feat(widget): Widget 配置、loader 与右下角悬浮入口

生成可嵌入站点的 loader 与悬浮按钮，支持展开收起和移动端；附独立宿主测试页。

backend/app/api/widget.py

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+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException, Request, Response, Header, Query, status
+from fastapi.responses import HTMLResponse
+from sqlalchemy.orm import Session
+from typing import List, Optional
+from uuid import UUID
+from datetime import datetime
+from pathlib import Path
+import json
+from urllib.parse import urlparse
+
+from app.models.agent import Agent
+from app.models.customer import Customer
+from app.models.widget import Widget
+from app.models.user import User
+
+from app.core.auth import get_current_user
+from app.database import get_db
+from app.repositories.widget import WidgetRepository
+from app.repositories.agent import AgentRepository
+from app.core.security import create_conversation_token, verify_conversation_token
+from app.services import conversation_token
+from app.utils.client_ip import forwarded_client_ip
+from app.repositories.customer import CustomerRepository
+from app.models.schemas.widget import WidgetCreate, WidgetResponse
+from app.core.logger import get_logger
+from app.repositories.session_to_agent import SessionToAgentRepository, session_in_scope
+from app.services.contact_capture import CONTACT_EMAIL_META_KEY
+from app.services.widget_identity import may_stand_for
+from app.models.session_to_agent import SessionStatus
+from app.core.config import settings
+from app.core.s3 import get_s3_signed_url
+from app.utils.business_hours import is_within_business_hours
+
+router = APIRouter()
+logger = get_logger(__name__)
+
+# The enterprise module can record where each widget is live; without it,
+# nothing is recorded.
+try:
+    from app.enterprise.services import widget_install
+except ImportError:
+    widget_install = None
+
+
+def _identity_expired() -> HTTPException:
+    """401 telling the widget its visitor's identity lapsed, not that it never had one.
+
+    The embed loader answers this by asking the host page for a fresh token
+    (`tokenProvider`) and retrying, so an identified visitor is never silently
+    re-created as an anonymous customer.
+    """
+    return HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail={
+            "code": conversation_token.IDENTITY_EXPIRED_CODE,
+            "message": "Conversation token expired. Issue a new one with /generate-token.",
+        },
+    )
+
+
+_ASSETS_DIR = Path(settings.WIDGET_ASSETS_DIR)
+
+
+def _asset_version() -> str:
+    """Cache-buster for the widget bundle URLs.
+
+    /assets/widget.js is served without a Cache-Control header and its URL never
+    changes, so browsers fall back to heuristic caching and can keep serving an old
+    bundle for hours after a release — the widget silently runs last week's code.
+    Stamping the build's mtime+size onto the URL makes a new build a new URL.
+    Recomputed per request (a stat is microseconds) so a rebuild takes effect
+    without restarting the backend.
+    """
+    try:
+        stat = (_ASSETS_DIR / "widget.js").stat()
+        return f"{int(stat.st_mtime)}-{stat.st_size}"
+    except OSError:
+        # Assets served from somewhere else (CDN, dev server) — nothing to stamp.
+        return ""
+
+
+def _widget_html_response(html: str) -> HTMLResponse:
+    """The widget HTML embeds a conversation token and the current customization,
+    and points at a versioned bundle URL. Caching it would hand a visitor someone
+    else's token from a shared cache, and would keep pinning them to a stale widget
+    build after a release."""
+    return HTMLResponse(html, headers={"Cache-Control": "no-store"})
+
+
+# BACKEND_URL defaults to http://localhost:8000 and neither compose file sets
+# it, so a self-hosted install that never overrode it used to serve every visitor
+# a widget whose socket dialled the visitor's own machine (#315). Loopback can
+# never be right for a browser on someone else's computer, so we fall back to the
+# origin the widget HTML was actually fetched over.
+_LOOPBACK_HOSTS = frozenset({"localhost", "127.0.0.1", "0.0.0.0", "::1", "[::1]"})
+
+_warned_about_loopback_backend_url = False
+
+
+def _is_loopback(url: str) -> bool:
+    host = urlparse(url).hostname
+    return host is not None and host.lower() in _LOOPBACK_HOSTS
+
+
+def _public_origin(request: Optional[Request]) -> Optional[str]:
+    """Scheme and host this request reached us on, as the browser sees them.
+
+    Reads the forwarding headers our nginx sets rather than ``request.url``, which
+    only reflects them when the ASGI server is started with proxy headers enabled.
+    """
+    if request is None:
+        return None
+
+    # Several proxies in a chain append to these, and the browser's own value is
+    # the first entry.
+    forwarded_host = request.headers.get("x-forwarded-host")
+    host = (forwarded_host or request.headers.get("host") or "").split(",")[0].strip()
+    if not host:
+        return None
+
+    forwarded_proto = request.headers.get("x-forwarded-proto")
+    if forwarded_proto:
+        scheme = forwarded_proto.split(",")[0].strip()
+    elif forwarded_host:
+        # A proxy that rewrites the host but not the protocol (Traefik and some
+        # Caddy setups, unlike our nginx) leaves request.url.scheme reading "http"
+        # for the proxy's own hop. Trusting that would hand an https page a ws://
+        # socket the browser refuses as mixed content, so assume the hop was TLS.
+        scheme = "https"
+    else:
+        scheme = request.url.scheme or "https"
+
+    return f"{scheme}://{host}"
+
+
+def _widget_runtime_config(request: Optional[Request] = None) -> dict:
+    """Runtime API/WS URLs to hand the widget iframe as ``window.APP_CONFIG``.
+
+    Derived from ``BACKEND_URL`` so a self-hosted widget talks to the configured
+    backend instead of the vendor cloud. On the hosted deployment BACKEND_URL is
+    ``https://api.chattermate.chat``, which yields exactly the widget's baked-in
+    defaults, so injecting this is a no-op there.
