diff --git a/riedel_rrcs.zip b/riedel_rrcs.zip
new file mode 100644
index 0000000..e8a9589
Binary files /dev/null and b/riedel_rrcs.zip differ
diff --git a/rrcs.py b/rrcs.py
new file mode 100644
index 0000000..543dbd3
--- /dev/null
+++ b/rrcs.py
@@ -0,0 +1,515 @@
+"""Minimal async XML-RPC client for the Riedel Router Control Software (RRCS).
+
+RRCS speaks plain XML-RPC over HTTP, by default on TCP 8193. Every request
+takes a transaction key ("TransKey") as its first parameter and echoes it back
+in the response. See the RRCS Interface Specification, chapter 5.
+
+Two shapes of reply are common:
+
+    [TransKey, ErrorCode, ...]                  most Set*/Get* calls
+    {"TransKey": ..., "ErrorCode": ..., ...}    the "dump" style calls
+
+A handful of calls (RegisterForAllEvents, XpVolumeChangeRegistry*) return a
+bare string TransKey with no error code at all, so error checking is opt-in per
+call rather than automatic.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import itertools
+import json
+import logging
+import re
+import xmlrpc.client
+from dataclasses import dataclass
+from typing import Any
+from xml.parsers.expat import ExpatError
+
+import aiohttp
+
+from .const import ERROR_CODES
+
+_LOGGER = logging.getLogger(__name__)
+
+_XML_DECL_RE = re.compile(rb"<\?xml[^>]*\?>")
+
+
+class RRCSError(Exception):
+    """Base error for RRCS communication."""
+
+    def __init__(self, message: str, code: int | None = None) -> None:
+        """Initialise with an optional RRCS error code."""
+        super().__init__(message)
+        self.code = code
+
+
+class RRCSConnectionError(RRCSError):
+    """Raised when the gateway could not be reached."""
+
+
+class RRCSProtocolError(RRCSError):
+    """Raised when the gateway replied with something unparseable."""
+
+
+class RRCSFaultError(RRCSError):
+    """Raised when the gateway returned an XML-RPC fault."""
+
+
+def describe_error(code: int) -> str:
+    """Return the human readable text for an RRCS error code."""
+    return ERROR_CODES.get(code, f"Unknown error code {code}")
+
+
+def parse_xmlrpc(raw: bytes) -> tuple[tuple[Any, ...], str | None]:
+    """Parse an XML-RPC document, tolerating a mismatched encoding declaration.
+
+    Some RRCS builds declare UTF-8 but emit single-byte port labels, which makes
+    expat refuse the document outright. Dropping the declaration and decoding
+    leniently recovers those responses instead of losing the whole poll.
+    """
+    try:
+        return xmlrpc.client.loads(raw)
+    except ExpatError:
+        stripped = _XML_DECL_RE.sub(b"", raw, count=1)
+        text = stripped.decode("utf-8", errors="replace")
+        try:
+            return xmlrpc.client.loads(text)
+        except ExpatError as err:
+            raise RRCSProtocolError(f"Could not parse RRCS response: {err}") from err
+
+
+def extract_error_code(result: Any) -> int | None:
+    """Pull the ErrorCode out of a reply, if it has one in a known position."""
+    if isinstance(result, dict):
+        code = result.get("ErrorCode")
+        return code if isinstance(code, int) else None
+    if isinstance(result, (list, tuple)) and len(result) >= 2:
+        code = result[1]
+        return code if isinstance(code, int) and not isinstance(code, bool) else None
+    return None
+
+
+@dataclass(frozen=True)
+class LogicSource:
+    """A logic source as returned by GetAllLogicSources_v2."""
+
+    object_id: int
+    long_name: str
+    label: str
+    state: bool
+
+
+@dataclass(frozen=True)
+class GpioAddress:
+    """Addressing tuple used by Set/GetGpOutput and GetGpInputState.
+
+    Chapter 6.9: for a GPIO card the port is 128 and the slot selects the bay;
+    for a panel GPIO the port is the panel's port address and the slot is
+    ignored.
+    """
+
+    net: int
+    node: int
+    port: int
+    slot: int
+    index: int
+    is_input: bool
+
+    @property
+    def key(self) -> str:
+        """Stable identifier used for unique IDs."""
+        direction = "in" if self.is_input else "out"
+        return f"{self.net}_{self.node}_{self.port}_{self.slot}_{self.index}_{direction}"
+
+    @property
+    def pretty(self) -> str:
+        """Human readable address."""
+        return (
+            f"Net {self.net} / Node {self.node} / Port {self.port} / "
+            f"Slot {self.slot} / GPIO {self.index}"
+        )
+
+
+class RRCSClient:
+    """Talks XML-RPC to an RRCS gateway.
+
+    Requests are serialised behind a lock. RRCS is a single Windows service
+    fronting a real intercom ring and it does not enjoy being hammered with
+    concurrent RPCs; the specification's own timing notes (chapter 12) assume an
+    otherwise idle gateway.
+    """
+
+    def __init__(
+        self,
+        session: aiohttp.ClientSession,
+        host: str,
+        port: int = 8193,
+        path: str = "/",
+        timeout: float = 15.0,
+        transkey_prefix: str = "C",
+    ) -> None:
+        """Initialise the client."""
