Fix (P2 comment accuracy): correct options-flow token clause in const.py

The comment block rewritten by the last commit claimed the options flow
validates that a saved token is non-empty (the user-facing guard). That
is false: options_flow.py treats an EMPTY token as valid ("not configured
yet") and only rejects malformed values (padded / whitespace-only /
non-string), pinned by test_options_flow.py
(test_options_flow_api_section_defaults_saved asserts a bare submit saves
CONF_PANEL_TOKEN == ""; test_options_flow_panel_token_validation
documents the empty-token-is-valid contract).

Comment-only correction, no code or test changes: the clause now says the
options flow accepts an empty token and the actual non-emptiness guard is
enforced at NestQuestApiClient construction.

custom_components/nestquest/api_client.py

@@ -0,0 +1,283 @@
+"""Panel-plane API client for the NestQuest integration (Feature 18).
+
+The integration talks to the NestQuest API service (Feature 16) over
+HTTP instead of reading the database: this module is the ONE place that
+speaks the API's panel plane — ``GET /api/v1/panel/snapshot`` (today's
+household snapshot) and ``POST /api/v1/panel/instances/{id}/complete``
+(completion as the tapped child profile) — authenticated with the
+static panel service token as a Bearer credential on every request.
+
+Transport-injected by construction: the constructor takes the base URL,
+the panel token, and the HTTP session to use.  The session speaks the
+aiohttp ``ClientSession`` surface (``request(method, url, headers=...,
+json=...)`` returning an async context manager whose response carries
+``status`` and ``await text()``), so tests stub the transport with NO
+network and NO aiohttp installed; production builds the client through
+:func:`client_from_entry`, which hands in Home Assistant's shared
+aiohttp session (``homeassistant.helpers.aiohttp_client
+.async_get_clientsession``).  The module itself imports NEITHER
+homeassistant NOR aiohttp at runtime (aiohttp appears only behind
+``TYPE_CHECKING`` for annotations), so the client is usable anywhere —
+the HA coupling lives in the one production factory.
+
+Every failure is typed: a transport failure (connection refused, DNS
+failure, timeout — the exchange never produced a response) and every
+non-2xx HTTP response raise :class:`NestQuestApiError`.  The error
+carries the HTTP status where there is one (so 401 and 404 are
+distinguishable at the call site) and ``None`` when there is not; the
+original transport error is chained as ``__cause__`` — nothing is
+swallowed.  There are NO retries and the client logs nothing: refresh
+cadence is the coordinator's concern (the next task), and the panel
+token is a secret that must never reach a log line or an error
+message — the error texts name the method, path, and status only.
+"""
+from __future__ import annotations
+
+import asyncio
+import json
+from typing import TYPE_CHECKING, Any
+from urllib.parse import urlparse
+
+from .const import (
+    CONF_API_BASE_URL,
+    CONF_PANEL_TOKEN,
+    DEFAULT_API_BASE_URL,
+    DEFAULT_PANEL_TOKEN,
+)
+
+if TYPE_CHECKING:
+    import aiohttp
+
+__all__ = [
+    "COMPLETE_INSTANCE_PATH",
+    "DEFAULT_TIMEOUT_SECONDS",
+    "NestQuestApiError",
+    "NestQuestApiClient",
+    "SNAPSHOT_PATH",
+    "client_from_entry",
+    "is_valid_base_url",
+    "resolve_api_config",
+]
+
+#: The panel plane's snapshot route (Feature 16).
+SNAPSHOT_PATH = "/api/v1/panel/snapshot"
+
+#: The panel plane's completion route template (Feature 16); the
+#: ``{instance_id}`` placeholder is filled per call.
+COMPLETE_INSTANCE_PATH = "/api/v1/panel/instances/{instance_id}/complete"
+
+#: Request timeout, in seconds.  One attempt, one timeout: a hung API
+#: call surfaces as a typed error for the coordinator to report, never
+#: a retry loop.
+DEFAULT_TIMEOUT_SECONDS = 10.0
+
+
+class NestQuestApiError(Exception):
+    """A failed NestQuest API exchange, raised for every failure mode.
+
+    ``status`` carries the HTTP status when a response arrived (a
+    non-2xx response — 401 for a bad token, 404 for an unknown
+    instance) and is ``None`` when the exchange failed at the transport
+    level (connection refused, DNS failure, timeout) — so callers
+    distinguish the two with ``is_transport_error``.  The original
+    transport error, where there is one, is chained as ``__cause__``.
+    Messages carry the method, path, and status — never the request
+    headers, so the panel token can never leak through an error.
+    """
+
+    def __init__(self, message: str, *, status: int | None = None) -> None:
+        super().__init__(message)
+        self.status = status
+
+    @property
+    def is_transport_error(self) -> bool:
+        """True when the exchange failed before any response arrived."""
+        return self.status is None
+
+
+def is_valid_base_url(value: object) -> bool:
+    """Return True when ``value`` is a usable API base URL.
+
+    A full ``http://`` or ``https://`` URL with a host — the exact
+    shape the options flow validates (form ergonomics) and the client
+    constructor enforces (fail fast, never build requests against a
+    scheme-less or host-less string).
+    """
+    if not isinstance(value, str):
+        return False
+    candidate = value.strip()
+    if not candidate:
+        return False
+    parsed = urlparse(candidate)
+    return parsed.scheme in ("http", "https") and bool(parsed.netloc)
+
+
+def resolve_api_config(entry: Any) -> tuple[str, str]:
+    """Resolve ``(base_url, panel_token)`` off a config entry.
+
+    Precedence mirrors the options flow's stored-values resolution:
+    ``entry.options`` first (the live options-flow copy), then
+    ``entry.data`` (the config-flow-era copy), then the const defaults.
+    The token is a secret: callers must never log the returned pair.
+    """
+    options = getattr(entry, "options", None) or {}
+    data = getattr(entry, "data", None) or {}
+
+    def _pick(key: str, default: str) -> str:
+        if key in options:
+            return options[key]
+        if key in data:
+            return data[key]
+        return default
+
+    return (
+        _pick(CONF_API_BASE_URL, DEFAULT_API_BASE_URL),
+        _pick(CONF_PANEL_TOKEN, DEFAULT_PANEL_TOKEN),
+    )
+
+
+def client_from_entry(hass: Any, entry: Any) -> NestQuestApiClient:
+    """Build the production client for a config entry.
+
+    Reads the configured base URL and panel token off the entry
+    (:func:`resolve_api_config`) and hands the client Home Assistant's
+    SHARED aiohttp session (``homeassistant.helpers.aiohttp_client
+    .async_get_clientsession``) so panel calls ride HA's one connection
+    pool.  The helper import is deferred into this function on purpose:
+    the test harness is mock-only and the module must import (and the
+    client must be stub-transport testable) without homeassistant or
+    aiohttp installed.
+    """
+    from homeassistant.helpers.aiohttp_client import async_get_clientsession
+
+    base_url, panel_token = resolve_api_config(entry)
+    return NestQuestApiClient(
+        base_url, panel_token, async_get_clientsession(hass)
+    )
+
+
+class NestQuestApiClient:
+    """Async client for the NestQuest API service's panel plane.
+
+    ONE instance per config entry (the coordinator task wires it into
+    the refresh cycle).  The client is deliberately thin: it adds the
+    Bearer credential and the base URL, enforces one timeout per
+    request, and turns every failure into :class:`NestQuestApiError` —
+    no business logic, no retries, no caching.
+    """
+
+    def __init__(
+        self,
+        base_url: str,
+        panel_token: str,
+        session: aiohttp.ClientSession,
+        *,
+        timeout_seconds: float = DEFAULT_TIMEOUT_SECONDS,
+    ) -> None:
+        """Store the connection settings; the session is injected.
+
+        ``session`` is an aiohttp ``ClientSession`` in production and a
+        stub transport in tests.  ``base_url`` must be a full http(s)
+        URL and ``panel_token`` must be non-empty — a client built
+        without either can only fail later at request time with a
+        less-explicable error, so construction fails fast instead.
+        """
+        if not is_valid_base_url(base_url):
+            raise ValueError(
+                f"base_url must be a full http(s) URL, got {base_url!r}"
+            )
+        if not isinstance(panel_token, str) or not panel_token.strip():
+            raise ValueError("panel_token must be a non-empty string")
+        if (
+            not isinstance(timeout_seconds, (int, float))
+            or isinstance(timeout_seconds, bool)
+            or timeout_seconds <= 0
+        ):
+            raise ValueError(
+                f"timeout_seconds must be a positive number, got {timeout_seconds!r}"
+            )
+        self._base_url = base_url.strip().rstrip("/")
+        self._panel_token = panel_token
+        self._session = session
+        self._timeout_seconds = float(timeout_seconds)
+
+    async def get_snapshot(self) -> dict[str, Any]:
+        """Fetch and parse today's household snapshot.
+
+        Returns the JSON the snapshot route returns (``today_iso``,
+        ``cycle_day``, and the per-child list — see
+        ``api/routes_panel.py`` for the documented shape).  Raises
+        :class:`NestQuestApiError` on transport failure, timeout, or a
+        non-2xx response.
+        """
+        return await self._request_json("GET", SNAPSHOT_PATH)
+
+    async def complete_instance(
+        self, instance_id: int, actor_child_id: int
+    ) -> dict[str, Any]:
+        """Complete one quest instance as the tapped child profile.
+
+        POSTs ``{"actor_child_id": actor_child_id}`` to the complete
+        route and returns the parsed response body (the route answers
+        ``{"status": ...}`` both for a first completion and for an
+        idempotent repeat, so a retried panel tap succeeds).  Raises
+        :class:`NestQuestApiError` on transport failure, timeout, or a
+        non-2xx response — 401 for a wrong token, 404 for an unknown
+        instance.
+        """
+        path = COMPLETE_INSTANCE_PATH.format(instance_id=instance_id)
+        return await self._request_json(
+            "POST", path, json_body={"actor_child_id": actor_child_id}
+        )
+
+    async def _request_json(
+        self,
+        method: str,
+        path: str,
+        *,
+        json_body: dict[str, Any] | None = None,
+    ) -> Any:
+        """Run ONE request and return the parsed JSON body.
+
+        The Bearer token rides the Authorization header only.  A
+        non-2xx response raises :class:`NestQuestApiError` with its
+        status; anything the transport raises (connection, timeout) is
+        wrapped as a transport-level :class:`NestQuestApiError` with
+        the original error chained — never swallowed, never retried.
+        A 2xx body that is not valid JSON is a protocol failure and
+        raises typed too, carrying the status it arrived with.
+        """
+        url = f"{self._base_url}{path}"
+        headers = {"Authorization": f"Bearer {self._panel_token}"}
+        try:
+            async with asyncio.timeout(self._timeout_seconds):
+                async with self._session.request(
+                    method, url, headers=headers, json=json_body
+                ) as response:
+                    status = response.status
+                    if not 200 <= status < 300:
+                        raise NestQuestApiError(
+                            f"NestQuest API {method} {path} failed with "
+                            f"HTTP {status}",
+                            status=status,
+                        )
+                    body_text = await response.text()
+        except asyncio.CancelledError:
+            # Cancellation is never converted: a shutting-down event
+            # loop must stop, not read a synthesized API error.
+            raise
+        except NestQuestApiError:
+            raise
+        except Exception as err:
+            raise NestQuestApiError(
+                f"NestQuest API {method} {path} transport failure: {err}",
+                status=None,
+            ) from err
+        try:
+            return json.loads(body_text)
+        except ValueError as err:
+            raise NestQuestApiError(
+                f"NestQuest API {method} {path} returned malformed "
+                f"JSON: {err}",
+                status=status,
+            ) from err

custom_components/nestquest/core/const.py

@@ -101,6 +101,32 @@ CONF_END_OF_DAY_REPORT_ENABLED = "end_of_day_report_enabled"
 CONF_CELEBRATION_ENABLED = "celebration_enabled"
 DEFAULT_AUTOMATION_ENABLED = True
 