+    """
+    global _warned_about_loopback_backend_url
+
+    api_base = settings.BACKEND_URL.rstrip("/")
+    if _is_loopback(api_base):
+        derived = _public_origin(request)
+        if derived and not _is_loopback(derived):
+            if not _warned_about_loopback_backend_url:
+                _warned_about_loopback_backend_url = True
+                logger.warning(
+                    "BACKEND_URL is %s, which no visitor's browser can reach. "
+                    "Serving widgets against %s instead, taken from the request. "
+                    "Set BACKEND_URL to this install's public API URL.",
+                    api_base, derived,
+                )
+            api_base = derived
+
+    if api_base.startswith("https://"):
+        ws_url = "wss://" + api_base[len("https://"):]
+    elif api_base.startswith("http://"):
+        ws_url = "ws://" + api_base[len("http://"):]
+    else:
+        ws_url = api_base
+    return {"API_URL": f"{api_base}/api/v1", "WS_URL": ws_url}
+
+@router.post("", response_model=WidgetResponse)
+def create_new_widget(
+    widget: WidgetCreate,
+    db: Session = Depends(get_db),
+    current_user=Depends(get_current_user)
+):
+    """Create a new widget for the organization"""
+    widget_repo = WidgetRepository(db)
+    return widget_repo.create_widget(widget, current_user.organization_id)
+
+
+def _note_install(db: Session, widget: Widget, request: Request, background_tasks: BackgroundTasks) -> None:
+    """Note where the widget is live (or blocked), after the response is
+    sent. Never lets a tracking error break the widget itself."""
+    if widget_install is None:
+        return
+    try:
+        sighting = widget_install.claim_write(db, widget, request.headers.get("origin"), forwarded_client_ip(request))
+        if sighting:
+            background_tasks.add_task(widget_install.record, widget.id, sighting)
+    except Exception:
+        logger.exception(f"Install tracking failed for widget {widget.id}")
+
+
+@router.get("/{widget_id}/data", response_class=HTMLResponse)
+async def get_widget_ui(
+    widget_id: str,
+    request: Request,
+    response: Response,
+    background_tasks: BackgroundTasks,
+    authorization: Optional[str] = Header(None),
+    source: Optional[str] = Query(None),
+    db: Session = Depends(get_db)
+):
+    """Get widget UI and handle customer authentication"""
+
+    widget = db.query(Widget).filter(Widget.id == widget_id).first()
+    if not widget:
+        raise HTTPException(status_code=404, detail="Widget not found")
+
+    _note_install(db, widget, request, background_tasks)
+
+    # Get agent data
+    agent_repo = AgentRepository(db)
+    agent = agent_repo.get_by_id(widget.agent_id)
+    if not agent:
+        raise HTTPException(status_code=404, detail="Agent not found")
+
+    # What the header may honestly claim. Only a human-handled agent needs the
+    # business-hours check: while the AI answers, it answers at 3am too.
+    presence = {
+        'mode': 'ai' if agent.ai_replies_enabled else 'human',
+        'available': True if agent.ai_replies_enabled
+                     else is_within_business_hours(agent.organization),
+    }
+
+    require_token_auth = getattr(agent, 'require_token_auth', False)
+    customer_id = None
+    token = None
+    token_payload = None
+
+    # Try to validate existing token if provided
+    if authorization and authorization.startswith('Bearer '):
+        token = authorization.split(' ')[1]
+        state = conversation_token.inspect(token, widget_id)
+        if state.is_live:
+            token_payload = state.payload
+            customer_id = state.payload.get("sub")
+        elif state.identity_lost:
+            # A lapsed token that named a customer means a signed-in visitor whose
+            # identity just ran out. Say so instead of rendering the frame as a
+            # brand-new anonymous visitor - the loader re-identifies and retries.
+            raise _identity_expired()
+        else:
+            token = None  # Invalid token
+
+    # SECURITY: If token auth is required, valid token MUST be provided
+    if require_token_auth:
+        if not token or customer_id is None:
+            logger.warning(f"Widget UI request denied: require_token_auth=true but no valid token for widget_id={widget_id}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Authentication required. Token must be obtained from /api/v1/generate-token endpoint with valid API key."
+            )
+        # Has valid token - return widget with existing token
+        return _widget_html_response(await get_widget_html(
+            widget_id=widget_id,
+            agent_name=agent.display_name or agent.name,
+            agent_customization=agent.customization,
+            customer_id=customer_id,
+            initial_token=token,
+            agent_workflow=bool(agent.use_workflow and agent.active_workflow_id),
+            allow_attachments=agent.allow_attachments,
+            ai_replies_enabled=agent.ai_replies_enabled,
+            presence=presence,
+            request=request
+        ))
+    
+    # Token auth NOT required - allow anonymous access
+    # If we have a valid token, use it; otherwise create a new one
+    if token and customer_id:
+        return _widget_html_response(await get_widget_html(
+            widget_id=widget_id,
+            agent_name=agent.display_name or agent.name,
+            agent_customization=agent.customization,
+            customer_id=customer_id,
+            initial_token=token,
+            agent_workflow=bool(agent.use_workflow and agent.active_workflow_id),
+            allow_attachments=agent.allow_attachments,
+            ai_replies_enabled=agent.ai_replies_enabled,
+            presence=presence,
+            request=request
+        ))
+
+    # No valid token - create new one for anonymous access. A live token that
+    # names no customer yet keeps its conversation key.