+        self._session = session
+        self.host = host
+        self.port = port
+        self.path = path if path.startswith("/") else f"/{path}"
+        self.timeout = timeout
+        self._prefix = (transkey_prefix or "C")[0]
+        self._counter = itertools.count(1)
+        self._lock = asyncio.Lock()
+
+    @property
+    def url(self) -> str:
+        """Return the endpoint URL."""
+        return f"http://{self.host}:{self.port}{self.path}"
+
+    def next_transkey(self) -> str:
+        """Return a fresh transaction key.
+
+        The specification wants a single leading character followed by exactly
+        ten digits. The counter wraps well before it runs out of room.
+        """
+        return f"{self._prefix}{next(self._counter) % 10_000_000_000:010d}"
+
+    async def call(self, method: str, *args: Any, check: bool = False) -> Any:
+        """Call an RRCS method, prepending a fresh transaction key.
+
+        Set ``check=True`` for methods whose reply is known to be
+        ``[TransKey, ErrorCode, ...]`` or a struct with an ``ErrorCode`` member.
+        It is off by default because some replies put a payload integer in the
+        same slot (GetLevelMeterValues returns the level there, for instance).
+        """
+        return await self.call_raw(method, (self.next_transkey(), *args), check=check)
+
+    async def call_raw(
+        self, method: str, params: tuple[Any, ...], *, check: bool = False
+    ) -> Any:
+        """Call an RRCS method with an explicit parameter tuple."""
+        body = xmlrpc.client.dumps(tuple(params), method, encoding="utf-8")
+        _LOGGER.debug("RRCS -> %s %s", method, params)
+
+        async with self._lock:
+            try:
+                async with self._session.post(
+                    self.url,
+                    data=body.encode("utf-8"),
+                    headers={"Content-Type": "text/xml; charset=utf-8"},
+                    timeout=aiohttp.ClientTimeout(total=self.timeout),
+                ) as response:
+                    if response.status != 200:
+                        raise RRCSConnectionError(
+                            f"{method}: gateway returned HTTP {response.status}"
+                        )
+                    raw = await response.read()
+            except asyncio.TimeoutError as err:
+                raise RRCSConnectionError(f"{method}: timed out after {self.timeout}s") from err
+            except aiohttp.ClientError as err:
+                raise RRCSConnectionError(f"{method}: {err}") from err
+
+        try:
+            parsed, _ = parse_xmlrpc(raw)
+        except xmlrpc.client.Fault as err:
+            raise RRCSFaultError(
+                f"{method}: fault {err.faultCode}: {err.faultString}", err.faultCode
+            ) from err
+
+        result = parsed[0] if parsed else None
+        _LOGGER.debug("RRCS <- %s %s", method, result)
+
+        if check:
+            code = extract_error_code(result)
+            if code:
+                raise RRCSError(f"{method}: {describe_error(code)}", code)
+
+        return result
+
+    # --- Convenience wrappers ------------------------------------------------------
+
+    async def get_version(self) -> str | None:
+        """Return the RRCS version string."""
+        result = await self.call("GetVersion")
+        if isinstance(result, (list, tuple)) and len(result) >= 3:
+            return str(result[2])
+        return None
+
+    async def get_state(self) -> str | None:
+        """Return the gateway state, 'Working' or 'Standby'."""
+        result = await self.call("GetState")
+        if isinstance(result, (list, tuple)) and len(result) >= 3:
+            return str(result[2])
+        return None
+
+    async def is_connected_to_artist(self) -> bool:
+        """Return whether RRCS currently has a working link to the Artist net."""
+        result = await self.call("IsConnectedToArtist")
+        if isinstance(result, dict):
+            return bool(result.get("IsConnected"))
+        return False
+
+    async def get_active_xp_count(self) -> int | None:
+        """Return the number of crosspoints RRCS considers active."""
+        result = await self.call("GetAllActiveXpsCount")
+        if isinstance(result, (list, tuple)) and len(result) >= 3:
+            value = result[2]
+            if isinstance(value, int):
+                return value
+        if isinstance(result, dict):
+            for key in ("XP Count", "XPCount", "Count"):
+                if isinstance(result.get(key), int):
+                    return result[key]
+        return None
+
+    async def get_logic_sources(self) -> dict[int, LogicSource]:
+        """Return every logic source in the system, keyed by object ID.
+
+        GetAllLogicSources_v2 returns a struct whose members are named
+        ``LogicSource#1``, ``LogicSource#2`` and so on, each an array of
+        ``[LongName, Label, ObjectID, State]``.