+# Panel-plane API client (Feature 18): the integration reaches the
+# NestQuest API service (Feature 16) over HTTP instead of the database.
+# The base URL points at the API service host serving ``/api/v1/panel/*``
+# (uvicorn's default host/port is the sensible starting point); the panel
+# service token is the static Bearer credential the panel plane requires
+# (``NESTQUEST_PANEL_TOKEN`` on the API side).  Both are stored on the
+# entry like every other setting — options first, then the entry-data
+# copy, then defaults.  The TOKEN IS A SECRET: it is never logged, never
+# echoed into error messages, and never committed.  The shipped default
+# token IS the empty string (DEFAULT_PANEL_TOKEN) — an entry with no
+# configured token is therefore NOT a working client: the options flow
+# accepts an empty token as "not configured yet" and only rejects
+# malformed (padded/whitespace-only/non-string) values — the actual
+# non-emptiness guard is enforced at client construction, where
+# NestQuestApiClient fails fast on an empty/whitespace token
+# (api_client.py).  So a caller building the client from a bare
+# entry must either ensure a token is configured first or handle the
+# construction ValueError and surface an "API not configured" state —
+# an unconfigured entry never yields a client that can only 401.
+# This mirrors the API service's fail-closed stance (api/config.py: no
+# default token exists).
+CONF_API_BASE_URL = "api_base_url"
+DEFAULT_API_BASE_URL = "http://127.0.0.1:8000"
+CONF_PANEL_TOKEN = "panel_token"
+DEFAULT_PANEL_TOKEN = ""
+
 # Quest windows (D-008): a definition may declare several day windows;
 # each produces its own instance per day and groups the panel's Quest
 # Log into three columns.  The clock ranges are stored here so they stay

custom_components/nestquest/options_flow.py

@@ -12,6 +12,7 @@ from .const import (
     CONF_ADMIN_USER_IDS,
     CONF_AFTERNOON_REMINDER_ENABLED,
     CONF_AFTERNOON_REMINDER_TIME,
+    CONF_API_BASE_URL,
     CONF_CELEBRATION_ENABLED,
     CONF_DAY_ROLLOVER_TIME,
     CONF_END_OF_DAY_REPORT_ENABLED,
@@ -21,7 +22,9 @@ from .const import (
     CONF_MORNING_SUMMARY_TIME,
     CONF_NOTIFY_TARGET,
     CONF_PANEL_IDLE_TIMEOUT,
+    CONF_PANEL_TOKEN,
     CONF_UPDATE_INTERVAL,
+    DEFAULT_API_BASE_URL,
     DEFAULT_AFTERNOON_REMINDER_TIME,
     DEFAULT_AUTOMATION_ENABLED,
     DEFAULT_DAY_ROLLOVER_TIME,
@@ -29,12 +32,14 @@ from .const import (
     DEFAULT_HORIZON_DAYS,
     DEFAULT_MORNING_SUMMARY_TIME,
     DEFAULT_PANEL_IDLE_TIMEOUT,
+    DEFAULT_PANEL_TOKEN,
     DEFAULT_UPDATE_INTERVAL,
     DOMAIN,
     MIN_UPDATE_INTERVAL,
     TIME_PATTERN,
 )
 from .admin_allowlist import list_admin_ids, set_admin_ids
+from .api_client import is_valid_base_url
 
 MIN_HORIZON_DAYS = 1
 MIN_PANEL_IDLE_TIMEOUT = 30
@@ -116,6 +121,25 @@ def _async_validate(user_input: dict[str, Any]) -> dict[str, str]:
         if toggle_value is not None and not isinstance(toggle_value, bool):
             errors[toggle_key] = "invalid"
 
+    # The panel-plane API connection (Feature 18) is OPTIONAL in raw
+    # submits the same way: a missing key keeps the current value.  The
+    # base URL must be a full http(s) URL with a host — the same check
+    # the client's constructor enforces, so a malformed URL fails at
+    # the form, not at the first request.  The token may be EMPTY (the
+    # API connection is simply not configured yet) but a non-empty one
+    # must be pasted unpadded: a padded or whitespace-only value is a
+    # clipboard mistake that would fail the token check at request
+    # time.
+    api_base_url = user_input.get(CONF_API_BASE_URL)
+    if api_base_url is not None and not is_valid_base_url(api_base_url):
+        errors[CONF_API_BASE_URL] = "invalid_url"
+    panel_token = user_input.get(CONF_PANEL_TOKEN)
+    if panel_token is not None and (
+        not isinstance(panel_token, str)
+        or panel_token != panel_token.strip()
+    ):
+        errors[CONF_PANEL_TOKEN] = "invalid"
+
     return errors
 
