Message catalog - ParlayX API

This page is the quick-reference index for the orderbook stream at wss://wss.parlayx.com/v1/orderbook. Each frame type links to the page that documents it in full. For a guided walkthrough, start with the Quickstart.

Frame conventions

Every server frame is a JSON object with a type, a v: 1 version discriminator, and a serverTimestamp (epoch milliseconds). Every client frame has a type and an optional requestId — a correlation token you choose (any string) that the server echoes on the matching reply, so you can pair async responses with the request that triggered them.

Client → server

`type`	Purpose	Reference
`subscribe`	Create subscriptions for one or more `(market, channel)` pairs.	Subscriptions & markets
`unsubscribe`	Tear down subscriptions by `subscriptionId`.	Subscriptions & markets
`list`	Snapshot every active subscription on this connection.	Subscriptions & markets
`ping`	Application-level keepalive; replies with `pong`.	Connection lifecycle

Server → client

`type`	When	Key fields	Reference
`welcome`	once, on connect	`customerId`, `connectionId`, `activeConnections`, `limits`	Connection lifecycle
`subscribed`	per market on a successful `subscribe`	`market`, `channel`, `subscriptionId`, `snapshotPending`	Subscriptions & markets
`unsubscribed`	per id on `unsubscribe`	`subscriptionId`, `market`, `channel`	Subscriptions & markets
`snapshot`	first book frame, and on every resync	`subscriptionId`, `seq`, `venueTimestamp`, `bids[]`, `asks[]`, `status`	Orderbook channel
`delta`	book changes	`subscriptionId`, `seq`, `venueTimestamp`, `changes[]`	Orderbook channel
`trade`	a fill on a trade-channel subscription	`subscriptionId`, `seq`, `venueTimestamp`, `price`, `size`, `takerSide`, `tradeId?`	Trades channel
`status`	subscription state change	`subscriptionId`, `state`, `reason?`	Errors & status
`error`	a request or subscription failed	`code`, `message`, plus addressing fields	Errors & status
`pong`	reply to `ping`	`requestId?`	Connection lifecycle
`subscriptions`	reply to `list`	`subscriptions[]`	Subscriptions & markets
`goodbye`	just before the server closes the socket	`reason`	Connection lifecycle

​Frame conventions

​Client → server

​Server → client

Frame conventions

Client → server

Server → client