---
phase: 21-polish-integration
plan: 04
subsystem: ui
tags: [sse, subscriptions, toast, sonner, error-handling, trpc]

# Dependency graph
requires:
  - phase: 21-01
    provides: Toast notification system (sonner Toaster component)
  - phase: 20-02
    provides: SSE subscription hooks on all three pages
provides:
  - Subscription error feedback with sticky toast notifications
  - User awareness when live updates disconnect
affects: [21-06]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Fixed toast ID for deduplication across concurrent subscription errors"
    - "Sticky (Infinity duration) toast for persistent connection state feedback"

key-files:
  created: []
  modified:
    - packages/web/src/routes/initiatives/index.tsx
    - packages/web/src/routes/initiatives/$id.tsx
    - packages/web/src/routes/inbox.tsx

key-decisions:
  - "21-04: Same toast ID 'sub-error' across all subscriptions prevents duplicate error notifications"
  - "21-04: duration: Infinity keeps toast visible until user dismisses — intentionally sticky"
  - "21-04: No reconnection logic added — tRPC SSE httpSubscriptionLink handles reconnection via EventSource retry"
  - "21-04: SpawnArchitectDropdown already covered by 21-01 — Task 2 was a verified no-op"

# Metrics
duration: 2min
completed: 2026-02-05
---

# Phase 21 Plan 04: Subscription Error Handling Summary

**Sticky toast notifications for SSE subscription errors with fixed ID deduplication across all three pages**

## Performance

- **Duration:** 2 min
- **Started:** 2026-02-05
- **Completed:** 2026-02-05
- **Tasks:** 2 (1 implemented, 1 verified no-op)
- **Files modified:** 3

## Accomplishments
- Replaced all silent `onError: () => {}` callbacks with sticky toast notifications on initiatives dashboard, initiative detail, and inbox pages
- Used fixed toast ID `sub-error` so multiple concurrent subscription failures show only one notification
- Verified SpawnArchitectDropdown already has full toast coverage from plan 21-01

## Task Commits

Each task was committed atomically:

1. **Task 1: Add subscription error handling with toast feedback on all pages** - `4ae85da` (feat)
2. **Task 2: Verify SpawnArchitectDropdown error toast coverage** - no-op (21-01 already applied)

## Files Created/Modified
- `packages/web/src/routes/initiatives/index.tsx` - Added toast import, replaced onError with error toast
- `packages/web/src/routes/initiatives/$id.tsx` - Added toast import, replaced both onError callbacks with error toast
- `packages/web/src/routes/inbox.tsx` - Replaced onError with error toast (toast already imported)

## Decisions Made
- Same toast ID `sub-error` across all subscriptions prevents duplicate error notifications when multiple subscriptions fail simultaneously
- `duration: Infinity` keeps toast visible until user dismisses it — intentionally sticky so users know live updates are broken
- No reconnection logic added — tRPC SSE httpSubscriptionLink already handles reconnection via EventSource retry
- SpawnArchitectDropdown was already fully covered by 21-01 (toast.error on onError, toast.success on onSuccess for both mutations)

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- Ready for 21-05-PLAN.md (Code Splitting & Performance)
- All subscription error handling in place
- No blockers

---
*Phase: 21-polish-integration*
*Completed: 2026-02-05*
