diff --git a/TransportClient.markdown b/TransportClient.markdown
new file mode 100644
index 0000000..0f9f619
--- /dev/null
+++ b/TransportClient.markdown
@@ -0,0 +1,24 @@
+TransportClient is a [BSP client](BSP) that synchronises transport properties between devices. Transport properties describe how to connect to a device over various transports.
+
+### Channel identifiers
+
+TransportClient has a single channel with the following random identifer:   
+`673e a091 6735 61e2 8f70 122f 6a8e a8f4 97c3 624b 86fa 07f7 85bb 15f0 9fb8 7b4b`
+
+### Message types
+
+**0: UPDATE** - The content is a [BDF](BDF) list with three elements: `transport_id` (string), `version` (int), and `properties` (dictionary). `transport_id` and `properties` are supplied by the transport plugin. `version` is incremented whenever the properties change.
+
+### Validity policy
+
+* An UPDATE is valid if it is well-formed.
+
+### Storage policy
+
+* For each transport, the local message with the highest version is stored.
+* For each transport and each remote peer, the remote message with the highest version is stored.
+
+### Sharing policy
+
+* Local messages are shared with all remote peers.
+* Each remote message is shared with the remote peer that created it.