+    token = _mint_widget_token(widget_id, _conversation_key(token_payload), source=source)
+    
+    return _widget_html_response(await get_widget_html(
+        widget_id=widget_id,
+        agent_name=agent.display_name or agent.name,
+        agent_customization=agent.customization,
+        customer_id=customer_id,
+        initial_token=token,
+        agent_workflow=bool(agent.use_workflow and agent.active_workflow_id),
+        allow_attachments=agent.allow_attachments,
+        ai_replies_enabled=agent.ai_replies_enabled,
+        presence=presence,
+        request=request
+    ))
+
+async def get_widget_html(widget_id: str, agent_name: str, agent_customization: dict, customer_id: Optional[str] = None, initial_token: Optional[str] = None, agent_workflow: bool = False, allow_attachments: bool = False, ai_replies_enabled: bool = True,
+                          presence: Optional[dict] = None, request: Optional[Request] = None) -> str:
+    """Generate widget HTML with embedded data"""
+    import html
+    widget_url = settings.VITE_WIDGET_URL
+    version = _asset_version()
+    asset_query = f"?v={version}" if version else ""
+
+    # Convert AgentCustomization to dict if it's a model instance
+    customization_dict = {}
+    if agent_customization:
+        # Get signed URL for photo if using S3
+        photo_url = agent_customization.photo_url
+        if settings.S3_FILE_STORAGE and photo_url:
+            photo_url = await get_s3_signed_url(photo_url)
+
+        customization_dict = {
+            "chat_background_color": agent_customization.chat_background_color,
+            "chat_text_color": agent_customization.chat_text_color,
+            "chat_bubble_color": agent_customization.chat_bubble_color,
+            "accent_color": agent_customization.accent_color,
+            "font_family": agent_customization.font_family,
+            "photo_url": photo_url,
+            "chat_style": agent_customization.chat_style.value if agent_customization.chat_style else "CHATBOT",
+            "widget_position": agent_customization.widget_position.value if agent_customization.widget_position else "FLOATING",
+            "welcome_title": agent_customization.welcome_title,
+            "welcome_subtitle": agent_customization.welcome_subtitle,
+            "welcome_message": agent_customization.welcome_message,
+            "chat_initiation_messages": agent_customization.chat_initiation_messages or [],
+            "quick_actions": agent_customization.quick_actions or [],
+            "show_citations": agent_customization.show_citations,
+            "collect_email": agent_customization.collect_email,
+            # A human-only agent never produces an AI reply, so disclosing one
+            # would be untrue — same reason the widget hides it after takeover.
+            "show_ai_disclaimer": agent_customization.show_ai_disclaimer and ai_replies_enabled,
+            "allow_new_chat": agent_customization.allow_new_chat,
+            "customization_metadata": agent_customization.customization_metadata or {}
+        }
+        
+
+    return f"""
+        <!DOCTYPE html>
+        <html>
+        <head>
+            <meta charset="UTF-8">
+            <meta name="viewport" content="width=device-width, initial-scale=1.0">
+            <title>Chat Widget</title>
+            <link rel="preconnect" href="https://fonts.googleapis.com">
+            <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
+            <link href="https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Instrument+Sans:wght@400;500;600&family=JetBrains+Mono:wght@400;500;600&display=swap" rel="stylesheet">
+            <script>
+                // Runtime backend config so the widget connects to THIS install's
+                // backend instead of falling back to the baked cloud default.
+                // Declared before the widget module loads.
+                window.APP_CONFIG = {json.dumps(_widget_runtime_config(request))};
+            </script>
+            <script type="module" crossorigin src="{widget_url}/assets/widget.js{asset_query}"></script>
+            <link rel="stylesheet" crossorigin href="{widget_url}/assets/widget.css{asset_query}">
+            <script>
+                window.__INITIAL_DATA__ = {{
+                    widgetId: "{html.escape(widget_id)}",
+                    agentName: "{html.escape(agent_name)}",
+                    customization: {json.dumps(customization_dict)},
+                    customerId: "{html.escape(customer_id or '')}",
+                    initialToken: "{html.escape(initial_token or '')}",
+                    customer: {{}},
+                    workflow: {str(agent_workflow).lower()},
+                    allowAttachments: {str(allow_attachments).lower()},
+                    presence: {json.dumps(presence or {'mode': 'ai', 'available': True})}
+                }};
+            </script>
+        </head>
+        <body>
+            <div id="app"></div>
+        </body>
+        </html>
+    """
+
+async def get_human_agent_session_info(db: Session, customer_id: str, scope: str) -> dict:
+    """Human agent assigned to the customer's open conversation this token may reach"""
+    human_agent_info = {}
+    session_repo = SessionToAgentRepository(db)
+    sessions = session_repo.get_customer_sessions(customer_id, SessionStatus.OPEN, scope=scope)
+
+    if sessions and len(sessions) > 0:
+        session_model,user_full_name, user_profile_pic = sessions[0]
+
+        if user_full_name:  # If there's a human agent assigned
+            # HumanAgentResponse signs human_agent_profile_pic on serialization.
+
+            # Get human agent info from session
+            human_agent_info = {
+                "human_agent_name": user_full_name,
+                "human_agent_profile_pic": user_profile_pic,
+            }
+
+    return human_agent_info
+
+
+def _conversation_key(token_payload: Optional[dict]) -> str:
+    """Keep the browser's conversation key across re-mints, or start one.
+
+    Never an account key: only our backend mints those, for one signed-in
+    dashboard account, and every token the widget issues is unverified.
+    """
+    key = (token_payload or {}).get(conversation_token.CONVERSATION_KEY_CLAIM)
+    if key and not conversation_token.is_account_key(key):
+        return key
+    return conversation_token.new_conversation_key()
+
+
+def _mint_widget_token(widget_id: str, conversation_key: str, customer_id: Optional[str] = None,
+                       source: Optional[str] = None, token_payload: Optional[dict] = None) -> str:
+    """A conversation token the widget issues itself - unverified, so always scoped.
+
+    Prefers a fresh `source` (first-visit Explore flow) over one the visitor's
+    earlier token carried.
+    """
+    extra_data = {conversation_token.CONVERSATION_KEY_CLAIM: conversation_key}
+    source = source or (token_payload or {}).get("source")
+    if widget_id == settings.EXPLORE_WIDGET_ID and source:
+        extra_data["source"] = source
+    return create_conversation_token(widget_id=widget_id, customer_id=customer_id, **extra_data)
+
+
+def _anonymous_customer(customer_repo: CustomerRepository, widget: Widget, conversation_key: str,
+                        claimed_email: Optional[str] = None) -> Customer:
+    """A customer of the visitor's own. An address they gave that belongs to
+    someone they can't stand for is kept where the inbox shows it."""
+    meta_data = {CONTACT_EMAIL_META_KEY: claimed_email} if claimed_email else None
+    return customer_repo.create_customer(
+        CustomerRepository.anonymous_email(), widget.organization_id,
+        meta_data=meta_data, conversation_key=conversation_key)
+
+
+def _widget_data_response(widget: Widget, agent: Agent, customer_id: Optional[str], human_agent_info: dict,
+                          token: Optional[str] = None) -> dict:
+    """GET /widgets/{id}'s answer; `token` only when the visitor needs a new one."""
