diff --git a/lib/types/tunnelbroker/message-to-tunnelbroker-types.js b/lib/types/tunnelbroker/message-to-tunnelbroker-types.js
--- a/lib/types/tunnelbroker/message-to-tunnelbroker-types.js
+++ b/lib/types/tunnelbroker/message-to-tunnelbroker-types.js
@@ -1,10 +1,19 @@
 // @flow
 
+import type { Platform } from '../device-types.js';
+
 export const messageToTunnelbrokerTypes = Object.freeze({
   SET_DEVICE_TOKEN: 'SetDeviceToken',
+  SET_DEVICE_TOKEN_WITH_PLATFORM: 'SetDeviceTokenWithPlatform',
 });
 
 export type SetDeviceToken = {
   +type: 'SetDeviceToken',
   +deviceToken: string,
 };
+
+export type SetDeviceTokenWithPlatform = {
+  +type: 'SetDeviceTokenWithPlatform',
+  +deviceToken: string,
+  +platform: Platform,
+};
diff --git a/shared/tunnelbroker_messages/src/messages/message_to_tunnelbroker.rs b/shared/tunnelbroker_messages/src/messages/message_to_tunnelbroker.rs
--- a/shared/tunnelbroker_messages/src/messages/message_to_tunnelbroker.rs
+++ b/shared/tunnelbroker_messages/src/messages/message_to_tunnelbroker.rs
@@ -1,4 +1,6 @@
 use serde::{Deserialize, Serialize};
+use std::fmt::{Display, Formatter, Result as FmtResult};
+use std::str::FromStr;
 
 /// Message sent by device to set device token.
 #[derive(Serialize, Deserialize, PartialEq, Debug)]
@@ -6,3 +8,80 @@
 pub struct SetDeviceToken {
   pub device_token: String,
 }
+
+#[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
+#[serde(rename_all = "lowercase")]
+pub enum Platform {
+  Android,
+  IOS,
+  Web,
+  Windows,
+  MacOS,
+}
+
+impl Display for Platform {
+  fn fmt(&self, f: &mut Formatter) -> FmtResult {
+    match self {
+      Platform::Web => write!(f, "web"),
+      Platform::IOS => write!(f, "ios"),
+      Platform::Android => write!(f, "android"),
+      Platform::Windows => write!(f, "windows"),
+      Platform::MacOS => write!(f, "macos"),
+    }
+  }
+}
+
+impl FromStr for Platform {
+  type Err = serde_json::Error;
+  fn from_str(value: &str) -> Result<Self, Self::Err> {
+    let quoted = format!("\"{}\"", value);
+    serde_json::from_str(&quoted)
+  }
+}
+
+/// Message sent by device to set device with platform.
+#[derive(Serialize, Deserialize, PartialEq, Debug)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub struct SetDeviceTokenWithPlatform {
+  pub device_token: String,
+  pub platform: Platform,
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_deserialization() {
+    let device_token = "some_device_token";
+    let example_payload = r#"{
+        "type": "SetDeviceTokenWithPlatform",
+        "deviceToken": "some_device_token",
+        "platform": "macos"
+    }"#;
+
+    let deserialized: SetDeviceTokenWithPlatform =
+      serde_json::from_str(example_payload).unwrap();
+
+    assert_eq!(deserialized.device_token, device_token);
+    assert_eq!(deserialized.platform, Platform::MacOS);
+  }
+
+  #[test]
+  fn test_try_from_for_platform() {
+    assert_eq!(Platform::from_str("web").unwrap(), Platform::Web);
+    assert_eq!(Platform::from_str("ios").unwrap(), Platform::IOS);
+    assert_eq!(Platform::from_str("android").unwrap(), Platform::Android);
+    assert_eq!(Platform::from_str("windows").unwrap(), Platform::Windows);
+    assert_eq!(Platform::from_str("macos").unwrap(), Platform::MacOS);
+  }
+
+  #[test]
+  fn test_display_for_platform() {
+    assert_eq!(format!("{}", Platform::Web), "web");
+    assert_eq!(format!("{}", Platform::IOS), "ios");
+    assert_eq!(format!("{}", Platform::Android), "android");
+    assert_eq!(format!("{}", Platform::Windows), "windows");
+    assert_eq!(format!("{}", Platform::MacOS), "macos");
+  }
+}