 
@@ -186,6 +210,18 @@ def _build_schema(
             CONF_CELEBRATION_ENABLED,
             default=current[CONF_CELEBRATION_ENABLED],
         ): _strict_bool,
+        # Panel-plane API connection (Feature 18): the base URL the API
+        # client talks to and the panel service token it presents as
+        # the Bearer credential.  Schema-validated submits always carry
+        # both (the defaults pre-fill from the stored values); raw
+        # callers omitting them keep their stored values (see
+        # _async_validate).
+        vol.Required(
+            CONF_API_BASE_URL, default=current[CONF_API_BASE_URL]
+        ): str,
+        vol.Required(
+            CONF_PANEL_TOKEN, default=current[CONF_PANEL_TOKEN]
+        ): str,
     }
     if admin_choices is not None:
         # HA's supported multi-select validator: the frontend can
@@ -336,6 +372,11 @@ class NestQuestOptionsFlow(config_entries.OptionsFlowWithConfigEntry):
             data[notification_key] = user_input.get(
                 notification_key, current[notification_key]
             )
+        # The API connection section (Feature 18) stores the base URL
+        # and panel token the same fall-back-to-current way, so raw
+        # submits that predate the section keep their stored values.
+        for api_key in (CONF_API_BASE_URL, CONF_PANEL_TOKEN):
+            data[api_key] = user_input.get(api_key, current[api_key])
         if admin_ids_present:
             data[CONF_ADMIN_USER_IDS] = admin_ids
         elif admin_default:
@@ -365,6 +406,8 @@ class NestQuestOptionsFlow(config_entries.OptionsFlowWithConfigEntry):
             (CONF_AFTERNOON_REMINDER_ENABLED, DEFAULT_AUTOMATION_ENABLED),
             (CONF_END_OF_DAY_REPORT_ENABLED, DEFAULT_AUTOMATION_ENABLED),
             (CONF_CELEBRATION_ENABLED, DEFAULT_AUTOMATION_ENABLED),
+            (CONF_API_BASE_URL, DEFAULT_API_BASE_URL),
+            (CONF_PANEL_TOKEN, DEFAULT_PANEL_TOKEN),
         ):
             if key in options:
                 values[key] = options[key]

custom_components/nestquest/strings.json

@@ -18,11 +18,13 @@
     "step": {
       "init": {
         "title": "NestQuest Settings",
-        "description": "Adjust how NestQuest plans, rolls over days, and idles its panel.",
+        "description": "Adjust how NestQuest plans, rolls over days, idles its panel, and reaches the NestQuest API service.",
         "data": {
           "horizon_days": "Generation horizon (days)",
           "day_rollover_time": "Day rollover time (HH:MM)",
           "panel_idle_timeout": "Panel idle timeout (seconds)",
+          "api_base_url": "NestQuest API base URL (http://host:port)",
+          "panel_token": "Panel service token",
           "admin_user_ids": "Admin users (parents)"
         }
       }
@@ -30,6 +32,7 @@
     "errors": {
       "invalid": "Invalid value.",
       "invalid_time": "Time must use 24-hour HH:MM format.",
+      "invalid_url": "Enter the API base URL as a full http:// or https:// URL with a host.",
       "no_admins": "Select at least one admin user; an empty allowlist would lock everyone out.",
       "invalid_admin": "Invalid admin selection."
     }

custom_components/nestquest/translations/en.json

@@ -18,11 +18,13 @@
     "step": {
       "init": {
         "title": "NestQuest Settings",
-        "description": "Adjust how NestQuest plans, rolls over days, and idles its panel.",
+        "description": "Adjust how NestQuest plans, rolls over days, idles its panel, and reaches the NestQuest API service.",
         "data": {
           "horizon_days": "Generation horizon (days)",
           "day_rollover_time": "Day rollover time (HH:MM)",
           "panel_idle_timeout": "Panel idle timeout (seconds)",
+          "api_base_url": "NestQuest API base URL (http://host:port)",
+          "panel_token": "Panel service token",
           "admin_user_ids": "Admin users (parents)"
         }
       }
@@ -30,6 +32,7 @@
     "errors": {
       "invalid": "Invalid value.",
       "invalid_time": "Time must use 24-hour HH:MM format.",
+      "invalid_url": "Enter the API base URL as a full http:// or https:// URL with a host.",
       "no_admins": "Select at least one admin user; an empty allowlist would lock everyone out.",
       "invalid_admin": "Invalid admin selection."
     }

