diff --git a/services/tunnelbroker/src/websockets/messages.rs b/services/tunnelbroker/src/websockets/messages.rs
deleted file mode 100644
--- a/services/tunnelbroker/src/websockets/messages.rs
+++ /dev/null
@@ -1,79 +0,0 @@
-// This file intends to preserve the original structure of the tunnelbroker
-// protobuf RPCs. However, this is converted to simple rust datastructures
-// to allow for deserialization and serialization into JSON websocket messages
-
-// Original Tunnelbroker Service definition:
-//
-// service TunnelbrokerService {
-// rpc SessionSignature(SessionSignatureRequest) returns (SessionSignatureResponse) {}
-// rpc NewSession(NewSessionRequest) returns (NewSessionResponse) {}
-// rpc MessagesStream(stream MessageToTunnelbroker) returns (stream MessageToClient) {}
-// }
-
-// Session
-pub struct SessionSignatureRequest {
- pub device_id: String,
-}
-pub struct SessionSignatureResponse {
- pub to_sign: String,
-}
-
-pub enum DeviceTypes {
- Mobile,
- Web,
- Keyserver,
-}
-
-pub struct SessionRequest {
- pub device_id: String,
- pub public_key: String,
- pub signature: String,
- pub notify_token: Option<String>,
- pub device_type: DeviceTypes,
- pub device_app_version: String,
- pub device_os: String,
-}
-
-pub struct SessionResponse {
- pub session_id: String,
-}
-
-// Common messages structures for the MessagesStream
-pub struct ProcessedMessages {
- pub message_id: Vec<String>,
-}
-
-// The messages from the Client to the Tunnelbroker
-pub struct MessageToTunnelbrokerStruct {
- pub to_device_id: String,
- pub payload: String,
- pub blob_hashes: Vec<String>,
-}
-
-pub struct MessagesToSend {
- pub messages: Vec<MessageToTunnelbrokerStruct>,
-}
-
-pub enum MessageToTunnelbroker {
- Messages(MessagesToSend),
- ProcessedMessages(ProcessedMessages),
- NewNotifyToken(String),
-}
-
-// The messages from the Tunnelbroker to the Client
-pub struct MessageToClientStruct {
- pub message_id: String,
- pub from_device_id: String,
- pub payload: String,
- pub blob_hashes: Vec<String>,
-}
-
-pub struct MessagesToDeliver {
- pub messages: Vec<MessageToClientStruct>,
-}
-
-pub enum MessageToClient {
- Messages(MessagesToDeliver),
- ProcessedMessages(ProcessedMessages),
- NewNotifyTokenRequired,
-}
diff --git a/services/tunnelbroker/src/websockets/mod.rs b/services/tunnelbroker/src/websockets/mod.rs
--- a/services/tunnelbroker/src/websockets/mod.rs
+++ b/services/tunnelbroker/src/websockets/mod.rs
@@ -1,5 +1,3 @@
-pub mod messages;
-
use std::{env, io::Error};
use tokio::net::{TcpListener, TcpStream};
diff --git a/shared/tunnelbroker_messages/.gitignore b/shared/tunnelbroker_messages/.gitignore
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/.gitignore
@@ -0,0 +1 @@
+target/
diff --git a/shared/tunnelbroker_messages/Cargo.lock b/shared/tunnelbroker_messages/Cargo.lock
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/Cargo.lock
@@ -0,0 +1,89 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "itoa"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "453ad9f582a441959e5f0d088b02ce04cfe8d51a8eaf077f12ac6d3e94164ca6"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b63bdb0cd06f1f4dedf69b254734f9b45af66e4a031e42a7480257d9898b435"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f91339c0467de62360649f8d3e185ca8de4224ff281f66000de5eb2a77a79041"
+
+[[package]]
+name = "serde"
+version = "1.0.160"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb2f3770c8bce3bcda7e149193a069a0f4365bda1fa5cd88e03bca26afc1216c"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.160"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291a097c63d8497e00160b166a967a4a79c64f3facdd01cbd7502231688d77df"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.96"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "057d394a50403bcac12672b2b18fb387ab6d289d957dab67dd201875391e52f1"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a34fcf3e8b60f57e6a14301a2e916d323af98b0ea63c599441eec8558660c822"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "tunnelbroker_messages"
