haos-hacs-immich-album-watcher/plans/primary-plan.md

Immich Watcher: Standalone Web App + Shared Core Architecture

Status: Planning Created: 2026-03-19

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Context

The current immich_album_watcher HA integration contains ~3,600 lines of tightly coupled code: Immich API client, change detection, Telegram notifications, and HA entities/services. A separate HA Blueprint (~2,000 lines) adds message templating, filtering, scheduled notifications, and memory mode.

Goal: Enable Immich album change notifications without Home Assistant via a standalone web application, while keeping the HAOS integration functional and sharing as much logic as possible.

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Decisions

Decision	Choice	Rationale
Architecture	Hybrid (Option C)	HAOS standalone with shared core lib, optional server sync. No breaking changes for HA-only users.
Frontend	SvelteKit + Shadcn-svelte	Small bundle, fast, calm UI aesthetic. Good fit for self-hosted.
Notifications	Telegram + Generic webhook	Telegram from existing code. Webhook enables Discord/Slack/ntfy/custom.
Auth	Multi-user (admin/user roles)	Supports shared Immich servers. Admin manages servers/users, users manage own trackers.
Backend	FastAPI + SQLite + APScheduler	Async-native Python, zero external DB deps, proven scheduler.

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Repository Structure

immich-watcher/
  packages/
    core/                              # Shared Python library
      pyproject.toml
      src/immich_watcher_core/
        immich_client.py               # Immich API (from coordinator.py)
        models.py                      # AssetInfo, AlbumData, AlbumChange, SharedLinkInfo
        change_detector.py             # Change detection (from coordinator.py)
        telegram/
          client.py                    # Telegram Bot API (from sensor.py)
          cache.py                     # File cache with pluggable backend
          media.py                     # Media download, size checks, group splitting
        webhook/
          client.py                    # Generic webhook notification provider
        templates.py                   # Jinja2 template engine
        storage.py                     # Abstract storage protocol + SQLite impl
        constants.py                   # Shared constants (from const.py)
      tests/

    server/                            # Standalone FastAPI app
      pyproject.toml
      src/immich_watcher_server/
        main.py                        # FastAPI entry point
        database/models.py             # SQLModel ORM
        database/migrations/           # Alembic
        api/                           # REST endpoints
        services/
          scheduler.py                 # APScheduler background polling
          watcher.py                   # Album polling orchestrator
          notifier.py                  # Notification dispatch
      Dockerfile
      docker-compose.yml

    haos/                              # Home Assistant integration (moved)
      custom_components/immich_album_watcher/
        ... (refactored to use core library)
      hacs.json

  frontend/                            # SvelteKit web UI source
    package.json
    src/
    dist/                              # Built static files served by FastAPI

  plans/                               # This folder
  README.md
  LICENSE

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Shared Core Library Extractions

Core Module	Source File	What Gets Extracted
immich_client.py	coordinator.py	All /api/ calls, session injection via constructor
models.py	coordinator.py L66-326	Dataclasses (already HA-independent)
change_detector.py	coordinator.py L979-1066	detect_album_changes() pure function
telegram/client.py	sensor.py (~1200 lines)	Full Telegram Bot API: send_message/photo/video/media_group
telegram/cache.py	storage.py	TelegramFileCache with CacheBackend protocol
templates.py	NEW (from blueprint logic)	Jinja2 renderer with ~40 variables matching blueprint
storage.py	storage.py	Abstract protocol + SQLite implementation
webhook/client.py	NEW	Generic webhook POST JSON with event data

The ImmichClient accepts an aiohttp.ClientSession in constructor -- HA provides its managed session, standalone creates its own.

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Standalone Server Design

Backend: FastAPI + SQLite + APScheduler

Database tables: users, immich_servers, notification_targets, message_templates, album_trackers, album_states, telegram_cache, notification_queue

Key API endpoints:

• POST /api/auth/setup / POST /api/auth/login -- JWT auth
• CRUD /api/servers -- Immich server connections
• GET /api/servers/{id}/albums -- Fetch album list from Immich
• CRUD /api/trackers -- Album trackers (album selection, event types, template overrides, targets)
• CRUD /api/templates -- Message templates with preview
• CRUD /api/targets -- Notification targets (Telegram chats, webhooks)
• CRUD /api/users -- User management (admin only)
• GET /api/status -- Dashboard data

Background: APScheduler runs one job per tracker at its scan interval. Each job: fetch album -> detect changes -> render template -> dispatch notification.

