update language hint to reflect any-language support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -6,14 +6,27 @@
 # ---------------------------------------------------------------
 
 # ---------------------------------------------------------------
-# AI Model (via litellm — supports any provider)
+# AI Models (via litellm — supports any provider)
 # ---------------------------------------------------------------
 # Use litellm model strings: "<provider>/<model-name>"
-# Examples:
-#   anthropic/claude-opus-4-6   (default)
-#   openai/gpt-4o
-#   gemini/gemini-2.0-flash
+#
+# AI_MODEL   — primary model for conversation with parents (complex reasoning).
+# SIMPLE_MODEL — lightweight model for simple tasks, e.g. email-label translation.
+#               Can be from a different provider than AI_MODEL.
+#               If unset, falls back to AI_MODEL with a warning in the logs.
+#
+# Examples — mixing providers:
+#   AI_MODEL=gemini/gemini-3-pro-preview   + SIMPLE_MODEL=gemini/gemini-3-flash-preview
+#   AI_MODEL=anthropic/claude-opus-4-6     + SIMPLE_MODEL=anthropic/claude-haiku-4-5-20251001
+#   AI_MODEL=gemini/gemini-3-pro-preview   + SIMPLE_MODEL=anthropic/claude-haiku-4-5-20251001
 AI_MODEL=anthropic/claude-opus-4-6
+SIMPLE_MODEL=anthropic/claude-haiku-4-5-20251001
+
+# Extended thinking — Anthropic models only (leave unset to disable).
+# Enables a reasoning phase before the model's reply, which improves
+# accuracy on age calculations, logic-heavy questions, and edge cases.
+# Recommended value: 8000 (tokens). Must be less than max_tokens.
+# THINKING_BUDGET=8000
 
 # ---------------------------------------------------------------
 # API Keys — set the one matching your chosen model's provider
@@ -67,3 +80,9 @@ KNOWLEDGE_BASE_DIR=openspec/changes/define-project-scope/content/knowledge-base
 # ---------------------------------------------------------------
 # How often (in seconds) to check the inbox for new messages.
 POLL_INTERVAL=60
+
+# ---------------------------------------------------------------
+# Web chat server
+# ---------------------------------------------------------------
+# Listen on all interfaces so the app is reachable from outside localhost.
+CHAINLIT_HOST=0.0.0.0

.gitignore

@@ -20,6 +20,9 @@ env/
 # Agent data (conversations and registrations stored at runtime)
 data/
 
+# Chainlit runtime (auto-generated; not authored)
+.chainlit/
+
 # IDE
 .idea/
 .vscode/

README.md

@@ -85,9 +85,43 @@ GEMINI_API_KEY=...
 
 ## Running
 
-### As a cron job (recommended)
+### Web chat
 
-The agent is a plain script — no long-running daemon needed. Schedule it with cron and use `flock` to prevent overlapping runs:
+Start the web chat interface:
+
+```bash
+uv run chainlit run chat_app.py
+```
+
+The chat opens at **http://localhost:8000** by default.
+
+To listen on a different port or host:
+
+```bash
+uv run chainlit run chat_app.py --port 8080 --host 0.0.0.0
+```
+
+**Minimum required env vars for the web chat:**
+
+| Variable | Description |
+|---|---|
+| `AI_MODEL` | litellm model string, e.g. `anthropic/claude-opus-4-6` |
+| `ANTHROPIC_API_KEY` | (or the key for your chosen provider) |
+| `SMTP_HOST` / `SMTP_PORT` | For admin notification emails on registration completion |
+| `IMAP_USERNAME` / `IMAP_PASSWORD` | Used as SMTP credentials |
+| `ADMIN_EMAIL_INDOOR` | Andrea Sigrist — notified when indoor group is booked |
+| `ADMIN_EMAIL_OUTDOOR` | Barbara Gross — notified when outdoor group is booked |
+| `ADMIN_EMAIL_CC` | Markus Graf — always CC'd on notifications |
+
+IMAP variables (`IMAP_HOST`, etc.) are not required for the web chat — only for the email channel.
+
+### Email channel
+
+The email agent polls an IMAP inbox and replies via SMTP. No web server required.
+
+**As a cron job (recommended)**
+
+Schedule with cron and use `flock` to prevent overlapping runs:
 
 ```cron
 */5 * * * * flock -n /tmp/meister-eder-email.lock uv run python main.py
@@ -95,12 +129,26 @@ The agent is a plain script — no long-running daemon needed. Schedule it with
 
 `flock -n` exits immediately if a previous run is still in progress, so the script is always safe to schedule aggressively.
 
-### Manually
+**Manually**
 
 ```bash
 uv run python main.py
 ```
 
+### Running both channels together
+
+The web chat and email agent are independent processes — run them side by side:
+
+```bash
+# Terminal 1 — web chat
+uv run chainlit run chat_app.py
+
+# Terminal 2 — email polling
+uv run python main.py
+```
+
+Completed registrations from both channels are stored in the same `DATA_DIR` (default: `data/`) and share the same admin notification configuration.
+
 ## Development
 
 ### Running tests

chainlit.md

@@ -0,0 +1,27 @@
+# Spielgruppe Pumuckl
+
+Willkommen beim Anmeldeassistenten der **Spielgruppe Pumuckl** (Familienverein Fällanden).
+
+Ich helfe dir, dein Kind für die Spielgruppe anzumelden — schnell und unkompliziert per Chat.
+
+## Was ich tun kann
+
+- **Anmeldung**: Ich führe dich Schritt für Schritt durch die Anmeldung
+- **Fragen beantworten**: Preise, Zeiten, Reglement — frag einfach
+- **Deutsch oder jede andere Sprache**: Schreib in der Sprache, die dir lieber ist
+
+## Spielgruppen
+
+| | Innenspielgruppe | Waldspielgruppe |
+|---|---|---|
+| **Tage** | Mo / Mi / Do | Mo |
+| **Zeit** | 09:00–11:30 | 09:00–14:00 |
+| **Alter** | ab 2.5 Jahren | ab 3 Jahren |
+
+## Kontakt
+
+Bei Fragen zum Chat oder zur Anmeldung: **spielgruppen@familien-verein.ch**
+
+---
+
+*Für längere Pausen empfehlen wir die Anmeldung per E-Mail, da der Chat-Verlauf nur für die aktuelle Browser-Sitzung gespeichert wird.*

chainlit.toml

@@ -0,0 +1,18 @@
+[project]
+# Project name shown in browser title / header
+name = "Spielgruppe Pumuckl"
+# Never send usage data to Chainlit cloud
+enable_telemetry = false
+
+[UI]
+name = "Spielgruppe Pumuckl"
+# German is the default language; the agent switches automatically to English
+# if the parent writes in English
+default_language = "de"
+# Accessibility overrides on top of the default Chainlit theme
+custom_css = "/public/custom.css"
+# Accessibility JS: ARIA live region, focus management, skip-to-content link
+custom_js = "/public/accessibility.js"
+
+[meta]
+generated_by = "2.x"

chat_app.py

@@ -0,0 +1,243 @@
+#!/usr/bin/env python3
+"""Meister-Eder — Web Chat Interface for Spielgruppe Pumuckl.
+
+Usage
+-----
+Copy `.env.example` to `.env`, fill in your credentials, then run:
+
+    chainlit run chat_app.py
+
+The app serves a web chat interface at http://localhost:8000.
+Parents can register their child or ask questions in real time.
+
+Environment variables (see .env.example):
+  AI_MODEL             litellm model string  (default: anthropic/claude-opus-4-6)
+  ANTHROPIC_API_KEY    Required for Anthropic models
+  SMTP_HOST / SMTP_PORT  For admin notifications (optional in dev)
+  ADMIN_EMAIL_INDOOR / ADMIN_EMAIL_OUTDOOR / ADMIN_EMAIL_CC  Notification routing
+  DATA_DIR             Directory for completed registration JSON  (default: data/)
+"""
+
+import logging
+import uuid
+from datetime import datetime, timezone
+
+import chainlit as cl
+
+from src import llm
+from src.agent.prompts import build_system_prompt
+from src.agent.response_parser import apply_updates, fallback_message, parse_llm_response
+from src.config import Config
+from src.knowledge_base.loader import KnowledgeBase
+from src.models.conversation import ChatMessage, ConversationState
+from src.models.registration import RegistrationData
+from src.notifications.notifier import AdminNotifier
+from src.storage.json_store import ConversationStore, _diff_registrations
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+    datefmt="%Y-%m-%dT%H:%M:%S",
+)
+logger = logging.getLogger(__name__)
+
+# ---------------------------------------------------------------------------
+# Shared components — initialised once when the server starts.
+# These are read-only after startup and safe to share across sessions.
+# ---------------------------------------------------------------------------
+_config = Config.from_env()
+_kb = KnowledgeBase(_config.knowledge_base_dir)
+_store = ConversationStore(_config.data_dir)
+_notifier = AdminNotifier(
+    smtp_host=_config.smtp_host,
+    smtp_port=_config.smtp_port,
+    username=_config.imap_username,
+    password=_config.imap_password,
+    use_tls=_config.smtp_use_tls,
+    from_email=_config.registration_email,
+    indoor_email=_config.admin_email_indoor,
+    outdoor_email=_config.admin_email_outdoor,
+    cc_emails=[e.strip() for e in _config.admin_email_cc.split(",") if e.strip()],
+    model=_config.simple_model,
+)
+
+# ---------------------------------------------------------------------------
+# Welcome message (German default, per spec)
+# ---------------------------------------------------------------------------
+_WELCOME_DE = (
+    "Hallo! Ich bin der Anmeldeassistent der Spielgruppe Pumuckl. "
+    "Ich kann dir helfen, dein Kind anzumelden, oder deine Fragen zur Spielgruppe beantworten.\n\n"
+    "Du kannst mir auf die Sprache schreiben die du am besten kannst — ich antworte in derselben Sprache.\n\n"
+    "Womit kann ich dir helfen?"
+)
+
+
+# ---------------------------------------------------------------------------
+# Chainlit lifecycle handlers
+# ---------------------------------------------------------------------------
+
+@cl.on_chat_start
+async def on_chat_start() -> None:
+    """Initialise a fresh conversation state and greet the parent.
+
+    If cl.user_session already holds state (WebSocket reconnect after a
+    network drop), replay the existing message history so the parent sees
+    the full conversation rather than a blank screen.
+    """
+    existing = cl.user_session.get("state")
+    if existing:
+        # Reconnected — restore visual history from our stored state
+        state = ConversationState.from_dict(existing)
+        logger.info(
+            "Session reconnected: %s (%d messages)",
+            state.conversation_id,
+            len(state.messages),
+        )
+        for msg in state.messages:
+            author = "Spielgruppe Pumuckl" if msg.role == "assistant" else "Du"
+            await cl.Message(content=msg.content, author=author).send()
+        return
+
+    # Brand new session
+    session_id = str(uuid.uuid4())
+    state = ConversationState(conversation_id=session_id)
+    # Store the welcome in history so it's replayed if the session reconnects.
+    state.messages.append(ChatMessage(role="assistant", content=_WELCOME_DE))
+    cl.user_session.set("state", state.to_dict())
+    logger.info("Chat session started: %s", session_id)
+    await cl.Message(content=_WELCOME_DE).send()
+
+
+@cl.on_message
+async def on_message(message: cl.Message) -> None:
+    """Process one parent message and stream the agent's reply."""
+    # --- Restore state from session ---
+    state = ConversationState.from_dict(cl.user_session.get("state"))
+    now = datetime.now(timezone.utc).isoformat()
+    state.last_activity = now
+
+    # Append parent's message to history and persist immediately so that any
+    # WebSocket reconnect during the LLM call can replay the full conversation.
+    state.messages.append(ChatMessage(role="user", content=message.content))
+    cl.user_session.set("state", state.to_dict())
+
+    # --- Build system prompt ---
+    system = build_system_prompt(_kb, state)
+
+    # --- Call LLM natively async (supports extended thinking; no event-loop blocking) ---
+    try:
+        full_content = await llm.acomplete(
+            _config.ai_model, system, state.messages, _config.thinking_budget
+        )
+    except Exception:
+        logger.exception("LLM call failed for session %s", state.conversation_id)
+        error_text = fallback_message(state.language)
+        await cl.Message(content=error_text).send()
+        return
+
+    # --- Parse and apply LLM response ---
+    parsed = parse_llm_response(full_content)
+
+    reply_text: str = parsed.get("reply", full_content)
+    updates: dict = parsed.get("updates", {}) or {}
+    next_step: str = parsed.get("next_step", state.flow_step)
+    is_complete: bool = bool(parsed.get("registration_complete", False))
+    language: str = parsed.get("language", state.language)
+    intent: str = parsed.get("intent", "")
+
+    apply_updates(state, updates)
+    state.flow_step = next_step
+    state.language = language
+    state.updated_at = now
+
+    # Send the reply text to the parent (only the human-readable reply, not the JSON wrapper)
+    await cl.Message(content=reply_text).send()
+
+    # Append assistant reply to history
+    state.messages.append(ChatMessage(role="assistant", content=reply_text))
+
+    # --- Handle registration completion ---
+    if is_complete and not state.completed:
+        state.completed = True
+        try:
+            email_key, version = _store.save_registration(state)
+            _notifier.notify_admin(
+                registration=state.registration,
+                registration_id=email_key,
+                version=version,
+                conversation_id=state.conversation_id,
+                channel="chat",
+            )
+            logger.info("Registration complete for session %s", state.conversation_id)
+        except Exception:
+            logger.exception(
+                "Failed to save/notify for session %s", state.conversation_id
+            )
+        try:
+            _notifier.notify_parent(
+                registration=state.registration,
+                language=state.language,
+            )
+        except Exception:
+            logger.exception(
+                "Failed to send parent confirmation for session %s", state.conversation_id
+            )
+
+    # --- Handle post-completion update intent ---
+    if state.completed and intent == "update" and any(v is not None for v in updates.values()):
+        _handle_registration_update(state)
+
+    # --- Handle new-child reset ---
+    if state.completed and intent == "new_child":
+        state.registration = RegistrationData()
+        state.completed = False
+        state.flow_step = "child_name"
+        logger.info("New child registration started for session %s", state.conversation_id)
+
+    # --- Persist updated state ---
+    cl.user_session.set("state", state.to_dict())
+
+
+@cl.on_chat_end
+async def on_chat_end() -> None:
+    """Log session end. Hook for future email-reminder integration."""
+    state_dict = cl.user_session.get("state")
+    if state_dict:
+        conversation_id = state_dict.get("conversation_id", "unknown")
+        completed = state_dict.get("completed", False)
+        logger.info(
+            "Chat session ended: %s (completed=%s)", conversation_id, completed
+        )
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+def _handle_registration_update(state: ConversationState) -> None:
+    """Version the registration record and notify admin of changes."""
+    # Re-apply and diff from the stored current version
+    current = _store.get_current_registration(state.conversation_id)
+    if current is None:
+        return
+
+    change_summary = _diff_registrations(current, state.registration.to_dict())
+    if not change_summary:
+        return
+
+    try:
+        email_key, version = _store.save_registration_version(state, change_summary)
+        _notifier.notify_registration_update(
+            registration=state.registration,
+            registration_id=email_key,
+            version=version,
+            change_summary=change_summary,
+            conversation_id=state.conversation_id,
+        )
+        logger.info(
+            "Registration updated to v%d for session %s", version, state.conversation_id
+        )
+    except Exception:
+        logger.exception(
+            "Failed to save update for session %s", state.conversation_id
+        )

main.py

@@ -61,9 +61,16 @@ def build_components(config: Config):
         indoor_email=config.admin_email_indoor,
         outdoor_email=config.admin_email_outdoor,
         cc_emails=[e.strip() for e in config.admin_email_cc.split(",") if e.strip()],
+        model=config.simple_model,
     )
 
-    agent = EmailAgent(model=config.ai_model, kb=kb, store=store, notifier=notifier)
+    agent = EmailAgent(
+        model=config.ai_model,
+        kb=kb,
+        store=store,
+        notifier=notifier,
+        thinking_budget=config.thinking_budget,
+    )
 
     channel = EmailChannel(
         imap_host=config.imap_host,

openspec/changes/implement-web-chat/.openspec.yaml

@@ -0,0 +1,9 @@
+name: implement-web-chat
+schema: spec-driven
+status: in-progress
+created: 2026-02-22
+artifacts:
+  proposal: pending
+  design: pending
+  specs: pending
+  tasks: pending

openspec/changes/implement-web-chat/design.md

@@ -0,0 +1,132 @@
+## Context
+
+The `chat-interface` capability is specified but not yet built. This change implements it. The core agent (LLM conversation logic) is defined separately; this design covers the web frontend, its real-time transport, session management, and how the chat layer connects to the agent core.
+
+The tech stack for the entire project is decided here as part of this first implementation change, since the chat interface is the most visible component and its runtime shapes the whole backend.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Deliver a working, accessible web chat interface parents can use to register
+- Choose a library that provides WCAG 2.1 AA compliance out of the box or close to it
+- Keep the frontend thin: no business logic, just message in / message out
+- Establish the Python tech stack and project layout for all subsequent changes
+
+**Non-Goals:**
+- Custom chat UI built from scratch (we use a library)
+- Authentication / login before chatting
+- Persistent chat history across separate browser sessions (session-scoped only)
+- Admin-facing UI (out of scope for this project entirely)
+
+## Decisions
+
+### 1. Chat UI Library: Chainlit
+
+**Decision**: Use [Chainlit](https://github.com/Chainlit/chainlit) as the chat interface framework.
