WebSocket Overview
The Vertex WebSocket feed is the real-time interface for consuming pricing and fixture data. It is push-based and low-latency, intended for integration into trading systems, risk engines, and odds displays.
Use REST for catalog discovery and bet placement; use the WebSocket feed for everything that moves.
What the feed delivers
The feed exposes two channels:
| Channel | Delivers | Typical volume |
|---|---|---|
event | Fixture lifecycle and metadata: competition, participants, start time, status | Low |
market | Market definitions, lines, and their selections with current prices, plus stake limits and their changes | Medium |
These are the channels available to a partner API key. The feed carries internal channels that an external key is not entitled to subscribe to. Attempting to subscribe to one is rejected (see Subscriptions).
Timestamps
Every timestamp on the feed is UTC. published_at and updated_at are ISO-8601 with a trailing Z — for example 2026-05-30T14:00:05.123Z.
The single exception is start_time on the event channel. It is still UTC, but it arrives without the Z (2026-05-30T14:00:00), so a parser that assumes local time will silently shift it. See Message Format for how to parse it safely.
When to use WebSocket vs REST
| Use case | Interface |
|---|---|
| Continuous real-time price consumption | WebSocket |
| Initial / bulk load of catalogs (sports, competitions, events) | REST |
| Re-establishing state after a disconnect | REST (re-fetch; the feed has no replay, see Reconnecting) |
| One-off lookup of a single event or market | REST |
| Placing or checking bets | REST (bets are REST-only) |
Connection URL
Connect to /ws and pass your API key as a token query parameter:
wss://trading-ws.vertex-api.com/ws?token=<your-token>
The token is the same key you use for the REST API, supplied differently. See Authentication.
How a session works
- Open the WebSocket connection with your token in the query string. The server authenticates at the handshake and rejects a bad key with HTTP 401 before the connection upgrades.
- Send one or more
subscribemessages to choose channels and optionally filter by event. - Receive a steady stream of update messages for everything you are subscribed to and entitled to. You can optionally probe liveness with an application-level ping (see Heartbeat).
The feed does not replay messages missed while disconnected and has no per-message sequence cursor. Reconnect handling is therefore a re-subscribe, not a resume. See Reconnecting.