Frontend: SvelteKit + Shadcn-svelte

Pages:

1. Setup wizard -- First-run: create admin account, connect Immich server
2. Login -- Username/password
3. Dashboard -- Active trackers overview, recent events timeline, server status
4. Servers -- Add/edit Immich server connections (URL + API key validation)
5. Trackers -- Create/edit album trackers:
   • Album picker (multi-select, fetched from Immich)
   • Event type toggles (assets added/removed, renamed, sharing changed, deleted)
   • Notification target selection
   • Template selection or per-tracker override
   • Scan interval, quiet hours
6. Templates -- Jinja2 template editor:
   • CodeMirror with Jinja2 syntax highlighting
   • Live preview with sample album data
   • Variable reference sidebar
   • Default templates for common use cases
7. Targets -- Manage notification destinations (Telegram chats, webhooks)
8. Users -- User management (admin only)
9. Settings -- Global defaults

Auth: Multi-user, bcrypt + JWT

• Multiple user accounts with admin/user roles
• Admin: full access (user management, server configuration)
• User: manage own trackers, templates, and targets
• First-run setup creates initial admin account

Deployment: Single Docker container, SQLite in mounted volume

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HAOS Integration Changes

The integration gets refactored to delegate to core:

# coordinator.py becomes thin wrapper
class ImmichAlbumWatcherCoordinator(DataUpdateCoordinator):
    def __init__(self, ...):
        self._client = ImmichClient(session, url, api_key)  # from core

    async def _async_update_data(self):
        album = await self._client.get_album(self._album_id)
        change = detect_album_changes(old, album, pending)  # from core
        if change: self._fire_events(change, album)          # HA-specific
        return album

# sensor.py Telegram methods delegate to core
async def _execute_telegram_notification(self, ...):
    telegram = TelegramClient(session, token, cache)  # from core
    return await telegram.send_notification(...)

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Phases

Rule 1: Before starting work on any phase, create a detailed trackable subplan at plans/phase-N-<name>.md with granular tasks, specific files to create/modify, and acceptance criteria. Do not begin implementation until the subplan is reviewed.

Rule 2: After completing each phase, perform a detailed code review of all changes. Use the code-reviewer agent to check for bugs, logic errors, security vulnerabilities, code quality issues, and adherence to project conventions. Document review findings in the phase subplan under a "## Review" section and fix any issues before committing.

Phase 1: Extract Core Library [x]

• Extract models, Immich client, change detection, Telegram client, cache into packages/core/
• Write unit tests for all extracted modules
• Subplan: plans/phase-1-core-library.md

Phase 2: Wire Core into HAOS Integration [x]

• Move integration to packages/haos/
• Refactor coordinator.py, sensor.py, storage.py to use core library
• Update manifest.json, hacs.json for new structure
• Verify identical behavior with real Immich server
• Subplan: plans/phase-2-haos-refactor.md

Phase 3: Build Server Backend [x]

• FastAPI app with database, scheduler, API endpoints
• Telegram + webhook notification providers
• Jinja2 template engine with variable system matching blueprint
• Subplan: plans/phase-3-server-backend.md

Phase 4: Build Frontend [x]

• SvelteKit app with all pages (setup, dashboard, trackers, templates, targets, users)
• Template editor with live preview
• Album picker connected to Immich API
• Subplan: plans/phase-4-frontend.md

Phase 5: HAOS-Server Sync (Optional) [ ]

• Add optional server URL to HA config flow
• Implement tracker/template config sync
• Subplan: plans/phase-5-haos-server-sync.md

Phase 6: Claude AI Telegram Bot Enhancement (Optional) [ ]

• Integrate Claude AI to enhance the Telegram notification bot
• Enable conversational interactions: users can ask questions about their albums, get summaries, request specific photos
• AI-powered message formatting: intelligent caption generation, album descriptions
• Smart notification filtering: AI decides notification importance/relevance
• Natural language tracker configuration via Telegram chat
• Subplan: plans/phase-6-claude-ai-bot.md

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Verification

1. Core library: Unit tests for Immich client (mocked HTTP), change detection (pure function), Telegram client (mocked API), template rendering
2. HAOS integration: After refactoring, verify all existing entities, services, and events work identically with a real Immich server
3. Server backend: API integration tests with SQLite in-memory DB, scheduler tests
4. Frontend: Manual testing of all pages, template editor preview, album picker
5. End-to-end: Docker Compose up -> create account -> connect Immich -> create tracker -> trigger album change -> verify notification received