diff --git a/app/integrations/tibber/__init__.py b/app/integrations/tibber/__init__.py
new file mode 100644
index 0000000..1e78c71
--- /dev/null
+++ b/app/integrations/tibber/__init__.py
@@ -0,0 +1,10 @@
+"""Tibber dynamic electricity pricing integration.
+
+This package provides:
+  - ``client``: HTTP client for the Tibber GraphQL API (price fetching).
+  - Custom exceptions: ``TibberError`` (base) and ``TibberAuthError`` (auth failure).
+
+Usage::
+
+    from app.integrations.tibber.client import fetch_price_range, TibberAuthError
+"""
diff --git a/app/integrations/tibber/client.py b/app/integrations/tibber/client.py
new file mode 100644
index 0000000..ce8df20
--- /dev/null
+++ b/app/integrations/tibber/client.py
@@ -0,0 +1,329 @@
+"""Tibber GraphQL API client for fetching electricity price data.
+
+Design decisions
+----------------
+- Uses ``httpx`` (already a project dependency) for all HTTP requests.
+- Token is **never** written to log messages or exception strings to prevent
+  credential leakage into log aggregators.
+- ``fetch_price_range`` returns a list of ``PricePoint`` objects with UTC-aware
+  ``starts_at`` datetimes; the number of nodes is not assumed — all returned
+  nodes are parsed regardless of count.
+- ``fetch_current_price`` uses a separate, simpler query that asks for the
+  *current* price point only; used by the connection-test endpoint (T09) to
+  produce a fast three-state result (success / auth-error / network-error).
+- Authentication failures (HTTP 401/403) are raised as ``TibberAuthError`` so
+  that callers (the test endpoint) can distinguish them from generic network or
+  API errors.
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from typing import Any
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+_TIBBER_API_URL = "https://api.tibber.com/v1-beta/gql"
+_DEFAULT_TIMEOUT = 15.0
+
+# GraphQL query to fetch a range of 15-minute price nodes.
+# ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` fetches up to
+# 96 quarter-hourly slots which covers today + tomorrow (2 × 24 × 4 = 192 max,
+# but the Tibber API typically starts from the current slot and returns at
+# most the remaining hours of today plus tomorrow, so 96 is a good cap for
+# "today + tomorrow").
+_PRICE_RANGE_QUERY = """
+{
+  viewer {
+    homes {
+      id
+      currentSubscription {
+        priceInfoRange(resolution: QUARTER_HOURLY, first: 96) {
+          nodes {
+            startsAt
+            total
+            energy
+            tax
+            currency
+            level
+          }
+        }
+      }
+    }
+  }
+}
+"""
+
+# GraphQL query to fetch the single *current* price point.
+_CURRENT_PRICE_QUERY = """
+{
+  viewer {
+    homes {
+      id
+      currentSubscription {
+        priceInfo {
+          current {
+            startsAt
+            total
+            energy
+            tax
+            currency
+            level
+          }
+        }
+      }
+    }
+  }
+}
+"""
+
+
+# ---------------------------------------------------------------------------
+# Custom exceptions
+# ---------------------------------------------------------------------------
+
+
+class TibberError(Exception):
+    """Base class for all Tibber client errors.
+
+    Raised for network failures, timeouts, unexpected HTTP status codes, and
+    malformed API responses.  The exception message will **never** contain the
+    API token.
+    """
+
+
+class TibberAuthError(TibberError):
+    """Raised when the Tibber API rejects the provided token (HTTP 401/403).
+
+    Callers that implement a three-state connection test should catch this
+    exception separately from ``TibberError`` to distinguish auth problems
+    from network / API problems.
+    """
+
+
+# ---------------------------------------------------------------------------
+# Data model
+# ---------------------------------------------------------------------------
+
+
+@dataclass(slots=True)
+class PricePoint:
+    """One 15-minute price slot returned by the Tibber API.
+
+    All monetary values are in ``currency`` and include VAT (user-facing).
+    ``starts_at`` is always a timezone-aware UTC datetime regardless of the
+    timezone offset that Tibber returns in ``startsAt``.
+    """
+
+    starts_at: datetime  # UTC-aware
+    total: float         # full all-in price (energy + tax)
+    energy: float        # spot energy component
+    tax: float           # tax component
+    currency: str        # ISO 4217 (typically "EUR")
+    level: str | None    # e.g. "CHEAP", "NORMAL", "EXPENSIVE"; None if absent
+    resolution: str      # label for the slot resolution (e.g. "QUARTER_HOURLY")
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+
+def _parse_starts_at(raw: str) -> datetime:
+    """Parse an ISO 8601 timestamp with timezone offset and convert to UTC.
+
+    Tibber returns timestamps like ``2026-06-23T00:00:00.000+02:00``.
+    ``datetime.fromisoformat`` handles this format in Python 3.11+; the result
+    is then converted to UTC via ``.astimezone(UTC)``.
+    """
+    return datetime.fromisoformat(raw).astimezone(UTC)
+
+
+def _parse_node(node: dict[str, Any], resolution: str) -> PricePoint:
+    """Parse a single price node dict into a ``PricePoint``."""
+    return PricePoint(
+        starts_at=_parse_starts_at(node["startsAt"]),
+        total=float(node["total"]),
+        energy=float(node["energy"]),
+        tax=float(node["tax"]),
+        currency=str(node["currency"]),
+        level=node.get("level") or None,
+        resolution=resolution,
+    )
+
+
+def _pick_home(homes: list[dict[str, Any]], home_id: str | None) -> dict[str, Any]:
+    """Return the home dict matching *home_id*, or the first home if None."""