+        """
+        result = await self.call("GetAllLogicSources_v2")
+        if not isinstance(result, dict):
+            raise RRCSProtocolError("GetAllLogicSources_v2 did not return a struct")
+
+        code = result.get("ErrorCode")
+        if isinstance(code, int) and code:
+            raise RRCSError(f"GetAllLogicSources_v2: {describe_error(code)}", code)
+
+        sources: dict[int, LogicSource] = {}
+        for name, value in result.items():
+            if not name.startswith("LogicSource#") or not isinstance(value, (list, tuple)):
+                continue
+            if len(value) < 3:
+                continue
+            long_name, label, object_id = value[0], value[1], value[2]
+            if not isinstance(object_id, int):
+                continue
+            state = bool(value[3]) if len(value) > 3 else False
+            sources[object_id] = LogicSource(
+                object_id=object_id,
+                long_name=str(long_name or "").strip(),
+                label=str(label or "").strip(),
+                state=state,
+            )
+        return sources
+
+    async def set_logic_source(self, object_id: int, state: bool) -> None:
+        """Activate or deactivate a logic source."""
+        await self.call("SetLogicSourceState", int(object_id), bool(state), check=True)
+
+    async def get_gp_input_state(self, address: GpioAddress) -> bool:
+        """Read a general purpose input."""
+        result = await self.call(
+            "GetGpInputState",
+            address.net,
+            address.node,
+            address.port,
+            address.slot,
+            address.index,
+        )
+        return _trailing_bool(result)
+
+    async def get_gp_output_state(self, address: GpioAddress) -> bool:
+        """Read a general purpose output."""
+        result = await self.call(
+            "GetGpOutputState",
+            address.net,
+            address.node,
+            address.port,
+            address.slot,
+            address.index,
+        )
+        return _trailing_bool(result)
+
+    async def set_gp_output(self, address: GpioAddress, state: bool) -> None:
+        """Drive a general purpose output."""
+        await self.call(
+            "SetGpOutput",
+            address.net,
+            address.node,
+            address.port,
+            address.slot,
+            address.index,
+            int(bool(state)),
+            check=True,
+        )
+
+    async def discover_gpios(self) -> list[GpioAddress]:
+        """Best-effort discovery of configured GPIOs (RRCS 8.8 and later).
+
+        GetAllGpIns / GetAllGpOuts are documented only by name, not by return
+        shape, so this walks whatever comes back looking for structs that carry
+        an addressable GPIO. Anything it cannot make sense of is skipped and
+        logged at debug level.
+        """
+        found: dict[str, GpioAddress] = {}
+        for method, is_input in (("GetAllGpIns", True), ("GetAllGpOuts", False)):
+            try:
+                result = await self.call(method)
+            except RRCSError as err:
+                _LOGGER.debug("%s unavailable (%s); skipping GPIO discovery", method, err)
+                continue
+            _LOGGER.debug("%s raw payload: %r", method, result)
+            for address in _walk_gpio_structs(result, is_input):
+                found.setdefault(address.key, address)
+        return list(found.values())
+
+    # --- Notification registration -------------------------------------------------
+
+    async def register_for_all_events(
+        self,
+        tcp_port: int,
+        url_path: str,
+        pipelining: bool = False,
+        multicall: bool = False,
+    ) -> None:
+        """Ask RRCS to push every event to us.
+
+        RRCS derives the destination host from the source address of this very
+        request, so the gateway must be able to reach Home Assistant back on the
+        same IP at ``tcp_port``.
+        """
+        await self.call(
+            "RegisterForAllEvents",
+            int(tcp_port),
+            str(url_path),
+            bool(pipelining),
+            bool(multicall),
+        )
+
+    async def unregister_for_all_events(self, tcp_port: int, url_path: str) -> None:
+        """Stop receiving notifications."""
+        await self.call("UnregisterForAllEvents", int(tcp_port), str(url_path))
+
+    async def is_registered_for_all_events(self, tcp_port: int, url_path: str) -> bool:
+        """Return whether RRCS still has our notification registration."""
+        result = await self.call(
+            "IsRegisteredForAllEvents", int(tcp_port), str(url_path)
+        )
+        if isinstance(result, dict):
+            return bool(result.get("IsRegistered"))
+        return False
+
+
+def parse_gpio_config(raw: Any) -> list[tuple[GpioAddress, str | None]]:
+    """Parse the manual GPIO list from the options flow.
+
+    Accepts a JSON array of objects, each with at minimum ``index`` and
+    ``node``. ``direction`` is ``in`` or ``out`` and defaults to ``in``;
+    ``net`` defaults to 1, ``port`` to 128 (the GPIO client card) and ``slot``
+    to 0.
+    """
+    if not raw:
+        return []
+    if isinstance(raw, str):
+        raw = raw.strip()
+        if not raw:
+            return []
+        try:
+            raw = json.loads(raw)
+        except json.JSONDecodeError as err:
+            raise ValueError(f"GPIO list is not valid JSON: {err}") from err
+    if isinstance(raw, dict):
+        raw = [raw]
+    if not isinstance(raw, list):
+        raise ValueError("GPIO list must be a JSON array of objects")
+
+    result: list[tuple[GpioAddress, str | None]] = []
+    for position, item in enumerate(raw, start=1):
+        if not isinstance(item, dict):
+            raise ValueError(f"GPIO entry {position} is not an object")
+        try:
+            node = int(item["node"])
+            index = int(item["index"])
+        except (KeyError, TypeError, ValueError) as err:
+            raise ValueError(
+                f"GPIO entry {position} needs numeric 'node' and 'index'"
+            ) from err
+        direction = str(item.get("direction", "in")).lower()
+        if direction not in ("in", "out", "input", "output"):
+            raise ValueError(
+                f"GPIO entry {position}: direction must be 'in' or 'out'"
+            )
+        address = GpioAddress(
+            net=int(item.get("net", 1)),
+            node=node,
+            port=int(item.get("port", 128)),
+            slot=int(item.get("slot", 0)),
+            index=index,
+            is_input=direction.startswith("in"),
+        )
+        name = item.get("name")
+        result.append((address, str(name) if name else None))
+    return result
+
+
+def _trailing_bool(result: Any) -> bool:
+    """Pull the boolean state out of a ``[TransKey, ErrorCode, state]`` reply."""
