WebSocket Protocol

Ondo’s native WebSocket endpoint and how the SDK discovers it

Ondo exposes a native WebSocket endpoint at wss://api.ondoperps.xyz/ws. The SDK discovers this URL from the wsUrl field in the GET /providers response. If you’re using the SDK, subscribe through Streaming rather than connecting to the endpoint directly.

Per-subscription dex field

When subscribing across providers, the per-subscription field that selects the venue is named dex (not provider). For Ondo the value is ondo.

await ws.subscribe(
  { channel: 'orderbook', dex: 'ondo', marketId: 'BTC-USD.P' },
  (event) => {
    // event.data: orderbook snapshot / updates
  }
);

See SDK / Streaming for the full list of normalized channels and the subscription lifecycle.

Channel mapping

The SDK maps each normalized channel to Ondo’s wire channel name:

Normalized channel	Wire channel	Scope
orderbook	depthBooksPerps	Per market
trades	tradesPerps	Per market
candle	kLinePerps	Per market
marketsContext / marketContext	markPricesPerps and fundingRatesPerps	Per market — both wire channels feed the aggregated context emit
orderUpdates	ordersPerps	Account-wide, authenticated
fills	fillsPerps	Account-wide, authenticated
positions	positionsPerps	Account-wide, authenticated
accountSummary	(none)	Derived client-side from positionsPerps and fillsPerps; not a wire channel of its own, but it reserves the connection’s authenticated-address binding like the channels above
spotBalances	(none)	Ondo publishes no balance channel — the SDK always emits one empty [] snapshot and never subscribes on the wire

Ondo publishes no mid price on either market-data channel, so markPrice stands in for midPrice in the aggregated market context.

Frames

Login — sent once per connection, before the first authenticated subscribe:

{ "op": "login", "args": { "token": "<session JWT>" } }

The venue rejects a second login on the same connection. The SDK reads the JWT from the client-held SIWE session; an absent or expired session throws before a login frame is ever sent, so callers re-run the SIWE login. A dropped socket forgets the login and re-authenticates on reconnect.

Subscribe — sent per channel, and re-sent verbatim on every reconnect:

{ "op": "subscribe", "channel": "depthBooksPerps", "markets": ["BTC-USD.P"] }

resolution is included instead of (or alongside) markets for kLinePerps.

Ping — the literal keep-alive payload the SDK sends on its heartbeat interval:

{"op":"ping"}

One authenticated address per connection

Ondo’s WebSocket authenticates the whole connection, not per-subscription. Once an authenticated channel (orderUpdates, fills, positions, or accountSummary) is subscribed for one address, subscribing an authenticated channel for a different address on the same connection throws — open a new connection per address instead.