update readme

Author: cctdaniel

apps/hermes/client/js/README.md

@@ -1,4 +1,4 @@
-# Price Service Client
+# Hermes Client
 
 [Pyth Network](https://pyth.network/) provides real-time pricing data in a variety of asset classes, including cryptocurrency, equities, FX and commodities.
 These prices are available either via HTTP or WebSocket from [Hermes](/apps/hermes).
@@ -9,70 +9,67 @@ This library is a client for interacting with Hermes, allowing your application
 ### npm
 
 ```
-$ npm install --save @pythnetwork/price-service-client
+$ npm install --save @pythnetwork/hermes-client
 ```
 
 ### Yarn
 
 ```
-$ yarn add @pythnetwork/price-service-client
+$ yarn add @pythnetwork/hermes-client
 ```
 
 ## Quickstart
 
 Typical usage of the connection is along the following lines:
 
 ```typescript
-const connection = new HermesConnection("https://hermes.pyth.network", {
-  priceFeedRequestConfig: {
-    // Provide this option to retrieve signed price updates for on-chain contracts.
-    // Ignore this option for off-chain use.
-    binary: true,
-  },
-}); // See Hermes endpoints section below for other endpoints
+const connection = new HermesConnection("https://hermes.pyth.network", {}); // See Hermes endpoints section below for other endpoints
 
 const priceIds = [
   // You can find the ids of prices at https://pyth.network/developers/price-feed-ids
   "0xe62df6c8b4a85fe1a67db44dc12de5db330f7ac66b72dc658afedf0f4a415b43", // BTC/USD price id
   "0xff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace", // ETH/USD price id
 ];
 
-// Get the latest values of the price feeds as json objects.
-// If you set `binary: true` above, then this method also returns signed price updates for the on-chain Pyth contract.
-const currentPrices = await connection.getLatestPriceFeeds(priceIds);
+// Get price feeds
+const priceFeeds = await connection.getPriceFeeds("btc", "crypto");
+console.log(priceFeeds);
 
-// You can also call this function to get price updates for the on-chain contract directly.
-const priceUpdateData = await connection.getLatestVaas(priceIds);
+// Latest price updates
+const priceUpdates = await connection.getLatestPriceUpdates(priceIds);
+console.log(priceUpdates);
 ```
 
-`HermesConnection` also allows subscribing to real-time price updates over a websocket connection:
+`HermesConnection` also allows subscribing to real-time price updates over a Server-Sent Events (SSE) connection:
 
 ```typescript
-connection.subscribePriceFeedUpdates(priceIds, (priceFeed) => {
-  // priceFeed here is the same as returned by getLatestPriceFeeds above.
-  // It will include signed price updates if the binary option was provided to the connection constructor.
-  console.log(
-    `Received update for ${priceFeed.id}: ${priceFeed.getPriceNoOlderThan(60)}`
-  );
-});
-
-// When using the subscription, make sure to close the websocket upon termination to finish the process gracefully.
-setTimeout(() => {
-  connection.closeWebSocket();
-}, 60000);
+// Streaming price updates
+const eventSource = await connection.getStreamingPriceUpdates(priceIds);
+
+eventSource.onmessage = (event) => {
+  console.log("Received price update:", event.data);
+};
+
+eventSource.onerror = (error) => {
+  console.error("Error receiving updates:", error);
+  eventSource.close();
+};
+
+await sleep(5000);
+
+// To stop listening to the updates, you can call eventSource.close();
+console.log("Closing event source.");
+eventSource.close();
 ```
 
 ### On-chain Applications
 
 On-chain applications will need to submit the price updates returned by Hermes to the Pyth contract on their blockchain.
-These applications should pass the `binary: true` option to the constructor as shown above, to ensure that all methods on `HermesConnection` return the required information.
-This option will add a `vaa` field to `PriceFeed` that represents a signed price update.
-The `vaa` is a binary blob serialized as a base64 string.
-Depending on the blockchain, you may need to reformat this into hex or another format before submitting it to the Pyth contract.
+By default, these updates are returned as binary data and is serialized as either a base64 string or a hex string depending on the chosen encoding. This binary data will need to be submitted to the Pyth contract.
 
 ### Examples
 
-The [HermesClient](./src/examples/HermesClient.ts) example demonstrates both the HTTP and websocket APIs described above.
+The [HermesClient](./src/examples/HermesClient.ts) example demonstrates both the examples above.
 You can run it with `npm run example`.
 A full command that prints BTC and ETH price feeds, in the testnet network, looks like so: