> ## Documentation Index > Fetch the complete documentation index at: https://docs.kalshi.com/llms.txt > Use this file to discover all available pages before exploring further. # Common Components > Standard header, trailer, and shared components across all FIX messages Kalshi's FIX implementation uses **FIXT.1.1** with application version **FIX50SP2**. Members on the Premier tier or above have FIX access by default. For all other tiers, contact [institutional@kalshi.com](mailto:institutional@kalshi.com) to inquire about access. ## FIX Dictionary Download the Kalshi-specific FIX dictionary for import into your FIX engine: * [Kalshi FIX Dictionary (XML)](https://assets.kalshi.com/fix/kalshi-fix-dictionary.xml) If you are using a FIX engine such as [QuickFIX/J](https://www.quickfixj.org/), [QuickFIX/N](https://quickfixn.readthedocs.io/), or [quickfix-go](https://github.com/quickfixgo/quickfix), the standard header and trailer fields below are managed automatically by the library. This section is primarily a reference for custom implementations or debugging. ## Standard Header Every FIX message begins with the following fields: | Tag | Name | Type | Required | Description | | --- | --------------- | ------------ | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 8 | BeginString | String | Y | Always `FIXT.1.1` | | 9 | BodyLength | Int | Y | Message length in bytes, from the tag after BodyLength up to (but not including) the CheckSum field. Must be the second field. | | 35 | MsgType | String | Y | Identifies the message type. Must be the third field. | | 49 | SenderCompID | String | Y | Your FIX API Key (UUID format) when sending; `Kalshi` when receiving. | | 56 | TargetCompID | String | Y | Session identifier (e.g. `KalshiRT`, `KalshiNR`) when sending; your API key when receiving. | | 34 | MsgSeqNum | Int | Y | Monotonically increasing sequence number, starting at 1. | | 52 | SendingTime | UTCTimestamp | Y | Time the message was sent, in UTC. Format: `YYYYMMDD-HH:MM:SS.mmm`. Must be within 30 seconds of server time or the message is rejected (`SessionRejectReason=10`). | | 43 | PossDupFlag | Boolean | N | `Y` if the message is a possible duplicate of a previously sent message (used during retransmission). | | 97 | PossResend | Boolean | N | `Y` if the message may contain information that has already been sent under a different sequence number. | | 122 | OrigSendingTime | UTCTimestamp | N | Original SendingTime of a message being resent. Required when `PossDupFlag=Y`. | ## Standard Trailer Every FIX message ends with: | Tag | Name | Type | Required | Description | | --- | -------- | ------ | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 10 | CheckSum | String | Y | Three-character checksum. Calculated by summing every byte in the message up to (but not including) the CheckSum field, then taking modulo 256. Always three digits, zero-padded (e.g. `007`). | ## Supported MsgTypes ### Session-Level (all sessions) | MsgType | Name | Direction | | ------- | ------------- | ------------------------------ | | A | Logon | Both | | 0 | Heartbeat | Both | | 1 | TestRequest | Both | | 2 | ResendRequest | Both (KalshiRT, KalshiPT only) | | 3 | Reject | Server -> Client | | 4 | SequenceReset | Both (KalshiRT, KalshiPT only) | | 5 | Logout | Both | ### Application-Level #### Order Entry | MsgType | Name | Sessions | Direction | | ------- | ------------------------- | ---------------------------- | ---------------- | | D | NewOrderSingle | KalshiNR, KalshiRT | Client -> Server | | F | OrderCancelRequest | KalshiNR, KalshiRT | Client -> Server | | G | OrderCancelReplaceRequest | KalshiNR, KalshiRT | Client -> Server | | q | OrderMassCancelRequest | KalshiNR | Client -> Server | | 8 | ExecutionReport | KalshiNR, KalshiRT, KalshiDC | Server -> Client | | 9 | OrderCancelReject | KalshiNR, KalshiRT | Server -> Client | | r | OrderMassCancelReport | KalshiNR | Server -> Client | | j | BusinessMessageReject | All | Server -> Client | #### Order Groups | MsgType | Name | Sessions | Direction | | ------- | ------------------ | ------------------ | ---------------- | | UOG | OrderGroupRequest | KalshiNR, KalshiRT | Client -> Server | | UOH | OrderGroupResponse | KalshiNR, KalshiRT | Server -> Client | #### Drop Copy | MsgType | Name | Sessions | Direction | | ------- | ------------------- | -------- | ---------------- | | U1 | EventResendRequest | KalshiDC | Client -> Server | | U2 | EventResendComplete | KalshiDC | Server -> Client | | U3 | EventResendReject | KalshiDC | Server -> Client | After an EventResendRequest, the server replays the matching historical order updates as ExecutionReport (35=8) messages and then sends EventResendComplete (35=U2) or EventResendReject (35=U3). #### Market Data | MsgType | Name | Sessions | Direction | | ------- | ----------------------------- | -------- | ---------------- | | V | MarketDataRequest | KalshiMD | Client -> Server | | W | MarketDataSnapshotFullRefresh | KalshiMD | Server -> Client | | X | MarketDataIncrementalRefresh | KalshiMD | Server -> Client | | Y | MarketDataRequestReject | KalshiMD | Server -> Client | | e | SecurityStatusRequest | KalshiMD | Client -> Server | | f | SecurityStatus | KalshiMD | Server -> Client | #### Post Trade | MsgType | Name | Sessions | Direction | | ------- | ---------------------- | ------------------ | ---------------- | | UMS | MarketSettlementReport | KalshiPT, KalshiRT | Server -> Client | #### RFQ | MsgType | Name | Sessions | Direction | | ------- | ------------------ | ------------------- | ------------------------------------------------------- | | R | QuoteRequest | KalshiRT, KalshiRFQ | KalshiRT: Client -> Server; KalshiRFQ: Server -> Client | | b | QuoteRequestAck | KalshiRT | Server -> Client | | S | Quote | KalshiRT, KalshiRFQ | KalshiRT: Server -> Client; KalshiRFQ: Client -> Server | | AI | QuoteStatusReport | KalshiRFQ | Server -> Client | | Z | QuoteCancel | KalshiRFQ | Client -> Server | | U9 | QuoteCancelStatus | KalshiRFQ | Server -> Client | | AG | QuoteRequestReject | KalshiRT, KalshiRFQ | Server -> Client | | UA | AcceptQuote | KalshiRT | Client -> Server | | UC | AcceptQuoteStatus | KalshiRT | Server -> Client | | U7 | QuoteConfirm | KalshiRFQ | Client -> Server | | U8 | QuoteConfirmStatus | KalshiRFQ | Server -> Client | | UE | RFQCancel | KalshiRT | Client -> Server | | UB | RFQCancelStatus | KalshiRT | Server -> Client |