+    if isinstance(result, (list, tuple)):
+        code = extract_error_code(result)
+        if code:
+            raise RRCSError(describe_error(code), code)
+        for value in reversed(result):
+            if isinstance(value, bool):
+                return value
+        if len(result) >= 3 and isinstance(result[2], int):
+            return bool(result[2])
+    return False
+
+
+def _walk_gpio_structs(node: Any, is_input: bool) -> list[GpioAddress]:
+    """Recursively collect GPIO addresses from an arbitrary decoded payload."""
+    found: list[GpioAddress] = []
+    if isinstance(node, dict):
+        address = _gpio_from_struct(node, is_input)
+        if address is not None:
+            found.append(address)
+        for value in node.values():
+            found.extend(_walk_gpio_structs(value, is_input))
+    elif isinstance(node, (list, tuple)):
+        for value in node:
+            found.extend(_walk_gpio_structs(value, is_input))
+    return found
+
+
+def _gpio_from_struct(struct: dict[str, Any], is_input: bool) -> GpioAddress | None:
+    """Map one decoded struct onto the Net/Node/Port/Slot/Index addressing.
+
+    Follows the three TGPIOAddress variants in chapter 6.7: a GPIO on a port
+    carries a nested PortAddress, one on a client card carries a Bay, and one on
+    a SIC carries only Node and Index.
+    """
+    index = struct.get("Index", struct.get("GpioNumber", struct.get("Gpio")))
+    if not isinstance(index, int) or isinstance(index, bool):
+        return None
+
+    direction = struct.get("IsInput")
+    if isinstance(direction, bool):
+        is_input = direction
+
+    net = struct.get("Net", 1)
+    net = net if isinstance(net, int) and not isinstance(net, bool) else 1
+
+    port_address = struct.get("PortAddress")
+    if isinstance(port_address, dict):
+        node = port_address.get("Node")
+        port = port_address.get("Port")
+        if isinstance(node, int) and isinstance(port, int):
+            return GpioAddress(net, node, port, 0, index, is_input)
+        return None
+
+    node = struct.get("Node")
+    if not isinstance(node, int) or isinstance(node, bool):
+        return None
+
+    bay = struct.get("Bay", struct.get("Slot"))
+    if isinstance(bay, int) and not isinstance(bay, bool):
+        # Bays are 1-based in TGPIOAddress, slots are 0-based in Set/GetGpOutput.
+        slot = bay - 1 if "Bay" in struct else bay
+        return GpioAddress(net, node, 128, max(slot, 0), index, is_input)
+
+    port = struct.get("Port")
+    if isinstance(port, int) and not isinstance(port, bool):
+        return GpioAddress(net, node, port, 0, index, is_input)
+
+    return None
diff --git a/services.yaml b/services.yaml
new file mode 100644
index 0000000..6adc91f
--- /dev/null
+++ b/services.yaml
@@ -0,0 +1,589 @@
+set_xp:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    source_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    source_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    source_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    dest_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    dest_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    dest_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    priority:
+      required: false
+      selector:
+        select:
+          options:
+          - label: 0 - below standard
+            value: '0'
+          - label: 1 - standard
+            value: '1'
+          - label: 2 - high
+            value: '2'
+          - label: 3 - paging
+            value: '3'
+          - label: 4 - emergency
+            value: '4'
+    destructive:
+      required: false
+      default: false
+      selector:
+        boolean: null
+kill_xp:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    source_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    source_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    source_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    dest_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    dest_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    dest_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+set_xp_volume:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    source_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    source_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    source_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    dest_net:
+      required: true
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    dest_node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    dest_port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    single:
+      required: false
+      default: true
+      selector:
+        boolean: null
+    conference:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    volume:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 256
+          mode: box
+set_gp_output:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    net:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    port:
+      required: false
+      default: 128
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    slot:
+      required: false
+      default: 0
+      selector:
+        number:
+          min: 0
+          max: 20
+          mode: box
+    index:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 63
+          mode: box
+    state:
+      required: true
+      selector:
+        boolean: null
+set_logic_source:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    object_id:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 4294967295
+          mode: box
+    state:
+      required: true
+      selector:
+        boolean: null
+press_key:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    node:
+      required: true
+      selector:
+        number:
+          min: 2
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    is_input:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    page:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 32
+          mode: box
+    expansion_panel:
+      required: false
+      default: 0
+      selector:
+        number:
+          min: 0
+          max: 16
+          mode: box
+    key_number:
+      required: true