tests/test_api_client.py

@@ -0,0 +1,450 @@
+"""Tests for the panel-plane API client (Feature 18).
+
+The client is exercised against a STUB transport only — no network, no
+aiohttp, no homeassistant: the injected session is a fake that speaks
+the same ``request(...)`` surface aiohttp's ``ClientSession`` exposes
+and records every call, so the tests assert exactly what the client
+puts on the wire (method, URL, Bearer header, JSON body) and how every
+failure mode (non-2xx, connection failure, timeout, malformed JSON)
+surfaces as the typed :class:`NestQuestApiError`.
+"""
+from __future__ import annotations
+
+import asyncio
+import json
+import sys
+import types
+
+import pytest
+
+from conftest import make_config_entry
+
+from custom_components.nestquest import api_client
+from custom_components.nestquest.api_client import (
+    NestQuestApiClient,
+    NestQuestApiError,
+    is_valid_base_url,
+    resolve_api_config,
+)
+from custom_components.nestquest.const import (
+    CONF_API_BASE_URL,
+    CONF_PANEL_TOKEN,
+    DEFAULT_API_BASE_URL,
+    DEFAULT_PANEL_TOKEN,
+)
+
+BASE_URL = "http://api.test:8000"
+TOKEN = "test-panel-token"
+
+#: A realistic panel snapshot payload (the documented shape of the
+#: Feature 16 snapshot route).
+SNAPSHOT_PAYLOAD = {
+    "today_iso": "2026-09-23",
+    "cycle_day": 2,
+    "children": [
+        {
+            "child_id": 1,
+            "child_name": "Ada",
+            "present": False,
+            "next_present": "2026-09-24",
+            "due_today": 1,
+            "completed_today": 0,
+            "remaining_today": 1,
+            "completion_pct": 0,
+            "instances": [
+                {
+                    "id": 7,
+                    "definition_id": 3,
+                    "child_id": 1,
+                    "title": "Pack bag",
+                    "icon": None,
+                    "window": "morning",
+                    "due_time": "10:00",
+                    "state": "open",
+                    "overdue": True,
+                    "completed_at": None,
+                    "on_time": None,
+                }
+            ],
+        }
+    ],
+}
+
+
+class StubResponse:
+    """A fake aiohttp response: ``status`` plus ``await text()``."""
+
+    def __init__(self, status: int, body: str) -> None:
+        self.status = status
+        self._body = body
+
+    async def text(self) -> str:
+        return self._body
+
+
+class _OutcomeContext:
+    """Async context manager yielding one scripted outcome.
+
+    Mirrors aiohttp's ``session.request(...)`` return value: entering
+    the context performs the request, so a scripted transport error
+    raises THERE — before any response object exists, exactly where
+    aiohttp's connector raises on a refused connection.
+    """
+
+    def __init__(self, response, error) -> None:
+        self._response = response
+        self._error = error
+
+    async def __aenter__(self):
+        if self._error is not None:
+            raise self._error
+        return self._response
+
+    async def __aexit__(self, exc_type, exc, tb) -> bool:
+        return False
+
+
+class StubTransport:
+    """A no-network stand-in for aiohttp's ``ClientSession``.
+
+    Records every ``request(...)`` call as a dict (method, url, headers,
+    json body) and answers from a scripted queue of outcomes — a
+    :class:`StubResponse` or an exception per call, consumed in order —
+    so each test drives exactly one exchange.
+    """
+
+    def __init__(self, *outcomes) -> None:
+        self.calls: list[dict] = []
+        self._outcomes = list(outcomes)
+
+    def request(self, method: str, url: str, **kwargs):
+        self.calls.append(
+            {
+                "method": method,
+                "url": url,
+                "headers": kwargs.get("headers"),
+                "json": kwargs.get("json"),
+            }
+        )
+        if not self._outcomes:
+            raise AssertionError("StubTransport ran out of scripted outcomes")
+        outcome = self._outcomes.pop(0)
+        if isinstance(outcome, BaseException):
+            return _OutcomeContext(None, outcome)
+        return _OutcomeContext(outcome, None)
+
+
+class HangingTransport:
+    """A transport whose request never answers (for the timeout test)."""
+
+    def __init__(self) -> None:
+        self.calls: list[dict] = []
+
+    def request(self, method: str, url: str, **kwargs):
+        self.calls.append({"method": method, "url": url})
+        return _HangingContext()
+
+
+class _HangingContext:
+    async def __aenter__(self):
+        await asyncio.sleep(5)
+        raise AssertionError("hanging transport was never cancelled")
+
+    async def __aexit__(self, exc_type, exc, tb) -> bool:
+        return False
+
+
+def make_client(transport, *, timeout_seconds: float = 5.0) -> NestQuestApiClient:
+    """Build a client over the stub transport with the test credentials."""
+    return NestQuestApiClient(
+        BASE_URL, TOKEN, transport, timeout_seconds=timeout_seconds
+    )
+
+
+# ---------------------------------------------------------------------------
+# Success paths
+# ---------------------------------------------------------------------------
+
+
+async def test_get_snapshot_parses_payload_and_sends_bearer() -> None:
+    transport = StubTransport(
+        StubResponse(200, json.dumps(SNAPSHOT_PAYLOAD))
+    )
+    client = make_client(transport)
+
+    snapshot = await client.get_snapshot()
+
+    assert snapshot == SNAPSHOT_PAYLOAD
+    call = transport.calls[0]
+    assert call["method"] == "GET"
+    assert call["url"] == f"{BASE_URL}/api/v1/panel/snapshot"
+    assert call["headers"] == {"Authorization": f"Bearer {TOKEN}"}
+    assert call["json"] is None
+
+
+async def test_complete_instance_posts_body_and_headers() -> None:
+    transport = StubTransport(StubResponse(200, '{"status": "done"}'))
+    client = make_client(transport)
+
+    result = await client.complete_instance(42, 3)
+
+    assert result == {"status": "done"}
+    call = transport.calls[0]
+    assert call["method"] == "POST"
+    assert call["url"] == f"{BASE_URL}/api/v1/panel/instances/42/complete"
+    assert call["json"] == {"actor_child_id": 3}
+    assert call["headers"]["Authorization"] == f"Bearer {TOKEN}"
+
+
+async def test_base_url_trailing_slash_is_normalized() -> None:
+    """A base URL with a trailing slash must not double the path slash."""
+    transport = StubTransport(StubResponse(200, "{}"))
+    client = NestQuestApiClient(
+        f"{BASE_URL}/", TOKEN, transport, timeout_seconds=5.0
+    )
+    await client.get_snapshot()
+    assert transport.calls[0]["url"] == f"{BASE_URL}/api/v1/panel/snapshot"
+
+
+# ---------------------------------------------------------------------------
+# HTTP failures: the typed error carries the status
+# ---------------------------------------------------------------------------
+
+
+async def test_snapshot_401_raises_typed_error() -> None:
+    """A wrong/missing token answers 401 and surfaces with that status."""
+    transport = StubTransport(
+        StubResponse(401, '{"detail": "Missing or invalid panel service token"}')
+    )
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.get_snapshot()
+
+    error = excinfo.value
+    assert error.status == 401
+    assert not error.is_transport_error
+    assert error.__cause__ is None
+    # The token is a secret: it never reaches the raised message.
+    assert TOKEN not in str(error)
+
+
+async def test_complete_unknown_instance_404_raises_typed_error() -> None:
+    transport = StubTransport(
+        StubResponse(404, '{"detail": "Quest instance not found"}')
