FIX Protocol

FIX Implementation Details

Overview

This document describes the Financial Information Exchange (FIX) implementation of the Bakkt order execution protocol. FIX provides an open standard that leverages the development and production efforts of securities transactions and standardizes requirements for accuracy and consistency. NOTE: Messages are in FIX 4.2 format (any exceptions are noted).

Table of Contents

• Data Types
• Message Headers and Trailers
• Session Messages
• Application Messages

📘

Maintenance Window

Bakkt sessions reset daily following a maintenance window when the system is offline. The maintenance window runs from 4:30PM-5:05PM CT, but after some time clients can request to remove this maintenance window to be once a month.

Gateway Messages

After establishing and testing the FIX Gateway Bakkt and the client communicate via session and application messages. Bakkt sends clients the application message configurations during the technical integration process. These messages include the following:

• NewOrderSingle - Clients submit investor cryptocurrency orders via this message. Clients can submit orders on any tradeable cryptocurrency symbol via a single session. Bakkt only supports market orders via this message.
• Execution Report - This is how order acknowledgements are communicated from Bakkt to the client along with any cancels, rejects, or order fills for clients' investors.
• OrderCancelRequest - Clients submit order cancellations using this message.
• OrderCancelReject - If Bakkt does not accept an order, or if there are insufficient funds to reconcile a cryptocurrency purchase, this message contains the order cancellation details.

---

Data Types

Data types are the attributes that Bakkt uses to interpret data in a consistent format with correct values so that each attribute performs as expected. Bakkt supports the following data types in its FIX implementation. NOTE: ASCII stands for American Standard Code for Information Interchange and provides the numerical representation of characters for formatting purposes.

Type	Description
Int	Signed 64-bit capacity integer (consists of ASCII characters '-' and '0' - '9'); only the first character can be a minus sign if the integer value is negative; leading zeroes are allowed but not spaces
Float	Signed decimal value (consists of ASCII characters '-', '.' and '0' - '9'); only the first character may be a minus sign if the decimal value is negative; leading zeroes are allowed; users may omit trailing zeroes after the decimal point or leading zeroes before the decimal point (supports up to nine decimal places and 16 significant digits)
Char	Single character of any alphanumeric value except the delimiter (ASCII 1-SOH); values are case-sensitive
Boolean	A char field containing only 'Y' or 'N' (for Yes or No)
String	A sequence of one or more characters consisting of any alphanumeric value except the delimiter
Date	Calendar date represented in YYYYMMDD format (e.g., 20221103)
Utctimestamp	Date/Time combination represented in UTC/GMT with millisecond precision using the format YYYYMMDD-HH-MM-SS.sss

---

Message Headers and Trailers

The following definitions provide information for standard FIX headers and trailers that clients send to Bakkt. NOTE: The SenderCompID and TargetCompID field values switch for messages that go from Bakkt to clients.

Standard Message Header

Tag	Field Name	Type	Definition	Optional/Required
8	BeginString	String	For FIX 4.2 the must be the first field in the message	Required
9	BodyLength	Int	Message length (in bytes) and must be the second field in the message; Bakkt rejects messages that are more than 2048 bytes in length	Required
35	MsgType	String	The type of FIX message	Required
34	MsgSeqNum	Int	The session sequence number; starts at 1 every day following the maintenance window	Required
49	SenderCompID	String	The Bakkt-provided session endpoint identifier bound to a specific legal entity	Required
52	SendingTime	Utctimestamp	UTC/GMT with millisecond precision	Required
56	TargetCompID	String	Must always be the string AC for Bakkt	Required

Standard Message Trailer

Tag	Field Name	Type	Definition	Optional/Required
10	CheckSum	Int	Three-character integer of all characters in the message up to and including the delimiter preceding the CheckSum field	Required

---

Session Messages

Bakkt supports the following messages to establish, maintain, and terminate a client connection.

