diff --git a/shared/tunnelbroker_messages/src/messages/message_to_device.rs b/shared/tunnelbroker_messages/src/messages/message_to_device.rs
new file mode 100644
index 000000000..b6b2e0abf
--- /dev/null
+++ b/shared/tunnelbroker_messages/src/messages/message_to_device.rs
@@ -0,0 +1,30 @@
+// Messages sent between Tunnelbroker and a device via WebSocket
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, PartialEq, Debug)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub struct MessageToDevice {
+  #[serde(rename = "deviceID")]
+  pub device_id: String,
+  pub payload: String,
+}
+
+#[cfg(test)]
+mod message_to_device_tests {
+  use super::*;
+
+  #[test]
+  fn test_message_to_device_deserialization() {
+    let example_payload = r#"{
+      "type": "MessageToDevice",
+      "deviceID": "alice",
+      "payload": "message from Bob"
+    }"#;
+
+    let request =
+      serde_json::from_str::<MessageToDevice>(example_payload).unwrap();
+    assert_eq!(request.device_id, "alice");
+    assert_eq!(request.payload, "message from Bob");
+  }
+}
diff --git a/shared/tunnelbroker_messages/src/messages/mod.rs b/shared/tunnelbroker_messages/src/messages/mod.rs
index 217799816..b29844f43 100644
--- a/shared/tunnelbroker_messages/src/messages/mod.rs
+++ b/shared/tunnelbroker_messages/src/messages/mod.rs
@@ -1,15 +1,18 @@
 // Messages sent between Tunnelbroker and a device
 pub mod keys;
+pub mod message_to_device;
 pub mod session;
 
 pub use keys::*;
+pub use message_to_device::*;
 pub use session::*;
 
 use serde::{Deserialize, Serialize};
 
 #[derive(Serialize, Deserialize)]
 #[serde(untagged)]
 pub enum Messages {
   RefreshKeysRequest(RefreshKeyRequest),
   ConnectionInitializationMessage(ConnectionInitializationMessage),
+  MessageToDevice(MessageToDevice),
 }