Drop Copy Session

This is not a traditional drop copy session. Kalshi’s Drop Copy uses a request-response pattern for querying historical execution reports. For a real-time streaming feed, use a Listener Session on KalshiRT instead.

Lookback window is limited to the last 3 hours. Only ExecutionReport (35=8) messages are returned. Rejects and pending orders (ExecID "-1;-1") are excluded.

Resent messages have new FIX sequence numbers, different from their original numbers on the trading session. Use ExecID to reconcile.

EventResendRequest (35=U1)

Request execution reports within a specified ExecID range.

Tag	Name	Description	Required
21001	BeginExecID	Starting ExecID (inclusive)	Yes
21002	EndExecID	Ending ExecID (inclusive). Defaults to latest ExecID if omitted.	No

Example:

8=FIXT.1.1|35=U1|21001=12345;67890|21002=12350;67895|

EventResendComplete (35=U2)

Sent after all requested events have been resent.

Tag	Name	Description	Required
45	RefSeqNum	MsgSeqNum of the EventResendRequest	Yes
21003	ResendEventCount	Total number of events resent	Yes

EventResendReject (35=U3)

Sent when a resend request cannot be fulfilled.

Tag	Name	Description	Required
45	RefSeqNum	MsgSeqNum of the EventResendRequest	Yes
21004	EventResendRejectReason	Rejection code: `1`=Too many resend requests, `2`=Server error, `3`=BeginExecID too small (outside window), `4`=EndExecID too large	Yes

Overview

REST

WebSockets

FIX

EventResendRequest (35=U1)

EventResendComplete (35=U2)

EventResendReject (35=U3)

​EventResendRequest (35=U1)

​EventResendComplete (35=U2)

​EventResendReject (35=U3)

EventResendRequest (35=U1)

EventResendComplete (35=U2)

EventResendReject (35=U3)