+    )
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.complete_instance(999999, 1)
+
+    assert excinfo.value.status == 404
+    assert not excinfo.value.is_transport_error
+
+
+async def test_snapshot_500_raises_typed_error() -> None:
+    """Any non-2xx response is typed, whatever the status."""
+    transport = StubTransport(StubResponse(500, "{}"))
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.get_snapshot()
+
+    assert excinfo.value.status == 500
+
+
+async def test_malformed_2xx_body_raises_typed_with_status() -> None:
+    """A 2xx body that is not JSON is a protocol failure, carrying its status."""
+    transport = StubTransport(StubResponse(200, "<html>not json</html>"))
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.get_snapshot()
+
+    assert excinfo.value.status == 200
+
+
+# ---------------------------------------------------------------------------
+# Transport failures: the typed error carries no status and chains the cause
+# ---------------------------------------------------------------------------
+
+
+async def test_connection_failure_raises_transport_error() -> None:
+    transport = StubTransport(OSError("connection refused"))
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.get_snapshot()
+
+    error = excinfo.value
+    assert error.status is None
+    assert error.is_transport_error
+    assert isinstance(error.__cause__, OSError)
+
+
+async def test_connection_failure_on_complete_is_typed() -> None:
+    transport = StubTransport(OSError("connection refused"))
+    client = make_client(transport)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.complete_instance(7, 1)
+
+    assert excinfo.value.status is None
+    assert excinfo.value.is_transport_error
+
+
+async def test_request_timeout_raises_transport_error() -> None:
+    """A hung API call surfaces as a typed transport error, once, with
+    no retry: the one request is cancelled by the client's timeout."""
+    transport = HangingTransport()
+    client = make_client(transport, timeout_seconds=0.05)
+
+    with pytest.raises(NestQuestApiError) as excinfo:
+        await client.get_snapshot()
+
+    assert excinfo.value.status is None
+    assert excinfo.value.is_transport_error
+    assert len(transport.calls) == 1
+
+
+# ---------------------------------------------------------------------------
+# Construction and config resolution
+# ---------------------------------------------------------------------------
+
+
+def test_constructor_requires_full_base_url() -> None:
+    for bad_url in (None, "", "   ", "api.lan:8000", "http://", "ftp://x"):
+        with pytest.raises(ValueError):
+            NestQuestApiClient(bad_url, TOKEN, StubTransport())
+
+
+def test_constructor_requires_non_empty_token() -> None:
+    for bad_token in (None, "", "   "):
+        with pytest.raises(ValueError):
+            NestQuestApiClient(BASE_URL, bad_token, StubTransport())
+
+
+def test_constructor_requires_positive_timeout() -> None:
+    for bad_timeout in (0, -1, "5", True, None):
+        with pytest.raises(ValueError):
+            NestQuestApiClient(
+                BASE_URL, TOKEN, StubTransport(), timeout_seconds=bad_timeout
+            )
+
+
+def test_is_valid_base_url_accepts_full_http_urls() -> None:
+    assert is_valid_base_url("http://127.0.0.1:8000")
+    assert is_valid_base_url("https://nestquest.lan")
+    assert is_valid_base_url(" http://127.0.0.1:8000 ")
+    assert not is_valid_base_url("api.lan:8000")
+    assert not is_valid_base_url("http://")
+    assert not is_valid_base_url("")
+    assert not is_valid_base_url(None)
+    assert not is_valid_base_url(42)
+
+
+def test_resolve_api_config_prefers_options_then_data_then_defaults() -> None:
+    options_only = make_config_entry(
+        options={CONF_API_BASE_URL: "http://from-options:1"}
+    )
+    assert resolve_api_config(options_only) == (
+        "http://from-options:1",
+        DEFAULT_PANEL_TOKEN,
+    )
+
+    data_only = make_config_entry(
+        data={
+            CONF_API_BASE_URL: "http://from-data:2",
+            CONF_PANEL_TOKEN: "from-data",
+        }
+    )
+    assert resolve_api_config(data_only) == ("http://from-data:2", "from-data")
+
+    both = make_config_entry(
+        options={CONF_API_BASE_URL: "http://from-options:3"},
+        data={
+            CONF_API_BASE_URL: "http://from-data:4",
+            CONF_PANEL_TOKEN: "from-data",
+        },
+    )
+    assert resolve_api_config(both) == (
+        "http://from-options:3",
+        "from-data",
+    )
+
+    bare = make_config_entry()
+    assert resolve_api_config(bare) == (DEFAULT_API_BASE_URL, DEFAULT_PANEL_TOKEN)
+
+
+def test_client_from_entry_reads_config_and_shared_session(monkeypatch) -> None:
+    """The production factory resolves the entry config and hands in HA's
+    shared aiohttp session (stubbed module — no real HA, no network)."""
+    fake_module = types.ModuleType("homeassistant.helpers.aiohttp_client")
+    shared_session = object()
+    fake_module.async_get_clientsession = lambda hass: shared_session
+    monkeypatch.setitem(
+        sys.modules, "homeassistant.helpers.aiohttp_client", fake_module
+    )
+    entry = make_config_entry(
+        options={
+            CONF_API_BASE_URL: "http://panel.lan:8443",
+            CONF_PANEL_TOKEN: "entry-token",
+        }
+    )
+
+    client = api_client.client_from_entry(object(), entry)
+
+    assert client._session is shared_session
+    assert client._base_url == "http://panel.lan:8443"
+    assert client._panel_token == "entry-token"
+
+
+def test_client_from_entry_unconfigured_token_raises_at_construction(
+    monkeypatch,
+) -> None:
+    """An entry with NO configured token (the shipped default) raises
+    ValueError AT CONSTRUCTION — the client's fail-fast guard — rather
+    than silently building a client that can only 401 (the documented
+    contract: the options flow's non-empty validation is the user-facing
+    guard; the coordinator must ensure a token is configured first or
+    handle the construction error as "API not configured")."""
+    fake_module = types.ModuleType("homeassistant.helpers.aiohttp_client")
+    fake_module.async_get_clientsession = lambda hass: object()
+    monkeypatch.setitem(
+        sys.modules, "homeassistant.helpers.aiohttp_client", fake_module
+    )
+    entry = make_config_entry(
+        options={CONF_API_BASE_URL: DEFAULT_API_BASE_URL},
+    )
+    assert resolve_api_config(entry)[1] == DEFAULT_PANEL_TOKEN == ""
+
+    with pytest.raises(ValueError, match="panel_token must be a non-empty"):
+        api_client.client_from_entry(object(), entry)
+
+    # Same for a whitespace-only stored token: whitespace is not a token.
+    entry_ws = make_config_entry(options={CONF_PANEL_TOKEN: "   "})
+    with pytest.raises(ValueError, match="panel_token must be a non-empty"):
+        api_client.client_from_entry(object(), entry_ws)
+
+
+async def test_client_logs_nothing() -> None:
+    """The client emits no log records at all (the token must never
+    reach a log line), success or failure."""
+    import logging
+
+    records: list[logging.LogRecord] = []
+
+    class _Capture(logging.Handler):
+        def emit(self, record: logging.LogRecord) -> None:
+            records.append(record)
+
+    handler = _Capture()
+    logging.getLogger().addHandler(handler)
+    try:
+        transport = StubTransport(StubResponse(401, "{}"))
+        client = make_client(transport)
+        with pytest.raises(NestQuestApiError):
+            await client.get_snapshot()
+    finally:
+        logging.getLogger().removeHandler(handler)
+    assert records == []