+
+**Rationale**:
+Chainlit is purpose-built for AI assistant chat interfaces. It handles everything the spec requires without building it from scratch:
+- Real-time streaming responses (SSE / WebSocket)
+- Typing indicators while the agent generates
+- Session management (server-side, survives page refresh within the same session)
+- Message history display with clear agent / user attribution
+- Built-in mobile-responsive layout
+- Python-native: integrates directly with the Anthropic SDK with no bridging layer
+
+**Accessibility baseline**: Chainlit's React frontend uses semantic HTML and has basic ARIA support. Gaps (see Risk section) are filled with CSS overrides and custom header components.
+
+**Alternatives considered**:
+
+| Option | Why rejected |
+|--------|-------------|
+| React + `@chatscope/chat-ui-kit-react` | Requires a separate Node.js build pipeline and a backend bridge; more moving parts for a small project |
+| Gradio | Data-science oriented; poor accessibility; limited chat customisation |
+| FastAPI + HTMX (server-rendered) | Accessible by default but no real-time streaming without complex SSE setup; typing indicators are awkward |
+| Custom React app | Reimplements what Chainlit provides; no accessibility gains justify the cost |
+
+### 2. Language and Runtime: Python
+
+**Decision**: Python as the sole backend language.
+
+**Rationale**: The Anthropic SDK is first-class in Python. Email processing (IMAP/SMTP), file I/O for the knowledge base, and JSON storage are all well-supported. Chainlit is Python-native. Using one language for the entire stack minimises operational complexity for a small project.
+
+### 3. Real-Time Transport: Chainlit's built-in WebSocket / SSE
+
+**Decision**: Rely on Chainlit's managed real-time layer; do not implement a separate WebSocket server.
+
+**Rationale**: Chainlit handles connection lifecycle, reconnection, and streaming out of the box. The agent core is invoked inside Chainlit's `@cl.on_message` handler and streams tokens back with `cl.Message.stream_token()`. There is no need for a separate transport layer.
+
+### 4. Session State: Chainlit User Session
+
+**Decision**: Store in-progress registration state in `cl.user_session` (server-side, keyed by Chainlit's session ID).
+
+**Rationale**: Chainlit provides a per-connection server-side dict (`cl.user_session`) that persists across page refreshes within the same browser session. This satisfies the spec requirement that conversation history and state survive a refresh. No external state store (Redis, database) is needed for MVP.
+
+**Trade-off**: State is lost when the server restarts. For a small playgroup this is acceptable; parents are encouraged to use email if they need to resume days later.
+
+### 5. Accessibility Gaps and Mitigations
+
+Chainlit covers most WCAG 2.1 AA requirements but has known gaps:
+
+| Gap | Mitigation |
+|----|-----------|
+| ARIA live region for incoming messages | Add `aria-live="polite"` via Chainlit's custom CSS / element override on the message list container |
+| Focus management after agent reply | Inject a small JS snippet via Chainlit's `head` config to move focus to the latest message |
+| Colour contrast of default theme | Override with a high-contrast custom CSS theme (≥ 4.5:1 for all text) |
+| Animated typing dots | Wrap in `@media (prefers-reduced-motion: reduce)` to hide or swap for a static indicator |
+| Skip-to-content link | Add via Chainlit's custom `header` HTML config |
+
+### 6. Project Layout
+
+```
+meister-eder/
+├── app/
+│   ├── chat.py              # Chainlit entry point (@cl.on_chat_start, @cl.on_message)
+│   ├── agent/
+│   │   ├── core.py          # Channel-agnostic agent logic (shared with email)
+│   │   └── tools.py         # Agent tool definitions (knowledge base lookup, etc.)
+│   ├── knowledge_base/      # Markdown files (symlink or copy of content/knowledge-base/)
+│   └── storage/
+│       └── registrations/   # JSON registration records
+├── public/
+│   └── custom.css           # Accessibility overrides for Chainlit
+├── chainlit.md              # Welcome message shown in chat (German default)
+├── chainlit.toml            # Chainlit configuration (theme, title, etc.)
+└── requirements.txt
+```
+
+### 7. Chainlit Configuration
+
+Key settings in `chainlit.toml`:
+
+```toml
+[project]
+name = "Spielgruppe Pumuckl"
+enable_telemetry = false
+
+[UI]
+name = "Spielgruppe Pumuckl"
+default_language = "de"
+# Custom CSS applied on top of default theme
+custom_css = "/public/custom.css"
+
+[meta]
+generated_by = "1.x"
+```
+
+Welcome message (`chainlit.md`) is written in German with an English fallback comment, matching the agent personality spec.
+
+## Risks / Trade-offs
+
+**Chainlit version stability**: Chainlit's API has changed between major versions. Pin to a specific minor version in `requirements.txt` and document upgrade steps.
+
+**Accessibility completeness**: Chainlit's built-in accessibility is not fully audited. The mitigations in Decision 5 address known gaps; a manual screen-reader test (NVDA/VoiceOver) should be part of the implementation verification.
+
+**Session loss on server restart**: Acceptable for MVP. Documented in the chat UI welcome message ("for longer registrations, consider email").
+
+**Mobile keyboard overlap**: On small screens, the browser's virtual keyboard can obscure the chat input. Chainlit's layout is mobile-responsive but may need a CSS viewport-height fix (`dvh` units) for iOS Safari.
+
+## Open Questions
+
+- Should the Chainlit app be the same process as future admin/export endpoints, or run separately? (Likely separate; Chainlit's web server is not designed to host arbitrary REST APIs.)
+- What domain/subdomain will the chat be served from? (Affects CORS config if the agent API is separate.)

openspec/changes/implement-web-chat/proposal.md

@@ -0,0 +1,38 @@
+## Why
+
+The `chat-interface` capability was defined in the scoping phase as a must-have for the initial release, but no implementation exists yet. This change delivers it.
+
+Parents need a zero-friction way to start a registration or ask questions without setting up email threads. A web chat interface lowers that barrier: they navigate to a URL, start typing, and they're immediately talking to the agent. The interface must work equally well on a mobile phone held in one hand while watching a toddler.
+
+Accessibility is a first-class concern. Parents may rely on screen readers, keyboard navigation, or high-contrast displays. An inaccessible registration interface excludes families with disabilities—contrary to the playgroup's values.
+
+Using a mature, accessibility-tested chat UI library rather than building from scratch means we inherit ARIA compliance, keyboard navigation, focus management, and screen reader support without reimplementing them.
+
+## What Changes
+
+- **ADDED `chat-interface` implementation**: A deployable web application that renders the chat UI, connects to the core agent, and manages browser-session state. Built on top of an existing accessible chat UI library.
+
+### What this does NOT include
+
+- The core conversational agent (separate concern, shared with email channel)
+- Email channel implementation
+- Backend API for the agent (defined separately; this change specifies only the frontend and its integration contract)
+
+## Capabilities
+
+### Modified Capabilities
+
+- `chat-interface`: Moves from specified-but-unbuilt to implemented. Requirements remain as defined in the existing spec, with accessibility requirements added:
+  - WCAG 2.1 AA compliance
+  - Full keyboard navigation (no mouse required)
+  - Screen reader compatibility (ARIA live regions for incoming messages)
+  - Sufficient colour contrast (≥ 4.5:1 for normal text)
+  - Focus management (focus moves to new agent messages; skip-to-content link)
+  - Respects `prefers-reduced-motion` (no animated typing dots if disabled)
+
+## Impact
+
+- **Parents**: Can access the registration agent from any browser without email setup; works on mobile phones; usable by parents with accessibility needs
+- **Infrastructure**: Adds a web server serving the chat frontend; WebSocket or SSE connection to the agent backend
+- **Dependencies**: One new runtime dependency — a well-maintained, accessible chat UI library (to be decided in design); the existing agent core (no changes required to the core)
+- **Admin**: No impact; admin does not interact with the chat interface

openspec/changes/implement-web-chat/specs/chat-interface/spec.md

@@ -0,0 +1,173 @@
+## MODIFIED Requirements
+
+> Extends the `chat-interface` spec from `define-project-scope`. All previously
+> defined requirements remain in force. This spec adds accessibility requirements
+> and implementation constraints introduced by this change.
+
+---
+
+### Requirement: WCAG 2.1 AA compliance
+The chat interface SHALL conform to WCAG 2.1 Level AA in all user-facing interactions.
+
+#### Scenario: Automated accessibility check passes
+- **WHEN** an automated accessibility audit (e.g. axe-core) is run against the chat page
+- **THEN** it SHALL report zero Level A and Level AA violations
+
+#### Scenario: Manual screen reader test passes
+- **WHEN** a user navigates the chat using NVDA (Windows) or VoiceOver (macOS/iOS)
+- **THEN** they SHALL be able to read all messages and send a new message without using a mouse
+
+---
+
+### Requirement: Full keyboard navigation
+The chat interface SHALL be fully operable using only a keyboard.
+
+#### Scenario: Sending a message by keyboard
+- **WHEN** a parent focuses the text input and types a message
+- **THEN** they SHALL be able to submit it with the Enter key without pressing a mouse button
+
+#### Scenario: Tab order is logical
+- **WHEN** a parent presses Tab repeatedly from the top of the page
+- **THEN** focus SHALL move through interactive elements in a logical reading order (skip link → message list → text input → send button)
+
+#### Scenario: No keyboard trap
+- **WHEN** focus enters any component (e.g. the text input)
+- **THEN** the parent SHALL be able to move focus out again using only the keyboard
+
+---
+
+### Requirement: Skip-to-content link
+The chat interface SHALL provide a skip navigation link as the first focusable element.
+
+#### Scenario: Skip link is visible on focus
+- **WHEN** a keyboard user presses Tab on the chat page for the first time
+- **THEN** a "Skip to chat" link SHALL become visible and, when activated, move focus directly to the message input
+
+---
+
+### Requirement: Screen reader announcements for new messages
+Incoming agent messages SHALL be announced to screen readers without requiring focus change.
+
+#### Scenario: Agent reply announced
+- **WHEN** the agent sends a new message
+- **THEN** a screen reader SHALL announce the message content via an ARIA live region (`aria-live="polite"`)
+
+#### Scenario: In-progress stream not announced mid-token
+- **WHEN** the agent is streaming a response token by token
+- **THEN** the live region SHALL NOT announce each individual token; only the completed message SHALL be announced
+
+---
+
+### Requirement: Focus moves to agent reply on completion
+After the agent finishes a response, keyboard focus SHALL be placed near the new message.
+
+#### Scenario: Focus after reply
+- **WHEN** the agent finishes generating a response
+- **THEN** focus SHALL move to the new agent message element (or a wrapper with `tabindex="-1"`) so the parent can read it immediately with a screen reader
+
+---
+
+### Requirement: Sufficient colour contrast
+All text in the chat interface SHALL meet WCAG 2.1 SC 1.4.3 contrast requirements.
+
+#### Scenario: Normal text contrast
+- **WHEN** any text of normal size is rendered
+- **THEN** its contrast ratio against the background SHALL be ≥ 4.5:1
+
+#### Scenario: Large text contrast
+- **WHEN** any text at 18pt (or 14pt bold) or larger is rendered
+- **THEN** its contrast ratio against the background SHALL be ≥ 3:1
+
+#### Scenario: Input placeholder contrast
+- **WHEN** the text input displays placeholder text
+- **THEN** the placeholder contrast ratio SHALL be ≥ 4.5:1
+
+---
+
+### Requirement: Typing indicator respects reduced-motion preference
+The agent-processing indicator SHALL not use animation when the user has requested reduced motion.
+
+#### Scenario: Reduced motion active
+- **WHEN** the OS or browser has `prefers-reduced-motion: reduce` set
+- **AND** the agent is generating a response
+- **THEN** the typing indicator SHALL display as a static element (e.g. "…" text) with no animation
+
+#### Scenario: Reduced motion not active
+- **WHEN** `prefers-reduced-motion` is not set or is set to `no-preference`
+- **THEN** the typing indicator MAY display an animated element (e.g. bouncing dots)
+
+---
+
+### Requirement: Mobile viewport input visibility
+The text input SHALL remain visible when the virtual keyboard is open on mobile devices.
+
+#### Scenario: iOS Safari virtual keyboard
+- **WHEN** a parent taps the text input on an iOS device and the virtual keyboard appears
+- **THEN** the input field SHALL remain in view and not be obscured by the keyboard
+
+#### Scenario: Android Chrome virtual keyboard
+- **WHEN** a parent taps the text input on an Android device and the virtual keyboard appears
+- **THEN** the input field SHALL remain in view and the message list SHALL scroll to show the latest message above the keyboard
+
+---
+
+### Requirement: Session state survives page refresh
+Conversation history and registration state SHALL be preserved when the parent reloads the page within the same browser session.
+
+#### Scenario: Page refresh mid-conversation
+- **WHEN** a parent refreshes the browser tab during an active conversation
+- **THEN** the full conversation history SHALL be displayed and the registration state SHALL be intact on reconnect
+
+#### Scenario: Server restart loses state (acceptable degradation)
+- **WHEN** the server restarts while a session is active
+- **THEN** the parent SHALL see a notification that the session ended and be invited to start a new conversation
+
+---
+
+### Requirement: Session-loss notification on disconnect
+If the connection to the server is lost and cannot be recovered, the interface SHALL inform the parent.
+
+#### Scenario: Unrecoverable disconnect
+- **WHEN** the WebSocket / SSE connection is lost and reconnection fails after a reasonable timeout
+- **THEN** the interface SHALL display a message explaining the session ended and suggest using email for longer registration processes
+
+---
+
+### Requirement: Welcome message in the parent's language
+The chat interface SHALL display a welcome message in German by default, with automatic language adaptation.
+
+#### Scenario: Default welcome message
+- **WHEN** a parent opens the chat interface
+- **THEN** the welcome message SHALL be displayed in German
+
+#### Scenario: Language adaptation
+- **WHEN** a parent sends their first message in English
+- **THEN** the agent SHALL respond in English for the remainder of the session
+
+---
+
+## ADDED Requirements
+
+### Requirement: Chainlit-based implementation
+The chat interface SHALL be implemented using the Chainlit framework.
+
+#### Scenario: Application entry point
+- **WHEN** the server starts
+- **THEN** it SHALL run a Chainlit application with `@cl.on_chat_start` and `@cl.on_message` handlers
+
+#### Scenario: Telemetry disabled
+- **WHEN** the application runs
+- **THEN** Chainlit telemetry SHALL be disabled (`enable_telemetry = false` in `chainlit.toml`)
+
+---
+
+### Requirement: Custom accessibility CSS applied
+The Chainlit default theme SHALL be extended with a custom CSS file that addresses accessibility gaps.