+    # photo_url is signed by AgentCustomizationResponse on serialization.
+    data = {
+        "id": widget.id,
+        "organization_id": widget.organization_id,
+        "customer_id": customer_id,
+        "human_agent": human_agent_info,
+        "agent": {
+            "id": agent.id,
+            "name": agent.name,
+            "display_name": agent.display_name,
+            "customization": agent.customization,
+            "workflow": bool(agent.use_workflow and agent.active_workflow_id),
+            "allow_attachments": agent.allow_attachments
+        }
+    }
+    if token:
+        data["token"] = token
+    return data
+
+
+@router.get("/{widget_id}", response_model=WidgetResponse)
+async def get_widget_data(
+    widget_id: str,
+    response: Response,
+    email: Optional[str] = None,
+    source: Optional[str] = Query(None),
+    authorization: Optional[str] = Header(None),
+    db: Session = Depends(get_db)
+):
+    """Get widget data including agent customization"""
+    logger.info(f"Getting widget data for widget_id {widget_id}, email {email}, has_token {bool(authorization)}")
+    # Binds this visitor to a customer: a stored copy would skip that and leave
+    # the widget holding the page's anonymous token.
+    response.headers["Cache-Control"] = "no-store"
+
+    widget = db.query(Widget).filter(Widget.id == widget_id).first()
+    if not widget:
+        raise HTTPException(status_code=404, detail="Widget not found")
+
+    agent_repo = AgentRepository(db)
+    agent = agent_repo.get_by_id(widget.agent_id)
+    if not agent:
+        raise HTTPException(status_code=404, detail="Agent not found")
+
+    require_token_auth = getattr(agent, 'require_token_auth', False)
+    customer_id = None
+    token = None
+    token_payload = None
+    scope = None
+
+    # Try to validate existing token if provided
+    if authorization and authorization.startswith('Bearer '):
+        token = authorization.split(' ')[1]
+        state = conversation_token.inspect(token, widget_id)
+        if state.is_live:
+            try:
+                scope = conversation_token.conversation_scope(state.payload)
+                token_payload = state.payload
+                customer_id = state.payload.get("sub")
+            except ValueError:
+                token = None
+        elif state.identity_lost:
+            # Identity ran out rather than never existing: minting a fresh anonymous
+            # customer here is what used to turn a signed-in visitor into "Anonymous"
+            # in the inbox the moment they started a new chat.
+            raise _identity_expired()
+        else:
+            token = None
+
+    # SECURITY: If token auth required, must have valid token with customer_id
+    if require_token_auth:
+        if not token or customer_id is None:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Unauthorized - Token required")
+
+    # Check if agent has workflow enabled
+    agent_has_workflow = bool(agent.use_workflow and agent.active_workflow_id)
+
+    # Check if agent has ASK_ANYTHING chat style
+    is_ask_anything_style = (agent.customization and
+                           agent.customization.chat_style and
+                           agent.customization.chat_style.value == "ASK_ANYTHING")
+
+    # Email is optional unless the agent explicitly opts into collecting it before chat.
+    # When not collecting email we bypass the gate (anonymous customer + token), like
+    # ASK_ANYTHING / workflow agents already do. NOTE: this runs AFTER the require_token_auth
+    # 401 check above, so token-protected widgets are unaffected.
+    email_bypass = not bool(agent.customization and getattr(agent.customization, 'collect_email', False))
+
+    customer_repo = CustomerRepository(db)
+    conversation_key = _conversation_key(token_payload)
+    # Judged on the customer the socket will act as - the merge survivor - or
+    # the widget would be told yes here and refused on every connect.
+    customer = customer_repo.resolve_merged(customer_id) if customer_id not in (None, "None") else None
+
+    if customer is not None:
+        # Once the embedding app signs this person in, a token the widget issued
+        # (from an email someone typed) may no longer name them - whoever claimed
+        # the address first would otherwise keep a token for the signed-in user.
+        # Hand that browser a customer of its own and keep the address it gave.
+        if not may_stand_for(customer, scope):
+            logger.info(f"Widget {widget_id}: unverified token names a signed-in customer; starting an anonymous one")
+            anonymous = _anonymous_customer(customer_repo, widget, conversation_key, claimed_email=customer.email)
+            new_token = _mint_widget_token(widget_id, conversation_key, customer_id=str(anonymous.id),
+                                           source=source, token_payload=token_payload)
+            return _widget_data_response(widget, agent, str(anonymous.id), {}, new_token)
+
+        logger.debug(f"Using existing token for customer_id: {customer_id}")
+        human_agent_info = await get_human_agent_session_info(db, str(customer.id), scope)
+        return _widget_data_response(widget, agent, customer_id, human_agent_info)
+
+    # A token-protected widget only ever runs on tokens its site issued: one whose
+    # customer is gone is no reason to issue a widget token of our own.
+    if require_token_auth:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Unauthorized - Token required")
+
+    # No customer yet - or the token's one no longer exists, which would otherwise
+    # refuse every connect while this answer kept the token. For workflow agents,
+    # ASK_ANYTHING style, or email-optional agents, create one with a blank email.
+    # Only email-collecting regular agents require email up front.
+    if not (email or agent_has_workflow or is_ask_anything_style or email_bypass):
+        # Regular agent without email/customer_id - return 401
+        raise HTTPException(status_code=401, detail="Unauthorized")
+
+    # The email is only what the visitor typed. It may still name the existing
+    # customer - one person in the inbox - because the token minted below is
+    # scoped to this browser's conversations, not to theirs. Never a person the
+    # embedding app signed in, though: only its own token may stand for them.
