WebSocket

const ws = new WebSocket(`wss://rpc.hypedexer.com/hyperevm/${process.env.HYPEDEXER_API_KEY}`);

ws.onopen = () =>
  ws.send(JSON.stringify({ jsonrpc: "2.0", id: 1, method: "eth_subscribe", params: ["newHeads"] }));

ws.onmessage = (e) => {
  const msg = JSON.parse(e.data);
  if (msg.method === "eth_subscription") console.log("block", parseInt(msg.params.result.number, 16));
};

import { createPublicClient, webSocket } from "viem";

const client = createPublicClient({
  transport: webSocket(`wss://rpc.hypedexer.com/hyperevm/${process.env.HYPEDEXER_API_KEY}`),
});

client.watchBlockNumber({ onBlockNumber: (n) => console.log("block", n) });

​

Subscriptions

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Limits and billing

• Connections per account and subscriptions per connection depend on the plan, see Limits & monthly quota. Over the limit, the handshake answers 429 or the subscription is refused with -32005.
• Messages you send are rate-limited and counted like HTTPS calls (eth_subscribe counts 1 request).
• Each notification counts 1 request against the monthly quota (one newHeads event per block, one logs event per matching log). A newHeads subscription on HyperEVM, about one block per second, uses about 2.6M requests a month. Usage is settled every few seconds, not per message.
• When the monthly quota is used up and the API credit balance is empty, the gateway sends an error and closes the connection with code 4402.
• If the chain’s node restarts, the connection closes with code 1012: reconnect and subscribe again.