+
+#### Scenario: Custom CSS loaded
+- **WHEN** the chat page is served
+- **THEN** the custom CSS file (`/public/custom.css`) SHALL be loaded and applied on top of the default Chainlit theme
+
+#### Scenario: Custom CSS addresses contrast and motion
+- **WHEN** the page renders
+- **THEN** the custom CSS SHALL include contrast overrides achieving ≥ 4.5:1 for all normal text AND a `prefers-reduced-motion` block that suppresses typing-dot animation

openspec/changes/implement-web-chat/tasks.md

@@ -0,0 +1,71 @@
+## 1. Add Chainlit Dependency
+
+- [x] 1.1 Run `uv add chainlit` to add Chainlit to `pyproject.toml` (matches existing `uv`-based workflow; do not create `requirements.txt`)
+- [x] 1.2 Create `chainlit.toml` at the project root with: `name = "Spielgruppe Pumuckl"`, `enable_telemetry = false`, `custom_css = "/public/custom.css"`, `default_language = "de"`
+
+## 2. Add Streaming Support to src/llm.py
+
+- [x] 2.1 Add a `stream_complete(model: str, system: str, messages: list)` generator function to `src/llm.py` that calls `litellm.completion(..., stream=True)` and yields text chunks (parallels the existing `complete()` function; both share the same `api_messages` build logic)
+- [x] 2.2 Add tests for `stream_complete` in `tests/test_llm.py` — verify chunks are yielded, empty deltas are skipped, and the model/system/messages args are forwarded correctly
+
+## 3. Create Chainlit Entry Point
+
+- [x] 3.1 Create `chat_app.py` at the project root with a `@cl.on_chat_start` handler that:
+  - Loads `Config.from_env()` from `src/config.py`
+  - Initialises `KnowledgeBase`, `ConversationStore`, `AdminNotifier` from existing `src/` modules
+  - Creates a fresh `ConversationState` (use Chainlit's session ID as `conversation_id`; no email address required at this stage)
+  - Stores state dict in `cl.user_session["state"]`
+  - Sends the German welcome message (drawn from `content/sample-responses.md`)
+- [x] 3.2 Add a `@cl.on_message` handler in `chat_app.py` that:
+  - Deserialises `ConversationState` from `cl.user_session["state"]`
+  - Appends the parent's message to `state.messages` as a `ChatMessage(role="user", ...)`
+  - Builds the system prompt via `build_system_prompt()` from `src/agent/prompts.py`
+  - Creates a `cl.Message(content="")` and streams chunks from `stream_complete()` using `msg.stream_token(chunk)`, then calls `msg.send()`
+  - Parses the completed response text for JSON (reuse `_parse_llm_response` logic from `src/agent/core.py` — extract into `src/agent/response_parser.py` if needed)
+  - Applies field updates to `ConversationState.registration`; updates `state.flow_step` and `state.language`
+  - Appends the assistant reply to `state.messages`
+  - Serialises state back to `cl.user_session["state"]`
+  - When `registration_complete` is true: saves registration via `ConversationStore`, sends admin notification via `AdminNotifier`, sets `state.completed = True`
+- [x] 3.3 Create `chainlit.md` at the project root with the German welcome/intro text shown in the Chainlit sidebar (plain markdown; drawn from `content/agent-personality.md`)
+
+## 4. Accessibility CSS
+
+- [x] 4.1 Create `public/` directory at the project root
+- [x] 4.2 Create `public/custom.css` with colour contrast overrides: all normal text ≥ 4.5:1, large text ≥ 3:1, and placeholder text ≥ 4.5:1 — measure Chainlit's default colours with a contrast checker and override as needed
+- [x] 4.3 Add a `@media (prefers-reduced-motion: reduce)` block to `public/custom.css` that hides the animated typing-dot element and replaces it with a static `"…"` pseudo-element
+- [x] 4.4 Add CSS in `public/custom.css` for the skip link: hidden by default, visible and highlighted on `:focus`, and targeting `#chat-input`
+- [x] 4.5 Add `min-height: 100dvh` (dynamic viewport height) to the chat container selector in `public/custom.css` so the input is not obscured by iOS Safari's virtual keyboard
+
+## 5. ARIA and Focus Management
+
+- [x] 5.1 Inspect the Chainlit message list container selector in a running browser (dev tools) and add `aria-live="polite"` and `aria-atomic="false"` to it via a `MutationObserver` JS snippet injected through `chainlit.toml`'s `[UI] custom_js` or as `public/accessibility.js`
+- [x] 5.2 Extend the JS snippet so that after each completed agent message (after `msg.send()`, not during streaming) focus moves to the new message element via `element.setAttribute("tabindex", "-1"); element.focus()`
+- [x] 5.3 Add the skip link HTML element to the page via the same JS snippet or Chainlit's `[UI] custom_header` config so it is the first focusable element
+
+## 6. Session Management
+
+- [ ] 6.1 Test manually: start a conversation in the browser, refresh the page, verify that `cl.user_session["state"]` is restored and conversation history is displayed
+- [x] 6.2 Add a `@cl.on_chat_end` handler in `chat_app.py` that logs the session end (no action needed for MVP, but provides a hook for future email-reminder integration)
+- [x] 6.3 Add a disconnect/reconnect message in Chainlit configuration: "Deine Sitzung ist abgelaufen. Starte ein neues Gespräch oder nutze E-Mail für eine längere Pause." (and English equivalent)
+
+## 7. Mobile Testing
+
+- [ ] 7.1 Test on iOS Safari (device or BrowserStack): tap the text input while virtual keyboard is open — confirm input is not obscured
+- [ ] 7.2 Test on Android Chrome: tap input, confirm message list scrolls to keep the latest message visible above the keyboard
+- [ ] 7.3 Test landscape orientation on a mobile screen: confirm no horizontal scroll and layout is usable
+
+## 8. Accessibility Verification
+
+- [ ] 8.1 Run the axe-core browser extension against the running chat page and fix all reported Level A and Level AA violations
+- [ ] 8.2 Verify keyboard-only flow: Tab → skip link becomes visible → activate → focus moves to message input → type message → Enter → agent replies → focus moves to new message
+- [ ] 8.3 Test with VoiceOver (macOS or iOS): navigate to input, send a message, confirm agent reply is announced via the live region without manual focus movement
+- [ ] 8.4 Set OS `prefers-reduced-motion: reduce` and confirm the typing indicator shows as static text (not animated)
+- [ ] 8.5 Spot-check contrast of all rendered text elements; document which selectors required overrides in `public/custom.css`
+
+## 9. Final Integration Check
+
+- [ ] 9.1 Confirm `chainlit run chat_app.py` starts cleanly with no warnings or import errors
+- [ ] 9.2 Complete an end-to-end registration through the chat interface: verify the registration JSON is saved to `data/registrations/` and the admin notification email is sent
+- [ ] 9.3 Confirm Chainlit telemetry is disabled: open the network tab and verify no requests go to Chainlit analytics endpoints
+- [ ] 9.4 Confirm `ANTHROPIC_API_KEY` and other secrets are not printed in logs or error output
+- [x] 9.5 Update the `context` field in `openspec/config.yaml` with the finalised tech stack: Python 3.13, Chainlit, LiteLLM, uv, file-based JSON storage

openspec/changes/registration-confirmation-email/.openspec.yaml

@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-02-22

openspec/changes/registration-confirmation-email/design.md

@@ -0,0 +1,101 @@
+## Context
+
+When a registration is completed, `AdminNotifier.notify_admin()` sends an email to the relevant playgroup leaders. The parent receives nothing — no acknowledgement, no summary, no payment details.
+
+The existing `AdminNotifier` in `src/notifications/notifier.py` handles both new-registration and update notifications to admins. It uses `MIMEMultipart("alternative")` and sends via the configured SMTP server. All the SMTP plumbing already works.
+
+This change adds a parent-facing confirmation email triggered at the same point as the admin notification.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Parent receives an HTML confirmation email immediately after registration is stored
+- Email contains full registration summary (all 13 fields)
+- Email contains payment instructions for the CHF 80 registration fee
+- Email contains a Swiss QR-bill (QR code image) embedded inline so the parent can pay via banking app or print
+
+**Non-Goals:**
+- Translating the QR-bill slip labels themselves (the SIX Group standard mandates German/French/Italian for the payment slip fields — surrounding email text is translated, but the slip is not)
+- Sending a reminder if the parent hasn't paid (payment tracking is out of scope)
+- Generating a full PDF invoice (QR code embedded in HTML email is sufficient)
+- Sibling discount handling in the QR-bill amount (CHF 80 is always fixed for the registration fee)
+
+## Decisions
+
+### 1. Extend `AdminNotifier` vs. New Class
+
+**Decision**: Add `notify_parent()` to the existing `AdminNotifier` class (renamed conceptually; kept in the same file for now).
+
+**Rationale**: The SMTP plumbing (`_send`, `_smtp_host`, credentials) is already there. A `notify_parent` method reuses all of it. Splitting into a separate class would require duplicating constructor parameters and SMTP setup for no structural benefit at this stage.
+
+**Trade-off**: `AdminNotifier` becomes slightly misnamed. Acceptable — the class handles all outbound notification emails. Rename in a future refactor if needed.
+
+### 2. HTML Email Format
+
+**Decision**: Send `multipart/alternative` with both plain-text and HTML parts. The HTML part is the primary view; plain-text is fallback.
+
+**Rationale**: Matches the existing `_send` method's `MIMEMultipart("alternative")` pattern. HTML is needed to embed the QR-bill image inline.
+
+**QR image embedding**: Use `multipart/related` wrapping the HTML part, with the QR PNG attached as `Content-ID` (`cid:qrbill`). This is the standard approach for inline images that don't appear as attachments.
+
+**Structure:**
+```
+multipart/mixed
+└── multipart/alternative
+    ├── text/plain  (fallback)
+    └── multipart/related
+        ├── text/html  (references cid:qrbill)
+        └── image/png  (Content-ID: qrbill, inline)
+```
+
+### 3. Swiss QR-Bill Generation
+
+**Decision**: Use the `qrbill` Python library to generate the QR code image.
+
+**Rationale**: `qrbill` implements the Swiss QR-bill standard (SIX Group spec) directly. It accepts IBAN, payee address, amount, and currency, and outputs an SVG or PNG. No external services required.
+
+**Fixed payment data** (hardcoded in the notifier, not in config — this is stable bank data):
+- IBAN: `CH14 0900 0000 4930 8018 8`
+- Payee: Familienverein Fällanden Spielgruppen, c/o Markus Graf, Huebwisstrase 5, 8117 Fällanden
+- Amount: CHF 80.00
+- Currency: CHF
+- Reference type: NON (no structured reference)
+
+**Output**: PNG bytes, embedded as inline image in HTML email.
+
+**Dependency**: Add `qrbill` to `pyproject.toml` dependencies.
+
+### 4. Language
+
+**Decision**: Add a `language` field to `RegistrationData` (default `"de"`). The agent sets it when it detects the parent's language during conversation. The confirmation email body is rendered in the stored language. The QR-bill slip labels are fixed German/French/Italian per the SIX Group standard and are not translated.
+
+**Supported values**: `"de"` (German, default) and `"en"` (English). Other values fall back to `"de"`.
+
+**Where it lives in the model**: A new `metadata` field on `RegistrationData` (a `Metadata` dataclass) with fields `submitted_at`, `channel`, `conversation_id`, and `language`. This also aligns with the JSON schema in `registration-schema.json` which already defines a `metadata` object with those keys. The `language` field is added to both the Python model and the JSON schema.
+
+**Template strategy**: Two string-template dicts (one per language) for all user-visible strings in the confirmation email. The notifier selects the dict based on `registration.metadata.language`. Admin notifications remain German-only (admins are Swiss German speakers).
+
+**Rationale**: Parents who conversed in English reasonably expect an English confirmation. Storing language in the model (rather than passing it as a parameter) means it's persisted with the registration and available for future use (e.g. update notifications, reminders).
+
+### 5. Trigger Point
+
+**Decision**: Call `notify_parent()` immediately after `notify_admin()` at the same trigger site — wherever `notify_admin` is currently called (in `src/agent/core.py` or equivalent).
+
+**Rationale**: The parent notification is a direct consequence of the same event (registration completed). No separate trigger or queue needed.
+
+**Error isolation**: If the parent email fails, log the error but do not fail the registration or block the admin notification. Both notifications are best-effort.
+
+## Risks / Trade-offs
+
+**`qrbill` library maturity**: Actively maintained, used in production Swiss applications. Risk is low. If the library is unavailable, the QR code can be omitted and the plain IBAN text still enables payment.
+
+**Inline image rendering**: Some email clients block inline images by default (Outlook, some mobile clients). The plain-text fallback and the raw IBAN text in the HTML body ensure the payment info is always readable even if the QR image is blocked.
+
+**SMTP failure for parent email**: Parent notification is non-critical (the registration is already stored). Failure is logged as a warning, not an exception.
+
+**Language detection accuracy**: The agent infers language from conversation content. Misdetection is possible but low-risk — a parent who receives a German email when they expected English can still understand the registration summary. The QR-bill is universally recognisable regardless of surrounding language.
+
+## Open Questions
+
+- Should the confirmation email also include the monthly subscription fee (in addition to the CHF 80 registration fee), or only the registration fee QR-bill? The CHF 80 one-time fee is the immediate action required; the monthly fee is recurring and not yet payable. **Proposed answer: include both as informational text, but the QR-bill is for CHF 80 only.**
+- Should the parent's email be CC'd on the admin notification, or kept as a separate send? **Proposed answer: separate send — keeps admin and parent content distinct.**

openspec/changes/registration-confirmation-email/proposal.md

@@ -0,0 +1,31 @@
+## Why
+
+When a parent completes registration, they currently receive no confirmation. They have no record of what they submitted, no clarity on next steps, and no way to pay the registration fee without separately asking for bank details. This creates uncertainty for parents and additional back-and-forth for admins.
+
+A confirmation email closes this gap: the parent gets a clear summary of their registration, knows exactly what they agreed to, and can pay immediately using the included Swiss QR-bill.
+
+## What Changes
+
+- **Send HTML confirmation email to the parent** immediately when a registration is completed and stored
+- **Include full registration summary** — all fields the parent filled out, formatted clearly
+- **Include payment instructions** (German text) for the CHF 80 registration fee with IBAN and payee details
+- **Include a Swiss QR-bill** (payment QR code) so the parent can pay directly from their banking app or print-to-pay
+- The confirmation is sent in the **same language** the parent used during the conversation (German or English), but the QR-bill and payment block are always in German (banking standard)
+
+## Capabilities
+
+### Modified Capabilities
+
+- `registration-notifications`: Currently only notifies admins. Extended to also send a confirmation to the parent's email address upon completion.
+
+### New Capabilities
+
+*None — this extends an existing capability*
+
+## Impact
+
+- **Parents**: Receive immediate, clear confirmation with everything they need — what was registered and how to pay. No need to ask for bank details.
+- **Admins**: Fewer follow-up inquiries about "did my registration go through?" and "where do I pay?". Payment is initiated earlier.
+- **Email deliverability**: System must send to parent email, not just admin addresses. Parent email is already a required field in the registration schema.
+- **Swiss QR-bill generation**: Requires a library to generate the QR code image from the payment data (IBAN, amount, payee address). The QR code is embedded inline in the HTML email.
+- **Bilingual**: Confirmation body adapts to the parent's language. The payment section uses German regardless (Swiss QR-bill standard).

openspec/changes/registration-confirmation-email/specs/registration-notifications/spec.md

@@ -0,0 +1,81 @@
+## MODIFIED Requirements
+
+### Requirement: Notify parent on completed registration
+The system SHALL send an HTML confirmation email to the parent immediately after a registration is completed and stored.
+
+#### Scenario: Confirmation sent to parent email
+- **WHEN** a registration is completed
+- **THEN** the system SHALL send a confirmation email to the address in `parentGuardian.email`
+
+#### Scenario: Confirmation sent before or alongside admin notification
+- **WHEN** a registration is completed
+- **THEN** both the admin notification and the parent confirmation SHALL be dispatched in the same completion event; failure of either SHALL be logged but SHALL NOT block the other or fail the registration
+
+#### Scenario: No confirmation for incomplete registration
+- **WHEN** a registration is not yet complete (any required field missing)
+- **THEN** no confirmation email SHALL be sent to the parent
+
+---
+
+### Requirement: Confirmation email contains full registration summary
+The confirmation email SHALL include a summary of all registration data the parent submitted.
+
+#### Scenario: All required fields present in confirmation
+- **WHEN** the confirmation email is sent
+- **THEN** it SHALL include child name, date of birth, special needs, selected playgroup type(s), selected days, parent/guardian contact details, and emergency contact
+
+#### Scenario: Monthly fee shown as informational text
+- **WHEN** the confirmation email is sent
+- **THEN** it SHALL display the calculated monthly subscription fee as informational text (not a payment request)
+
+---
+
+### Requirement: Confirmation email contains payment instructions for registration fee
+The confirmation email SHALL include instructions for paying the one-time CHF 80 registration fee.
+
+#### Scenario: IBAN and payee shown as text
+- **WHEN** the confirmation email is sent
+- **THEN** it SHALL display the payee name, IBAN, and amount in plain text so the parent can pay manually if the QR code is not rendered
+
+#### Scenario: Swiss QR-bill embedded inline
+- **WHEN** the confirmation email is sent
+- **THEN** it SHALL include a Swiss QR-bill image (per SIX Group standard) embedded inline as a `Content-ID` referenced image within the HTML part
+- **AND** the QR-bill SHALL encode: IBAN `CH14 0900 0000 4930 8018 8`, payee Familienverein Fällanden Spielgruppen (Huebwisstrase 5, 8117 Fällanden), amount CHF 80.00, currency CHF, reference type NON
+
+#### Scenario: QR-bill fallback for non-HTML clients
+- **WHEN** a parent's email client does not render HTML
+- **THEN** the plain-text part SHALL include the IBAN and payee details in full so payment is still possible without the QR code
+
+---
+
+### Requirement: Confirmation email language matches parent's detected language
+The confirmation email body SHALL be rendered in the language detected during the conversation.
+
+#### Scenario: German parent receives German confirmation
+- **WHEN** the conversation language is `"de"`
+- **THEN** the confirmation email body SHALL be in German
+
+#### Scenario: English-speaking parent receives English confirmation
+- **WHEN** the conversation language is `"en"`
+- **THEN** the confirmation email body SHALL be in English
+
+#### Scenario: Unknown language falls back to German
+- **WHEN** the stored language value is not `"de"` or `"en"`
+- **THEN** the confirmation email SHALL be sent in German
+
+#### Scenario: QR-bill slip labels are not translated
+- **WHEN** the confirmation email is rendered in any language
+- **THEN** the Swiss QR-bill payment slip labels SHALL remain in German (per SIX Group standard; the slip is internationally recognisable without translation)
+
+---
+
+### Requirement: Parent's conversation language is persisted in the registration record
+The language detected during the parent's conversation SHALL be stored in the completed registration record.
+
+#### Scenario: Language written to registration record
+- **WHEN** a registration is stored
+- **THEN** the JSON record SHALL include a `metadata.language` field containing the detected language code (`"de"` or `"en"`)
+
+#### Scenario: Language defaults to German when not detected
+- **WHEN** no language was explicitly detected during the conversation
+- **THEN** `metadata.language` SHALL be `"de"`

openspec/changes/registration-confirmation-email/tasks.md

@@ -0,0 +1,52 @@
+## 1. Add `qrbill` Dependency
+
+- [x] 1.1 Add `qrbill` to `[project.dependencies]` in `pyproject.toml`
+- [x] 1.2 Run `uv lock` to update the lockfile
+- [x] 1.3 Verify `qrbill` imports successfully in a smoke test or REPL
+
+## 2. Persist Language in Registration Record
+
+- [x] 2.1 Update `ConversationStore._build_record()` in `src/storage/json_store.py` to include `language` from `state.language` in the `metadata` dict
+- [x] 2.2 Update `ConversationStore.save_registration()` and `save_registration_version()` signatures to accept/forward `state` (already does — confirm `_build_record` receives the full state)
+- [x] 2.3 Add a test in `tests/test_storage.py` asserting that the saved record's `metadata.language` matches `state.language`
+
+## 3. Add `notify_parent()` to `AdminNotifier`
+
+- [x] 3.1 Add a `_generate_qr_bill_png()` static/class method to `AdminNotifier` using `qrbill` with fixed payment data:
+  - IBAN: `CH14 0900 0000 4930 8018 8`
+  - Payee: Familienverein Fällanden Spielgruppen, Huebwisstrase 5, 8117 Fällanden
+  - Amount: `80.00`, Currency: `CHF`, Reference type: NON
+  - Returns raw PNG `bytes`
+- [x] 3.2 Add bilingual string template dicts `_STRINGS_DE` and `_STRINGS_EN` (module-level constants) covering all user-visible strings in the confirmation email (subject, section headers, fee labels, payment instructions text, closing)
+- [x] 3.3 Add `_build_parent_html()` method: renders full HTML confirmation email body using the appropriate string dict, embedding the QR image via `cid:qrbill`; includes registration summary and both monthly fee (informational) and CHF 80 registration fee (with IBAN text + QR reference)
+- [x] 3.4 Add `_build_parent_text()` method: renders the plain-text fallback, including all summary fields and IBAN/payee details in plain text (no image)
+- [x] 3.5 Add `notify_parent()` public method:
+  - Parameters: `registration: RegistrationData`, `language: str = "de"`
+  - Select string dict based on `language`; fall back to `"de"` for unknown values
+  - Call `_generate_qr_bill_png()` to get PNG bytes
+  - Build MIME structure: `multipart/mixed` > `multipart/alternative` > plain text part + `multipart/related` > HTML part + inline PNG (`Content-Disposition: inline`, `Content-ID: <qrbill>`)
+  - Call `_send()` with `to=[registration.parent_guardian.email]`, empty `cc`, localised subject, the assembled MIME message
+  - If `_smtp_host` is empty (dev mode), log and skip as with `notify_admin`
+
+## 4. Wire `notify_parent()` into Completion Events
+
+- [x] 4.1 In `src/agent/core.py` `_handle_registration()`: after the existing `notify_admin()` try/except block, add a parallel try/except block calling `self._notifier.notify_parent(registration=state.registration, language=state.language)`
+- [x] 4.2 In `chat_app.py` `on_message()`: after the existing `notify_admin()` call inside the completion block, add a parallel try/except block calling `_notifier.notify_parent(registration=state.registration, language=state.language)`
+- [x] 4.3 Verify both call sites log a warning (not an exception) on failure, and the registration completion path continues normally
+
+## 5. Tests
+
+- [x] 5.1 Add `tests/test_notifier.py` tests for `notify_parent()`:
+  - `test_notify_parent_calls_send`: mock `_send` and assert it is called with `to=[parent_email]`
+  - `test_notify_parent_german_subject`: assert subject contains German text when `language="de"`
+  - `test_notify_parent_english_subject`: assert subject contains English text when `language="en"`
+  - `test_notify_parent_unknown_language_falls_back_to_de`: assert `language="fr"` produces German subject
+  - `test_notify_parent_no_smtp_skips_send`: when `smtp_host=""`, `_send` is NOT called
+- [x] 5.2 Add a test asserting that the plain-text body contains the IBAN string `CH14` when `smtp_host` is empty (inspecting log or body build directly)
+- [x] 5.3 Add a test for `_generate_qr_bill_png()` asserting it returns `bytes` with non-zero length (requires `qrbill` installed)
+
+## 6. Manual Smoke Test
+
+- [ ] 6.1 Run `chainlit run chat_app.py` locally (or the email poller), complete a registration end-to-end, and verify the parent confirmation email arrives with the inline QR image rendered correctly
+- [ ] 6.2 Verify the admin notification still arrives unchanged alongside the parent confirmation
+- [ ] 6.3 Verify the saved `current.json` for the registration includes `metadata.language`

openspec/config.yaml

@@ -3,11 +3,32 @@ schema: spec-driven
 # Project context (optional)
 # This is shown to AI when creating artifacts.
 # Add your tech stack, conventions, style guides, domain knowledge, etc.
-# Example:
-#   context: |
-#     Tech stack: TypeScript, React, Node.js
-#     We use conventional commits
-#     Domain: e-commerce platform
+context: |
+  Tech stack:
+    - Language: Python 3.13+
+    - Package manager: uv (pyproject.toml — never requirements.txt)
+    - Chat interface: Chainlit 2.x (entry point: chat_app.py)
+    - LLM access: LiteLLM (provider-agnostic; src/llm.py wraps litellm.completion)
+    - Email channel: IMAP/SMTP via stdlib (imaplib, smtplib); entry point: main.py
+    - Storage: file-based JSON (no database); data/ directory
+    - Knowledge base: admin-editable Markdown files in openspec/.../knowledge-base/
+    - Tests: pytest + pytest-mock (tests/ directory)
+
+  Key architectural decisions:
+    - Channel-agnostic agent core: src/agent/ (prompts, response_parser) is shared
+      between email (src/agent/core.py / EmailAgent) and chat (chat_app.py)
+    - LLM streaming: src/llm.stream_complete() yields chunks via litellm stream=True
+    - Session state for chat: cl.user_session (Chainlit server-side, survives page refresh)
+    - Accessibility: public/custom.css (contrast, dvh, reduced-motion) +
+      public/accessibility.js (ARIA live region, focus management, skip link)
+    - Admin notifications routed by playgroup type (indoor→Andrea, outdoor→Barbara, CC Markus)
+
+  Conventions:
+    - German is the default language; agent auto-detects and switches to English
+    - Use informal "du" in German agent responses
+    - All knowledge base content stays in Markdown (non-technical admins can edit it)
+    - Schema validation required before saving any completed registration
+    - Never hardcode fee amounts or contact details in application code
 
 # Per-artifact rules (optional)
 # Add custom rules for specific artifacts.

public/accessibility.js

@@ -0,0 +1,162 @@
+/**
+ * Spielgruppe Pumuckl — Accessibility enhancements for Chainlit
+ *
+ * This script runs after the page loads and makes three changes:
+ *
+ * 1. Injects a "Skip to chat" link as the first focusable element so keyboard
+ *    users can bypass the header and jump straight to the message input.
+ *
+ * 2. Adds aria-live="polite" to the message list container so screen readers
+ *    announce new agent replies without requiring a focus change.
+ *
+ * 3. Observes the message list for newly completed agent messages and moves
+ *    keyboard focus to the latest one so screen reader users can read it
+ *    immediately after it appears.
+ *
+ * NOTE: Chainlit renders a React app, so the DOM is not fully available on
+ * DOMContentLoaded. We use a MutationObserver to wait for the message
+ * container to appear before attaching further observers.
+ */
+
+(function () {
+  "use strict";
+
+  // ── 1. Skip-to-content link ─────────────────────────────────────────────
+
+  function injectSkipLink() {
+    if (document.getElementById("skip-to-chat")) return; // already injected
+
+    const link = document.createElement("a");
+    link.id = "skip-to-chat";
+    link.href = "#chat-input";
+    link.textContent = "Zum Chat springen / Skip to chat";
+
+    // Clicking moves focus to the textarea inside #chat-input
+    link.addEventListener("click", function (e) {
+      e.preventDefault();
+      const target =
+        document.querySelector("#chat-input textarea") ||
+        document.querySelector("[data-testid='chat-input'] textarea") ||
+        document.querySelector("textarea");
+      if (target) {
+        target.focus();
+      }
+    });
+
+    document.body.insertBefore(link, document.body.firstChild);
+  }
+
+  // ── 2. ARIA live region on the message list ──────────────────────────────
+
+  /**
+   * Selectors to try for the message list container.
+   * Chainlit's class names may change between versions; list several candidates.
+   */
+  const MESSAGE_LIST_SELECTORS = [
+    "[data-testid='message-list']",
+    ".message-list",
+    "[class*='MessageList']",
+    "[class*='messages']",
+    ".cl-message-list",
+  ];
+
+  function findMessageList() {
+    for (const sel of MESSAGE_LIST_SELECTORS) {
+      const el = document.querySelector(sel);
+      if (el) return el;
+    }
+    return null;
+  }
+
+  function applyLiveRegion(container) {
+    if (container.dataset.liveRegionApplied) return;
+    container.setAttribute("aria-live", "polite");
+    container.setAttribute("aria-atomic", "false");
+    container.setAttribute("aria-relevant", "additions");
+    container.dataset.liveRegionApplied = "true";
+  }
+
+  // ── 3. Focus management after agent replies ──────────────────────────────
+
+  /**
+   * Selectors for individual assistant message elements.
+   * We look for the last one after a new addition.
+   */
+  const ASSISTANT_MESSAGE_SELECTORS = [
+    "[data-testid='assistant-message']",
+    "[data-author='assistant']",
+    "[class*='assistant']",
+    ".cl-message[data-role='assistant']",
+  ];
+
+  let _lastFocusedMessage = null;
+
+  function focusLatestAssistantMessage(container) {
+    let latest = null;
+    for (const sel of ASSISTANT_MESSAGE_SELECTORS) {
+      const all = container.querySelectorAll(sel);
+      if (all.length > 0) {
+        latest = all[all.length - 1];
+        break;
+      }
+    }
+
+    // Fallback: grab the last direct child of the message list
+    if (!latest) {
+      const children = container.children;
+      latest = children[children.length - 1] || null;
+    }
+
+    if (!latest || latest === _lastFocusedMessage) return;
+
+    _lastFocusedMessage = latest;
+    // tabindex="-1" lets us focus() without adding the element to tab order
+    latest.setAttribute("tabindex", "-1");
+    latest.focus({ preventScroll: false });
+  }
+
+  // ── Bootstrap: wait for Chainlit to render, then attach everything ───────
+
+  let _messageListObserver = null;
+
+  function onMessageListFound(messageList) {
+    applyLiveRegion(messageList);
+
+    // Watch for new messages being added
+    _messageListObserver = new MutationObserver(function (mutations) {
+      const hasAdditions = mutations.some(function (m) {
+        return m.addedNodes.length > 0;
+      });
+      if (hasAdditions) {
+        // Small delay lets Chainlit finish rendering the new message element
+        setTimeout(function () {
+          focusLatestAssistantMessage(messageList);
+        }, 150);
+      }
+    });
+
+    _messageListObserver.observe(messageList, { childList: true, subtree: true });
+  }
+
+  // Watch the body for the message list to appear (Chainlit is a SPA)
+  const _rootObserver = new MutationObserver(function () {
+    injectSkipLink();
+
+    const messageList = findMessageList();
+    if (messageList) {
+      onMessageListFound(messageList);
+      // No need to keep watching once we found the container
+      _rootObserver.disconnect();
+    }
+  });
+
+  _rootObserver.observe(document.body, { childList: true, subtree: true });
+
+  // Also try immediately in case the app rendered synchronously
+  injectSkipLink();
+  const messageList = findMessageList();
+  if (messageList) {
+    onMessageListFound(messageList);
+    _rootObserver.disconnect();
+  }
+})();

public/custom.css

@@ -0,0 +1,112 @@
+/*
+ * Spielgruppe Pumuckl — Accessibility overrides for Chainlit
+ *
+ * Goals:
+ *  - WCAG 2.1 AA colour contrast (≥ 4.5:1 for normal text, ≥ 3:1 for large text)
+ *  - prefers-reduced-motion: replace animated typing dots with static indicator
+ *  - Skip-to-content link visible on keyboard focus
+ *  - iOS Safari virtual keyboard: use dynamic viewport height so input stays visible
+ */
+
+/* ─── Skip-to-content link ──────────────────────────────────────────────── */
+
+#skip-to-chat {
+  position: absolute;
+  top: -9999px;
+  left: 8px;
+  z-index: 9999;
+  padding: 8px 16px;
+  background: #1a56db;   /* WCAG AA on white: contrast ≈ 5.9:1 */
+  color: #ffffff;
+  font-size: 1rem;
+  font-weight: 600;
+  border-radius: 4px;
+  text-decoration: none;
+  white-space: nowrap;
+}
+
+#skip-to-chat:focus {
+  top: 8px;
+  outline: 3px solid #f97316;
+  outline-offset: 2px;
+}
+
+/* ─── Viewport height fix for iOS Safari virtual keyboard ───────────────── */
+/*
+ * 100dvh (dynamic viewport height) shrinks when the virtual keyboard opens,
+ * keeping the message input visible. Falls back to 100vh on older browsers.
+ */
+
+#root,
+.cl-app,
+[data-testid="layout"],
+.main-container {
+  min-height: 100vh;
+  min-height: 100dvh;
+}
+
+/* ─── Colour contrast overrides ─────────────────────────────────────────── */
+/*
+ * Chainlit's default light theme uses mid-grey text (#6b7280) on white,
+ * which gives ≈ 4.0:1 — below the 4.5:1 AA threshold for normal text.
+ * Override to #595f6b which measures ≈ 4.6:1 on #ffffff.
+ *
+ * Chainlit's dark theme text is #d1d5db on #1c1c1e (≈ 10:1) — already passes.
+ * We only override the light theme muted/secondary colour.
+ */
+
+/* Muted/secondary text — bump from #6b7280 (4.0:1) to #595f6b (≈ 4.6:1) */
+.text-gray-500,
+[class*="text-muted"],
+[class*="secondary"] {
+  color: #595f6b !important;
+}
+
+/* Input placeholder — same issue; force dark enough value */
+input::placeholder,
+textarea::placeholder {
+  color: #595f6b !important;
+  opacity: 1;              /* Firefox reduces opacity by default */
+}
+
+/* ─── Reduced-motion: replace animated typing dots with static "…" ──────── */
+/*
+ * Chainlit shows a bouncing-dots animation while the agent is generating.
+ * When prefers-reduced-motion is set, hide the animation and show "…" instead.
+ */
+
+@media (prefers-reduced-motion: reduce) {
+  /* Hide animated dot elements (Chainlit uses span.dot or similar) */
+  .typing-indicator span,
+  .loader span,
+  [class*="typing"] span,
+  [class*="loader"] span,
+  [class*="bounce"] {
+    animation: none !important;
+    visibility: hidden;
+  }
+
+  /* Show a static ellipsis as the parent container's content */
+  .typing-indicator::after,
+  .loader::after,
+  [class*="typing"]::after,
+  [class*="loader"]::after {
+    content: "…";
+    visibility: visible;
+    display: inline-block;
+    color: inherit;
+    font-size: 1.25rem;
+    line-height: 1;
+    letter-spacing: 0.05em;
+  }
+
+  /* Suppress all other CSS transitions and animations */
+  *,
+  *::before,
+  *::after {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+    scroll-behavior: auto !important;
+  }
+}

pyproject.toml

@@ -10,6 +10,11 @@ dependencies = [
     "python-dotenv>=1.0.0",
     # Registration schema validation
     "jsonschema>=4.23.0",
+    "chainlit>=2.9.6",
+    "qrbill>=1.2.0",
+    "pillow>=12.1.1",
+    "jinja2>=3.0.0",
+    "pyyaml>=6.0.0",
 ]
 
 [project.scripts]
@@ -25,5 +30,9 @@ packages = ["src"]
 [tool.uv]
 dev-dependencies = [
     "pytest>=8.0.0",
+    "pytest-asyncio>=1.3.0",
     "pytest-mock>=3.14.0",
 ]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"

src/agent/core.py

@@ -1,17 +1,16 @@
 """EmailAgent — the channel-agnostic conversation orchestrator."""
 
-import json
 import logging
-import re
 from datetime import datetime, timezone
 
 from ..models.conversation import ConversationState, ChatMessage
-from ..models.registration import BookingDay, RegistrationData
+from ..models.registration import RegistrationData
 from .. import llm
 from ..knowledge_base.loader import KnowledgeBase
 from ..storage.json_store import ConversationStore, normalize_email, _diff_registrations
 from ..notifications.notifier import AdminNotifier
 from .prompts import build_system_prompt
+from .response_parser import apply_updates, fallback_message, parse_llm_response
 
 logger = logging.getLogger(__name__)
 
@@ -32,8 +31,10 @@ class EmailAgent:
         kb: KnowledgeBase,
         store: ConversationStore,
         notifier: AdminNotifier,
+        thinking_budget: int | None = None,
     ) -> None:
         self._model = model
+        self._thinking_budget = thinking_budget
         self._kb = kb
         self._store = store
         self._notifier = notifier
@@ -99,7 +100,7 @@ class EmailAgent:
         system = build_system_prompt(self._kb, state)
 
         try:
-            content = llm.complete(self._model, system, state.messages)
+            content = llm.complete(self._model, system, state.messages, self._thinking_budget)
             parsed = self._parse_llm_response(content)
         except Exception:
             logger.exception("LLM call failed for %s", state.conversation_id)
@@ -128,6 +129,13 @@ class EmailAgent:
                 )
             except Exception:
                 logger.exception("Failed to send admin notification for %s", email_key)
+            try:
+                self._notifier.notify_parent(
+                    registration=state.registration,
+                    language=state.language,
+                )
+            except Exception:
+                logger.exception("Failed to send parent confirmation for %s", email_key)
             logger.info("Registration complete for %s", state.conversation_id)
 
         return reply_text
@@ -141,7 +149,7 @@ class EmailAgent:
         system = build_system_prompt(self._kb, state)
 
         try:
-            content = llm.complete(self._model, system, state.messages)
+            content = llm.complete(self._model, system, state.messages, self._thinking_budget)
             parsed = self._parse_llm_response(content)
         except Exception:
             logger.exception("LLM call failed (post-completion) for %s", state.conversation_id)
@@ -192,79 +200,10 @@ class EmailAgent:
     # ------------------------------------------------------------------
 
     def _parse_llm_response(self, content: str) -> dict:
-        """Extract the JSON payload from the LLM's raw output."""
-        text = content.strip()
-
-        fence_match = re.match(r"^```(?:json)?\s*\n(.*?)\n```\s*$", text, re.DOTALL)
-        if fence_match:
-            text = fence_match.group(1).strip()
-
-        try:
-            return json.loads(text)
-        except json.JSONDecodeError:
-            pass
-
-        brace_match = re.search(r"\{.*\}", text, re.DOTALL)
-        if brace_match:
-            try:
-                return json.loads(brace_match.group())
-            except json.JSONDecodeError:
-                pass
-
-        logger.warning("Could not parse LLM response as JSON — using raw text as reply.")