+    if not homes:
+        raise TibberError("Tibber API returned no homes")
+    if home_id is not None:
+        for h in homes:
+            if h.get("id") == home_id:
+                return h
+        raise TibberError("Tibber home id not found in API response")
+    return homes[0]
+
+
+def _post_graphql(token: str, query: str, timeout: float) -> dict[str, Any]:
+    """POST the GraphQL *query* and return the parsed ``data`` dict.
+
+    Raises
+    ------
+    TibberAuthError
+        On HTTP 401 or 403.
+    TibberError
+        On timeouts, network errors, non-2xx responses, or unexpected body shape.
+    """
+    headers = {
+        "Authorization": f"Bearer {token}",
+        "Content-Type": "application/json",
+    }
+    try:
+        response = httpx.post(
+            _TIBBER_API_URL,
+            json={"query": query},
+            headers=headers,
+            timeout=timeout,
+        )
+    except httpx.TimeoutException as exc:
+        raise TibberError("Tibber API request timed out") from exc
+    except httpx.HTTPError as exc:
+        raise TibberError("Tibber API request failed") from exc
+
+    if response.status_code in (401, 403):
+        raise TibberAuthError("Tibber API authentication failed")
+
+    try:
+        response.raise_for_status()
+    except httpx.HTTPStatusError as exc:
+        raise TibberError(f"Tibber API returned unexpected status {response.status_code}") from exc
+
+    try:
+        body = response.json()
+    except Exception as exc:
+        raise TibberError("Tibber API returned non-JSON response") from exc
+
+    if "errors" in body:
+        # GraphQL errors are not HTTP errors; surface them as TibberError.
+        # Do not include token in the message.
+        raise TibberError("Tibber GraphQL returned errors")
+
+    data = body.get("data")
+    if data is None:
+        raise TibberError("Tibber API response missing 'data' field")
+
+    return data
+
+
+# ---------------------------------------------------------------------------
+# Public API
+# ---------------------------------------------------------------------------
+
+
+def fetch_price_range(
+    token: str,
+    home_id: str | None = None,
+    *,
+    timeout: float = _DEFAULT_TIMEOUT,
+) -> list[PricePoint]:
+    """Fetch a range of 15-minute price nodes from the Tibber API.
+
+    Sends the ``priceInfoRange(resolution: QUARTER_HOURLY, first: 96)`` query
+    and parses every returned node into a ``PricePoint``.  The number of nodes
+    is not assumed — all returned nodes are parsed regardless of count.
+
+    Parameters
+    ----------
+    token:
+        Tibber API token.  **Never** logged or included in exception messages.
+    home_id:
+        If given, the home with this Tibber home ID is selected.  If ``None``,
+        the first home in the account is used.
+    timeout:
+        HTTP request timeout in seconds (default 15 s).
+
+    Returns
+    -------
+    list[PricePoint]
+        List of price points with UTC-aware ``starts_at`` values.
+
+    Raises
+    ------
+    TibberAuthError
+        If the token is rejected (HTTP 401/403).
+    TibberError
+        For network failures, timeouts, or unexpected API responses.
+    """
+    data = _post_graphql(token, _PRICE_RANGE_QUERY, timeout)
+
+    try:
+        homes = data["viewer"]["homes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response has unexpected shape") from exc
+
+    home = _pick_home(homes, home_id)
+
+    try:
+        nodes = home["currentSubscription"]["priceInfoRange"]["nodes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response missing priceInfoRange nodes") from exc
+
+    return [_parse_node(node, "QUARTER_HOURLY") for node in nodes]
+
+
+def fetch_current_price(
+    token: str,
+    home_id: str | None = None,
+    *,
+    timeout: float = _DEFAULT_TIMEOUT,
+) -> PricePoint:
+    """Fetch the *current* price point from the Tibber API.
+
+    Uses the lighter ``priceInfo { current { ... } }`` query rather than the
+    full range query, making it suitable for a fast connection test.
+
+    Parameters
+    ----------
+    token:
+        Tibber API token.  **Never** logged or included in exception messages.
+    home_id:
+        If given, the home with this Tibber home ID is selected.  If ``None``,
+        the first home in the account is used.
+    timeout:
+        HTTP request timeout in seconds (default 15 s).
+
+    Returns
+    -------
+    PricePoint
+        The current price point with a UTC-aware ``starts_at``.
+
+    Raises
+    ------
+    TibberAuthError
+        If the token is rejected (HTTP 401/403).
+    TibberError
+        For network failures, timeouts, missing current price, or unexpected
+        API responses.
+    """
+    data = _post_graphql(token, _CURRENT_PRICE_QUERY, timeout)
+
+    try:
+        homes = data["viewer"]["homes"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response has unexpected shape") from exc
+
+    home = _pick_home(homes, home_id)
+
+    try:
+        current = home["currentSubscription"]["priceInfo"]["current"]
+    except (KeyError, TypeError) as exc:
+        raise TibberError("Tibber API response missing current price") from exc
+
+    if current is None:
+        raise TibberError("Tibber API returned null for current price")
+
+    return _parse_node(current, "QUARTER_HOURLY")
diff --git a/app/main.py b/app/main.py
index f507fbc..82aa9ce 100644
--- a/app/main.py
+++ b/app/main.py
@@ -31,6 +31,7 @@ from app.services.config_page import build_runtime_settings, seed_missing_config
 from app.services.public_ip import check_public_ipv4_and_notify
 from app.services.modbus_poll import poll_all_enabled_devices, BASE_POLL_TICK_SECONDS
 from app.services.ha_discovery import publish_discovery, publish_states
+from app.services.tibber_prices import refresh_prices
 from scripts.app_db_adopt import AppDatabaseAdoptionError, validate_app_runtime_db
 
 logger = logging.getLogger(__name__)
@@ -63,6 +64,33 @@ def _run_scheduled_modbus_poll() -> None:
         session.close()
 
 
+def _run_scheduled_tibber_refresh() -> None:
+    """Scheduled job: fetch Tibber 15-minute prices and upsert into tibber_price.