+version = "0.1.0"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
diff --git a/shared/tunnelbroker_messages/Cargo.toml b/shared/tunnelbroker_messages/Cargo.toml
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "tunnelbroker_messages"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+serde = { version = "1.0.160", features = [ "derive" ] }
+serde_json = "1.0.96"
diff --git a/shared/tunnelbroker_messages/src/lib.rs b/shared/tunnelbroker_messages/src/lib.rs
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/src/lib.rs
@@ -0,0 +1,3 @@
+pub mod messages;
+
+pub use messages::*;
diff --git a/shared/tunnelbroker_messages/src/messages/keys.rs b/shared/tunnelbroker_messages/src/messages/keys.rs
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/src/messages/keys.rs
@@ -0,0 +1,28 @@
+// Messages sent between tunnelbroker and a device
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub struct RefreshKeyRequest {
+ pub device_id: String,
+ pub number_of_keys: u32,
+}
+
+#[cfg(test)]
+mod key_tests {
+ use super::*;
+
+ #[test]
+ fn test_refresh_deserialization() {
+ let example_payload = r#"{
+ "type": "RefreshKeyRequest",
+ "deviceId": "adfjEDFS",
+ "numberOfKeys": 6
+ }"#;
+
+ let request =
+ serde_json::from_str::<RefreshKeyRequest>(example_payload).unwrap();
+ assert_eq!(request.number_of_keys, 6);
+ }
+}
diff --git a/shared/tunnelbroker_messages/src/messages/mod.rs b/shared/tunnelbroker_messages/src/messages/mod.rs
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/src/messages/mod.rs
@@ -0,0 +1,6 @@
+// Messages sent between tunnelbroker and a device
+pub mod keys;
+pub mod session;
+
+pub use keys::*;
+pub use session::*;
diff --git a/shared/tunnelbroker_messages/src/messages/session.rs b/shared/tunnelbroker_messages/src/messages/session.rs
new file mode 100644
--- /dev/null
+++ b/shared/tunnelbroker_messages/src/messages/session.rs
@@ -0,0 +1,68 @@
+// Messages sent between tunnelbroker and a device
+
+use serde::{Deserialize, Serialize};
+
+/// The workflow when estabilishing a tunnelbroker connection:
+/// - Client sends SessionRequest
+/// - Tunnelbroker validates access_token with identity service
+/// - Tunnelbroker emits an AMQP message declaring that it has opened a new
+/// connection with a given device, so that the respective tunnelbroker
+/// instance can close the existing connection.
+/// - Tunnelbroker returns a session_id representing that the connection was
+/// accepted
+/// - Tunnelbroker will flush all messages related to device from RabbitMQ.
+/// This must be done first before flushing DynamoDB to prevent duplicated
+/// messages.
+/// - Tunnelbroker flushes all messages in DynamoDB
+/// - Tunnelbroker orders messages by creation date (oldest first), and sends
+/// messages to device
+/// - Tunnelbroker then polls for incoming messages from device
+
+#[derive(Serialize, Deserialize, Debug, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub enum DeviceTypes {
+ Mobile,
+ Web,
+ Keyserver,
+}
+
+/// Message sent by a client to tunnelbroker to initiate a websocket
+/// session. Tunnelbroker will then validate the access token with identity
+/// service before continuing with the request.
+#[derive(Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub struct SessionRequest {
+ pub device_id: String,
+ pub access_token: String,
+ pub notify_token: Option<String>,
+ pub device_type: DeviceTypes,
+ pub device_app_version: Option<String>,
+ pub device_os: Option<String>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct SessionResponse {
+ pub session_id: String,
+}
+
+#[cfg(test)]
+mod session_tests {
+ use super::*;
+
+ #[test]
+ fn test_session_deserialization() {
+ let example_payload = r#"{
+ "type": "sessionRequest",
+ "accessToken": "xkdeifjsld",
+ "deviceId": "foo",
+ "deviceType": "keyserver"
+ }"#;
+
+ let request =
+ serde_json::from_str::<SessionRequest>(example_payload).unwrap();
+ assert_eq!(request.device_id, "foo");
+ assert_eq!(request.access_token, "xkdeifjsld");
+ assert_eq!(request.device_os, None);
+ assert_eq!(request.device_type, DeviceTypes::Keyserver);
+ }
+}