+      selector:
+        number:
+          min: 1
+          max: 128
+          mode: box
+    is_virt_key:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    press:
+      required: false
+      default: true
+      selector:
+        boolean: null
+    trigger:
+      required: false
+      selector:
+        select:
+          options:
+          - label: 1 - primary (lever down / left key)
+            value: '1'
+          - label: 2 - secondary (lever up / right key)
+            value: '2'
+    pool_port:
+      required: false
+      default: 0
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+set_key_label:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    node:
+      required: true
+      selector:
+        number:
+          min: 2
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    is_input:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    page:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 32
+          mode: box
+    expansion_panel:
+      required: false
+      default: 0
+      selector:
+        number:
+          min: 0
+          max: 16
+          mode: box
+    key_number:
+      required: true
+      selector:
+        number:
+          min: 1
+          max: 128
+          mode: box
+    is_virt_key:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    label:
+      required: true
+      selector:
+        text: null
+    marker:
+      required: false
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+clear_key_label:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    node:
+      required: true
+      selector:
+        number:
+          min: 2
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    is_input:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    page:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 32
+          mode: box
+    expansion_panel:
+      required: false
+      default: 0
+      selector:
+        number:
+          min: 0
+          max: 16
+          mode: box
+    key_number:
+      required: true
+      selector:
+        number:
+          min: 1
+          max: 128
+          mode: box
+    is_virt_key:
+      required: false
+      default: false
+      selector:
+        boolean: null
+    clear_marker:
+      required: false
+      default: false
+      selector:
+        boolean: null
+set_port_alias:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    net:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    alias:
+      required: true
+      selector:
+        text: null
+    is_input:
+      required: false
+      default: false
+      selector:
+        boolean: null
+set_input_gain:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    net:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    gain:
+      required: true
+      selector:
+        number:
+          min: -128
+          max: 36
+          mode: box
+set_output_gain:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    net:
+      required: false
+      default: 1
+      selector:
+        number:
+          min: 1
+          max: 255
+          mode: box
+    node:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 255
+          mode: box
+    port:
+      required: true
+      selector:
+        number:
+          min: 0
+          max: 1151
+          mode: box
+    gain:
+      required: true
+      selector:
+        number:
+          min: -128
+          max: 36
+          mode: box
+call_method:
+  fields:
+    entry_id:
+      required: false
+      selector:
+        config_entry:
+          integration: riedel_rrcs
+    method:
+      required: true
+      example: GetAllPorts
+      selector:
+        text: null
+    params:
+      required: false
+      example: '[2, 0, false]'
+      selector:
+        object: null
+    include_transkey:
+      required: false
+      default: true
+      selector:
+        boolean: null
diff --git a/switch.py b/switch.py
new file mode 100644
index 0000000..7a1e473
--- /dev/null
+++ b/switch.py
@@ -0,0 +1,172 @@
+"""Switch platform for the Riedel RRCS integration."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.components.switch import SwitchEntity
+from homeassistant.core import HomeAssistant, callback
+from homeassistant.exceptions import HomeAssistantError
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
+
+from .coordinator import RRCSCoordinator
+from .entity import RRCSEntity
+from .models import RRCSConfigEntry
+from .rrcs import GpioAddress, RRCSError
+
+
+async def async_setup_entry(
+    hass: HomeAssistant,
+    entry: RRCSConfigEntry,
+    async_add_entities: AddEntitiesCallback,
+) -> None:
+    """Set up the switch entities."""
+    runtime = entry.runtime_data
+    coordinator = runtime.coordinator
+
+    entities: list[SwitchEntity] = [
+        RRCSLogicSourceSwitch(coordinator, entry.entry_id, object_id)
+        for object_id in (coordinator.data.logic_sources if coordinator.data else {})
+    ]
+    entities.extend(
+        RRCSGpOutputSwitch(
+            coordinator,
+            entry.entry_id,
+            address,
+            runtime.gpio_names.get(address.key),
+        )
+        for address in runtime.gpio_outputs
+    )
+
+    async_add_entities(entities)
+
+    known = {
+        object_id for object_id in (coordinator.data.logic_sources if coordinator.data else {})
+    }
+
+    @callback
+    def _add_new_logic_sources() -> None:
+        """Pick up logic sources added to the Artist configuration later."""
+        if coordinator.data is None:
+            return
+        new = set(coordinator.data.logic_sources) - known
+        if not new:
+            return
+        known.update(new)
+        async_add_entities(
+            RRCSLogicSourceSwitch(coordinator, entry.entry_id, object_id)
+            for object_id in new
+        )
+
+    entry.async_on_unload(coordinator.async_add_listener(_add_new_logic_sources))
+
+
+class RRCSLogicSourceSwitch(RRCSEntity, SwitchEntity):
+    """A logic source, driven through SetLogicSourceState."""
+
+    _attr_icon = "mdi:toggle-switch-outline"
+
+    def __init__(
+        self, coordinator: RRCSCoordinator, entry_id: str, object_id: int
+    ) -> None:
+        """Initialise the switch."""