+
+    Runs every hour so that:
+    - Today's prices are available from startup.
+    - Tomorrow's prices (published by Tibber around 13:00 CET / 11:00 UTC) are
+      picked up within an hour of publication without requiring a server restart.
+
+    The job is a no-op when:
+    - No active energy contract with kind="tibber" exists.
+    - The Tibber API token is empty in the runtime settings.
+
+    Any client exceptions (auth failures, network errors) are caught and logged
+    so that a single failed fetch does not crash the scheduler or affect the
+    other background jobs.
+    """
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        runtime_settings = build_runtime_settings(session, get_settings())
+        refresh_prices(session, runtime_settings)
+    except Exception:
+        logger.exception("_run_scheduled_tibber_refresh: unexpected error")
+    finally:
+        session.close()
+
+
 def _run_scheduled_ha_state_publish() -> None:
     """Periodic job: publish discovery configs + state + availability for all enabled exposed entities.
 
@@ -148,6 +176,17 @@ async def lifespan(_: FastAPI):
         max_instances=1,
         coalesce=True,
     )
+    # Tibber price refresh: fetch today + tomorrow every hour.
+    # The job is a no-op when no active tibber contract or token is configured,
+    # so it is safe to register unconditionally.
+    scheduler.add_job(
+        _run_scheduled_tibber_refresh,
+        trigger=IntervalTrigger(hours=1),
+        id="tibber-refresh",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
     scheduler.start()
 
     # MQTT: connect using DB-merged runtime settings so broker configured via UI
diff --git a/app/services/tibber_prices.py b/app/services/tibber_prices.py
new file mode 100644
index 0000000..98bef19
--- /dev/null
+++ b/app/services/tibber_prices.py
@@ -0,0 +1,139 @@
+"""Service layer for fetching and persisting Tibber 15-minute electricity prices.
+
+``refresh_prices`` is the main entry point.  It is designed to be called from a
+scheduled background job (see ``app/main.py``) and from tests.
+
+Design decisions
+----------------
+- **Guard clause**: if no active contract with ``kind="tibber"`` exists, or if
+  the Tibber API token is empty in the runtime settings, the function is a
+  complete no-op (returns 0) and does not raise.  This means the scheduler can
+  call ``refresh_prices`` unconditionally; the service itself decides whether to
+  do anything based on current configuration.
+- **Upsert idempotency**: rows are matched by ``starts_at`` (the unique
+  constraint on ``tibber_price``).  If a row already exists, its price fields
+  and ``fetched_at`` are updated in-place; if it does not exist, a new row is
+  inserted.  Running ``refresh_prices`` twice in a row must not double-insert.
+- **No destructive operations**: this service never deletes ``tibber_price``
+  rows.  Only INSERT or UPDATE.
+- **Exception propagation**: exceptions from the Tibber client are *not*
+  swallowed here.  The scheduled job wrapper in ``main.py`` is responsible for
+  catching and logging errors so that a single fetch failure does not crash the
+  scheduler.
+- **SQLite timezone note**: ``DateTime(timezone=True)`` columns come back as
+  timezone-naive UTC datetimes on read.  We store UTC-aware datetimes on write
+  (``starts_at`` from ``PricePoint`` is already UTC-aware; ``fetched_at`` is
+  ``datetime.now(UTC)``).  Reads elsewhere that compare against these values
+  must normalise accordingly.
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import UTC, datetime
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.integrations.tibber.client import fetch_price_range
+from app.models.energy import EnergyContract, TibberPrice
+
+logger = logging.getLogger(__name__)
+
+
+def _active_tibber_contract_exists(session: Session) -> bool:
+    """Return True if there is an active contract with kind='tibber'."""
+    row = session.execute(
+        select(EnergyContract).where(
+            EnergyContract.active.is_(True),
+            EnergyContract.kind == "tibber",
+        ).limit(1)
+    ).scalar_one_or_none()
+    return row is not None
+
+
+def refresh_prices(session: Session, settings: object) -> int:
+    """Fetch today-and-tomorrow Tibber prices and upsert them into ``tibber_price``.
+
+    Parameters
+    ----------
+    session:
+        An active SQLAlchemy session.  The caller is responsible for closing it;
+        this function commits each upserted row individually to keep transactions
+        short.
+    settings:
+        A runtime settings object that exposes ``tibber_api_token`` and
+        ``tibber_home_id`` attributes (typically a ``Settings`` or merged
+        runtime-settings instance from ``build_runtime_settings``).
+
+    Returns
+    -------
+    int
+        Number of rows upserted (inserted or updated).  Returns 0 for a no-op.
+
+    Notes
+    -----
+    - No-op (returns 0) when:
+        * No active contract exists with ``kind="tibber"``, OR
+        * ``settings.tibber_api_token`` is empty or whitespace.
+    - Exceptions from the Tibber client are *not* caught here; they propagate to
+      the caller (the scheduled job wrapper swallows them and logs).