+    existing = customer_repo.get_customer_by_email(email, widget.organization_id) if email else None
+    if existing is not None and not existing.is_authenticated:
+        customer = existing
+    elif existing is not None:
+        customer = _anonymous_customer(customer_repo, widget, conversation_key, claimed_email=email)
+    elif email:
+        customer = customer_repo.create_customer(email, widget.organization_id, conversation_key=conversation_key)
+    else:
+        customer = _anonymous_customer(customer_repo, widget, conversation_key)
+
+    human_agent_info = await get_human_agent_session_info(db, str(customer.id), conversation_key)
+    new_token = _mint_widget_token(widget_id, conversation_key, customer_id=str(customer.id),
+                                   source=source, token_payload=token_payload)
+    return _widget_data_response(widget, agent, str(customer.id), human_agent_info, new_token)
+
+
+@router.post("/{widget_id}/end-chat")
+async def end_chat_acknowledgment(
+    widget_id: str,
+    session_id: str,
+    reason: Optional[str] = None,
+    description: Optional[str] = None,
+    authorization: Optional[str] = Header(None),
+    db: Session = Depends(get_db)
+):
+    """Acknowledge end_chat event from widget and close session on backend"""
+    try:
+        logger.info(f"End chat request received: widget_id={widget_id}, session_id={session_id}, reason={reason}, has_token={bool(authorization)}")
+
+        # A conversation token is REQUIRED. This used to validate the token only
+        # when one was sent, so a request with no Authorization header fell
+        # straight through and closed any session by id, unauthenticated.
+        if not authorization or not authorization.startswith('Bearer '):
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated")
+
+        try:
+            token_data = verify_conversation_token(authorization.split(' ')[1])
+        except Exception:
+            token_data = None
+        if not token_data:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
+
+        customer_id = token_data.get("sub")
+        if token_data.get("widget_id") != widget_id:
+            raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Widget mismatch")
+        try:
+            scope = conversation_token.conversation_scope(token_data)
+        except ValueError:
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
+
+        # The token proves who the caller is, not that this session is theirs —
+        # without this any visitor could close another customer's conversation,
+        # or another browser's conversation of a customer it only claimed to be.
+        session_repo = SessionToAgentRepository(db)
+        session = session_repo.get_session(session_id)
+        if not session or str(session.customer_id) != str(customer_id) or not session_in_scope(session, scope):
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Session not found")
+
+        success = session_repo.close_session(
+            session_id=session_id,
+            reason=reason,
+            description=description
+        )
+
+        if success:
+            logger.info(f"End chat acknowledged: widget_id={widget_id}, session_id={session_id}, reason={reason}")
+            return {
+                "success": True,
+                "message": "Chat session closed",
+                "session_id": session_id,
+                "closed_at": datetime.utcnow().isoformat()
+            }
+        else:
+            logger.warning(f"Failed to close session: widget_id={widget_id}, session_id={session_id}")
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Session not found")
+    
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error in end_chat_acknowledgment: {str(e)}")
+        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail="Failed to process end chat")
+
+
+@router.get("", response_model=List[WidgetResponse])
+def list_widgets(
+    db: Session = Depends(get_db),
+    current_user=Depends(get_current_user)
+):
+    """List all widgets for the organization"""
+    widget_repo = WidgetRepository(db)
+    return widget_repo.get_widgets(current_user.organization_id)
+
+
+@router.get("/agent/{agent_id}", response_model=List[WidgetResponse])
+def get_widgets_by_agent(
+    agent_id: UUID,
+    db: Session = Depends(get_db),
+    current_user=Depends(get_current_user)
+):
+    """Get all widgets for a specific agent"""
+    widget_repo = WidgetRepository(db)
+    widgets = widget_repo.get_widgets_by_agent(agent_id)
+    
+    # Verify the agent belongs to the user's organization
+    agent_repo = AgentRepository(db)
+    agent = agent_repo.get_by_id(agent_id)
+    if not agent or str(agent.organization_id) != str(current_user.organization_id):
+        raise HTTPException(status_code=404, detail="Agent not found")
+    
+    return widgets
+
+
+@router.delete("/{widget_id}")
+def remove_widget(
+    widget_id: str,
+    db: Session = Depends(get_db),
+    current_user=Depends(get_current_user)
+):
+    """Delete a widget"""
+    widget_repo = WidgetRepository(db)
+    widget = widget_repo.get_widget(widget_id)
+    if not widget or widget.organization_id != current_user.organization_id:
+        raise HTTPException(status_code=404, detail="Widget not found")
+    widget_repo.delete_widget(widget_id)
+    return {"message": "Widget deleted"}

backend/app/api/widget_apps.py

@@ -0,0 +1,337 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+from app.database import get_db
+from app.models.user import User
+from app.core.auth import require_permissions
+from app.repositories.widget_app import WidgetAppRepository
+from app.models.schemas.widget_app import (
+    WidgetAppCreate,
+    WidgetAppUpdate,
+    WidgetAppResponse,
+    WidgetAppWithKeyResponse,
+    WidgetAppListResponse
+)
+from uuid import UUID
+from app.core.logger import get_logger
+
+# Enterprise feature check
+try:
+    from app.enterprise.repositories.plan import PlanRepository
+    from app.enterprise.services.feature_access import require_accessible_subscription
+    HAS_ENTERPRISE = True
+except ImportError:
+    HAS_ENTERPRISE = False
+
+router = APIRouter()
+logger = get_logger(__name__)
+
+
+def check_widget_app_feature_access(current_user: User, db: Session):
+    """Check if user has access to widget apps feature (requires pro plan)"""
+    if not HAS_ENTERPRISE:
+        return  # Allow access in non-enterprise mode
+
+    # Accessible subscription = active/trial/past-due-in-period OR cancelled-but-
+    # still-in-paid-period. Raises 403 when the org has no accessible plan.
+    subscription = require_accessible_subscription(db, current_user.organization_id)
+    plan_repo = PlanRepository(db)
+
+    # Check if api_access feature is available in the plan (required for widget apps)
+    if not plan_repo.check_feature_availability(str(subscription.plan_id), 'api_access'):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Widget Apps feature is not available in your current plan. Please upgrade to Pro to access this feature."
+        )
+
+
+@router.post("", response_model=WidgetAppWithKeyResponse, status_code=status.HTTP_201_CREATED)
+async def create_widget_app(
+    app_data: WidgetAppCreate,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    Create a new widget app with generated API key.
+
+    **IMPORTANT:** The API key is shown only once in this response.
+    Save it securely - it cannot be retrieved later.