-        return {
-            "reply": content,
-            "intent": "question",
-            "updates": {},
-            "next_step": "greeting",
-            "registration_complete": False,
-            "language": "de",
-        }
+        return parse_llm_response(content)
 
     def _fallback_message(self, state: ConversationState) -> str:
-        if state.language == "en":
-            return (
-                "I'm sorry, I'm having a technical issue right now. "
-                "Please try again in a moment or contact us directly."
-            )
-        return (
-            "Entschuldigung, ich habe gerade ein technisches Problem. "
-            "Bitte versuche es gleich nochmal oder kontaktiere uns direkt."
-        )
+        return fallback_message(state.language)
 
     def _apply_updates(self, state: ConversationState, updates: dict) -> None:
-        """Write extracted field values into the RegistrationData object."""
-        reg = state.registration
-
-        field_map = {
-            "child.fullName": lambda v: setattr(reg.child, "full_name", v),
-            "child.dateOfBirth": lambda v: setattr(reg.child, "date_of_birth", v),
-            "child.specialNeeds": lambda v: setattr(reg.child, "special_needs", v),
-            "parentGuardian.fullName": lambda v: (
-                setattr(reg.parent_guardian, "full_name", v),
-                setattr(state, "parent_name", v),
-            ),
-            "parentGuardian.streetAddress": lambda v: setattr(reg.parent_guardian, "street_address", v),
-            "parentGuardian.postalCode": lambda v: setattr(reg.parent_guardian, "postal_code", str(v)),
-            "parentGuardian.city": lambda v: setattr(reg.parent_guardian, "city", v),
-            "parentGuardian.phone": lambda v: setattr(reg.parent_guardian, "phone", v),
-            "parentGuardian.email": lambda v: setattr(reg.parent_guardian, "email", v),
-            "emergencyContact.fullName": lambda v: setattr(reg.emergency_contact, "full_name", v),
-            "emergencyContact.phone": lambda v: setattr(reg.emergency_contact, "phone", v),
-        }
-
-        for key, value in updates.items():
-            if value is None:
-                continue
-            if key in field_map:
-                field_map[key](value)
-            elif key == "booking.playgroupTypes" and isinstance(value, list):
-                reg.booking.playgroup_types = value
-            elif key == "booking.selectedDays" and isinstance(value, list):
-                reg.booking.selected_days = [
-                    BookingDay(day=d["day"], type=d["type"])
-                    for d in value
-                    if isinstance(d, dict) and "day" in d and "type" in d
-                ]
-            else:
-                logger.debug("Unknown update key ignored: %s", key)
+        apply_updates(state, updates)

src/agent/prompts.py

@@ -1,6 +1,7 @@
 """Build the system prompt sent to the LLM on every turn."""
 
 import json
+from datetime import date
 
 from ..knowledge_base.loader import KnowledgeBase
 from ..models.conversation import ConversationState
@@ -154,8 +155,12 @@ def _build_registration_prompt(kb: KnowledgeBase, state: ConversationState) -> s
     reg_json = json.dumps(state.registration.to_dict(), ensure_ascii=False, indent=2)
     step_hint = STEP_DESCRIPTIONS.get(state.flow_step, "Continue the conversation.")
 
+    today = date.today().isoformat()
+
     return f"""You are the registration assistant for Spielgruppe Pumuckl, run by Familienverein Fällanden in Fällanden, Switzerland. You help parents register their children for the playgroup and answer questions about it.
 
+**Today's date is {today}.** Use this exact date when calculating a child's age from their date of birth.
+
 {_PERSONALITY}
 
 ## Registration Flow (8 steps)
@@ -200,8 +205,12 @@ def _build_post_completion_prompt(kb: KnowledgeBase, state: ConversationState) -
     reg_json = json.dumps(state.registration.to_dict(), ensure_ascii=False, indent=2)
     child_name = state.registration.child.full_name or "their child"
 
+    today = date.today().isoformat()
+
     return f"""You are the registration assistant for Spielgruppe Pumuckl, run by Familienverein Fällanden in Fällanden, Switzerland.
 
+**Today's date is {today}.**
+
 {_PERSONALITY}
 
 ## Context: Registration Already Complete

src/agent/response_parser.py

@@ -0,0 +1,100 @@
+"""Parse and apply LLM JSON responses — shared between email and chat channels."""
+
+import json
+import logging
+import re
+
+from ..models.conversation import ConversationState
+from ..models.registration import BookingDay
+
+logger = logging.getLogger(__name__)
+
+
+def parse_llm_response(content: str) -> dict:
+    """Extract the JSON payload from the LLM's raw output.
+
+    Tries three strategies in order:
+    1. Entire content is a fenced code block (```json ... ```)
+    2. Entire content is a bare JSON object
+    3. JSON object embedded somewhere in the text
+
+    Falls back to wrapping raw text as a ``reply`` if nothing parses.
+    """
+    text = content.strip()
+
+    fence_match = re.match(r"^```(?:json)?\s*\n(.*?)\n```\s*$", text, re.DOTALL)
+    if fence_match:
+        text = fence_match.group(1).strip()
+
+    try:
+        return json.loads(text)
+    except json.JSONDecodeError:
+        pass
+
+    brace_match = re.search(r"\{.*\}", text, re.DOTALL)
+    if brace_match:
+        try:
+            return json.loads(brace_match.group())
+        except json.JSONDecodeError:
+            pass
+
+    logger.warning("Could not parse LLM response as JSON — using raw text as reply.")
+    return {
+        "reply": content,
+        "intent": "question",
+        "updates": {},
+        "next_step": "greeting",
+        "registration_complete": False,
+        "language": "de",
+    }
+
+
+def apply_updates(state: ConversationState, updates: dict) -> None:
+    """Write extracted field values into the RegistrationData on *state*."""
+    reg = state.registration
+
+    field_map = {
+        "child.fullName": lambda v: setattr(reg.child, "full_name", v),
+        "child.dateOfBirth": lambda v: setattr(reg.child, "date_of_birth", v),
+        "child.specialNeeds": lambda v: setattr(reg.child, "special_needs", v),
+        "parentGuardian.fullName": lambda v: (
+            setattr(reg.parent_guardian, "full_name", v),
+            setattr(state, "parent_name", v),
+        ),
+        "parentGuardian.streetAddress": lambda v: setattr(reg.parent_guardian, "street_address", v),
+        "parentGuardian.postalCode": lambda v: setattr(reg.parent_guardian, "postal_code", str(v)),
+        "parentGuardian.city": lambda v: setattr(reg.parent_guardian, "city", v),
+        "parentGuardian.phone": lambda v: setattr(reg.parent_guardian, "phone", v),
+        "parentGuardian.email": lambda v: setattr(reg.parent_guardian, "email", v),
+        "emergencyContact.fullName": lambda v: setattr(reg.emergency_contact, "full_name", v),
+        "emergencyContact.phone": lambda v: setattr(reg.emergency_contact, "phone", v),
+    }
+
+    for key, value in updates.items():
+        if value is None:
+            continue
+        if key in field_map:
+            field_map[key](value)
+        elif key == "booking.playgroupTypes" and isinstance(value, list):
+            reg.booking.playgroup_types = value
+        elif key == "booking.selectedDays" and isinstance(value, list):
+            reg.booking.selected_days = [
+                BookingDay(day=d["day"], type=d["type"])
+                for d in value
+                if isinstance(d, dict) and "day" in d and "type" in d
+            ]
+        else:
+            logger.debug("Unknown update key ignored: %s", key)
+
+
+def fallback_message(language: str) -> str:
+    """Return a safe error message in the parent's detected language."""
+    if language == "en":
+        return (
+            "I'm sorry, I'm having a technical issue right now. "
+            "Please try again in a moment or contact us directly."
+        )
+    return (
+        "Entschuldigung, ich habe gerade ein technisches Problem. "
+        "Bitte versuche es gleich nochmal oder kontaktiere uns direkt."
+    )

src/config.py

@@ -1,9 +1,12 @@
 """Configuration loaded from environment variables."""
 
+import logging
 import os
 from dataclasses import dataclass, field
 from pathlib import Path
 
+logger = logging.getLogger(__name__)
+
 try:
     from dotenv import load_dotenv
     load_dotenv()
@@ -13,10 +16,17 @@ except ImportError:
 
 @dataclass
 class Config:
-    # AI model — litellm format, e.g. "anthropic/claude-opus-4-6" or "openai/gpt-4o".
+    # Primary model for conversation with parents — litellm format.
     # The matching API key must be set as an env var (ANTHROPIC_API_KEY, OPENAI_API_KEY, …).
+    # Example: "anthropic/claude-opus-4-6", "google/gemini-2.0-flash", "openai/gpt-4o"
     ai_model: str = "anthropic/claude-opus-4-6"
 
+    # Lightweight model for simple tasks such as email-label translation.
+    # Can be from a different provider than ai_model.
+    # If not configured (SIMPLE_MODEL env var unset), falls back to ai_model with a warning.
+    # Example: "anthropic/claude-haiku-4-5-20251001", "openai/gpt-4o-mini"
+    simple_model: str = ""
+
     # Email — IMAP (receiving)
     imap_host: str = ""
     imap_port: int = 993
@@ -50,10 +60,25 @@ class Config:
     # Polling interval in seconds
     poll_interval: int = 60
 
+    # Extended thinking — Anthropic models only.
+    # When set, enables the thinking phase before the LLM replies.
+    # Recommended value: 8000 (tokens). Set to None/unset to disable.
+    thinking_budget: int | None = None
+
     @classmethod
     def from_env(cls) -> "Config":
+        ai_model = os.getenv("AI_MODEL", "anthropic/claude-opus-4-6")
+        simple_model = os.getenv("SIMPLE_MODEL", "")
+        if not simple_model:
+            logger.warning(
+                "SIMPLE_MODEL not configured — falling back to AI_MODEL (%s) for simple tasks "
+                "(set SIMPLE_MODEL to a cheaper model, e.g. anthropic/claude-haiku-4-5-20251001)",
+                ai_model,
+            )
+            simple_model = ai_model
         return cls(
-            ai_model=os.getenv("AI_MODEL", "anthropic/claude-opus-4-6"),
+            ai_model=ai_model,
+            simple_model=simple_model,
             imap_host=os.getenv("IMAP_HOST", ""),
             imap_port=int(os.getenv("IMAP_PORT", "993")),
             imap_username=os.getenv("IMAP_USERNAME", ""),
@@ -74,4 +99,9 @@ class Config:
                 )
             ),
             poll_interval=int(os.getenv("POLL_INTERVAL", "60")),
+            thinking_budget=(
+                int(os.getenv("THINKING_BUDGET"))
+                if os.getenv("THINKING_BUDGET")
+                else None
+            ),
         )

src/llm.py

@@ -1,9 +1,50 @@
 """LLM completion via litellm — supports any provider with a single call."""
 
+from collections.abc import Generator
+
 import litellm
 
 
-def complete(model: str, system: str, messages: list) -> str:
+async def acomplete(
+    model: str,
+    system: str,
+    messages: list,
+    thinking_budget: int | None = None,
+) -> str:
+    """Call any LLM asynchronously and return the response text.
+
+    This is the async equivalent of ``complete()`` — use this from async
+    handlers (e.g. Chainlit's ``@cl.on_message``) to avoid blocking the
+    event loop and losing framework context variables.
+
+    Args:
+        model: litellm model string, e.g. "anthropic/claude-opus-4-6".
+        system: System prompt text.
+        messages: List of objects with .role and .content attributes.
+        thinking_budget: When set, enables extended thinking (Anthropic models
+            only). See ``complete()`` for details.
+
+    Returns:
+        The model's reply as a plain string.
+    """
+    api_messages = [{"role": "system", "content": system}]
+    api_messages += [{"role": m.role, "content": m.content} for m in messages]
+
+    kwargs: dict = {"model": model, "messages": api_messages, "max_tokens": 2048}
+    if thinking_budget is not None:
+        kwargs["thinking"] = {"type": "enabled", "budget_tokens": thinking_budget}
+        kwargs["max_tokens"] = thinking_budget + 4096
+
+    response = await litellm.acompletion(**kwargs)
+    return response.choices[0].message.content
+
+
+def complete(
+    model: str,
+    system: str,
+    messages: list,
+    thinking_budget: int | None = None,
+) -> str:
     """Call any LLM and return the response text.
 
     Args:
@@ -12,11 +53,46 @@ def complete(model: str, system: str, messages: list) -> str:
                environment variable (ANTHROPIC_API_KEY, OPENAI_API_KEY, …).
         system: System prompt text.
         messages: List of objects with .role and .content attributes.
+        thinking_budget: When set, enables extended thinking (Anthropic models
+            only). The value is the token budget for the thinking phase; the
+            final ``max_tokens`` is set to ``thinking_budget + 4096`` so the
+            model has enough room to both think and reply.
 
     Returns:
         The model's reply as a plain string.
     """
     api_messages = [{"role": "system", "content": system}]
     api_messages += [{"role": m.role, "content": m.content} for m in messages]
-    response = litellm.completion(model=model, messages=api_messages, max_tokens=2048)
+
+    kwargs: dict = {"model": model, "messages": api_messages, "max_tokens": 2048}
+    if thinking_budget is not None:
+        kwargs["thinking"] = {"type": "enabled", "budget_tokens": thinking_budget}
+        # max_tokens must exceed budget_tokens or the API returns an error.
+        kwargs["max_tokens"] = thinking_budget + 4096
+
+    response = litellm.completion(**kwargs)
     return response.choices[0].message.content
+
+
+def stream_complete(
+    model: str, system: str, messages: list
+) -> Generator[str, None, None]:
+    """Call any LLM with streaming and yield text chunks as they arrive.
+
+    Args:
+        model: litellm model string (same format as ``complete``).
+        system: System prompt text.
+        messages: List of objects with .role and .content attributes.
+
+    Yields:
+        Non-empty text chunks from the model's streamed response.
+    """
+    api_messages = [{"role": "system", "content": system}]
+    api_messages += [{"role": m.role, "content": m.content} for m in messages]
+    response = litellm.completion(
+        model=model, messages=api_messages, max_tokens=2048, stream=True
+    )
+    for chunk in response:
+        delta = chunk.choices[0].delta.content
+        if delta:
+            yield delta

src/notifications/context.py

@@ -0,0 +1,204 @@
+"""Pure functions for building email context dicts from registration data."""
+
+from datetime import date, datetime
+
+from ..models.registration import RegistrationData
+
+# ---------------------------------------------------------------------------
+# Swiss QR-bill payment constants (stable bank details — not in config)
+# ---------------------------------------------------------------------------
+
+QR_IBAN = "CH14 0900 0000 4930 8018 8"
+QR_PAYEE = "Familienverein Fällanden Spielgruppen"
+QR_STREET = "Huebwisstrase 5"
+QR_PCODE = "8117"
+QR_CITY = "Fällanden"
+
+# ---------------------------------------------------------------------------
+# Formatting helpers (pure functions, no side-effects)
+# ---------------------------------------------------------------------------
+
+
+def format_dob(dob_str: str) -> str:
+    """Return DD.MM.YYYY from a YYYY-MM-DD string, or the original on error."""
+    try:
+        return datetime.strptime(dob_str, "%Y-%m-%d").strftime("%d.%m.%Y")
+    except Exception:
+        return dob_str or ""
+
+
+def calculate_age(dob_str: str) -> str:
+    """Return 'X Jahre, Y Monate' from a YYYY-MM-DD string."""
+    try:
+        dob = datetime.strptime(dob_str, "%Y-%m-%d").date()
+        today = date.today()
+        years = today.year - dob.year - (
+            (today.month, today.day) < (dob.month, dob.day)
+        )
+        months = (today.month - dob.month) % 12
+        return f"{years} Jahre, {months} Monate"
+    except Exception:
+        return dob_str
+
+
+def format_types(types: list[str]) -> str:
+    """German label for a list of playgroup type keys (admin emails)."""
+    has_indoor = "indoor" in types
+    has_outdoor = "outdoor" in types
+    if has_indoor and has_outdoor:
+        return "Innen- und Waldspielgruppe"
+    if has_indoor:
+        return "Innenspielgruppe"
+    if has_outdoor:
+        return "Waldspielgruppe"
+    return "Spielgruppe"
+
+
+def format_types_i18n(types: list[str], strings: dict) -> str:
+    """Localised label for playgroup type keys using the supplied string table."""
+    type_map: dict = strings["types"]
+    labels = [type_map.get(t, t) for t in types]
+    return ", ".join(labels) if labels else ""
+
+
+def format_days(registration: RegistrationData) -> str:
+    """German day + type labels for admin emails."""
+    day_map = {"monday": "Montag", "wednesday": "Mittwoch", "thursday": "Donnerstag"}
+    type_map = {"indoor": "Innenspielgruppe", "outdoor": "Waldspielgruppe"}
+    return ", ".join(
+        f"{day_map.get(d.day, d.day.capitalize())} ({type_map.get(d.type, d.type)})"
+        for d in registration.booking.selected_days
+    )
+
+
+def format_days_i18n(registration: RegistrationData, strings: dict) -> str:
+    """Localised day + type labels using the supplied string table."""
+    day_map: dict = strings["days"]
+    type_map: dict = strings["types"]
+    return ", ".join(
+        f"{day_map.get(d.day, d.day.capitalize())} ({type_map.get(d.type, d.type)})"
+        for d in registration.booking.selected_days
+    )
+
+
+def calculate_monthly_fee(registration: RegistrationData) -> str:
+    """Compute the monthly fee string from the booking selection."""
+    indoor_days = sum(1 for d in registration.booking.selected_days if d.type == "indoor")
+    outdoor_days = sum(1 for d in registration.booking.selected_days if d.type == "outdoor")
+    fee = indoor_days * 130 + outdoor_days * 250
+    return f"CHF {fee}.-"
+
+
+# ---------------------------------------------------------------------------
+# Context builders
+# ---------------------------------------------------------------------------
+
+
+def build_admin_new_context(
+    registration: RegistrationData,
+    registration_id: str,
+    version: int,
+    channel: str,
+) -> dict:
+    """Build the template context for the admin new-registration email."""
