nexus/.planning/milestones/v1.3-phases/26-pwa-performance/26-04-SUMMARY.md

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phase: 26-pwa-performance plan: "04" subsystem: api, database, ui tags: [push-notifications, web-push, vapid, service-worker, pwa, drizzle, postgres]

requires:

• phase: 26-00 provides: Service worker push event handler and idb infrastructure
• phase: 26-02 provides: MobileChatView and responsive layout modifications to ChatPanel
• phase: 26-03 provides: InstallPromptBanner and OfflineBanner already rendered in ChatPanel

provides:

• push_subscriptions PostgreSQL table via pgTable drizzle schema
• 0055_create_push_subscriptions.sql migration
• pushService with initVapid, saveSubscription, removeSubscription, sendPushToAll
• pushRoutes mounted at /api/push (GET vapid-public-key, POST/DELETE subscribe)
• ui/src/api/push.ts client API module
• ui/src/hooks/usePushNotifications.ts subscription hook with SW pushManager
• ui/src/components/NotificationPermissionPrompt.tsx with engagement gate

affects:

• Any future phase triggering push notifications on agent events
• Plan 26-05 (final PWA plan, if any)

tech-stack: added: - web-push 3.x (server VAPID + push protocol) - "@types/web-push" (TypeScript types) - idb 8.x (installed for UI to fix missing 26-00 dependency) patterns: - pushService functions (not class) matching existing service pattern - Graceful VAPID skip when env vars not configured - Auto-delete stale 410/404 push subscriptions on send failure - Engagement gate (agentResponseCount >= 3) before showing permission prompt - localStorage nexus.notifPromptDismissed for dismiss persistence

key-files: created: - packages/db/src/schema/push_subscriptions.ts - packages/db/src/migrations/0055_create_push_subscriptions.sql - server/src/services/pushService.ts - server/src/routes/push.ts - ui/src/api/push.ts - ui/src/hooks/usePushNotifications.ts - ui/src/components/NotificationPermissionPrompt.tsx modified: - packages/db/src/schema/index.ts - server/src/app.ts - ui/src/components/ChatPanel.tsx - pnpm-lock.yaml

key-decisions:

• "pushService uses named exports (not class) matching existing chat.ts service pattern"
• "initVapid is graceful — checks env vars before calling setVapidDetails, logs warning if absent"
• "sendPushToAll uses Promise.allSettled so one failed delivery doesn't block others"
• "Stale subscriptions auto-deleted on 410/404 response per RESEARCH Pitfall 6"
• "DELETE /api/push/subscribe uses request body (not URL param) since endpoints can be long URLs"
• "ui/src/api/push.ts uses direct fetch for DELETE with body — api client only supports parameterless DELETE"
• "agentResponseCount derived via useMemo from messages array with role === assistant filter"
• "urlBase64ToUint8Array uses .buffer as ArrayBuffer cast for TypeScript strict mode compatibility"
• "idb installed as explicit ui dependency — was missing from 26-00 causing build failure"

patterns-established:

• "Push routes pattern: pushRoutes(db) returning Express Router, mounted at /api/push"
• "VAPID init at app startup, wrapped in try/catch for graceful degradation"
• "Notification engagement gate: check agentResponseCount >= 3 before showing prompt"

requirements-completed:

• PWA-06

duration: 15min completed: 2026-04-02

Phase 26 Plan 04: Push Notifications Summary

End-to-end web push notifications: PostgreSQL push_subscriptions table, VAPID server service, /api/push routes, SW pushManager subscription hook, and engagement-gated permission prompt

Performance

• Duration: ~15 min
• Started: 2026-04-02T02:27:38Z
• Completed: 2026-04-02T02:42:00Z
• Tasks: 2
• Files modified: 10

Accomplishments

• Push subscription DB table with pg-core schema (uuid, text, timestamp with timezone), index on endpoint
• Server-side VAPID management via web-push library — initVapid() called at startup, graceful skip if env vars absent
• Three push API routes: GET vapid-public-key, POST subscribe, DELETE subscribe — stale 410/404 endpoints auto-cleaned
• Client hook (usePushNotifications) handles permission request + SW pushManager.subscribe + server sync
• NotificationPermissionPrompt renders after 3rd agent response, respects localStorage dismiss state
• Fixed pre-existing missing idb dependency that was blocking UI build

