diff --git a/api-demo/src/demo/envoy.rs b/api-demo/src/demo/envoy.rs
index 7a0e342..913064a 100644
--- a/api-demo/src/demo/envoy.rs
+++ b/api-demo/src/demo/envoy.rs
@@ -72,7 +72,11 @@ impl Envoy {
         loop {
             chapter_title("💸 Envoy tells Passport the USD exchange rate.");
             let msg = EnvoyMessage::new(
-                QuantumLinkMessage::ExchangeRate(ExchangeRate::new("USD", 65432.21)),
+                QuantumLinkMessage::ExchangeRate(ExchangeRate {
+                    currency_code: String::from("USD"),
+                    rate: 65432.21,
+                    timestamp: 0,
+                }),
                 12345,
             );
 
diff --git a/api/src/api/fx.rs b/api/src/api/fx.rs
index 6251d1a..bec1a35 100644
--- a/api/src/api/fx.rs
+++ b/api/src/api/fx.rs
@@ -6,21 +6,22 @@ pub struct ExchangeRate {
     pub currency_code: String,
     #[n(1)]
     pub rate: f32,
+    #[n(2)]
+    pub timestamp: u64,
 }
 
-impl ExchangeRate {
-    pub fn new(currency_code: &str, rate: f32) -> Self {
-        Self {
-            currency_code: currency_code.to_string(),
-            rate,
-        }
-    }
-
-    pub fn currency_code(&self) -> &str {
-        &self.currency_code
-    }
+#[quantum_link]
+pub struct ExchangeRateHistory {
+    #[n(0)]
+    pub history: Vec<PricePoint>,
+    #[n(1)]
+    pub currency_code: String,
+}
 
-    pub fn rate(&self) -> f32 {
-        self.rate
-    }
+#[quantum_link]
+pub struct PricePoint {
+    #[n(0)]
+    pub rate: f32,
+    #[n(1)]
+    pub timestamp: u64,
 }
diff --git a/api/src/api/message.rs b/api/src/api/message.rs
index 4a3c020..f9eca59 100644
--- a/api/src/api/message.rs
+++ b/api/src/api/message.rs
@@ -14,7 +14,7 @@ use crate::{
         FirmwareFetchEvent, FirmwareFetchRequest, FirmwareUpdateCheckRequest,
         FirmwareUpdateCheckResponse, FirmwareUpdateResult,
     },
-    fx::ExchangeRate,
+    fx::{ExchangeRate, ExchangeRateHistory},
     pairing::{PairingRequest, PairingResponse},
     scv::SecurityCheck,
     status::{DeviceStatus, EnvoyStatus},
@@ -74,6 +74,9 @@ impl PassportMessage {
 pub enum QuantumLinkMessage {
     #[n(0)]
     ExchangeRate(#[n(0)] ExchangeRate),
+    #[n(26)]
+    ExchangeRateHistory(#[n(0)] ExchangeRateHistory),
+
     #[n(1)]
     FirmwareUpdateCheckRequest(#[n(0)] FirmwareUpdateCheckRequest),
     #[n(2)]
diff --git a/api/src/api/quantum_link.rs b/api/src/api/quantum_link.rs
index 07cb0e0..75895dc 100644
--- a/api/src/api/quantum_link.rs
+++ b/api/src/api/quantum_link.rs
@@ -256,7 +256,11 @@ mod tests {
 
     #[test]
     fn test_encode_decode_quantumlink_message() {
-        let fx_rate = ExchangeRate::new("USD", 0.85);
+        let fx_rate = ExchangeRate {
+            currency_code: String::from("USD"),
+            rate: 0.85,
+            timestamp: 0,
+        };
         let original_message = QuantumLinkMessage::ExchangeRate(fx_rate.clone());
 
         // Encode the message
@@ -271,7 +275,7 @@ mod tests {
         };
 
         // Assert that the original and decoded messages are the same
-        assert_eq!(fx_rate.rate(), fx_rate_decoded.rate());
+        assert_eq!(fx_rate.rate, fx_rate_decoded.rate);
     }
 
     #[test]
@@ -279,7 +283,11 @@ mod tests {
         let envoy = QuantumLinkIdentity::generate();
         let passport = QuantumLinkIdentity::generate();
 
-        let fx_rate = ExchangeRate::new("USD", 0.85);
+        let fx_rate = ExchangeRate {
+            currency_code: String::from("USD"),
+            rate: 0.85,
+            timestamp: 0,
+        };
         let original_message = EnvoyMessage {
             message: QuantumLinkMessage::ExchangeRate(fx_rate.clone()),
             timestamp: 123456,
@@ -302,7 +310,7 @@ mod tests {
         };
 
         // Assert that the original and decoded messages are the same
-        assert_eq!(fx_rate.rate(), fx_rate_decoded.rate());
+        assert_eq!(fx_rate.rate, fx_rate_decoded.rate);
     }
 
     #[test]
@@ -325,7 +333,11 @@ mod tests {
         let passport = QuantumLinkIdentity::generate();
         let mut arid_cache = ARIDCache::new();
 
-        let fx_rate = ExchangeRate::new("USD", 0.85);
+        let fx_rate = ExchangeRate {
+            currency_code: String::from("USD"),
+            rate: 0.85,
+            timestamp: 0,
+        };
         let original_message = EnvoyMessage {
             message: QuantumLinkMessage::ExchangeRate(fx_rate.clone()),
             timestamp: 123456,
@@ -366,7 +378,11 @@ mod tests {
         let passport = QuantumLinkIdentity::generate();
 
         // Create and seal multiple messages
-        let fx_rate = ExchangeRate::new("USD", 0.85);
+        let fx_rate = ExchangeRate {
+            currency_code: String::from("USD"),
+            rate: 0.85,
+            timestamp: 0,
+        };
         let message1 = EnvoyMessage {
             message: QuantumLinkMessage::ExchangeRate(fx_rate.clone()),
             timestamp: 123456,
@@ -439,7 +455,11 @@ fn test_replay_check() {
     let envoy = QuantumLinkIdentity::generate();
     let passport = QuantumLinkIdentity::generate();
 
-    let fx_rate = ExchangeRate::new("USD", 0.85);
+    let fx_rate = ExchangeRate {
+        currency_code: String::from("USD"),
+        rate: 0.85,
+        timestamp: 0,
+    };
     let message = EnvoyMessage {
         message: QuantumLinkMessage::ExchangeRate(fx_rate),
         timestamp: 123456,