+        super().__init__(coordinator, entry_id)
+        self._object_id = object_id
+        self._attr_unique_id = f"{entry_id}_logic_source_{object_id}"
+        source = coordinator.data.logic_sources.get(object_id) if coordinator.data else None
+        self._attr_name = (source.long_name or source.label) if source else f"Logic source {object_id}"
+
+    @property
+    def available(self) -> bool:
+        """Return whether the logic source is still in the configuration."""
+        return (
+            super().available
+            and self.coordinator.data is not None
+            and self._object_id in self.coordinator.data.logic_sources
+        )
+
+    @property
+    def is_on(self) -> bool | None:
+        """Return the logic source state."""
+        if self.coordinator.data is None:
+            return None
+        source = self.coordinator.data.logic_sources.get(self._object_id)
+        return source.state if source else None
+
+    @property
+    def extra_state_attributes(self) -> dict[str, Any]:
+        """Expose the Artist identifiers for use in automations."""
+        source = (
+            self.coordinator.data.logic_sources.get(self._object_id)
+            if self.coordinator.data
+            else None
+        )
+        return {
+            "object_id": self._object_id,
+            "label": source.label if source else None,
+        }
+
+    async def async_turn_on(self, **kwargs: Any) -> None:
+        """Activate the logic source."""
+        await self._async_set(True)
+
+    async def async_turn_off(self, **kwargs: Any) -> None:
+        """Deactivate the logic source.
+
+        RRCS only clears logic sources it set itself; one driven from a panel
+        key will not respond here.
+        """
+        await self._async_set(False)
+
+    async def _async_set(self, state: bool) -> None:
+        try:
+            await self.coordinator.client.set_logic_source(self._object_id, state)
+        except RRCSError as err:
+            raise HomeAssistantError(f"Could not set logic source: {err}") from err
+        self.coordinator.apply_logic_source_change(self._object_id, state)
+
+
+class RRCSGpOutputSwitch(RRCSEntity, SwitchEntity):
+    """A general purpose output."""
+
+    _attr_icon = "mdi:electric-switch"
+
+    def __init__(
+        self,
+        coordinator: RRCSCoordinator,
+        entry_id: str,
+        address: GpioAddress,
+        name: str | None,
+    ) -> None:
+        """Initialise the switch."""
+        super().__init__(coordinator, entry_id)
+        self._address = address
+        self._attr_unique_id = f"{entry_id}_gpo_{address.key}"
+        self._attr_name = name or f"GP out {address.node}.{address.slot}.{address.index}"
+
+    @property
+    def is_on(self) -> bool | None:
+        """Return the output state."""
+        if self.coordinator.data is None:
+            return None
+        return self.coordinator.data.gpio_outputs.get(self._address.key)
+
+    @property
+    def extra_state_attributes(self) -> dict[str, Any]:
+        """Expose the GPIO address."""
+        return {"address": self._address.pretty}
+
+    async def async_turn_on(self, **kwargs: Any) -> None:
+        """Close the output."""
+        await self._async_set(True)
+
+    async def async_turn_off(self, **kwargs: Any) -> None:
+        """Open the output."""
+        await self._async_set(False)
+
+    async def _async_set(self, state: bool) -> None:
+        try:
+            await self.coordinator.client.set_gp_output(self._address, state)
+        except RRCSError as err:
+            raise HomeAssistantError(f"Could not switch GP output: {err}") from err
+        self.coordinator.apply_gpio_change(self._address, state)
diff --git a/test_client.py b/test_client.py
new file mode 100644
index 0000000..b03db72
--- /dev/null
+++ b/test_client.py
@@ -0,0 +1,269 @@
+"""Exercise the RRCS client against a mock gateway that speaks spec-shaped XML."""
+
+import asyncio
+import sys
+import xmlrpc.client
+
+import aiohttp
+from aiohttp import web
+
+import pathlib
+
+ROOT = pathlib.Path(__file__).resolve().parents[1] / "custom_components"
+DIR = str(ROOT / "riedel_rrcs")
+
+
+def _load_module():
+    """Load rrcs.py without dragging in the Home Assistant package __init__."""
