);
     };
   }, [frame, cbs]);
@@ -188,6 +253,7 @@ export default function DailyRoom({ meeting, room }: DailyRoomProps) {
   const joinMutation = useRoomJoinMeeting();
   const startRecordingMutation = useMeetingStartRecording();
   const [joinedMeeting, setJoinedMeeting] = useState<Meeting | null>(null);
+  const [fatalError, setFatalError] = useState<FatalError | null>(null);
 
   // Generate deterministic instanceIds so all participants use SAME IDs
   const cloudInstanceId = parseNonEmptyString(meeting.id);
@@ -234,8 +300,18 @@ export default function DailyRoom({ meeting, room }: DailyRoomProps) {
   const roomUrl = joinedMeeting?.room_url;
 
   const handleLeave = useCallback(() => {
+    // If a fatal error occurred, don't redirect — let the error UI show
+    if (fatalError) return;
     router.push("/browse");
-  }, [router]);
+  }, [router, fatalError]);
+
+  const handleError = useCallback((ev: DailyEventObjectFatalError) => {
+    const error: FatalError = {
+      type: ev.error?.type ?? "unknown",
+      message: ev.errorMsg,
+    };
+    setFatalError(error);
+  }, []);
 
   const handleCustomButtonClick = useCallback(
     (ev: DailyEventObjectCustomButtonClick) => {
@@ -324,6 +400,7 @@ export default function DailyRoom({ meeting, room }: DailyRoomProps) {
     onLeftMeeting: handleLeave,
     onCustomButtonClick: handleCustomButtonClick,
     onJoinMeeting: handleFrameJoinMeeting,
+    onError: handleError,
   });
 
   useEffect(() => {
@@ -380,13 +457,27 @@ export default function DailyRoom({ meeting, room }: DailyRoomProps) {
   }
 
   if (joinMutation.isError) {
+    const apiDetail = printApiError(
+      joinMutation.error as /*ref 095959E6-01CC-4CF0-B3A9-F65F12F046D3*/ ApiError,
+    );
     return (
       <Center width="100vw" height="100vh">
-        <Text color="red.500">Failed to join meeting. Please try again.</Text>
+        <VStack gap={4}>
+          <Text color="red.500">
+            {apiDetail ?? "Failed to join meeting. Please try again."}
+          </Text>
+          <Button onClick={() => router.push(`/${roomName}`)}>
+            Back to Room
+          </Button>
+        </VStack>
       </Center>
     );
   }
 
+  if (fatalError) {
+    return <FatalErrorScreen error={fatalError} roomName={roomName} />;
+  }
+
   if (!roomUrl) {
     return null;
   }

www/app/lib/apiHooks.ts

@@ -9,6 +9,7 @@ import { MeetingId } from "./types";
 import { NonEmptyString } from "./utils";
 
 /*
+ * ref 095959E6-01CC-4CF0-B3A9-F65F12F046D3
  * XXX error types returned from the hooks are not always correct; declared types are ValidationError but real type could be string or any other
  * this is either a limitation or incorrect usage of Python json schema generator
  * or, limitation or incorrect usage of .d type generator from json schema