+    """
+    token: str = getattr(settings, "tibber_api_token", "") or ""
+    if not token.strip():
+        logger.debug("refresh_prices: tibber_api_token is empty — no-op")
+        return 0
+
+    if not _active_tibber_contract_exists(session):
+        logger.debug("refresh_prices: no active tibber contract — no-op")
+        return 0
+
+    home_id: str = getattr(settings, "tibber_home_id", "") or ""
+    home_id_or_none: str | None = home_id.strip() or None
+
+    logger.info("refresh_prices: fetching Tibber price range (home_id=%r)", home_id_or_none)
+
+    # May raise TibberError or TibberAuthError — let them propagate.
+    price_points = fetch_price_range(token, home_id_or_none)
+
+    if not price_points:
+        logger.info("refresh_prices: API returned zero price points — nothing to upsert")
+        return 0
+
+    fetched_at = datetime.now(UTC)
+    upserted = 0
+
+    for point in price_points:
+        existing = session.execute(
+            select(TibberPrice).where(TibberPrice.starts_at == point.starts_at)
+        ).scalar_one_or_none()
+
+        if existing is not None:
+            # Update in-place — price fields may change (e.g. Tibber corrects a
+            # forecast), but starts_at and resolution stay the same.
+            existing.total = point.total
+            existing.energy = point.energy
+            existing.tax = point.tax
+            existing.level = point.level
+            existing.currency = point.currency
+            existing.fetched_at = fetched_at
+        else:
+            session.add(
+                TibberPrice(
+                    starts_at=point.starts_at,
+                    resolution=point.resolution,
+                    total=point.total,
+                    energy=point.energy,
+                    tax=point.tax,
+                    level=point.level,
+                    currency=point.currency,
+                    fetched_at=fetched_at,
+                )
+            )
+
+        upserted += 1
+
+    session.commit()
+
+    logger.info("refresh_prices: upserted %d price points", upserted)
+    return upserted
diff --git a/docs/design/m6-tibber-dynamic-energy.md b/docs/design/m6-tibber-dynamic-energy.md
index b0a5b54..2616a17 100644
--- a/docs/design/m6-tibber-dynamic-energy.md
+++ b/docs/design/m6-tibber-dynamic-energy.md
@@ -347,7 +347,7 @@ Phase D（API + 前端）
 - **Reviewer checklist**: 版本只增不改（不覆盖旧版本）；激活互斥；删除受 FK RESTRICT（有版本/有费用记录不可裸删）；数值校验走 T03 `validate_values`；路径键用合同 id。
 
 ### M6-T05 — Tibber 客户端 + 抓价 service + 调度 + tibber/test
-- **Status**: `todo` · **Depends**: M6-T01, M6-T02, M6-T03
+- **Status**: `done` · **Depends**: M6-T01, M6-T02, M6-T03
 - **Context**: httpx 拉 15min 价 upsert `tibber_price`；启动+每日抓（仅 active=tibber）；连接测试。
 - **Files**: `create app/integrations/tibber/__init__.py`、`tibber/client.py`、`app/services/tibber_prices.py`；`modify app/main.py`（抓价 job）；`create tests/test_tibber_client.py`、`tests/test_tibber_prices.py`
 - **Steps**:
diff --git a/tests/test_tibber_client.py b/tests/test_tibber_client.py
new file mode 100644
index 0000000..5ea1886
--- /dev/null
+++ b/tests/test_tibber_client.py
@@ -0,0 +1,439 @@
+"""Tests for M6-T05: Tibber API client (app/integrations/tibber/client.py).
+
+Covers:
+  1. ``fetch_price_range``: happy path parses nodes into PricePoint objects with
+     UTC-aware starts_at; does not assume a fixed number of nodes (tested with 3).
+  2. ``fetch_price_range``: HTTP 401 → TibberAuthError.
+  3. ``fetch_price_range``: HTTP 403 → TibberAuthError.
+  4. ``fetch_price_range``: httpx.TimeoutException → TibberError.
+  5. ``fetch_price_range``: generic HTTP error → TibberError.
+  6. Token does not appear in any raised exception's string representation.
+  7. ``fetch_price_range``: home_id selection (picks correct home).
+  8. ``fetch_current_price``: happy path returns a single PricePoint.
+  9. ``fetch_current_price``: HTTP 401 → TibberAuthError.
+  10. GraphQL-level errors in response body → TibberError.
+
+All HTTP calls are intercepted via ``httpx.MockTransport`` (httpx built-in) so
+no network access is required.
+"""
+
+from __future__ import annotations
+
+import json
+from datetime import UTC, datetime, timedelta
+
+import httpx
+import pytest
+
+from app.integrations.tibber.client import (
+    PricePoint,
+    TibberAuthError,
+    TibberError,
+    fetch_current_price,
+    fetch_price_range,
+)
+
+
+# ---------------------------------------------------------------------------
+# Helpers / fixture builders
+# ---------------------------------------------------------------------------
+
+_FAKE_TOKEN = "fake-secret-token-do-not-log"
+
+# A minimal set of 3 price nodes to verify that the parser does not assume a
+# fixed number of nodes (e.g. 96).