Task Commits

1. Task 1: Backend — schema, migration, pushService, push routes - ad4cc035 (feat)
2. Task 2: Frontend — push API client, hook, prompt, ChatPanel update - 57d7a730 (feat)

Files Created/Modified

• packages/db/src/schema/push_subscriptions.ts - pgTable with endpoint, p256dh, auth, userId, companyId, deviceLabel
• packages/db/src/migrations/0055_create_push_subscriptions.sql - CREATE TABLE + endpoint index
• packages/db/src/schema/index.ts - Added export for pushSubscriptions
• server/src/services/pushService.ts - initVapid, getVapidPublicKey, saveSubscription, removeSubscription, sendPushToAll
• server/src/routes/push.ts - Express Router with GET /vapid-public-key, POST /subscribe, DELETE /subscribe
• server/src/app.ts - Import + mount pushRoutes at /api/push, call initVapid() at startup
• ui/src/api/push.ts - pushApi client with getVapidPublicKey, subscribe, unsubscribe methods
• ui/src/hooks/usePushNotifications.ts - Hook with urlBase64ToUint8Array, pushManager.subscribe flow
• ui/src/components/NotificationPermissionPrompt.tsx - Engagement-gated permission prompt with "Stay in the loop"
• ui/src/components/ChatPanel.tsx - Added agentResponseCount + rendered NotificationPermissionPrompt

Decisions Made

• pushService uses named function exports (not a class), matching the existing chatService pattern
• initVapid() checks env vars before calling webPush.setVapidDetails — no crash if unconfigured
• sendPushToAll uses Promise.allSettled so one failed delivery doesn't block others
• Stale 410/404 subscriptions are auto-deleted during send via removeSubscription
• DELETE /api/push/subscribe uses request body rather than URL param (endpoints are long URLs)
• ui/src/api/push.ts uses a direct fetch for DELETE with body since api.delete() has no body support
• agentResponseCount derived via useMemo filtering messages by role === "assistant"
• urlBase64ToUint8Array returns .buffer as ArrayBuffer cast for TypeScript strict-mode applicationServerKey

Deviations from Plan

Auto-fixed Issues

1. [Rule 1 - Bug] Fixed TypeScript error in usePushNotifications.ts

• Found during: Task 2 — UI build
• Issue: Uint8Array<ArrayBufferLike> is not assignable to applicationServerKey type in strict TypeScript
• Fix: Changed urlBase64ToUint8Array(publicKey) to urlBase64ToUint8Array(publicKey).buffer as ArrayBuffer
• Files modified: ui/src/hooks/usePushNotifications.ts
• Verification: UI build passes after fix
• Committed in: 57d7a730 (Task 2 commit)

2. [Rule 3 - Blocking] Installed missing idb dependency for UI

• Found during: Task 2 — UI build (pre-existing issue from plan 26-00 dependencies)
• Issue: useOfflineQueue.ts imports idb but package was not installed in ui/package.json
• Fix: pnpm --filter @paperclipai/ui add idb
• Files modified: ui/package.json, pnpm-lock.yaml
• Verification: UI build passes after installing idb
• Committed in: 57d7a730 (Task 2 commit)

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Total deviations: 2 auto-fixed (1 bug, 1 blocking dependency) Impact on plan: Both fixes necessary for the build to succeed. No scope creep.

Issues Encountered

• Pre-existing TypeScript errors in server/src/services/plugin-host-services.ts and missing @paperclipai/plugin-sdk module caused server build to fail, but these are unrelated to push notifications — verified no TS errors in new files specifically

User Setup Required

Push notifications require VAPID keys configured as environment variables:

• VAPID_PUBLIC_KEY — VAPID public key (base64url)
• VAPID_PRIVATE_KEY — VAPID private key (base64url)
• VAPID_SUBJECT — Contact email, e.g. mailto:admin@nexus.local (defaults to this if unset)

Generate with: npx web-push generate-vapid-keys

Server initializes gracefully without these keys (push features disabled, no crash).

Next Phase Readiness

• Push notification infrastructure complete end-to-end
• Server can send push notifications to all subscriptions via sendPushToAll(db, companyId, payload)
• Client subscribes through SW pushManager after user grants permission
• Permission prompt appears after 3rd agent response, respects user dismiss state
• Phase 26 plan 05 (if any) can trigger push notifications on agent events using pushService

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Phase: 26-pwa-performance Completed: 2026-04-02