Quickstart

1. Get access

HyperCore streaming is in beta and is enabled per team. To request access, contact [email protected]. Once your team has access, HyperCore appears in your Alchemy dashboard and works with your existing API key.

2. Connect and subscribe

websocat wss://hypercore-mainnet.g.alchemy.com/v2/<API_KEY>

After {"channel":"connected"}, send:

{"method":"subscribe","subscriptionId":"eth-top","subscription":{"type":"bbo","coins":["ETH"]}}

You'll receive an acknowledgement, a snapshot, then an update whenever the best bid or ask changes:

{"channel":"subscriptionResponse","subscriptionId":"eth-top","data":{"type":"bbo","coins":["ETH"]}}
{"seq":1,"channel":"bbo","subscriptionId":"eth-top","data":{"blockNumber":1183716828,"blockTime":1791996538119,"isSnapshot":true,"books":[{"coin":"ETH","bbo":[{"px":"2442.5","sz":"36.3142","n":7},{"px":"2442.6","sz":"237.042","n":44}]}]}}

3. Before going to production

• Reconnect automatically with backoff, and resubscribe after every reconnect. See connection lifecycle.
• Track seq per subscription to catch missed messages.
• Resume fill streams with fromBlock. See replay and recovery.
• Filter with coins or users to keep volume (and cost) down.
• Coming from Hyperliquid's public API? Read migrating from the Hyperliquid API.