+_THREE_NODES = [
+    {
+        "startsAt": "2026-06-23T00:00:00.000+02:00",
+        "total": 0.25,
+        "energy": 0.20,
+        "tax": 0.05,
+        "currency": "EUR",
+        "level": "NORMAL",
+    },
+    {
+        "startsAt": "2026-06-23T00:15:00.000+02:00",
+        "total": 0.22,
+        "energy": 0.18,
+        "tax": 0.04,
+        "currency": "EUR",
+        "level": "CHEAP",
+    },
+    {
+        "startsAt": "2026-06-23T00:30:00.000+02:00",
+        "total": 0.30,
+        "energy": 0.24,
+        "tax": 0.06,
+        "currency": "EUR",
+        "level": None,
+    },
+]
+
+_PRICE_RANGE_RESPONSE = {
+    "data": {
+        "viewer": {
+            "homes": [
+                {
+                    "id": "home-id-1",
+                    "currentSubscription": {
+                        "priceInfoRange": {
+                            "nodes": _THREE_NODES,
+                        }
+                    },
+                }
+            ]
+        }
+    }
+}
+
+_CURRENT_PRICE_RESPONSE = {
+    "data": {
+        "viewer": {
+            "homes": [
+                {
+                    "id": "home-id-1",
+                    "currentSubscription": {
+                        "priceInfo": {
+                            "current": {
+                                "startsAt": "2026-06-23T10:00:00.000+02:00",
+                                "total": 0.28,
+                                "energy": 0.22,
+                                "tax": 0.06,
+                                "currency": "EUR",
+                                "level": "EXPENSIVE",
+                            }
+                        }
+                    },
+                }
+            ]
+        }
+    }
+}
+
+
+def _make_transport(status_code: int, body: dict | None = None, raise_timeout: bool = False):
+    """Create an ``httpx.MockTransport`` that returns the given response.
+
+    If *raise_timeout* is True, the transport raises ``httpx.TimeoutException``
+    instead of returning a response.
+    """
+
+    def _handler(request: httpx.Request) -> httpx.Response:
+        if raise_timeout:
+            raise httpx.TimeoutException("timed out", request=request)
+        payload = json.dumps(body or {}).encode()
+        return httpx.Response(
+            status_code=status_code,
+            content=payload,
+            headers={"Content-Type": "application/json"},
+        )
+
+    return httpx.MockTransport(_handler)
+
+
+# ---------------------------------------------------------------------------
+# fetch_price_range — happy path
+# ---------------------------------------------------------------------------
+
+
+def test_fetch_price_range_parses_nodes(monkeypatch):
+    """Successful response with 3 nodes is parsed into 3 PricePoint objects."""
+    transport = _make_transport(200, _PRICE_RANGE_RESPONSE)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    points = fetch_price_range(_FAKE_TOKEN)
+
+    assert len(points) == 3
+
+    # All starts_at must be UTC-aware.
+    for p in points:
+        assert isinstance(p, PricePoint)
+        assert p.starts_at.tzinfo is not None
+        assert p.starts_at.tzinfo == UTC or p.starts_at.utcoffset() == timedelta(0)
+
+    # First node: 2026-06-23T00:00:00+02:00 → 2026-06-22T22:00:00Z
+    first = points[0]
+    assert first.starts_at == datetime(2026, 6, 22, 22, 0, 0, tzinfo=UTC)
+    assert first.total == pytest.approx(0.25)
+    assert first.energy == pytest.approx(0.20)
+    assert first.tax == pytest.approx(0.05)
+    assert first.currency == "EUR"
+    assert first.level == "NORMAL"
+    assert first.resolution == "QUARTER_HOURLY"
+
+    # Third node has level=None in the raw API response.
+    third = points[2]
+    assert third.level is None
+
+
+def test_fetch_price_range_does_not_assume_node_count(monkeypatch):
+    """Parser handles an arbitrary number of nodes (not hardcoded to 96)."""
+    # Build a response with a single node only.
+    one_node_response = {
+        "data": {
+            "viewer": {
+                "homes": [
+                    {
+                        "id": "home-id-1",
+                        "currentSubscription": {
+                            "priceInfoRange": {
+                                "nodes": [_THREE_NODES[0]],
+                            }
+                        },
+                    }
+                ]
+            }
+        }
+    }
+    transport = _make_transport(200, one_node_response)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    points = fetch_price_range(_FAKE_TOKEN)
+    assert len(points) == 1
+
+
+def test_fetch_price_range_home_id_selection(monkeypatch):
+    """When home_id is specified, the matching home is selected."""
+    two_homes_response = {
+        "data": {
+            "viewer": {
+                "homes": [
+                    {
+                        "id": "home-id-first",
+                        "currentSubscription": {
+                            "priceInfoRange": {
+                                "nodes": [_THREE_NODES[0]],
+                            }
+                        },
+                    },
+                    {
+                        "id": "home-id-second",
+                        "currentSubscription": {
+                            "priceInfoRange": {
+                                "nodes": [_THREE_NODES[1], _THREE_NODES[2]],
+                            }
+                        },
+                    },
+                ]
+            }
+        }
+    }
+    transport = _make_transport(200, two_homes_response)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    # Selecting the second home should return 2 nodes.
+    points = fetch_price_range(_FAKE_TOKEN, home_id="home-id-second")
+    assert len(points) == 2
+
+    # Selecting the first home (default when home_id=None) returns 1 node.
+    points_default = fetch_price_range(_FAKE_TOKEN)
+    assert len(points_default) == 1
+
+
+# ---------------------------------------------------------------------------
+# fetch_price_range — authentication errors
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.parametrize("status_code", [401, 403])
+def test_fetch_price_range_auth_error(monkeypatch, status_code):
+    """HTTP 401 or 403 raises TibberAuthError (subclass of TibberError)."""
+    transport = _make_transport(status_code, {})
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberAuthError):
+        fetch_price_range(_FAKE_TOKEN)
+
+
+def test_fetch_price_range_auth_error_is_tibber_error(monkeypatch):
+    """TibberAuthError is a subclass of TibberError for broad catches."""
