WebSocket API

HyperLink's WebSocket API for real-time private order, fill, and account updates, plus signed trading actions over one persistent connection to Hyperliquid.

HyperLink's WebSocket API delivers real-time order, fill, and account updates and accepts signed trading actions over one persistent connection. It mirrors Hyperliquid's WebSocket protocol, so existing Hyperliquid tooling works against the HyperLink base URL. Only private user-state channels are streamed; there are no public market-data feeds.

Use WebSocket for live updates or low-latency order entry; use Exchange Methods (POST /exchange) for one-off requests.

Connect

Open an HTTP upgrade to /ws at wss://api.hyperlink.xyz/ws. All messages are JSON text frames; the maximum message size is 1 MiB.

websocat wss://api.hyperlink.xyz/ws

Keep the connection alive with a ping; the server replies on the pong channel:

{ "method": "ping" }

Send signed actions: the post channel

The post channel runs the same signed payload as POST /exchange. Wrap the full /exchange envelope as request.payload. Only type: "action" is supported.

Field	Required	Notes
method	Yes	Must be "post".
id	Yes	Client-chosen u64, echoed back to correlate the response.
request.type	Yes	Must be "action".
request.payload	Yes	The full /exchange envelope (action, signature, nonce, optional expiresAfter / vaultAddress).

Send a GTC limit buy of 0.1 of asset index 0:

{
  "method": "post",
  "id": 1,
  "request": {
    "type": "action",
    "payload": {
      "action": {
        "type": "order",
        "orders": [
          { "a": 0, "b": true, "p": "50000", "s": "0.1", "r": false, "t": { "limit": { "tif": "Gtc" } }, "c": "0x1234567890abcdef1234567890abcdef" }
        ],
        "grouping": "na"
      },
      "signature": { "r": "0x...", "s": "0x...", "v": 27 },
      "nonce": 1712140800000
    }
  }
}

Receive on the post channel with the matching id; the inner payload mirrors the HTTP /exchange response:

{
  "channel": "post",
  "data": {
    "id": 1,
    "response": {
      "type": "action",
      "payload": { "status": "ok", "response": { "type": "order", "data": { "statuses": [ { "resting": { "oid": 77738308 } } ] } } }
    }
  }
}

On a rejected request, response.type is "error". Read queries (for example openOrders) also work over post.

Subscriptions

Subscribe to stream updates for one account. Each subscribe message is signed with the Agent EIP-712 domain, the same signing used for queries (see Authentication & Keys); an SDK builds this for you.

Field	Required	Notes
method	Yes	"subscribe" or "unsubscribe".
subscription.type	Yes	One of the types below.
subscription.user	Yes	Master account address to stream.
subscription.coin	Conditional	Required for activeAssetData; ignored otherwise.
subscription.dex	No	For openOrders only; omit or set "ALL_DEXS".
signature	Yes	Agent-domain signature over the subscription object.
nonce	Yes	Unix time in milliseconds, single-use per signer.

Send:

{
  "method": "subscribe",
  "subscription": { "type": "orderUpdates", "user": "0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb1" },
  "signature": { "r": "0x...", "s": "0x...", "v": 27 },
  "nonce": 1712140800000
}

The server acknowledges on subscriptionResponse, then pushes updates on a channel named after the subscription type:

{
  "channel": "orderUpdates",
  "data": [
    { "order": { "coin": "ETH", "side": "B", "limitPx": "50000", "sz": "0.1", "oid": 77738308, "timestamp": 1712140800123 }, "status": "open", "statusTimestamp": 1712140800123 }
  ]
}

Subscription types

Type	Streams
orderUpdates	Order status changes (open, filled, canceled, rejected).
openOrders	Current open orders across all DEXs.
userFills	Real-time fills.
spotState	Spot token balances.
allDexsClearinghouseState	Perp positions and margin summary across all DEXs.
activeAssetData	Per-asset leverage and margin context. Requires a coin.
userHistoricalOrders	Historical order status changes.
userFundings	Funding payments.
userNonFundingLedgerUpdates	Deposits, withdrawals, transfers.

To stop, send the same subscription object with method: "unsubscribe" (no signature or nonce needed).

Errors

Subscription and frame-level errors return on the error channel; errors tied to a post request return on the post channel with the request's id and response.type: "error".

{ "channel": "error", "data": { "message": "Invalid signature" } }

Common errors: Invalid signature, Invalid nonce: <reason>, Unknown subscription type: <type>, Invalid user address, activeAssetData subscription requires non-empty coin, No matching subscription found, and Too many pending requests. Malformed frames with no id are dropped silently.

Rate limits

The connection enforces per-IP limits on connections, subscriptions, message rate, and in-flight post requests. Exceeding the message rate or connection cap closes the connection; exceeding the in-flight post cap returns "Too many pending requests".

Next steps

• Exchange Methods: the /exchange envelope shared by the post channel.

• Authentication & Keys: EIP-712 domains for actions and subscriptions.