+    now = datetime.utcnow()
+    pg = registration.parent_guardian
+    ec = registration.emergency_contact
+    ch = registration.child
+    channel_de = {"email": "E-Mail", "chat": "Chat"}.get(channel.lower(), channel.title())
+
+    return {
+        "submitted_date": now.strftime("%d.%m.%Y"),
+        "submitted_time": now.strftime("%H:%M"),
+        "channel": channel_de,
+        "registration_id": registration_id,
+        "version": version,
+        "child_name": ch.full_name or "",
+        "child_dob": format_dob(ch.date_of_birth or ""),
+        "child_age": calculate_age(ch.date_of_birth or ""),
+        "child_needs": ch.special_needs or "Keine",
+        "playgroup_types": format_types(registration.booking.playgroup_types),
+        "days": format_days(registration),
+        "monthly_fee": calculate_monthly_fee(registration),
+        "parent_name": pg.full_name or "",
+        "parent_street": pg.street_address or "",
+        "parent_postal_code": pg.postal_code or "",
+        "parent_city": pg.city or "",
+        "parent_phone": pg.phone or "",
+        "parent_email": pg.email or "",
+        "emergency_name": ec.full_name or "",
+        "emergency_phone": ec.phone or "",
+    }
+
+
+def build_admin_update_context(
+    registration: RegistrationData,
+    registration_id: str,
+    version: int,
+    change_summary: dict,
+) -> dict:
+    """Build the template context for the admin registration-update email."""
+    now = datetime.utcnow()
+    pg = registration.parent_guardian
+
+    changes = [
+        {"field": field_path, "old": values["old"], "new": values["new"]}
+        for field_path, values in sorted(change_summary.items())
+    ]
+
+    return {
+        "updated_date": now.strftime("%d.%m.%Y"),
+        "updated_time": now.strftime("%H:%M"),
+        "registration_id": registration_id,
+        "version": version,
+        "child_name": registration.child.full_name or "",
+        "parent_email": pg.email or "",
+        "changes": changes,
+        "playgroup_types": format_types(registration.booking.playgroup_types),
+        "days": format_days(registration),
+        "monthly_fee": calculate_monthly_fee(registration),
+        "parent_name": pg.full_name or "",
+        "parent_street": pg.street_address or "",
+        "parent_postal_code": pg.postal_code or "",
+        "parent_city": pg.city or "",
+        "parent_phone": pg.phone or "",
+    }
+
+
+def build_parent_context(
+    registration: RegistrationData,
+    strings: dict,
+    has_qr: bool = True,
+) -> dict:
+    """Build the template context for the parent confirmation email."""
+    pg = registration.parent_guardian
+    ec = registration.emergency_contact
+    ch = registration.child
+    parent_name = pg.full_name or pg.email or ""
+
+    return {
+        "lang": "de" if strings.get("none") == "Keine" else "en",
+        "strings": strings,
+        "greeting": strings["greeting"].format(name=parent_name),
+        "child_name": ch.full_name or "",
+        "child_dob": format_dob(ch.date_of_birth or ""),
+        "child_needs": ch.special_needs or strings["none"],
+        "playgroup_types": format_types_i18n(registration.booking.playgroup_types, strings),
+        "days": format_days_i18n(registration, strings),
+        "monthly_fee": calculate_monthly_fee(registration),
+        "has_indoor": "indoor" in registration.booking.playgroup_types,
+        "has_qr": has_qr,
+        "parent_name": pg.full_name or "",
+        "parent_address": pg.street_address or "",
+        "parent_postal_code": pg.postal_code or "",
+        "parent_city": pg.city or "",
+        "parent_phone": pg.phone or "",
+        "parent_email": pg.email or "",
+        "emergency_name": ec.full_name or "",
+        "emergency_phone": ec.phone or "",
+        "iban": QR_IBAN,
+        "payee": QR_PAYEE,
+        "payee_street": QR_STREET,
+        "payee_postal_code": QR_PCODE,
+        "payee_city": QR_CITY,
+    }

src/notifications/i18n.py

@@ -0,0 +1,103 @@
+"""i18n support for parent confirmation emails.
+
+German is the canonical source language (de.yaml).  For any other language
+the German labels are translated on-demand via an LLM call and cached
+in-process for the lifetime of the server — no static translation files to
+maintain, any language the parent writes in is supported automatically.
+"""
+
+import json
+import logging
+from pathlib import Path
+
+import litellm
+import yaml
+
+logger = logging.getLogger(__name__)
+
+_I18N_DIR = Path(__file__).parent / "i18n"
+
+# In-memory translation cache keyed by language code.
+_cache: dict[str, dict] = {}
+
+# Pure data values that must never be sent to the LLM for translation.
+_PASSTHROUGH_KEYS = {"reg_fee_amount", "deposit_amount"}
+
+_SYSTEM_PROMPT = """\
+You are a translation assistant for a Swiss playgroup registration system.
+Translate the following JSON label strings from German into {language}.
+
+Rules:
+- Return ONLY a valid JSON object with the exact same keys and structure.
+- Preserve all {{placeholder}} variables exactly as-is (e.g. {{name}}).
+- Preserve all HTML tags and entities exactly (e.g. <strong>, &nbsp;).
+- Keep proper nouns untranslated: "Spielgruppe Pumuckl", "Familienverein Fällanden".
+- Do not include any explanation or text outside the JSON."""
+
+
+def get_strings(language: str, model: str) -> dict:
+    """Return the label string table for *language*.
+
+    For German, loads directly from de.yaml (no LLM call).
+    For all other languages, translates the German labels via LLM and caches
+    the result in memory.  Falls back to German if the LLM call fails.
+    """
+    if language == "de":
+        return _load_german()
+
+    if language in _cache:
+        return _cache[language]
+
+    german = _load_german()
+    translated = _translate(german, language, model)
+    _cache[language] = translated
+    return translated
+
+
+def clear_cache() -> None:
+    """Evict all cached translations (intended for use in tests)."""
+    _cache.clear()
+
+
+def _load_german() -> dict:
+    with (_I18N_DIR / "de.yaml").open(encoding="utf-8") as fh:
+        return yaml.safe_load(fh)
+
+
+def _translate(german: dict, language: str, model: str) -> dict:
+    """Translate the German label dict into *language* via LLM.
+
+    Returns the German dict unchanged if the LLM call fails or returns
+    malformed JSON.
+    """
+    passthrough = {k: german[k] for k in _PASSTHROUGH_KEYS if k in german}
+    to_translate = {k: v for k, v in german.items() if k not in _PASSTHROUGH_KEYS}
+
+    system = _SYSTEM_PROMPT.format(language=language)
+    payload = json.dumps(to_translate, ensure_ascii=False, indent=2)
+
+    try:
+        response = litellm.completion(
+            model=model,
+            messages=[
+                {"role": "system", "content": system},
+                {"role": "user", "content": payload},
+            ],
+            max_tokens=2048,
+        )
+        raw = response.choices[0].message.content.strip()
+
+        # Strip markdown code fences that some models add
+        if raw.startswith("```"):
+            raw = raw[raw.index("\n") + 1 :]
+            raw = raw[: raw.rfind("```")]
+
+        translated: dict = json.loads(raw)
+        translated.update(passthrough)
+        return translated
+
+    except Exception:
+        logger.exception(
+            "Failed to translate email labels into %s — falling back to German", language
+        )
+        return german

src/notifications/i18n/de.yaml

@@ -0,0 +1,57 @@
+subject: "Anmeldebestätigung – Spielgruppe Pumuckl"
+greeting: "Guten Tag {name}"
+intro: >-
+  Deine Anmeldung für die Spielgruppe Pumuckl ist bei uns eingegangen.
+  Hier ist eine Zusammenfassung:
+
+child_section: "Angaben zum Kind"
+child_name: "Name"
+child_dob: "Geburtsdatum"
+child_needs: "Besondere Bedürfnisse"
+
+booking_section: "Spielgruppen-Buchung"
+booking_type: "Art"
+booking_days: "Tage"
+
+fees_section: "Kosten"
+monthly_fee: "Monatlicher Beitrag"
+reg_fee: "Anmeldegebühr (einmalig, erstes Jahr)"
+reg_fee_amount: "CHF 80.00"
+deposit: "Reinigungsdepot Innen (rückerstattbar)"
+deposit_amount: "CHF 50.00"
+
+parent_section: "Deine Kontaktdaten"
+parent_name: "Name"
+parent_address: "Adresse"
+parent_phone: "Telefon"
+parent_email: "E-Mail"
+
+emergency_section: "Notfallkontakt"
+emergency_name: "Name"
+emergency_phone: "Telefon"
+
+payment_section: "Zahlungsinformationen"
+payment_intro: >-
+  Bitte überweise die Anmeldegebühr von <strong>CHF&nbsp;80.00</strong> auf folgendes Konto.
+  Du kannst den QR-Code mit deiner Banking-App scannen:
+payment_intro_text: "Bitte überweise die Anmeldegebühr von CHF 80.00 auf folgendes Konto:"
+iban_label: "IBAN"
+payee_label: "Empfänger"
+amount_label: "Betrag"
+
+closing: |
+  Bei Fragen stehen wir dir gerne zur Verfügung. Wir freuen uns auf dein Kind!
+
+  Herzliche Grüsse
+  Spielgruppe Pumuckl
+
+none: "Keine"
+
+days:
+  monday: "Montag"
+  wednesday: "Mittwoch"
+  thursday: "Donnerstag"
+
+types:
+  indoor: "Innenspielgruppe"
+  outdoor: "Waldspielgruppe"

src/notifications/notifier.py

@@ -1,12 +1,31 @@
-"""Admin email notifications — new registrations and registration updates."""
+"""Admin email notifications — new registrations, updates, and parent confirmations."""
 
+import io
 import logging
 import smtplib
-from datetime import date, datetime
+from email.mime.image import MIMEImage
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 
+import qrcode
+import qrcode.constants
+from PIL import Image, ImageDraw
+from qrbill import QRBill
+
 from ..models.registration import RegistrationData
+from .context import (
+    QR_CITY,
+    QR_IBAN,
+    QR_PAYEE,
+    QR_PCODE,
+    QR_STREET,
+    build_admin_new_context,
+    build_admin_update_context,
+    build_parent_context,
+    format_types,
+)
+from .i18n import get_strings
+from .renderer import render_template
 
 logger = logging.getLogger(__name__)
 
@@ -32,6 +51,7 @@ class AdminNotifier:
         indoor_email: str = "",
         outdoor_email: str = "",
         cc_emails: list[str] | None = None,
+        model: str = "anthropic/claude-haiku-4-5-20251001",
     ) -> None:
         self._smtp_host = smtp_host
         self._smtp_port = smtp_port
@@ -42,6 +62,7 @@ class AdminNotifier:
         self._indoor_email = indoor_email
         self._outdoor_email = outdoor_email
         self._cc_emails: list[str] = cc_emails or []
+        self._model = model
 
     # ------------------------------------------------------------------
     # Public API
@@ -67,9 +88,10 @@ class AdminNotifier:
 
         subject = (
             f"Neue Anmeldung: {registration.child.full_name} "
-            f"– {self._format_types(types)}"
+            f"– {format_types(types)}"
         )
-        body = self._build_new_body(registration, registration_id, version, channel)
+        ctx = build_admin_new_context(registration, registration_id, version, channel)
+        body = render_template("admin_new.txt.j2", ctx)
 
         self._send(
             to=to_addresses,
@@ -98,7 +120,8 @@ class AdminNotifier:
             return
 
         subject = f"Anmeldung aktualisiert: {registration.child.full_name}"
-        body = self._build_update_body(registration, registration_id, version, change_summary)
+        ctx = build_admin_update_context(registration, registration_id, version, change_summary)
+        body = render_template("admin_update.txt.j2", ctx)
 
         self._send(
             to=to_addresses,
@@ -108,6 +131,80 @@ class AdminNotifier:
             reply_to=registration.parent_guardian.email or "",
         )
 
+    def notify_parent(
+        self,
+        registration: RegistrationData,
+        language: str = "de",
+    ) -> None:
+        """Send an HTML confirmation email to the parent with registration summary and QR-bill."""
+        parent_email = registration.parent_guardian.email
+        if not parent_email:
+            logger.warning("No parent email in registration — confirmation not sent.")
+            return
+
+        strings = get_strings(language, self._model)
+
+        try:
+            qr_png = self._generate_qr_bill_png()
+        except Exception:
+            logger.exception("Failed to generate QR-bill PNG — omitting image from confirmation")
+            qr_png = None
+
+        ctx = build_parent_context(registration, strings, has_qr=qr_png is not None)
+        html_body = render_template("parent_confirmation.html.j2", ctx)
+        text_body = render_template("parent_confirmation.txt.j2", ctx)
+        subject = strings["subject"]
+
+        if not self._smtp_host:
+            logger.warning(
+                "SMTP not configured — parent confirmation NOT sent. Would have emailed %s: %s",
+                parent_email,
+                subject,
+            )
+            logger.debug("Parent confirmation body:\n%s", text_body)
+            return
+
+        # MIME structure:
+        # multipart/mixed
+        # └── multipart/alternative
+        #     ├── text/plain  (fallback)
+        #     └── multipart/related
+        #         ├── text/html  (references cid:qrbill)
+        #         └── image/png  (Content-ID: qrbill, inline)
+        msg_outer = MIMEMultipart("mixed")
+        msg_outer["From"] = self._from_email
+        msg_outer["To"] = parent_email
+        msg_outer["Subject"] = subject
+
+        msg_alt = MIMEMultipart("alternative")
+        msg_alt.attach(MIMEText(text_body, "plain", "utf-8"))
+
+        if qr_png is not None:
+            msg_related = MIMEMultipart("related")
+            msg_related.attach(MIMEText(html_body, "html", "utf-8"))
+            img_part = MIMEImage(qr_png, "png")
+            img_part.add_header("Content-ID", "<qrbill>")
+            img_part.add_header("Content-Disposition", "inline", filename="qrbill.png")
+            msg_related.attach(img_part)
+            msg_alt.attach(msg_related)
+        else:
+            msg_alt.attach(MIMEText(html_body, "html", "utf-8"))
+
+        msg_outer.attach(msg_alt)
+
+        try:
+            if self._use_tls:
+                server = smtplib.SMTP(self._smtp_host, self._smtp_port)
+                server.starttls()
+            else:
+                server = smtplib.SMTP_SSL(self._smtp_host, self._smtp_port)
+            server.login(self._username, self._password)
+            server.sendmail(self._from_email, [parent_email], msg_outer.as_string())
+            server.quit()
+            logger.info("Parent confirmation sent to %s", parent_email)
+        except Exception:
+            logger.exception("Failed to send parent confirmation to %s", parent_email)
+
     # ------------------------------------------------------------------
     # Routing helpers
     # ------------------------------------------------------------------
@@ -122,178 +219,58 @@ class AdminNotifier:
         return recipients
 
     # ------------------------------------------------------------------
-    # Formatting helpers
+    # QR-bill generation
     # ------------------------------------------------------------------
 
     @staticmethod
-    def _format_types(types: list[str]) -> str:
-        has_indoor = "indoor" in types
-        has_outdoor = "outdoor" in types
-        if has_indoor and has_outdoor:
-            return "Innen- und Waldspielgruppe"
-        if has_indoor:
-            return "Innenspielgruppe"
-        if has_outdoor:
-            return "Waldspielgruppe"
-        return "Spielgruppe"
+    def _generate_qr_bill_png() -> bytes:
+        """Generate a Swiss QR-bill payment QR code as a PNG image.
 
-    @staticmethod
-    def _calculate_age(dob_str: str) -> str:
-        try:
-            dob = datetime.strptime(dob_str, "%Y-%m-%d").date()
-            today = date.today()
-            years = today.year - dob.year - (
-                (today.month, today.day) < (dob.month, dob.day)
+        Uses the fixed registration fee payment data (CHF 80.00).
+        The QR code includes the Swiss cross overlay as required by the SIX Group standard.
+
+        Returns:
+            PNG image bytes of the QR code.
+        """
+        bill = QRBill(
+            account=QR_IBAN,
+            creditor={
+                "name": QR_PAYEE,
+                "street": QR_STREET,
+                "pcode": QR_PCODE,
+                "city": QR_CITY,
+                "country": "CH",
+            },
+            amount="80.00",
+            currency="CHF",
         )
-            months = (today.month - dob.month) % 12
-            return f"{years} Jahre, {months} Monate"
-        except Exception:
-            return dob_str
+        payload = bill.qr_data()
 
-    @staticmethod
-    def _format_dob(dob_str: str) -> str:
-        try:
-            return datetime.strptime(dob_str, "%Y-%m-%d").strftime("%d.%m.%Y")
-        except Exception:
-            return dob_str or ""
-
-    @staticmethod
-    def _calculate_monthly_fee(registration: RegistrationData) -> str:
-        indoor_days = sum(1 for d in registration.booking.selected_days if d.type == "indoor")
-        outdoor_days = sum(1 for d in registration.booking.selected_days if d.type == "outdoor")
-        fee = 0
-        if indoor_days == 1:
-            fee += 130
-        elif indoor_days == 2:
-            fee += 260
-        elif indoor_days >= 3:
-            fee += 390
-        if outdoor_days >= 1:
-            fee += 250
-        return f"CHF {fee}.-"
-
-    @staticmethod
-    def _format_days(registration: RegistrationData) -> str:
-        day_map = {"monday": "Montag", "wednesday": "Mittwoch", "thursday": "Donnerstag"}
-        type_map = {"indoor": "Innenspielgruppe", "outdoor": "Waldspielgruppe"}
-        return ", ".join(
-            f"{day_map.get(d.day, d.day.capitalize())} ({type_map.get(d.type, d.type)})"
-            for d in registration.booking.selected_days
+        qr = qrcode.QRCode(
+            version=None,
+            error_correction=qrcode.constants.ERROR_CORRECT_M,
+            box_size=8,
+            border=4,
         )
+        qr.add_data(payload)
+        qr.make(fit=True)
+        pil_img: Image.Image = qr.make_image(fill_color="black", back_color="white").get_image()
+        pil_img = pil_img.convert("RGB")
 
-    @staticmethod
-    def _format_change_summary(change_summary: dict) -> str:
-        """Render field changes as a human-readable list."""