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+
+        # Create app (returns app and plain key)
+        app, plain_key = repo.create_app(
+            organization_id=current_user.organization_id,
+            created_by=current_user.id,
+            name=app_data.name,
+            description=app_data.description
+        )
+
+        # Return app with key (shown only once)
+        return WidgetAppWithKeyResponse(
+            id=app.id,
+            name=app.name,
+            description=app.description,
+            organization_id=app.organization_id,
+            created_by=app.created_by,
+            is_active=app.is_active,
+            created_at=app.created_at,
+            updated_at=app.updated_at,
+            api_key=plain_key  # ONLY time key is exposed
+        )
+
+    except Exception as e:
+        logger.exception(f"Error creating widget app: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to create widget app"
+        )
+
+
+@router.get("", response_model=WidgetAppListResponse)
+async def list_widget_apps(
+    include_inactive: bool = False,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    List all widget apps for current organization.
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+        apps = repo.get_apps_by_organization(
+            organization_id=current_user.organization_id,
+            include_inactive=include_inactive
+        )
+
+        return WidgetAppListResponse(
+            total=len(apps),
+            apps=[WidgetAppResponse.from_orm(app) for app in apps]
+        )
+
+    except Exception as e:
+        logger.exception(f"Error listing widget apps: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to list widget apps"
+        )
+
+
+@router.get("/{app_id}", response_model=WidgetAppResponse)
+async def get_widget_app(
+    app_id: UUID,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    Get widget app details by ID.
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+        app = repo.get_app_by_id(
+            app_id=app_id,
+            organization_id=current_user.organization_id
+        )
+
+        if not app:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=f"Widget app {app_id} not found"
+            )
+
+        return WidgetAppResponse.from_orm(app)
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.exception(f"Error getting widget app: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to get widget app"
+        )
+
+
+@router.patch("/{app_id}", response_model=WidgetAppResponse)
+async def update_widget_app(
+    app_id: UUID,
+    update_data: WidgetAppUpdate,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    Update widget app (name, description, active status).
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+        app = repo.update_app(
+            app_id=app_id,
+            organization_id=current_user.organization_id,
+            name=update_data.name,
+            description=update_data.description,
+            is_active=update_data.is_active
+        )
+
+        if not app:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=f"Widget app {app_id} not found"
+            )
+
+        return WidgetAppResponse.from_orm(app)
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.exception(f"Error updating widget app: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to update widget app"
+        )
+
+
+@router.delete("/{app_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_widget_app(
+    app_id: UUID,
+    hard_delete: bool = False,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    Delete widget app (soft delete by default, hard delete if hard_delete=true).
+
+    Soft delete (default): Sets is_active=False, keeps record for audit trail.
+    Hard delete: Permanently removes record (use with caution).
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+
+        if hard_delete:
+            success = repo.delete_app(app_id, current_user.organization_id)
+        else:
+            success = repo.deactivate_app(app_id, current_user.organization_id)
+
+        if not success:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=f"Widget app {app_id} not found"
+            )
+
+        # Invalidate cache if we have the key prefix (can't do this without key)
+        # Cache will naturally expire after TTL
+
+        return None  # 204 No Content
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.exception(f"Error deleting widget app: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to delete widget app"
+        )
+
+
+@router.post("/{app_id}/regenerate-key", response_model=WidgetAppWithKeyResponse)
+async def regenerate_api_key(
+    app_id: UUID,
+    current_user: User = Depends(require_permissions("manage_organization")),
+    db: Session = Depends(get_db)
+):
+    """
+    Regenerate API key for widget app.
+
+    **IMPORTANT:** The new API key is shown only once in this response.
+    Save it securely - it cannot be retrieved later.
+    The old key will be immediately invalidated.
+
+    Requires: manage_organization permission (admin only)
+    Requires: Pro plan with widget_apps feature
+    """
+    try:
+        # Check widget apps feature access
+        check_widget_app_feature_access(current_user, db)
+
+        repo = WidgetAppRepository(db)
+
+        result = repo.regenerate_api_key(
+            app_id=app_id,
+            organization_id=current_user.organization_id
+        )
+
+        if not result:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=f"Widget app {app_id} not found"
+            )
+
+        app, new_plain_key = result
+
+        # Invalidate cache (old key is now invalid)
+        # Note: We don't have the old key here, so cache will expire naturally
+
+        return WidgetAppWithKeyResponse(
+            id=app.id,
+            name=app.name,
+            description=app.description,
+            organization_id=app.organization_id,
+            created_by=app.created_by,
+            is_active=app.is_active,
+            created_at=app.created_at,
+            updated_at=app.updated_at,
+            api_key=new_plain_key  # New key shown only once
+        )
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.exception(f"Error regenerating API key: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to regenerate API key"
+        )

backend/app/core/crawler_policy.py

@@ -0,0 +1,88 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Keep crawlers out of the API origin.
+
+The API host had no robots.txt at all, so search engines were free to crawl
+(and then report as 404s) endpoints that were never pages: /api/v1/... routes
+and the YOUR_WIDGET_ID placeholder our docs use in examples.
+
+Two halves, because they do different jobs. robots.txt stops the fetch;
+X-Robots-Tag stops a URL discovered elsewhere from being indexed anyway.
+"""
+
+from fastapi import FastAPI
+from fastapi.responses import PlainTextResponse
+
+from app.core.config import settings
+
+NOINDEX_HEADER = (b"x-robots-tag", b"noindex")
+
+
+def api_robots_txt() -> str:
+    """The API origin's robots.txt body.
+
+    Disallows everything — except, under path dispatch, the help center. That
+    mode (the self-host default) serves public help-center pages from
+    {BACKEND_URL}/help/{slug} on this very origin, and those are meant to be
+    indexed; a bare "Disallow: /" would quietly de-index every self-hosted
+    help center. Cloud runs subdomain mode, where nothing on this origin is a
+    page and the carve-out is absent.
+
+    The Allow goes FIRST. RFC 9309 crawlers take the most specific match and
+    would get this right either way, but ones that take the first match read
+    a leading "Disallow: /" and stop — skipping the very pages the carve-out
+    exists to keep crawlable.
+    """
+    lines = ["User-agent: *"]
+    if settings.HELP_CENTER_PUBLIC_MODE == "path":
+        lines.append("Allow: /help/")
+    lines.append("Disallow: /")
+    return "\n".join(lines) + "\n"
+
+
+class NoIndexHeaderMiddleware:
+    """Stamp ``X-Robots-Tag: noindex`` on every response under ``prefix``.
