feat(protocol): add update subscription message type

lazer/sdk/js/examples/index.ts

@@ -38,4 +38,14 @@ client.ws.addEventListener("open", () => {
     channel: "fixed_rate@200ms",
     jsonBinaryEncoding: "hex",
   });
+
+  // Example: Update an existing subscription
+  setTimeout(() => {
+    client.send({
+      type: "updateSubscription",
+      subscriptionId: 1,
+      priceFeedIds: [1, 2, 3],
+      properties: ["price", "bestBidPrice"],
+    });
+  }, 2000); // Wait 2 seconds before updating
 });

lazer/sdk/js/src/protocol.ts

@@ -19,6 +19,12 @@ export type Request =
   | {
       type: "unsubscribe";
       subscriptionId: number;
+    }
+  | {
+      type: "updateSubscription";
+      subscriptionId: number;
+      priceFeedIds: number[];
+      properties: PriceFeedProperty[];
     };
 
 export type ParsedFeedPayload = {

lazer/sdk/rust/protocol/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyth-lazer-protocol"
-version = "0.1.3"
+version = "0.1.4"
 edition = "2021"
 description = "Pyth Lazer SDK - protocol types."
 license = "Apache-2.0"

lazer/sdk/rust/protocol/src/subscription.rs

@@ -14,6 +14,7 @@ use {
 pub enum Request {
     Subscribe(SubscribeRequest),
     Unsubscribe(UnsubscribeRequest),
+    UpdateSubscription(UpdateSubscriptionRequest),
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
@@ -33,6 +34,20 @@ pub struct UnsubscribeRequest {
     pub subscription_id: SubscriptionId,
 }
 
+/// A request to update an existing subscription with new parameters.
+/// This is idempotent - the new parameters completely replace the old ones.
+/// The subscription parameters include:
+/// - price_feed_ids: List of price feeds to subscribe to
+/// - properties: List of properties to include in updates (e.g., price, confidence, timestamp)
+///   These properties determine what data fields will be included in price feed updates
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateSubscriptionRequest {
+    pub subscription_id: SubscriptionId,
+    #[serde(flatten)]
+    pub params: SubscriptionParams,
+}
+
 /// A response sent from the server to the client.
 #[derive(Debug, Clone, Serialize, Deserialize, From)]
 #[serde(tag = "type")]