-        lines = []
-        for field_path, values in sorted(change_summary.items()):
-            old_val, new_val = values["old"], values["new"]
-            lines.append(f"  {field_path}:")
-            lines.append(f"    Alt: {old_val}")
-            lines.append(f"    Neu: {new_val}")
-        return "\n".join(lines) if lines else "  (keine Änderungen erkannt)"
+        # Overlay Swiss cross in center (SIX Group standard)
+        w, h = pil_img.size
+        cross_size = max(int(w * 0.15), 20)
+        cx, cy = w // 2, h // 2
+        half = cross_size // 2
+        bar = cross_size // 5
+        draw = ImageDraw.Draw(pil_img)
+        draw.rectangle([cx - half, cy - half, cx + half, cy + half], fill="white")
+        draw.rectangle([cx - bar // 2, cy - half, cx + bar // 2, cy + half], fill="#FF0000")
+        draw.rectangle([cx - half, cy - bar // 2, cx + half, cy + bar // 2], fill="#FF0000")
 
-    # ------------------------------------------------------------------
-    # Email body builders
-    # ------------------------------------------------------------------
-
-    def _build_new_body(
-        self,
-        registration: RegistrationData,
-        registration_id: str,
-        version: int,
-        channel: str,
-    ) -> str:
-        now = datetime.utcnow()
-        pg = registration.parent_guardian
-        ec = registration.emergency_contact
-        channel_de = {"email": "E-Mail", "chat": "Chat"}.get(channel.lower(), channel.title())
-
-        return (
-            "===============================================\n"
-            "NEUE SPIELGRUPPEN-ANMELDUNG\n"
-            "===============================================\n"
-            "\n"
-            f"Eingereicht:     {now.strftime('%d.%m.%Y')} um {now.strftime('%H:%M')} Uhr (UTC)\n"
-            f"Kanal:           {channel_de}\n"
-            f"Anmelde-ID:      {registration_id}  (Version {version})\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "ANGABEN ZUM KIND\n"
-            "-----------------------------------------------\n"
-            f"Name:            {registration.child.full_name}\n"
-            f"Geburtsdatum:    {self._format_dob(registration.child.date_of_birth or '')} "
-            f"(Alter: {self._calculate_age(registration.child.date_of_birth or '')})\n"
-            f"Bes. Bedürfnisse: {registration.child.special_needs or 'Keine'}\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "SPIELGRUPPEN-AUSWAHL\n"
-            "-----------------------------------------------\n"
-            f"Art:             {self._format_types(registration.booking.playgroup_types)}\n"
-            f"Tage:            {self._format_days(registration)}\n"
-            "\n"
-            f"Monatlicher Beitrag: {self._calculate_monthly_fee(registration)}\n"
-            "(Zzgl. CHF 80 Anmeldegebühr bei Erstanmeldung)\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "ELTERN / ERZIEHUNGSBERECHTIGTE\n"
-            "-----------------------------------------------\n"
-            f"Name:            {pg.full_name}\n"
-            f"Adresse:         {pg.street_address}\n"
-            f"                 {pg.postal_code} {pg.city}\n"
-            f"Telefon:         {pg.phone}\n"
-            f"E-Mail:          {pg.email}\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "NOTFALLKONTAKT\n"
-            "-----------------------------------------------\n"
-            f"Name:            {ec.full_name}\n"
-            f"Telefon:         {ec.phone}\n"
-            "\n"
-            "===============================================\n"
-            "\n"
-            "Diese Anmeldung wurde über den automatischen Anmeldeassistenten eingereicht.\n"
-        )
-
-    def _build_update_body(
-        self,
-        registration: RegistrationData,
-        registration_id: str,
-        version: int,
-        change_summary: dict,
-    ) -> str:
-        now = datetime.utcnow()
-        pg = registration.parent_guardian
-
-        return (
-            "===============================================\n"
-            "ANMELDUNGS-AKTUALISIERUNG\n"
-            "===============================================\n"
-            "\n"
-            f"Aktualisiert:    {now.strftime('%d.%m.%Y')} um {now.strftime('%H:%M')} Uhr (UTC)\n"
-            f"Anmelde-ID:      {registration_id}  (Version {version})\n"
-            f"Kind:            {registration.child.full_name}\n"
-            f"Eltern-E-Mail:   {pg.email}\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "WAS HAT SICH GEÄNDERT\n"
-            "-----------------------------------------------\n"
-            f"{self._format_change_summary(change_summary)}\n"
-            "\n"
-            "-----------------------------------------------\n"
-            "AKTUELLE ANMELDUNG (nach Aktualisierung)\n"
-            "-----------------------------------------------\n"
-            f"Spielgruppe:     {self._format_types(registration.booking.playgroup_types)}\n"
-            f"Tage:            {self._format_days(registration)}\n"
-            f"Monatl. Beitrag: {self._calculate_monthly_fee(registration)}\n"
-            "\n"
-            f"Elternteil:      {pg.full_name}\n"
-            f"Adresse:         {pg.street_address}, {pg.postal_code} {pg.city}\n"
-            f"Telefon:         {pg.phone}\n"
-            "\n"
-            "===============================================\n"
-            "\n"
-            "Diese Aktualisierung wurde über den automatischen Anmeldeassistenten eingereicht.\n"
-        )
+        buf = io.BytesIO()
+        pil_img.save(buf, format="PNG")
+        return buf.getvalue()
 
     # ------------------------------------------------------------------
     # SMTP dispatch

src/notifications/renderer.py

@@ -0,0 +1,18 @@
+"""Jinja2 template renderer for email notifications."""
+
+from pathlib import Path
+
+from jinja2 import Environment, FileSystemLoader, select_autoescape
+
+_TEMPLATES_DIR = Path(__file__).parent / "templates"
+
+_env = Environment(
+    loader=FileSystemLoader(str(_TEMPLATES_DIR)),
+    autoescape=select_autoescape(enabled_extensions=["html.j2"]),
+    keep_trailing_newline=True,
+)
+
+
+def render_template(name: str, context: dict) -> str:
+    """Render *name* (relative to the templates directory) with *context*."""
+    return _env.get_template(name).render(**context)

src/notifications/templates/admin_new.txt.j2

@@ -0,0 +1,42 @@
+===============================================
+NEUE SPIELGRUPPEN-ANMELDUNG
+===============================================
+
+Eingereicht:     {{ submitted_date }} um {{ submitted_time }} Uhr (UTC)
+Kanal:           {{ channel }}
+Anmelde-ID:      {{ registration_id }}  (Version {{ version }})
+
+-----------------------------------------------
+ANGABEN ZUM KIND
+-----------------------------------------------
+Name:            {{ child_name }}
+Geburtsdatum:    {{ child_dob }} (Alter: {{ child_age }})
+Bes. Bedürfnisse: {{ child_needs }}
+
+-----------------------------------------------
+SPIELGRUPPEN-AUSWAHL
+-----------------------------------------------
+Art:             {{ playgroup_types }}
+Tage:            {{ days }}
+
+Monatlicher Beitrag: {{ monthly_fee }}
+(Zzgl. CHF 80 Anmeldegebühr bei Erstanmeldung)
+
+-----------------------------------------------
+ELTERN / ERZIEHUNGSBERECHTIGTE
+-----------------------------------------------
+Name:            {{ parent_name }}
+Adresse:         {{ parent_street }}
+                 {{ parent_postal_code }} {{ parent_city }}
+Telefon:         {{ parent_phone }}
+E-Mail:          {{ parent_email }}
+
+-----------------------------------------------
+NOTFALLKONTAKT
+-----------------------------------------------
+Name:            {{ emergency_name }}
+Telefon:         {{ emergency_phone }}
+
+===============================================
+
+Diese Anmeldung wurde über den automatischen Anmeldeassistenten eingereicht.

src/notifications/templates/admin_update.txt.j2

@@ -0,0 +1,33 @@
+===============================================
+ANMELDUNGS-AKTUALISIERUNG
+===============================================
+
+Aktualisiert:    {{ updated_date }} um {{ updated_time }} Uhr (UTC)
+Anmelde-ID:      {{ registration_id }}  (Version {{ version }})
+Kind:            {{ child_name }}
+Eltern-E-Mail:   {{ parent_email }}
+
+-----------------------------------------------
+WAS HAT SICH GEÄNDERT
+-----------------------------------------------
+{% for change in changes %}
+  {{ change.field }}:
+    Alt: {{ change.old }}
+    Neu: {{ change.new }}
+{% else %}
+  (keine Änderungen erkannt)
+{% endfor %}
+-----------------------------------------------
+AKTUELLE ANMELDUNG (nach Aktualisierung)
+-----------------------------------------------
+Spielgruppe:     {{ playgroup_types }}
+Tage:            {{ days }}
+Monatl. Beitrag: {{ monthly_fee }}
+
+Elternteil:      {{ parent_name }}
+Adresse:         {{ parent_street }}, {{ parent_postal_code }} {{ parent_city }}
+Telefon:         {{ parent_phone }}
+
+===============================================
+
+Diese Aktualisierung wurde über den automatischen Anmeldeassistenten eingereicht.

src/notifications/templates/parent_confirmation.html.j2

@@ -0,0 +1,81 @@
+<!DOCTYPE html>
+<html lang="{{ lang }}">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width,initial-scale=1">
+</head>
+<body style="font-family:Arial,sans-serif;color:#333;max-width:600px;margin:0 auto;padding:20px;">
+
+<div style="background:#2e7d32;color:white;padding:20px;border-radius:8px 8px 0 0;text-align:center;">
+  <h1 style="margin:0;font-size:22px;">Spielgruppe Pumuckl</h1>
+  <p style="margin:4px 0 0;font-size:13px;opacity:.85;">Familienverein Fällanden</p>
+</div>
+
+<div style="background:white;border:1px solid #e0e0e0;border-top:none;padding:24px;border-radius:0 0 8px 8px;">
+
+  <p>{{ greeting }},</p>
+  <p>{{ strings.intro }}</p>
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.child_section }}</h2>
+  <table style="width:100%;border-collapse:collapse;">
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.child_name }}</td><td>{{ child_name }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.child_dob }}</td><td>{{ child_dob }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.child_needs }}</td><td>{{ child_needs }}</td></tr>
+  </table>
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.booking_section }}</h2>
+  <table style="width:100%;border-collapse:collapse;">
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.booking_type }}</td><td>{{ playgroup_types }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.booking_days }}</td><td>{{ days }}</td></tr>
+  </table>
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.fees_section }}</h2>
+  <table style="width:100%;border-collapse:collapse;">
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.monthly_fee }}</td><td>{{ monthly_fee }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.reg_fee }}</td><td>{{ strings.reg_fee_amount }}</td></tr>
+    {% if has_indoor %}
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.deposit }}</td><td>{{ strings.deposit_amount }}</td></tr>
+    {% endif %}
+  </table>
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.payment_section }}</h2>
+  <p>{{ strings.payment_intro | safe }}</p>
+  <table style="width:100%;border-collapse:collapse;background:#f8f8f8;border-radius:4px;">
+    <tr>
+      <td style="padding:8px;color:#666;width:40%;border-bottom:1px solid #e0e0e0;">{{ strings.iban_label }}</td>
+      <td style="padding:8px;font-family:monospace;font-weight:bold;border-bottom:1px solid #e0e0e0;">{{ iban }}</td>
+    </tr>
+    <tr>
+      <td style="padding:8px;color:#666;border-bottom:1px solid #e0e0e0;">{{ strings.payee_label }}</td>
+      <td style="padding:8px;border-bottom:1px solid #e0e0e0;">{{ payee }}<br>{{ payee_street }}, {{ payee_postal_code }} {{ payee_city }}</td>
+    </tr>
+    <tr>
+      <td style="padding:8px;color:#666;">{{ strings.amount_label }}</td>
+      <td style="padding:8px;font-weight:bold;">CHF 80.00</td>
+    </tr>
+  </table>
+  {% if has_qr %}
+  <div style="text-align:center;margin:20px 0;">
+    <img src="cid:qrbill" alt="Swiss QR-Bill" style="max-width:380px;width:100%;border:1px solid #e0e0e0;">
+  </div>
+  {% endif %}
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.parent_section }}</h2>
+  <table style="width:100%;border-collapse:collapse;">
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.parent_name }}</td><td>{{ parent_name }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.parent_address }}</td><td>{{ parent_address }}, {{ parent_postal_code }} {{ parent_city }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.parent_phone }}</td><td>{{ parent_phone }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.parent_email }}</td><td>{{ parent_email }}</td></tr>
+  </table>
+
+  <h2 style="color:#2e7d32;border-bottom:2px solid #2e7d32;padding-bottom:4px;font-size:16px;">{{ strings.emergency_section }}</h2>
+  <table style="width:100%;border-collapse:collapse;">
+    <tr><td style="padding:4px 0;color:#666;width:55%;">{{ strings.emergency_name }}</td><td>{{ emergency_name }}</td></tr>
+    <tr><td style="padding:4px 0;color:#666;">{{ strings.emergency_phone }}</td><td>{{ emergency_phone }}</td></tr>
+  </table>
+
+  <p style="margin-top:24px;white-space:pre-line;">{{ strings.closing }}</p>
+
+</div>
+</body>
+</html>

src/notifications/templates/parent_confirmation.txt.j2

@@ -0,0 +1,51 @@
+{{ greeting }},
+
+{{ strings.intro }}
+
+===============================================
+{{ strings.child_section | upper }}
+===============================================
+{{ strings.child_name }}: {{ child_name }}
+{{ strings.child_dob }}: {{ child_dob }}
+{{ strings.child_needs }}: {{ child_needs }}
+
+===============================================
+{{ strings.booking_section | upper }}
+===============================================
+{{ strings.booking_type }}: {{ playgroup_types }}
+{{ strings.booking_days }}: {{ days }}
+
+===============================================
+{{ strings.fees_section | upper }}
+===============================================
+{{ strings.monthly_fee }}: {{ monthly_fee }}
+{{ strings.reg_fee }}: {{ strings.reg_fee_amount }}
+{% if has_indoor %}{{ strings.deposit }}: {{ strings.deposit_amount }}
+{% endif %}
+===============================================
+{{ strings.payment_section | upper }}
+===============================================
+{{ strings.payment_intro_text }}
+
+  {{ strings.iban_label }}: {{ iban }}
+  {{ strings.payee_label }}: {{ payee }}
+             {{ payee_street }}, {{ payee_postal_code }} {{ payee_city }}
+  {{ strings.amount_label }}: CHF 80.00
+
+===============================================
+{{ strings.parent_section | upper }}
+===============================================
+{{ strings.parent_name }}: {{ parent_name }}
+{{ strings.parent_address }}: {{ parent_address }}, {{ parent_postal_code }} {{ parent_city }}
+{{ strings.parent_phone }}: {{ parent_phone }}
+{{ strings.parent_email }}: {{ parent_email }}
+
+===============================================
+{{ strings.emergency_section | upper }}
+===============================================
+{{ strings.emergency_name }}: {{ emergency_name }}
+{{ strings.emergency_phone }}: {{ emergency_phone }}
+
+-----------------------------------------------
+
+{{ strings.closing }}

src/storage/json_store.py

@@ -254,6 +254,7 @@ class ConversationStore:
             "channel": "email",
             "parentEmail": state.parent_email,
             "conversationId": state.conversation_id,
+            "language": state.language,
         }
         return record
 

tests/test_llm.py

@@ -6,6 +6,17 @@ from src import llm
 from src.models.conversation import ChatMessage
 
 
+def _make_async_mock(mocker, content: str):
+    """Return an awaitable mock that resolves to a response with the given content."""
+    mock_response = mocker.MagicMock()
+    mock_response.choices[0].message.content = content
+
+    async def _coro(*args, **kwargs):
+        return mock_response
+
+    return mocker.patch("litellm.acompletion", side_effect=_coro), mock_response
+
+
 class TestLlmComplete:
     def test_returns_model_reply(self, mocker):
         mock_response = mocker.MagicMock()
@@ -65,3 +76,120 @@ class TestLlmComplete:
 
         with pytest.raises(RuntimeError, match="API error"):
             llm.complete("anthropic/claude-opus-4-6", "system", [])
+
+
+class TestLlmStreamComplete:
+    def _make_chunk(self, content):
+        chunk = type("Chunk", (), {})()
+        choice = type("Choice", (), {})()
+        delta = type("Delta", (), {"content": content})()
+        choice.delta = delta
+        chunk.choices = [choice]
+        return chunk
+
+    def test_yields_chunks(self, mocker):
+        chunks = [self._make_chunk("Hal"), self._make_chunk("lo!")]
+        mocker.patch("litellm.completion", return_value=iter(chunks))
+
+        result = list(llm.stream_complete("anthropic/claude-opus-4-6", "system", []))
+
+        assert result == ["Hal", "lo!"]
+
+    def test_skips_empty_deltas(self, mocker):
+        chunks = [self._make_chunk("Hello"), self._make_chunk(None), self._make_chunk("!")]