+    transport = _make_transport(401, {})
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError):
+        fetch_price_range(_FAKE_TOKEN)
+
+
+# ---------------------------------------------------------------------------
+# fetch_price_range — network / timeout errors
+# ---------------------------------------------------------------------------
+
+
+def test_fetch_price_range_timeout_raises_tibber_error(monkeypatch):
+    """httpx.TimeoutException is wrapped in TibberError."""
+    transport = _make_transport(200, raise_timeout=True)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError):
+        fetch_price_range(_FAKE_TOKEN)
+
+
+def test_fetch_price_range_timeout_not_auth_error(monkeypatch):
+    """A timeout should raise TibberError but NOT TibberAuthError."""
+    transport = _make_transport(200, raise_timeout=True)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError) as exc_info:
+        fetch_price_range(_FAKE_TOKEN)
+    assert not isinstance(exc_info.value, TibberAuthError)
+
+
+def test_fetch_price_range_http_500_raises_tibber_error(monkeypatch):
+    """An unexpected 5xx response raises TibberError."""
+    transport = _make_transport(500, {"error": "internal"})
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError):
+        fetch_price_range(_FAKE_TOKEN)
+
+
+# ---------------------------------------------------------------------------
+# Token safety — token must not appear in exception messages
+# ---------------------------------------------------------------------------
+
+
+def test_token_not_in_auth_error_message(monkeypatch):
+    """The API token must not appear in TibberAuthError's string representation."""
+    transport = _make_transport(401, {})
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberAuthError) as exc_info:
+        fetch_price_range(_FAKE_TOKEN)
+
+    # The token must not appear anywhere in the exception string.
+    assert _FAKE_TOKEN not in str(exc_info.value)
+    assert _FAKE_TOKEN not in repr(exc_info.value)
+
+
+def test_token_not_in_timeout_error_message(monkeypatch):
+    """The API token must not appear in TibberError's string representation on timeout."""
+    transport = _make_transport(200, raise_timeout=True)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError) as exc_info:
+        fetch_price_range(_FAKE_TOKEN)
+
+    assert _FAKE_TOKEN not in str(exc_info.value)
+    assert _FAKE_TOKEN not in repr(exc_info.value)
+
+
+# ---------------------------------------------------------------------------
+# GraphQL errors in response body
+# ---------------------------------------------------------------------------
+
+
+def test_graphql_errors_raise_tibber_error(monkeypatch):
+    """A 200 response that contains a GraphQL 'errors' field raises TibberError."""
+    graphql_error_body = {
+        "errors": [{"message": "Some GraphQL error"}],
+        "data": None,
+    }
+    transport = _make_transport(200, graphql_error_body)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberError):
+        fetch_price_range(_FAKE_TOKEN)
+
+
+# ---------------------------------------------------------------------------
+# fetch_current_price — happy path
+# ---------------------------------------------------------------------------
+
+
+def test_fetch_current_price_returns_single_price_point(monkeypatch):
+    """Successful response returns a single UTC-aware PricePoint."""
+    transport = _make_transport(200, _CURRENT_PRICE_RESPONSE)
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    point = fetch_current_price(_FAKE_TOKEN)
+
+    assert isinstance(point, PricePoint)
+    # 2026-06-23T10:00:00+02:00 → 2026-06-23T08:00:00Z
+    assert point.starts_at == datetime(2026, 6, 23, 8, 0, 0, tzinfo=UTC)
+    assert point.total == pytest.approx(0.28)
+    assert point.energy == pytest.approx(0.22)
+    assert point.tax == pytest.approx(0.06)
+    assert point.currency == "EUR"
+    assert point.level == "EXPENSIVE"
+    assert point.resolution == "QUARTER_HOURLY"
+    # UTC-aware check
+    assert point.starts_at.tzinfo is not None
+
+
+# ---------------------------------------------------------------------------
+# fetch_current_price — authentication errors
+# ---------------------------------------------------------------------------
+
+
+def test_fetch_current_price_auth_error(monkeypatch):
+    """HTTP 401 on current-price query raises TibberAuthError."""
+    transport = _make_transport(401, {})
+
+    def _patched_post(url, *, json, headers, timeout):  # noqa: A002
+        client = httpx.Client(transport=transport)
+        return client.post(url, json=json, headers=headers, timeout=timeout)
+
+    monkeypatch.setattr("app.integrations.tibber.client.httpx.post", _patched_post)
+
+    with pytest.raises(TibberAuthError):
+        fetch_current_price(_FAKE_TOKEN)
diff --git a/tests/test_tibber_prices.py b/tests/test_tibber_prices.py
new file mode 100644
index 0000000..5d65def
--- /dev/null
+++ b/tests/test_tibber_prices.py
@@ -0,0 +1,394 @@
+"""Tests for M6-T05: Tibber price refresh service (app/services/tibber_prices.py).
+
+Covers:
+  1. With active tibber contract + non-empty token: ``refresh_prices`` calls the
+     client, upserts returned price points, and returns the count.
+  2. Idempotency: running ``refresh_prices`` twice does not double-insert rows;
+     rows are updated in-place (``starts_at`` remains unique).
+  3. No active contract → no-op (returns 0, no DB writes).
+  4. Active contract with kind="manual" (not tibber) → no-op.
+  5. Token is empty string → no-op.
+  6. Token is whitespace-only → no-op.
+  7. Client errors propagate (not swallowed by the service).
+
+All Tibber API calls are intercepted via monkeypatching ``fetch_price_range``
+so no real network access is needed.