+
+    Pure ASGI rather than BaseHTTPMiddleware: this fronts every API request,
+    and BaseHTTPMiddleware would pull streaming responses through a queue for
+    the sake of one header.
+    """
+
+    def __init__(self, app, prefix: str):
+        self.app = app
+        self.prefix = prefix
+
+    async def __call__(self, scope, receive, send):
+        if scope["type"] != "http" or not scope.get("path", "").startswith(self.prefix):
+            await self.app(scope, receive, send)
+            return
+
+        async def send_with_noindex(message):
+            if message["type"] == "http.response.start":
+                message["headers"] = [*(message.get("headers") or []), NOINDEX_HEADER]
+            await send(message)
+
+        await self.app(scope, receive, send_with_noindex)
+
+
+def install_crawler_policy(app: FastAPI) -> None:
+    """Register the robots.txt route and the noindex header middleware."""
+
+    @app.get("/robots.txt", response_class=PlainTextResponse, include_in_schema=False)
+    async def robots_txt():
+        return PlainTextResponse(api_robots_txt())
+
+    app.add_middleware(NoIndexHeaderMiddleware, prefix=settings.API_V1_STR)

backend/app/services/domain_verification.py

@@ -0,0 +1,188 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Custom-domain verification for the public help center.
+
+The customer proves control of the domain with a TXT record
+(_chattermate.<domain> = cm-verify=<token>) and routes traffic with a CNAME
+to HELP_CENTER_CNAME_TARGET (A/AAAA records matching HELP_CENTER_TARGET_IPS
+are accepted for providers that flatten CNAMEs). Both must pass before the
+host dispatcher will ever serve the domain. SSL turns active once an HTTPS
+probe against /healthz succeeds with a valid certificate.
+"""
+
+import os
+import secrets
+from datetime import datetime, timezone
+
+from sqlalchemy.orm import Session
+
+from app.core.config import settings
+from app.core.logger import get_logger
+from app.models.help_center import HelpCenterSettings, SSLStatus
+from app.repositories.help_center import HelpCenterRepository
+
+logger = get_logger(__name__)
+
+DNS_LIFETIME_SECONDS = 5.0
+SSL_PROBE_TIMEOUT_SECONDS = 10.0
+TXT_RECORD_PREFIX = "_chattermate"
+# Public resolvers for verification lookups. The container's own resolver is
+# Docker's embedded DNS (127.0.0.11) for service discovery — it negatively
+# caches names that didn't exist when first queried (so a TXT added *after* the
+# customer set up the domain keeps returning NXDOMAIN). Query public DNS
+# directly, and let self-hosters override if their network blocks these.
+_PUBLIC_DNS_RESOLVERS = [
+    ip.strip()
+    for ip in os.getenv("DOMAIN_VERIFY_DNS_RESOLVERS", "1.1.1.1,8.8.8.8,9.9.9.9").split(",")
+    if ip.strip()
+]
+
+
+def generate_verification_token() -> str:
+    return secrets.token_hex(16)
+
+
+def txt_record_host(domain: str) -> str:
+    return f"{TXT_RECORD_PREFIX}.{domain}"
+
+
+def expected_txt_value(row: HelpCenterSettings) -> str:
+    return f"cm-verify={row.domain_verification_token}"
+
+
+def _resolver():
+    import dns.resolver
+
+    resolver = dns.resolver.Resolver()
+    if _PUBLIC_DNS_RESOLVERS:
+        resolver.nameservers = _PUBLIC_DNS_RESOLVERS
+    resolver.lifetime = DNS_LIFETIME_SECONDS
+    return resolver
+
+
+def check_txt_record(row: HelpCenterSettings) -> bool:
+    """True when the verification TXT record is present."""
+    import dns.resolver
+
+    expected = expected_txt_value(row)
+    try:
+        answers = _resolver().resolve(txt_record_host(row.custom_domain), "TXT")
+    except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer, dns.resolver.NoNameservers,
+            dns.resolver.LifetimeTimeout):
+        return False
+    for record in answers:
+        value = b"".join(record.strings).decode("utf-8", errors="replace")
+        if value.strip() == expected:
+            return True
+    return False
+
+
+def check_cname_record(domain: str) -> bool:
+    """True when the domain points at us: CNAME to the target, or (for
+    CNAME-flattening providers) A/AAAA records matching the target IPs."""
+    import dns.resolver
+
+    target = settings.HELP_CENTER_CNAME_TARGET.rstrip(".").lower()
+    try:
+        answers = _resolver().resolve(domain, "CNAME")
+        return any(str(record.target).rstrip(".").lower() == target for record in answers)
+    except (dns.resolver.NXDOMAIN, dns.resolver.NoNameservers, dns.resolver.LifetimeTimeout):
+        return False
+    except dns.resolver.NoAnswer:
+        pass  # no CNAME — fall through to flattened A/AAAA comparison
+    if not settings.HELP_CENTER_TARGET_IPS:
+        return False
+    resolved = set()
+    for rtype in ("A", "AAAA"):
+        try:
+            resolved.update(str(r) for r in _resolver().resolve(domain, rtype))
+        except Exception:
+            continue
+    return bool(resolved) and resolved <= settings.HELP_CENTER_TARGET_IPS
+
+
+def probe_ssl(domain: str) -> bool:
+    """HTTPS reachability + certificate validation, resolving via PUBLIC DNS.
+    The container's own resolver (Docker embedded DNS) negatively caches a
+    custom domain that didn't exist before its cert was provisioned — so httpx
+    (which uses the system resolver) would keep failing. Resolve the A record
+    ourselves and connect to that IP with SNI = the domain, which also verifies
+    the served cert is actually issued for this domain."""