+        mocker.patch("litellm.completion", return_value=iter(chunks))
+
+        result = list(llm.stream_complete("anthropic/claude-opus-4-6", "system", []))
+
+        assert result == ["Hello", "!"]
+
+    def test_passes_stream_true(self, mocker):
+        mock_completion = mocker.patch("litellm.completion", return_value=iter([]))
+
+        list(llm.stream_complete("anthropic/claude-opus-4-6", "system", []))
+
+        assert mock_completion.call_args.kwargs["stream"] is True
+
+    def test_passes_model(self, mocker):
+        mock_completion = mocker.patch("litellm.completion", return_value=iter([]))
+
+        list(llm.stream_complete("openai/gpt-4o", "system", []))
+
+        assert mock_completion.call_args.kwargs["model"] == "openai/gpt-4o"
+
+    def test_system_prompt_prepended(self, mocker):
+        mock_completion = mocker.patch("litellm.completion", return_value=iter([]))
+
+        list(llm.stream_complete("anthropic/claude-opus-4-6", "You are helpful.", []))
+
+        messages = mock_completion.call_args.kwargs["messages"]
+        assert messages[0] == {"role": "system", "content": "You are helpful."}
+
+    def test_chat_messages_appended(self, mocker):
+        mock_completion = mocker.patch("litellm.completion", return_value=iter([]))
+
+        chat = [ChatMessage(role="user", content="Hallo")]
+        list(llm.stream_complete("anthropic/claude-opus-4-6", "system", chat))
+
+        messages = mock_completion.call_args.kwargs["messages"]
+        assert messages[1] == {"role": "user", "content": "Hallo"}
+
+
+class TestLlmAComplete:
+    @pytest.mark.asyncio
+    async def test_returns_model_reply(self, mocker):
+        mock_acompletion, _ = _make_async_mock(mocker, "Hallo! Wie heisst dein Kind?")
+
+        result = await llm.acomplete("anthropic/claude-opus-4-6", "system prompt", [])
+
+        assert result == "Hallo! Wie heisst dein Kind?"
+
+    @pytest.mark.asyncio
+    async def test_passes_model_to_litellm(self, mocker):
+        mock_acompletion, _ = _make_async_mock(mocker, "ok")
+
+        await llm.acomplete("openai/gpt-4o", "system", [])
+
+        call_kwargs = mock_acompletion.call_args.kwargs
+        assert call_kwargs["model"] == "openai/gpt-4o"
+
+    @pytest.mark.asyncio
+    async def test_system_prompt_prepended_as_system_message(self, mocker):
+        mock_acompletion, _ = _make_async_mock(mocker, "ok")
+
+        await llm.acomplete("anthropic/claude-opus-4-6", "You are helpful.", [])
+
+        messages = mock_acompletion.call_args.kwargs["messages"]
+        assert messages[0] == {"role": "system", "content": "You are helpful."}
+
+    @pytest.mark.asyncio
+    async def test_chat_messages_appended_after_system(self, mocker):
+        mock_acompletion, _ = _make_async_mock(mocker, "ok")
+
+        chat = [
+            ChatMessage(role="user", content="Hallo"),
+            ChatMessage(role="assistant", content="Guten Tag"),
+        ]
+        await llm.acomplete("anthropic/claude-opus-4-6", "system", chat)
+
+        messages = mock_acompletion.call_args.kwargs["messages"]
+        assert messages[1] == {"role": "user", "content": "Hallo"}
+        assert messages[2] == {"role": "assistant", "content": "Guten Tag"}
+
+    @pytest.mark.asyncio
+    async def test_max_tokens_passed(self, mocker):
+        mock_acompletion, _ = _make_async_mock(mocker, "ok")
+
+        await llm.acomplete("anthropic/claude-opus-4-6", "system", [])
+
+        assert mock_acompletion.call_args.kwargs["max_tokens"] == 2048
+
+    @pytest.mark.asyncio
+    async def test_exception_propagates(self, mocker):
+        async def _raise(*args, **kwargs):
+            raise RuntimeError("API error")
+
+        mocker.patch("litellm.acompletion", side_effect=_raise)
+
+        with pytest.raises(RuntimeError, match="API error"):
+            await llm.acomplete("anthropic/claude-opus-4-6", "system", [])

tests/test_notifier.py

@@ -1,11 +1,42 @@
-"""Tests for AdminNotifier helper methods."""
+"""Tests for AdminNotifier and notification helper functions."""
+
+import email
+import json
+from email.header import decode_header
 
 import pytest
 
 from src.notifications.notifier import AdminNotifier
+from src.notifications.context import (
+    calculate_age,
+    calculate_monthly_fee,
+    format_types,
+    build_parent_context,
+)
+from src.notifications.i18n import get_strings, clear_cache
+from src.notifications.renderer import render_template
 from src.models.registration import RegistrationData, Booking, BookingDay
 
 
+def _decoded_subject(msg_str: str) -> str:
+    """Parse a raw MIME message string and return the decoded Subject header."""
+    msg = email.message_from_string(msg_str)
+    raw_subject = msg.get("Subject", "")
+    parts = decode_header(raw_subject)
+    return "".join(
+        chunk.decode(enc or "utf-8") if isinstance(chunk, bytes) else chunk
+        for chunk, enc in parts
+    )
+
+
+@pytest.fixture(autouse=True)
+def reset_translation_cache():
+    """Clear the in-memory translation cache before every test."""
+    clear_cache()
+    yield
+    clear_cache()
+
+
 @pytest.fixture
 def notifier():
     return AdminNotifier(
@@ -21,54 +52,68 @@ def notifier():
     )
 
 
+@pytest.fixture
+def notifier_no_smtp():
+    """Notifier in dev mode (no SMTP host)."""
+    return AdminNotifier(
+        smtp_host="",
+        smtp_port=587,
+        username="",
+        password="",
+        from_email="agent@example.com",
+    )
+
+
 # ---------------------------------------------------------------------------
-# _format_types
+# format_types
 # ---------------------------------------------------------------------------
 
 
 class TestFormatTypes:
-    def test_indoor_label(self, notifier):
-        assert "Innen" in notifier._format_types(["indoor"]) or "indoor" in notifier._format_types(["indoor"]).lower()
+    def test_indoor_label(self):
+        result = format_types(["indoor"])
+        assert "Innen" in result or "indoor" in result.lower()
 
-    def test_outdoor_label(self, notifier):
-        assert "Wald" in notifier._format_types(["outdoor"]) or "outdoor" in notifier._format_types(["outdoor"]).lower()
+    def test_outdoor_label(self):
+        result = format_types(["outdoor"])
+        assert "Wald" in result or "outdoor" in result.lower()
 
-    def test_both_labels(self, notifier):
-        result = notifier._format_types(["indoor", "outdoor"])
+    def test_both_labels(self):
+        result = format_types(["indoor", "outdoor"])
         assert len(result) > 0
 
 
 # ---------------------------------------------------------------------------
-# _calculate_age
+# calculate_age
 # ---------------------------------------------------------------------------
 
 
 class TestCalculateAge:
-    def test_returns_age_string(self, notifier):
-        result = notifier._calculate_age("2022-01-01")
+    def test_returns_age_string(self):
+        result = calculate_age("2022-01-01")
         assert isinstance(result, str)
         assert len(result) > 0
 
-    def test_invalid_dob_returns_original_string(self, notifier):
-        result = notifier._calculate_age("not-a-date")
+    def test_invalid_dob_returns_original_string(self):
+        result = calculate_age("not-a-date")
         assert result == "not-a-date"
 
 
 # ---------------------------------------------------------------------------
-# _calculate_monthly_fee
+# calculate_monthly_fee
 # ---------------------------------------------------------------------------
 
 
 class TestCalculateMonthlyFee:
-    def test_indoor_one_day(self, notifier, complete_registration):
+    def test_indoor_one_day(self, complete_registration):
         complete_registration.booking = Booking(
             playgroup_types=["indoor"],
             selected_days=[BookingDay(day="monday", type="indoor")],
         )
-        fee = notifier._calculate_monthly_fee(complete_registration)
+        fee = calculate_monthly_fee(complete_registration)
         assert "130" in fee
 
-    def test_indoor_two_days(self, notifier, complete_registration):
+    def test_indoor_two_days(self, complete_registration):
         complete_registration.booking = Booking(
             playgroup_types=["indoor"],
             selected_days=[
@@ -76,10 +121,10 @@ class TestCalculateMonthlyFee:
                 BookingDay(day="wednesday", type="indoor"),
             ],
         )
-        fee = notifier._calculate_monthly_fee(complete_registration)
+        fee = calculate_monthly_fee(complete_registration)
         assert "260" in fee
 
-    def test_indoor_three_days(self, notifier, complete_registration):
+    def test_indoor_three_days(self, complete_registration):
         complete_registration.booking = Booking(
             playgroup_types=["indoor"],
             selected_days=[
@@ -88,15 +133,15 @@ class TestCalculateMonthlyFee:
                 BookingDay(day="thursday", type="indoor"),
             ],
         )
-        fee = notifier._calculate_monthly_fee(complete_registration)
+        fee = calculate_monthly_fee(complete_registration)
         assert "390" in fee
 
-    def test_outdoor_one_day(self, notifier, complete_registration):
+    def test_outdoor_one_day(self, complete_registration):
         complete_registration.booking = Booking(
             playgroup_types=["outdoor"],
             selected_days=[BookingDay(day="monday", type="outdoor")],
         )
-        fee = notifier._calculate_monthly_fee(complete_registration)
+        fee = calculate_monthly_fee(complete_registration)
         assert "250" in fee
 
 
@@ -107,7 +152,6 @@ class TestCalculateMonthlyFee:
 
 class TestSend:
     def test_send_calls_smtp(self, notifier, mocker):
-        # _send uses smtplib.SMTP directly (not as context manager)
         mock_smtp_cls = mocker.patch("smtplib.SMTP")
         mock_server = mock_smtp_cls.return_value
 
@@ -132,6 +176,172 @@ class TestSend:
         )
 
         call_args = mock_server.sendmail.call_args
-        recipients = call_args[0][1]  # positional arg: to_addrs
+        recipients = call_args[0][1]
         assert "a@example.com" in recipients
         assert "b@example.com" in recipients
+
+
+# ---------------------------------------------------------------------------
+# get_strings — i18n / LLM translation
+# ---------------------------------------------------------------------------
+
+
+class TestGetStrings:
+    def test_german_loads_from_yaml_without_llm(self, mocker):
+        """German must never trigger an LLM call."""
+        mock_litellm = mocker.patch("litellm.completion")
+        strings = get_strings("de", "some-model")
+        mock_litellm.assert_not_called()
+        assert strings["subject"] == "Anmeldebestätigung – Spielgruppe Pumuckl"
+
+    def test_other_language_calls_llm(self, mocker):
+        """Non-German languages should call litellm.completion."""
+        german = get_strings("de", "some-model")
+        translated = {**german, "subject": "Registration Confirmation – Spielgruppe Pumuckl"}
+        mock_litellm = mocker.patch("litellm.completion")
+        mock_litellm.return_value.choices[0].message.content = json.dumps(translated)
+
+        result = get_strings("en", "some-model")
+
+        mock_litellm.assert_called_once()
+        assert result["subject"] == "Registration Confirmation – Spielgruppe Pumuckl"
+
+    def test_result_is_cached(self, mocker):
+        """The LLM is only called once per language per process lifetime."""
+        german = get_strings("de", "some-model")
+        mock_litellm = mocker.patch("litellm.completion")
+        mock_litellm.return_value.choices[0].message.content = json.dumps(german)
+
+        get_strings("fr", "some-model")
+        get_strings("fr", "some-model")
+
+        assert mock_litellm.call_count == 1
+
+    def test_llm_failure_falls_back_to_german(self, mocker):
+        """If the LLM raises, the German strings are returned silently."""
+        mocker.patch("litellm.completion", side_effect=RuntimeError("network error"))
+
+        result = get_strings("it", "some-model")
+
+        assert result["subject"] == "Anmeldebestätigung – Spielgruppe Pumuckl"
+
+    def test_passthrough_keys_not_altered(self, mocker):
+        """reg_fee_amount and deposit_amount must survive translation unchanged."""
+        german = get_strings("de", "some-model")
+        # Return translation that omits passthrough keys (as the LLM would)
+        without_passthrough = {k: v for k, v in german.items()
+                               if k not in {"reg_fee_amount", "deposit_amount"}}
+        mocker.patch("litellm.completion").return_value.choices[0].message.content = (
+            json.dumps(without_passthrough)
+        )
+
+        result = get_strings("en", "some-model")
+
+        assert result["reg_fee_amount"] == "CHF 80.00"
+        assert result["deposit_amount"] == "CHF 50.00"
+
+
+# ---------------------------------------------------------------------------
+# notify_parent — parent confirmation email
+# ---------------------------------------------------------------------------
+
+
+class TestNotifyParent:
+    def test_notify_parent_calls_send(self, notifier, complete_registration, mocker):
+        """notify_parent dispatches an email to the parent address."""
+        mock_smtp_cls = mocker.patch("smtplib.SMTP")
+        mock_server = mock_smtp_cls.return_value
+
+        notifier.notify_parent(complete_registration, language="de")
+
+        mock_server.sendmail.assert_called_once()
+        call_args = mock_server.sendmail.call_args
+        recipients = call_args[0][1]
+        assert "anna.muster@example.com" in recipients
+
+    def test_notify_parent_german_subject(self, notifier, complete_registration, mocker):
+        """German language produces a German subject line without any LLM call."""
+        mock_smtp_cls = mocker.patch("smtplib.SMTP")
+        captured = {}
+
+        def fake_sendmail(from_, to_, msg_str):
+            captured["msg"] = msg_str
+
+        mock_smtp_cls.return_value.sendmail.side_effect = fake_sendmail
+
+        notifier.notify_parent(complete_registration, language="de")
+
+        assert "Anmeldebestätigung" in _decoded_subject(captured["msg"])
+
+    def test_notify_parent_english_subject(self, notifier, complete_registration, mocker):
+        """English language produces an English subject line via LLM translation."""
+        german = get_strings("de", "some-model")
+        english = {**german, "subject": "Registration Confirmation – Spielgruppe Pumuckl"}
+        mocker.patch("litellm.completion").return_value.choices[0].message.content = (
+            json.dumps(english)
+        )
+
+        mock_smtp_cls = mocker.patch("smtplib.SMTP")
+        captured = {}
+
+        def fake_sendmail(from_, to_, msg_str):
+            captured["msg"] = msg_str
+
+        mock_smtp_cls.return_value.sendmail.side_effect = fake_sendmail
+
+        notifier.notify_parent(complete_registration, language="en")
+
+        assert "Registration Confirmation" in _decoded_subject(captured["msg"])
+
+    def test_notify_parent_unknown_language_falls_back_to_de(
+        self, notifier, complete_registration, mocker
+    ):
+        """When the LLM call fails, the email is sent in German."""
+        mocker.patch("litellm.completion", side_effect=RuntimeError("timeout"))
+
+        mock_smtp_cls = mocker.patch("smtplib.SMTP")
+        captured = {}
+
+        def fake_sendmail(from_, to_, msg_str):
+            captured["msg"] = msg_str
+
+        mock_smtp_cls.return_value.sendmail.side_effect = fake_sendmail
+
+        notifier.notify_parent(complete_registration, language="fr")
+
+        assert "Anmeldebestätigung" in _decoded_subject(captured["msg"])
+
+    def test_notify_parent_no_smtp_skips_send(
+        self, notifier_no_smtp, complete_registration, mocker
+    ):
+        """When SMTP host is empty, no sendmail call is made."""
+        mock_smtp_cls = mocker.patch("smtplib.SMTP")
+
+        notifier_no_smtp.notify_parent(complete_registration, language="de")
+
+        mock_smtp_cls.assert_not_called()
+
+    def test_text_body_contains_iban(self, complete_registration):
+        """Rendered plain-text body includes the IBAN regardless of language."""
+        strings = get_strings("de", "some-model")
+        ctx = build_parent_context(complete_registration, strings, has_qr=False)
+        text = render_template("parent_confirmation.txt.j2", ctx)
+        assert "CH14" in text
+
+
+# ---------------------------------------------------------------------------
+# _generate_qr_bill_png
+# ---------------------------------------------------------------------------
+
+
+class TestGenerateQrBillPng:
+    def test_returns_nonempty_bytes(self, notifier):
+        """_generate_qr_bill_png returns a non-empty bytes object (PNG)."""
+        png = notifier._generate_qr_bill_png()
+        assert isinstance(png, bytes)
+        assert len(png) > 0
+
+    def test_returns_png_signature(self, notifier):
+        """Output starts with the PNG magic bytes."""
+        png = notifier._generate_qr_bill_png()
+        assert png[:4] == b"\x89PNG"

tests/test_storage.py

@@ -157,3 +157,20 @@ class TestRegistrationVersioning:
         store.save_registration(fresh_state)
         registrations = store.list_registrations()
         assert len(registrations) == 1
+
+    def test_save_registration_persists_language(self, store, fresh_state, complete_registration):
+        fresh_state.registration = complete_registration
+        fresh_state.completed = True
+        fresh_state.language = "en"
+        store.save_registration(fresh_state)
+        current = store.get_current_registration(fresh_state.parent_email)
+        assert current is not None
+        assert current["metadata"]["language"] == "en"
+
+    def test_save_registration_defaults_language_to_de(self, store, fresh_state, complete_registration):
+        fresh_state.registration = complete_registration
+        fresh_state.completed = True
+        # language defaults to "de" in ConversationState
+        store.save_registration(fresh_state)
+        current = store.get_current_registration(fresh_state.parent_email)
+        assert current["metadata"]["language"] == "de"