tests/test_options_flow.py

@@ -15,22 +15,26 @@ from custom_components.nestquest import config_flow
 from custom_components.nestquest import options_flow
 from custom_components.nestquest.const import (
     CONF_ADMIN_USER_IDS,
-    CONF_DAY_ROLLOVER_TIME,
-    CONF_HORIZON_DAYS,
-    CONF_PANEL_IDLE_TIMEOUT,
-    CONF_UPDATE_INTERVAL,
     CONF_AFTERNOON_REMINDER_ENABLED,
     CONF_AFTERNOON_REMINDER_TIME,
+    CONF_API_BASE_URL,
     CONF_CELEBRATION_ENABLED,
+    CONF_DAY_ROLLOVER_TIME,
     CONF_END_OF_DAY_REPORT_ENABLED,
     CONF_END_OF_DAY_REPORT_TIME,
+    CONF_HORIZON_DAYS,
     CONF_MORNING_SUMMARY_ENABLED,
     CONF_MORNING_SUMMARY_TIME,
     CONF_NOTIFY_TARGET,
+    CONF_PANEL_IDLE_TIMEOUT,
+    CONF_PANEL_TOKEN,
+    CONF_UPDATE_INTERVAL,
+    DEFAULT_API_BASE_URL,
     DEFAULT_AFTERNOON_REMINDER_TIME,
     DEFAULT_AUTOMATION_ENABLED,
     DEFAULT_END_OF_DAY_REPORT_TIME,
     DEFAULT_MORNING_SUMMARY_TIME,
+    DEFAULT_PANEL_TOKEN,
     DEFAULT_UPDATE_INTERVAL,
     DEFAULT_DAY_ROLLOVER_TIME,
     DEFAULT_HORIZON_DAYS,
@@ -49,8 +53,9 @@ VALID_INPUT = {
 }
 
 #: What a schema-validated submit produces from a bare VALID_INPUT on a
-#: fresh entry: the Feature 10 refresh interval and the Feature 11
-#: notification section fill from their defaults.
+#: fresh entry: the Feature 10 refresh interval, the Feature 11
+#: notification section, and the Feature 18 API connection fill from
+#: their defaults.
 FULL_INPUT = {
     **VALID_INPUT,
     CONF_UPDATE_INTERVAL: DEFAULT_UPDATE_INTERVAL,
@@ -62,6 +67,8 @@ FULL_INPUT = {
     CONF_AFTERNOON_REMINDER_ENABLED: DEFAULT_AUTOMATION_ENABLED,
     CONF_END_OF_DAY_REPORT_ENABLED: DEFAULT_AUTOMATION_ENABLED,
     CONF_CELEBRATION_ENABLED: DEFAULT_AUTOMATION_ENABLED,
+    CONF_API_BASE_URL: DEFAULT_API_BASE_URL,
+    CONF_PANEL_TOKEN: DEFAULT_PANEL_TOKEN,
 }
 
 
@@ -259,6 +266,8 @@ def test_options_flow_schema_applies_stored_defaults() -> None:
         CONF_AFTERNOON_REMINDER_ENABLED: True,
         CONF_END_OF_DAY_REPORT_ENABLED: True,
         CONF_CELEBRATION_ENABLED: True,
+        CONF_API_BASE_URL: DEFAULT_API_BASE_URL,
+        CONF_PANEL_TOKEN: DEFAULT_PANEL_TOKEN,
         CONF_ADMIN_USER_IDS: [],
     }
 
