Symbol<55>.
KalshiMD does not support message retransmission. Use ResetSeqNumFlag<141>=Y on Logon.
Message Flow
Market Data Request (35=V)
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 263 | SubscriptionRequestType | Char | Y | 0=Snapshot, 1=Snapshot plus updates, 2=Disable previous snapshot plus update request |
| 146 | NoRelatedSym | Integer | C | Number of 55=Symbol entries in the repeating group that follows. Required for 263=0 and 263=1. For 263=2, the listed symbols are unsubscribed; omit to cancel all of the session’s subscriptions. |
| 55 | Symbol | String | C | Repeating group field. The market tickers to subscribe to or cancel. |
Example snapshot request
Example snapshot-plus-updates subscription
Example cancel a symbol
Example cancel all subscriptions
Market Data Snapshot Full Refresh (35=W)
Sent in response to a snapshot request and immediately after a snapshot-plus-updates subscription is accepted. Correlate bySymbol<55>.
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 55 | Symbol | String | Y | Market ticker. |
| 268 | NoMDEntries | Integer | Y | Number of book levels. |
| 269 | MDEntryType | Char | Y | Repeating group field. 0=Bid, 1=Offer |
| 270 | MDEntryPx | Price | Y | Book level price in dollars. |
| 271 | MDEntrySize | Quantity | Y | Book level size in contracts. |
Example snapshot response
Market Data Incremental Refresh (35=X)
Sent after a subscribed market’s aggregated book levels change or a trade occurs. Correlate bySymbol<55> on each entry.
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 268 | NoMDEntries | Integer | Y | Number of market data entries. |
| 279 | MDUpdateAction | Char | Y | Repeating group field. 0=New, 1=Change, 2=Delete. |
| 55 | Symbol | String | Y | Repeating group field. Market ticker. |
| 269 | MDEntryType | Char | Y | Repeating group field. 0=Bid, 1=Offer, 2=Trade |
| 270 | MDEntryPx | Price | Y | Price in dollars. |
| 271 | MDEntrySize | Quantity | Y | Size in contracts. |
| 2446 | AggressorSide | Char | C | Trade entries only. 1=Buy, 2=Sell. |
Example incremental update
Example trade update
Market Data Request Reject (35=Y)
Sent when a market data request cannot be accepted. Unknown market tickers are not currently rejected; the server sends an empty snapshot if it has no order book for the requested symbol.| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 281 | MDReqRejReason | Char | N | Reject reason. |
| 58 | Text | String | N | Human-readable rejection detail. |
Common Reject Reasons (281)
2=Insufficient bandwidth, including request or session symbol limits4=UnsupportedSubscriptionRequestType
Security Status
KalshiMD also streams per-market trading-status changes as SecurityStatus<35=f>. Subscribe by Symbol<55> with SecurityStatusRequest<35=e>. Updates are changes-only; no initial status is sent on subscribe.
Security Status Request (35=e)
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 263 | SubscriptionRequestType | Char | Y | 1=Subscribe, 2=Unsubscribe. |
| 55 | Symbol | String | Y | The single market ticker to subscribe to or unsubscribe. |
Example subscribe
Example unsubscribe
Security Status (35=f)
Streamed when a subscribed market changes trading state. Correlate bySymbol<55>.
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 55 | Symbol | String | Y | Market ticker. |
| 326 | SecurityTradingStatus | Int | Y | See Trading Status Lifecycle. |
Example trading halt
Trading Status Lifecycle (326)
3=Resume: the market was activated and is open for trading2=Trading halt: the market was deactivated100=Kalshi determined: the market was determined; trading has ended and the result is known101=Kalshi settled: the market settled. The subscription for that symbol is then dropped.