+"""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime, timedelta
+from pathlib import Path
+import pytest
+from alembic import command
+from alembic.config import Config
+from sqlalchemy import create_engine, select
+from sqlalchemy.orm import Session
+
+from app.integrations.tibber.client import PricePoint, TibberError
+from app.models.energy import EnergyContract, EnergyContractVersion, TibberPrice
+from app.services.tibber_prices import refresh_prices
+
+
+# ---------------------------------------------------------------------------
+# Fixtures
+# ---------------------------------------------------------------------------
+
+
+def _make_app_alembic_config(database_url: str) -> Config:
+    cfg = Config("alembic_app.ini")
+    cfg.set_main_option("sqlalchemy.url", database_url)
+    return cfg
+
+
+@pytest.fixture()
+def energy_db(tmp_path: Path):
+    """Temporary SQLite DB upgraded to head (has all energy tables)."""
+    db_path = tmp_path / "tibber_prices_test.db"
+    db_url = f"sqlite:///{db_path}"
+    alembic_cfg = _make_app_alembic_config(db_url)
+    command.upgrade(alembic_cfg, "head")
+    engine = create_engine(db_url, connect_args={"check_same_thread": False})
+    session = Session(engine)
+    yield session
+    session.close()
+    engine.dispose()
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+_UTC = UTC
+
+
+def _ts(hour: int, minute: int = 0) -> datetime:
+    """Return a UTC datetime on 2026-06-23 at the given hour:minute."""
+    return datetime(2026, 6, 23, hour, minute, 0, tzinfo=_UTC)
+
+
+def _make_price_points(count: int = 3) -> list[PricePoint]:
+    """Build a list of *count* fake PricePoint objects 15 minutes apart."""
+    base = _ts(10, 0)
+    points = []
+    for i in range(count):
+        starts_at = base + timedelta(minutes=15 * i)
+        points.append(
+            PricePoint(
+                starts_at=starts_at,
+                total=0.20 + i * 0.01,
+                energy=0.16 + i * 0.01,
+                tax=0.04,
+                currency="EUR",
+                level="NORMAL",
+                resolution="QUARTER_HOURLY",
+            )
+        )
+    return points
+
+
+class _FakeSettings:
+    """Minimal settings stand-in with Tibber fields."""
+
+    def __init__(self, token: str = "valid-token", home_id: str = ""):
+        self.tibber_api_token = token
+        self.tibber_home_id = home_id
+
+
+def _create_active_tibber_contract(session: Session) -> EnergyContract:
+    """Insert and commit an active tibber contract + one open version."""
+    now = datetime.now(UTC)
+    contract = EnergyContract(
+        name="Tibber Test",
+        kind="tibber",
+        active=True,
+        currency="EUR",
+        created_at=now,
+        updated_at=now,
+    )
+    session.add(contract)
+    session.flush()
+    version = EnergyContractVersion(
+        contract_id=contract.id,
+        effective_from=now,
+        effective_to=None,
+        values={"energy": {"energy_tax": 0.1108, "sell_adjust": 0.0}, "standing": {}, "credits": {}},
+        created_at=now,
+    )
+    session.add(version)
+    session.commit()
+    return contract
+
+
+def _create_active_manual_contract(session: Session) -> EnergyContract:
+    """Insert and commit an active manual contract."""
+    now = datetime.now(UTC)
+    contract = EnergyContract(
+        name="Manual Test",
+        kind="manual",
+        active=True,
+        currency="EUR",
+        created_at=now,
+        updated_at=now,
+    )
+    session.add(contract)
+    session.flush()
+    version = EnergyContractVersion(
+        contract_id=contract.id,
+        effective_from=now,
+        effective_to=None,
+        values={},
+        created_at=now,
+    )
+    session.add(version)
+    session.commit()
+    return contract
+
+
+def _count_tibber_price_rows(session: Session) -> int:
+    """Return the current number of rows in tibber_price."""
+    return len(session.execute(select(TibberPrice)).scalars().all())
+
+
+# ---------------------------------------------------------------------------
+# Test: happy path (active tibber contract + valid token)
+# ---------------------------------------------------------------------------
+
+
+def test_refresh_prices_upserts_price_points(energy_db, monkeypatch):
+    """Active tibber contract + token → price points are upserted and count returned."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+    points = _make_price_points(3)
+
+    monkeypatch.setattr(
+        "app.services.tibber_prices.fetch_price_range",
+        lambda token, home_id_or_none: points,
+    )
+
+    count = refresh_prices(session, _FakeSettings())
+
+    assert count == 3
+    rows = session.execute(select(TibberPrice).order_by(TibberPrice.starts_at)).scalars().all()
+    assert len(rows) == 3
+
+    for row, point in zip(rows, points):
+        # starts_at is stored UTC-aware; SQLite may return naive — normalise.
+        stored_starts_at = row.starts_at
+        if stored_starts_at.tzinfo is None:
+            stored_starts_at = stored_starts_at.replace(tzinfo=UTC)
+        assert stored_starts_at == point.starts_at
+        assert row.total == pytest.approx(point.total)
+        assert row.energy == pytest.approx(point.energy)
+        assert row.tax == pytest.approx(point.tax)
+        assert row.currency == point.currency
+        assert row.resolution == "QUARTER_HOURLY"
+
+
+# ---------------------------------------------------------------------------
+# Test: idempotency (running twice must not double-insert)
+# ---------------------------------------------------------------------------
+
+
+def test_refresh_prices_is_idempotent(energy_db, monkeypatch):
+    """Running refresh_prices twice does not increase the row count."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+    points = _make_price_points(4)
+
+    call_count = {"n": 0}
+
+    def _fake_fetch(token, home_id_or_none):
+        call_count["n"] += 1
+        return points
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count1 = refresh_prices(session, _FakeSettings())
+    count2 = refresh_prices(session, _FakeSettings())
+
+    assert call_count["n"] == 2  # fetch was called twice
+    assert count1 == 4
+    assert count2 == 4  # same number of "upserted" (all updated in-place)
+
+    # DB must still have exactly 4 rows (not 8).
