diff --git a/docs/conf.py b/docs/conf.py
index 1cdee97..0a9423e 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -6,6 +6,7 @@ extensions = [
     "sphinx.ext.autodoc",
     "sphinx.ext.napoleon",
     "myst_parser",
-]
+]  # , "autodoc2"
+# autodoc2_packages = ["../heisskleber"]
 autodoc_typehints = "description"
 html_theme = "furo"
diff --git a/docs/reference.md b/docs/reference.md
index 27c6947..20ff891 100644
--- a/docs/reference.md
+++ b/docs/reference.md
@@ -1,8 +1,40 @@
 # Reference
 
-## heisskleber
+## Network
 
 ```{eval-rst}
-.. automodule:: heisskleber
+.. automodule:: heisskleber.network
    :members:
+.. automodule:: heisskleber.network.mqtt
+.. autoclass:: MqttPublisher
+.. autoclass:: MqttSubscriber
+.. automodule:: heisskleber.network.zmq
+   :members:
+.. autoclass:: ZmqPublisher
+.. autoclass:: ZmqSubscriber
+```
+
+### Broker
+
+```{eval-rst}
+.. automodule:: heisskleber.broker
+    :members:
+```
+
+## Config
+
+### Loading configs
+```{eval-rst}
+.. automodule:: heisskleber.config
+   :members: load_config
+```
+
+### Config types
+
+Configs are extended dataclasses, which inherit from the BaseConf class.
+```{eval-rst}
+.. autoclass:: heisskleber.config.BaseConf
+.. autoclass:: heisskleber.network.mqtt.config.MqttConf
+.. autoclass:: heisskleber.network.zmq.config.ZmqConf
+.. autoclass:: heisskleber.network.serial.config.SerialConf
 ```
diff --git a/heisskleber/broker/__init__.py b/heisskleber/broker/__init__.py
new file mode 100644
index 0000000..961abcd
--- /dev/null
+++ b/heisskleber/broker/__init__.py
@@ -0,0 +1,3 @@
+from .msb_broker import msb_broker as start_zmq_broker
+
+__all__ = ["start_zmq_broker"]
diff --git a/heisskleber/broker/msb_broker.py b/heisskleber/broker/msb_broker.py
new file mode 100644
index 0000000..db4394e
--- /dev/null
+++ b/heisskleber/broker/msb_broker.py
@@ -0,0 +1,63 @@
+import signal
+import sys
+
+import zmq
+
+from heisskleber.config import load_config
+from heisskleber.network.zmq.config import ZmqConf as BrokerConf
+
+
+def signal_handler(sig, frame):
+    print("msb_broker.py exit")
+    sys.exit(0)
+
+
+class BrokerBindingError(Exception):
+    pass
+
+
+def bind_socket(socket, address, socket_type, verbose=False):
+    """Bind a ZMQ socket and handle errors."""
+    if verbose:
+        print(f"creating {socket_type} socket")
+    try:
+        socket.bind(address)
+    except Exception as err:
+        raise BrokerBindingError(f"failed to bind to {socket_type}: {err}") from err
+    if verbose:
+        print(f"successfully bound to {socket_type} socket: {address}")
+
+
+def create_proxy(xpub, xsub, verbose=False):
+    """Create a ZMQ proxy to connect XPUB and XSUB sockets."""
+    if verbose:
+        print("creating proxy")
+    try:
+        zmq.proxy(xpub, xsub)
+    except Exception as err:
+        raise BrokerBindingError(f"failed to create proxy: {err}") from err
+
+
+def msb_broker(config: BrokerConf) -> None:
+    """Start a zmq broker.
+
+    Binds to a publisher and subscriber port, allowing many to many connections."""
+    ctx = zmq.Context()
+
+    xpub = ctx.socket(zmq.XPUB)
+    xsub = ctx.socket(zmq.XSUB)
+
+    try:
+        bind_socket(xpub, config.publisher_address, "publisher", config.verbose)
+        bind_socket(xsub, config.subscriber_address, "subscriber", config.verbose)
+        create_proxy(xpub, xsub, config.verbose)
+    except BrokerBindingError as e:
+        print(e)
+        sys.exit(-1)
+
+
+def main() -> None:
+    """Start a zmq broker, with a user specified configuration."""
+    signal.signal(signal.SIGINT, signal_handler)
+    broker_config = load_config(BrokerConf(), "zmq")
+    msb_broker(broker_config)