@@ -272,6 +281,9 @@ def test_options_flow_schema_coerces_field_types() -> None:
     assert validators[CONF_HORIZON_DAYS] is int
     assert validators[CONF_DAY_ROLLOVER_TIME] is str
     assert validators[CONF_PANEL_IDLE_TIMEOUT] is int
+    # The Feature 18 API connection fields are free-text strings.
+    assert validators[CONF_API_BASE_URL] is str
+    assert validators[CONF_PANEL_TOKEN] is str
 
 
 @pytest.mark.parametrize("bad_horizon", [0, -5])
@@ -326,8 +338,10 @@ def test_options_flow_rejects_invalid_idle_timeout(bad_timeout) -> None:
     assert result["errors"] == {CONF_PANEL_IDLE_TIMEOUT: "invalid"}
 
 
-def test_options_flow_creates_entry_with_four_keys() -> None:
-    """A valid submit creates an entry with exactly the four validated keys."""
+def test_options_flow_creates_entry_with_validated_keys() -> None:
+    """A valid submit creates an entry with exactly the validated keys
+    (the legacy settings plus every later section's keys, filled from
+    defaults where the raw submit omitted them)."""
     flow = _make_flow(_make_entry())
     result = _run(flow.async_step_init(dict(VALID_INPUT)))
     assert result["type"] == "create_entry"
@@ -799,3 +813,91 @@ def test_options_flow_no_hard_coded_personal_target_in_source() -> None:
     assert const.__dict__.get("DEFAULT_NOTIFY_TARGET", "") == ""
     form = _run(_make_flow(_make_entry()).async_step_init(None))
     assert form["data_schema"]({})[CONF_NOTIFY_TARGET] == ""
+
+
+# ---------------------------------------------------------------------------
+# Panel-plane API connection section (Feature 18)
+# ---------------------------------------------------------------------------
+
+
+def test_options_flow_api_section_defaults_saved() -> None:
+    """A bare submit saves the API connection defaults: the const base
+    URL and an EMPTY panel token (no token is ever invented)."""
+    flow = _make_flow(_make_entry())
+    result = _run(flow.async_step_init(dict(VALID_INPUT)))
+    assert result["type"] == "create_entry"
+    assert result["data"][CONF_API_BASE_URL] == DEFAULT_API_BASE_URL
+    assert result["data"][CONF_PANEL_TOKEN] == ""
+
+
+def test_options_flow_api_base_url_must_be_full_http_url() -> None:
+    """Scheme-less, host-less, empty, and non-string base URLs reject
+    with a field error — the same rule the client's constructor
+    enforces, so a malformed URL fails at the form, not at the first
+    request."""
+    flow = _make_flow(_make_entry())
+    for bad_url in ("api.lan:8000", "http://", "", "   ", 42):
+        result = _run(
+            flow.async_step_init(
+                {**VALID_INPUT, CONF_API_BASE_URL: bad_url}
+            )
+        )
+        assert result["type"] == "form"
+        assert result["errors"] == {CONF_API_BASE_URL: "invalid_url"}
+
+
+def test_options_flow_panel_token_validation() -> None:
+    """The EMPTY token is valid (the API connection is simply not
+    configured yet); padded and non-string values reject — a padded
+    paste would fail the token check at request time instead."""
+    flow = _make_flow(_make_entry())
+    result = _run(
+        flow.async_step_init({**VALID_INPUT, CONF_PANEL_TOKEN: ""})
+    )
+    assert result["type"] == "create_entry"
+    assert result["data"][CONF_PANEL_TOKEN] == ""
+
+    for bad_token in ("  secret  ", "   ", 42):
+        flow = _make_flow(_make_entry())
+        result = _run(
+            flow.async_step_init(
+                {**VALID_INPUT, CONF_PANEL_TOKEN: bad_token}
+            )
+        )
+        assert result["type"] == "form"
+        assert result["errors"] == {CONF_PANEL_TOKEN: "invalid"}
+
+
+def test_options_flow_api_section_stored_values_round_trip() -> None:
+    """Stored API settings are the form's defaults and a raw legacy
+    submit without them keeps the stored values."""
+    entry = _make_entry(
+        options={
+            **VALID_INPUT,
+            CONF_API_BASE_URL: "http://panel.lan:8443",
+            CONF_PANEL_TOKEN: "stored-token",
+        }
+    )
+    flow = _make_flow(entry)
+    form = _run(flow.async_step_init(None))
+    schema_defaults = form["data_schema"]({})
+    assert schema_defaults[CONF_API_BASE_URL] == "http://panel.lan:8443"
+    assert schema_defaults[CONF_PANEL_TOKEN] == "stored-token"
+
+    # A raw submit carrying only the legacy keys keeps the stored
+    # API connection settings.
+    result = _run(flow.async_step_init(dict(VALID_INPUT)))
+    assert result["type"] == "create_entry"
+    assert result["data"][CONF_API_BASE_URL] == "http://panel.lan:8443"
+    assert result["data"][CONF_PANEL_TOKEN] == "stored-token"
+
+
+def test_options_flow_strings_cover_api_section(
+    strings: dict, translations_en: dict
+) -> None:
+    """Both string files name the API fields and the URL error."""
+    data = strings["options"]["step"]["init"]["data"]
+    for key in (CONF_API_BASE_URL, CONF_PANEL_TOKEN):
+        assert data.get(key), f"Missing field name for '{key}'"
+    assert strings["options"]["errors"]["invalid_url"]
+    assert translations_en["options"] == strings["options"]