+    assert _count_tibber_price_rows(session) == 4
+
+
+def test_refresh_prices_idempotent_updates_fields(energy_db, monkeypatch):
+    """On second run, existing rows are updated (not duplicated)."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+    points = _make_price_points(2)
+
+    monkeypatch.setattr(
+        "app.services.tibber_prices.fetch_price_range",
+        lambda token, home_id_or_none: points,
+    )
+
+    refresh_prices(session, _FakeSettings())
+
+    # Modify the points to simulate Tibber updating a price.
+    updated_points = [
+        PricePoint(
+            starts_at=p.starts_at,
+            total=p.total + 0.10,  # price changed
+            energy=p.energy + 0.08,
+            tax=p.tax + 0.02,
+            currency=p.currency,
+            level="EXPENSIVE",
+            resolution=p.resolution,
+        )
+        for p in points
+    ]
+
+    monkeypatch.setattr(
+        "app.services.tibber_prices.fetch_price_range",
+        lambda token, home_id_or_none: updated_points,
+    )
+
+    refresh_prices(session, _FakeSettings())
+
+    rows = session.execute(select(TibberPrice).order_by(TibberPrice.starts_at)).scalars().all()
+    assert len(rows) == 2  # still 2, not 4
+
+    for row, up in zip(rows, updated_points):
+        assert row.total == pytest.approx(up.total)
+        assert row.level == "EXPENSIVE"
+
+
+# ---------------------------------------------------------------------------
+# Test: no-op conditions
+# ---------------------------------------------------------------------------
+
+
+def test_refresh_prices_noop_no_active_contract(energy_db, monkeypatch):
+    """No active contract at all → no-op (returns 0, no DB writes)."""
+    session = energy_db
+    fetch_called = {"called": False}
+
+    def _fake_fetch(token, home_id_or_none):
+        fetch_called["called"] = True
+        return _make_price_points(3)
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count = refresh_prices(session, _FakeSettings())
+
+    assert count == 0
+    assert not fetch_called["called"]
+    assert _count_tibber_price_rows(session) == 0
+
+
+def test_refresh_prices_noop_manual_contract(energy_db, monkeypatch):
+    """Active manual contract (not tibber) → no-op."""
+    session = energy_db
+    _create_active_manual_contract(session)
+    fetch_called = {"called": False}
+
+    def _fake_fetch(token, home_id_or_none):
+        fetch_called["called"] = True
+        return _make_price_points(3)
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count = refresh_prices(session, _FakeSettings())
+
+    assert count == 0
+    assert not fetch_called["called"]
+    assert _count_tibber_price_rows(session) == 0
+
+
+def test_refresh_prices_noop_empty_token(energy_db, monkeypatch):
+    """Empty token → no-op even if tibber contract is active."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+    fetch_called = {"called": False}
+
+    def _fake_fetch(token, home_id_or_none):
+        fetch_called["called"] = True
+        return _make_price_points(3)
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count = refresh_prices(session, _FakeSettings(token=""))
+
+    assert count == 0
+    assert not fetch_called["called"]
+    assert _count_tibber_price_rows(session) == 0
+
+
+def test_refresh_prices_noop_whitespace_token(energy_db, monkeypatch):
+    """Whitespace-only token → no-op (treated as not configured)."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+    fetch_called = {"called": False}
+
+    def _fake_fetch(token, home_id_or_none):
+        fetch_called["called"] = True
+        return _make_price_points(2)
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count = refresh_prices(session, _FakeSettings(token="   "))
+
+    assert count == 0
+    assert not fetch_called["called"]
+
+
+# ---------------------------------------------------------------------------
+# Test: inactive tibber contract
+# ---------------------------------------------------------------------------
+
+
+def test_refresh_prices_noop_inactive_tibber_contract(energy_db, monkeypatch):
+    """Inactive tibber contract → no-op (active flag is False)."""
+    session = energy_db
+
+    # Create a tibber contract but do NOT activate it.
+    now = datetime.now(UTC)
+    contract = EnergyContract(
+        name="Inactive Tibber",
+        kind="tibber",
+        active=False,  # <-- inactive
+        currency="EUR",
+        created_at=now,
+        updated_at=now,
+    )
+    session.add(contract)
+    session.commit()
+
+    fetch_called = {"called": False}
+
+    def _fake_fetch(token, home_id_or_none):
+        fetch_called["called"] = True
+        return _make_price_points(2)
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _fake_fetch)
+
+    count = refresh_prices(session, _FakeSettings())
+
+    assert count == 0
+    assert not fetch_called["called"]
+
+
+# ---------------------------------------------------------------------------
+# Test: client errors propagate
+# ---------------------------------------------------------------------------
+
+
+def test_refresh_prices_propagates_client_error(energy_db, monkeypatch):
+    """TibberError from the client is NOT swallowed by the service."""
+    session = energy_db
+    _create_active_tibber_contract(session)
+
+    def _failing_fetch(token, home_id_or_none):
+        raise TibberError("simulated network failure")
+
+    monkeypatch.setattr("app.services.tibber_prices.fetch_price_range", _failing_fetch)
+
+    with pytest.raises(TibberError):
+        refresh_prices(session, _FakeSettings())
+
+    # No rows should have been written.
+    assert _count_tibber_price_rows(session) == 0