+    import importlib.util
+    import types
+
+    pkg = types.ModuleType("rrcspkg")
+    pkg.__path__ = [DIR]
+    sys.modules["rrcspkg"] = pkg
+    for name in ("const", "rrcs"):
+        spec = importlib.util.spec_from_file_location(f"rrcspkg.{name}", f"{DIR}/{name}.py")
+        module = importlib.util.module_from_spec(spec)
+        sys.modules[f"rrcspkg.{name}"] = module
+        spec.loader.exec_module(module)
+    return sys.modules["rrcspkg.rrcs"]
+
+
+R = _load_module()
+
+RECEIVED = []
+
+
+def resp(body: str) -> web.Response:
+    return web.Response(
+        body=('<?xml version="1.0"?><methodResponse><params><param>'
+              f"{body}</param></params></methodResponse>").encode(),
+        content_type="text/xml",
+    )
+
+
+async def handler(request: web.Request) -> web.Response:
+    raw = await request.read()
+    params, method = xmlrpc.client.loads(raw)
+    RECEIVED.append((method, params))
+    tk = params[0]
+
+    if method == "GetVersion":
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>0</int></value>"
+                    "<value><string>8.9.1.0</string></value></data></array></value>")
+    if method == "GetState":
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>0</int></value>"
+                    "<value><string>Working</string></value></data></array></value>")
+    if method == "IsConnectedToArtist":
+        return resp("<value><struct>"
+                    "<member><name>IsConnected</name><value><boolean>1</boolean></value></member>"
+                    f"<member><name>TransKey</name><value><string>{tk}</string></value></member>"
+                    "</struct></value>")
+    if method == "GetAllActiveXpsCount":
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>0</int></value>"
+                    "<value><i4>42</i4></value></data></array></value>")
+    if method == "GetAllLogicSources_v2":
+        return resp("<value><struct>"
+                    "<member><name>ErrorCode</name><value><int>0</int></value></member>"
+                    f"<member><name>TransKey</name><value><string>{tk}</string></value></member>"
+                    "<member><name>LogicSourceCount</name><value><int>2</int></value></member>"
+                    "<member><name>LogicSource#1</name><value><array><data>"
+                    "<value><string>Ben Busy</string></value>"
+                    "<value><string>BenBusy</string></value>"
+                    "<value><i4>1454317500</i4></value>"
+                    "<value><boolean>1</boolean></value>"
+                    "</data></array></value></member>"
+                    "<member><name>LogicSource#2</name><value><array><data>"
+                    "<value><string>Studio Red Light</string></value>"
+                    "<value><string>RedLight</string></value>"
+                    "<value><i4>1454317501</i4></value>"
+                    "<value><boolean>0</boolean></value>"
+                    "</data></array></value></member>"
+                    "</struct></value>")
+    if method in ("SetLogicSourceState", "SetGpOutput", "SetXp", "SetKeyLabel"):
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>0</int></value></data></array></value>")
+    if method == "SetInputGain":
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>6</int></value></data></array></value>")
+    if method in ("GetGpInputState", "GetGpOutputState"):
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>0</int></value>"
+                    "<value><boolean>1</boolean></value></data></array></value>")
+    if method == "GetLevelMeterValues":
+        # Deliberately puts a payload int where ErrorCode usually sits.
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><int>17</int></value><value><int>4</int></value>"
+                    "<value><boolean>0</boolean></value>"
+                    "<value><int>21</int></value></data></array></value>")
+    if method == "GetAllGpIns":
+        return resp(f"<value><array><data><value><string>{tk}</string></value>"
+                    "<value><array><data>"
+                    "<value><struct>"
+                    "<member><name>Index</name><value><i4>5</i4></value></member>"
+                    "<member><name>IsInput</name><value><boolean>1</boolean></value></member>"
+                    "<member><name>Node</name><value><i4>2</i4></value></member>"
+                    "<member><name>Bay</name><value><i4>6</i4></value></member>"
+                    "</struct></value>"
+                    "<value><struct>"
+                    "<member><name>PortAddress</name><value><struct>"
+                    "<member><name>IsInput</name><value><boolean>1</boolean></value></member>"
+                    "<member><name>Node</name><value><i4>4</i4></value></member>"
+                    "<member><name>Port</name><value><i4>9</i4></value></member>"
+                    "</struct></value></member>"
+                    "<member><name>Index</name><value><i4>0</i4></value></member>"
+                    "<member><name>IsInput</name><value><boolean>1</boolean></value></member>"
+                    "</struct></value>"
+                    "</data></array></value></data></array></value>")
+    if method == "GetAllGpOuts":
+        raise web.HTTPInternalServerError()
+    if method == "RegisterForAllEvents":
+        return resp(f"<value><string>{tk}</string></value>")
+    if method == "IsRegisteredForAllEvents":
+        return resp("<value><struct>"
+                    "<member><name>IsRegistered</name><value><boolean>1</boolean></value></member>"
+                    f"<member><name>TransKey</name><value><string>{tk}</string></value></member>"
+                    "</struct></value>")
+    if method == "BadLabel":
+        # UTF-8 declared, Latin-1 emitted: the tolerant parser must recover.
