AsyncAPI channel · Kalshi
· Kalshi WebSocket Streaming API
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Single multiplexed WebSocket endpoint. Clients send subscribe / unsubscribe / update_subscription commands and receive channel messages and acknowledgements over the same connection.
Send a command frame (subscribe, unsubscribe, update_subscription).
subscribe
receiveServerMessage
Receive channel messages and control replies from Kalshi.
Messages
SubscribeCommand
Subscribe to one or more channels.
Content-Type:
UnsubscribeCommand
Unsubscribe Command
Content-Type:
UpdateSubscriptionCommand
Add or remove markets from an existing subscription, or fetch a snapshot.
Content-Type:
SubscribedAck
Subscribed Acknowledgement
Content-Type:
ErrorMessage
Error
Content-Type:
OrderbookSnapshot
Full orderbook snapshot for a market (orderbook_delta channel).
Content-Type:
OrderbookDelta
Incremental orderbook update.
Content-Type:
Ticker
Market price, volume, and open interest update.
Content-Type:
Trade
Public trade execution notification.
Content-Type:
Fill
Notification of a fill on one of your orders (authenticated).
Content-Type:
UserOrder
Real-time order created/updated notification (authenticated).
Content-Type:
MarketPosition
Real-time per-market position update (authenticated).
Content-Type:
MarketLifecycleV2
Market state transitions and lifecycle events.
Content-Type:
EventLifecycle
Event creation notification.
Content-Type:
EventFeeUpdate
Event-level fee override updates.
Content-Type:
MultivariateMarketLifecycle
Lifecycle notifications for multivariate markets.
Content-Type:
MultivariateLookup
Legacy multivariate lookup notification. Deprecated - predates RFQs and should not be used for new integrations.
Content-Type:
Communications
Real-time RFQ (Request for Quote) and quote lifecycle events (authenticated). Message types: RFQCreated, RFQDeleted, QuoteCreated, QuoteAccepted, QuoteExecuted.
Content-Type:
OrderGroupUpdates
Lifecycle and limit-tracking updates for order groups (authenticated).
Content-Type:
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.