+    import socket
+    import ssl
+
+    try:
+        ip = str(_resolver().resolve(domain, "A")[0])
+    except Exception as e:
+        logger.info(f"SSL probe DNS for {domain} not ready: {e}")
+        return False
+    try:
+        ctx = ssl.create_default_context()
+        ctx.minimum_version = ssl.TLSVersion.TLSv1_2
+        with socket.create_connection((ip, 443), timeout=SSL_PROBE_TIMEOUT_SECONDS) as sock:
+            with ctx.wrap_socket(sock, server_hostname=domain) as tls:
+                tls.sendall(
+                    f"GET /healthz HTTP/1.1\r\nHost: {domain}\r\nConnection: close\r\n\r\n".encode()
+                )
+                status_line = tls.recv(128).split(b"\r\n", 1)[0]
+        return b" 200 " in status_line
+    except (OSError, ssl.SSLError) as e:
+        logger.info(f"SSL probe for {domain} not ready: {e}")
+        return False
+
+
+def set_custom_domain(db: Session, row: HelpCenterSettings, domain: str) -> HelpCenterSettings:
+    """Claim a (normalized) domain: fresh token, verification state reset."""
+    base_suffix = f".{settings.HELP_CENTER_BASE_DOMAIN}"
+    if domain == settings.HELP_CENTER_BASE_DOMAIN or domain.endswith(base_suffix):
+        raise ValueError(f"{settings.HELP_CENTER_BASE_DOMAIN} subdomains are assigned automatically and cannot be claimed.")
+    row.custom_domain = domain
+    row.domain_verification_token = generate_verification_token()
+    row.txt_record_verified = False
+    row.cname_record_verified = False
+    row.ssl_status = SSLStatus.NONE
+    row.domain_verified_at = None
+    return HelpCenterRepository(db).update(row)
+
+
+def clear_custom_domain(db: Session, row: HelpCenterSettings) -> HelpCenterSettings:
+    row.custom_domain = None
+    row.domain_verification_token = None
+    row.txt_record_verified = False
+    row.cname_record_verified = False
+    row.ssl_status = SSLStatus.NONE
+    row.domain_verified_at = None
+    return HelpCenterRepository(db).update(row)
+
+
+def verify_custom_domain(db: Session, row: HelpCenterSettings) -> HelpCenterSettings:
+    """Run both DNS checks (and the SSL probe once verified) and persist the
+    outcome. Blocking (DNS/HTTP I/O) — callers run it off the event loop."""
+    if not row.custom_domain:
+        raise ValueError("No custom domain configured.")
+    row.txt_record_verified = check_txt_record(row)
+    row.cname_record_verified = check_cname_record(row.custom_domain)
+    if row.domain_verified:
+        if not row.domain_verified_at:
+            row.domain_verified_at = datetime.now(timezone.utc)
+        if row.ssl_status != SSLStatus.ACTIVE.value:
+            row.ssl_status = (
+                SSLStatus.ACTIVE if probe_ssl(row.custom_domain) else SSLStatus.PENDING
+            )
+    else:
+        row.domain_verified_at = None
+        row.ssl_status = SSLStatus.NONE
+    return HelpCenterRepository(db).update(row)

backend/app/services/widget_identity.py

@@ -0,0 +1,95 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+What a widget conversation token may do to the customer it names.
+
+A widget visitor can be bound to a customer by an email they only typed, so the
+token naming a customer is not proof of being them. Conversations are already
+fenced by the token's scope (see conversation_token.conversation_scope); this
+module fences the customer row itself - its contact details, merges, and whether
+an unverified token may stand for a person the embedding app has signed in.
+"""
+
+from typing import Optional
+from uuid import UUID
+
+from sqlalchemy.orm import Session
+
+from app.models.customer import Customer
+from app.models.session_to_agent import SessionToAgent
+from app.repositories.customer import CustomerRepository
+from app.repositories.session_to_agent import SessionToAgentRepository
+from app.services.conversation_token import (
+    LEGACY_SCOPE_PREFIX,
+    is_verified_scope,
+    scope_for_session_key,
+)
+
+
+def can_act_as(db: Session, customer: Optional[Customer], scope: Optional[str]) -> bool:
+    """True when a token with `scope` may change `customer` as if it were them.
+
+    A verified token always may. An unverified one only for a customer its own
+    scope created - "no conversations elsewhere" is not ownership: a customer
+    made by a ticket or an import has none - and only while every conversation
+    of that customer is still its own.
+    """
+    if customer is None or not scope:
+        return False
+    if is_verified_scope(scope):
+        return True
+    if customer.is_authenticated or not _created_by(customer, scope):
+        return False
+    return not SessionToAgentRepository(db).customer_has_sessions_outside_scope(customer.id, scope)
+
+
+def _created_by(customer: Customer, scope: str) -> bool:
+    if customer.conversation_key:
+        return customer.conversation_key == scope
+    # Customers from before conversation keys: the anonymous row a legacy
+    # widget token created for itself is the only kind such a token can own.
+    return scope.startswith(LEGACY_SCOPE_PREFIX) and CustomerRepository.is_placeholder_email(customer.email)
+
+
+def may_stand_for(customer: Optional[Customer], scope: Optional[str]) -> bool:
+    """True when an unverified token may keep naming `customer` at all.
+
+    Once the embedding app has signed a person in, only a token our side vouched
+    for may name them - otherwise whoever claimed the address first would keep a
+    token for the signed-in user's row.
+    """
+    if customer is None or not scope:
+        return False
+    return is_verified_scope(scope) or not customer.is_authenticated
+
+
+def trusts_identity_in_conversation(
+    db: Session, customer: Optional[Customer], conversation: Optional[SessionToAgent]
+) -> bool:
+    """True when the visitor in `conversation` may be told, or change, what we
+    know of `customer`.
+
+    Reciting a stored name or email back is how a visitor who only typed someone
+    else's address would learn who they are. Unknown conversation: nothing.
+    """
+    if conversation is None:
+        return False
+    return can_act_as(db, customer, scope_for_session_key(conversation.conversation_key))
+
+
+def trusts_identity_in_session(db: Session, customer: Optional[Customer], session_id: UUID | str | None) -> bool:
+    """trusts_identity_in_conversation, for a caller holding only the session id."""
+    conversation = SessionToAgentRepository(db).get_session(session_id) if session_id else None
+    return trusts_identity_in_conversation(db, customer, conversation)

backend/assets/widget.css

@@ -0,0 +1 @@
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