+        body = ('<?xml version="1.0" encoding="UTF-8"?><methodResponse><params><param>'
+                f'<value><array><data><value><string>{tk}</string></value>'
+                '<value><int>0</int></value>'
+                '<value><string>Caf\xe9 Mic</string></value>'
+                '</data></array></value></param></params></methodResponse>')
+        return web.Response(body=body.encode("latin-1"), content_type="text/xml")
+    if method == "Faulty":
+        return web.Response(
+            body=xmlrpc.client.dumps(
+                xmlrpc.client.Fault(14, "XML-RPC parameters wrong")
+            ).encode(),
+            content_type="text/xml",
+        )
+    return resp(f"<value><string>{tk}</string></value>")
+
+
+async def main() -> int:
+    app = web.Application()
+    app.router.add_post("/", handler)
+    runner = web.AppRunner(app)
+    await runner.setup()
+    site = web.TCPSite(runner, "127.0.0.1", 18193)
+    await site.start()
+
+    failures = []
+
+    def check(label, got, want):
+        ok = got == want
+        print(f"{'PASS' if ok else 'FAIL'}  {label}: {got!r}")
+        if not ok:
+            failures.append((label, got, want))
+
+    async with aiohttp.ClientSession() as session:
+        c = R.RRCSClient(session, "127.0.0.1", 18193)
+
+        check("url", c.url, "http://127.0.0.1:18193/")
+        check("transkey format", len(c.next_transkey()), 11)
+
+        check("get_version", await c.get_version(), "8.9.1.0")
+        check("get_state", await c.get_state(), "Working")
+        check("is_connected_to_artist", await c.is_connected_to_artist(), True)
+        check("get_active_xp_count", await c.get_active_xp_count(), 42)
+
+        sources = await c.get_logic_sources()
+        check("logic source count", len(sources), 2)
+        check("logic source name", sources[1454317500].long_name, "Ben Busy")
+        check("logic source label", sources[1454317500].label, "BenBusy")
+        check("logic source state on", sources[1454317500].state, True)
+        check("logic source state off", sources[1454317501].state, False)
+
+        await c.set_logic_source(1454317500, True)
+        method, params = RECEIVED[-1]
+        check("SetLogicSourceState params", params[1:], (1454317500, True))
+
+        addr = R.GpioAddress(1, 2, 128, 0, 5, True)
+        check("gp input read", await c.get_gp_input_state(addr), True)
+        await c.set_gp_output(R.GpioAddress(1, 2, 128, 0, 5, False), True)
+        check("SetGpOutput params", RECEIVED[-1][1][1:], (1, 2, 128, 0, 5, 1))
+
+        # A payload integer in slot 1 must not be mistaken for an error code.
+        level = await c.call("GetLevelMeterValues", 2, 0, 0)
+        check("level meter untouched", level[1:], [17, 4, False, 21])
+
+        # ...but a real error code on a checked call must raise.
+        try:
+            await c.call("SetInputGain", 1, 2, 3, 99, check=True)
+            check("error raised", False, True)
+        except R.RRCSError as err:
+            check("error code", err.code, 6)
+            check("error text", str(err), "SetInputGain: Input gain invalid")
+
+        gpios = await c.discover_gpios()
+        keys = sorted(g.key for g in gpios)
+        check("discovered client-card gpio", "1_2_128_5_5_in" in keys, True)
+        check("discovered port gpio", "1_4_9_0_0_in" in keys, True)
+        check("failed GetAllGpOuts tolerated", len(gpios), 2)
+
+        check("mojibake tolerated", (await c.call("BadLabel"))[2], "Caf\ufffd Mic")
+
+        try:
+            await c.call("Faulty")
+            check("fault raised", False, True)
+        except R.RRCSFaultError as err:
+            check("fault code", err.code, 14)
+
+        await c.register_for_all_events(8123, "/api/riedel_rrcs/abc123")
+        check("register params", RECEIVED[-1][1][1:],
+              (8123, "/api/riedel_rrcs/abc123", False, False))
+        check("still registered",
+              await c.is_registered_for_all_events(8123, "/api/riedel_rrcs/abc123"), True)
+
+        # Unreachable host must surface as a connection error, not a crash.
+        dead = R.RRCSClient(session, "127.0.0.1", 18194, timeout=2)
+        try:
+            await dead.get_version()
+            check("dead host raises", False, True)
+        except R.RRCSConnectionError:
+            check("dead host raises", True, True)
+
+    # --- Manual GPIO config parsing ---
+    parsed = R.parse_gpio_config(
+        '[{"name":"Tally A","direction":"in","node":2,"index":3},'
+        ' {"name":"Red Light","direction":"out","net":1,"node":2,"port":128,'
+        '  "slot":1,"index":5}]'
+    )
+    check("parsed count", len(parsed), 2)
+    check("parsed defaults", parsed[0][0], R.GpioAddress(1, 2, 128, 0, 3, True))
+    check("parsed name", parsed[1][1], "Red Light")
+    check("parsed direction", parsed[1][0].is_input, False)
+    check("empty config", R.parse_gpio_config(""), [])
+    for bad, label in (("not json", "bad json"), ('[{"node":1}]', "missing index"),
+                       ('[{"node":1,"index":2,"direction":"sideways"}]', "bad direction")):
+        try:
+            R.parse_gpio_config(bad)
+            check(label, False, True)
+        except ValueError:
+            check(label, True, True)
+
+    # --- Inbound notification decoding ---
+    call = xmlrpc.client.dumps(("R0000000001", 1454317500, True), "LogicSourceChange")
+    params, method = R.parse_xmlrpc(call.encode())
+    check("notification method", method, "LogicSourceChange")
+    check("notification params", params, ("R0000000001", 1454317500, True))
+
+    ack = xmlrpc.client.dumps((["R0000000001", 0],), methodresponse=True)
+    check("ack parses", xmlrpc.client.loads(ack.encode())[0][0], ["R0000000001", 0])
+
+    await runner.cleanup()
+
+    print()
+    if failures:
+        print(f"{len(failures)} FAILURE(S)")
+        return 1
+    print("all checks passed")
+    return 0
+
+
+sys.exit(asyncio.run(main()))