Message	Description
Logon	Clients initiate a Logon with the Bakkt-provided username and password fields. Clients cannot reset sequence numbers as part of the Logon process. Heartbeats must be in the range of five to 60 seconds. Clients must logon with a MsgSeqNum of 1 following the maintenance window.
Logout	Clients may initiate a Logout any time. Bakkt then acknowledges the initiation with a Logout of its own. Bakkt may issue a Logout followed by a disconnect in the following situations: – Receiving a message (including a Logon) with a MsgSeqNum that is too low – Failing to parse messages due to invalid BeginString, BodyLength, CheckSum or for bad data formatting, missing delimiters, or unsupported tag – Invalid HeartBtInt, Password, or EncryptMethod during Logon
Heartbeat/TestRequest	Bakkt issues heartbeats (i.e., systematic connection tests) periodically during periods of inactivity to ensure connection integrity. Bakkt issues clients a TestRequest message if it does not receive an update within the heartbeat interval plus 100 milliseconds; it terminates the connection if it still does not receive a response within another heartbeat interval.
Session Level Reject	Bakkt issues a Session Level Reject when it receives a message, but the Application level cannot process it. The reasons for issuing a Session Level Reject include: – Unexpected or invalid MsgType post Logon – Missing required fields/tags.
Resend Request	Both the client and Bakkt can issue this message as part of initialization or to recover lost messages mid-stream.
Sequence Reset	Both the client and Bakkt can issue this message as part of the message recovery process. Bakkt only supports GapFill sequence resets.

Logon

See the following definitions of Logon submitted by the client to Bakkt. If successful, Bakkt responds with a Logon acknowledgement with the password omitted. NOTE: The asterisk (*) indicates user-defined fields from FIX 4.4.

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = A	Required
98	EncryptMethod	Int	Must always be 0; corresponds to "no encryption"	Required
108	HeartbeatInt	Int	Must be between five and 60 seconds	Required
*553	Username	String	Bakkt-provided username for this session; required on Logon; submitted by the client	Required
*554	Password	String	Bakkt-provided password for this session; required on Logon; submitted by the client	Required
	Standard Trailer			Required

Logout

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 5	Required
58	Text	String	Free form text for logout	Optional
	Standard Trailer			Required

Heartbeat

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 0	Required
112	TestReqID	String	Required if sending a heartbeat in response to a TestRequest	Required
	Standard Trailer			Required

TestRequest

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 1	Required
112	TestReqID	String	Identifier set by initiator	Required
	Standard Trailer			Required

ResendRequest

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 2	Required
7	BeginSeqNo	Int	Sequence number of first message to recover; use this value in Tag 34 (MsgSeqNum) of the first resent message	Required
16	EndSeqNo	Int	Sequence number of last message in the range to resend; use this value in Tag 34 (MsgSeqNum) of the last message; if the request is for a single message, then Tag 7 (BeginSeqNo) must equal Tag 16 (EndSeqNo) For each resend request, the Bakkt system does not allow the client system to request more than 10,000 messages; in response to the resend request from the client system, Bakkt sends all messages for the requested range up to the last 10,000 messages	Required
	Standard Trailer			Required

Sequence Reset

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 4	Required
123	GapFillFlag	Boolean	Must be ‘Y’; Bakkt does not support sequence number resets	Required
36	NewSeqNo	Int	Sequence number of next message to send	Required
	Standard Trailer			Required

Session Level Reject

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 3	Required
45	RefSeqNum	Int	The sequence number of the received message that triggers the rejection	Required
58	Text	String	A message explaining the rejection reason	Optional
371	RefTagID	Int	The tag number of the problem field in the received message that triggers the rejection	Optional
372	RefMsgType	String	The MsgType of the received message that triggers the reject	Optional
373	SessionRejectReason	Int	A code indicating the reason for the rejection	Optional
	Standard Trailer			Required

Business Level Reject

The system rejects messages as Business Level Rejects when they are missing conditionally required fields.

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = j	Required
45	RefSeqNum	Int	The sequence number of received message that triggers the rejection	Optional
58	Text	String	A message explaining the reason for the rejection	Optional
372	RefMsgType	String	MsgType of the received message that triggers the rejection	Required
380	BusinessRejectReason	String	A code indicating the reason for the rejection	Required
	Standard Trailer			Required

---

Application Messages

The Bakkt system sends clients the following application message configurations for order execution sessions during the technical integration process.

Message	Description
NewOrderSingle	Clients submit investor cryptocurrency and NFT orders via this message. Clients can submit orders on any tradeable symbol via a single session. The Bakkt system supports market and limit orders via this message.
Execution Report	This message includes the order acknowledgement from the Bakkt system to the client along with any cancels, rejects, or order fills for clients' investors.
OrderCancelRequest	Clients submit order cancellations using this message.
OrderCancelReject	If the Bakkt system does not accept an order, or if there are insufficient funds to reconcile a cryptocurrency purchase, this message contains the order cancellation details.

NewOrderSingle

Clients submit NewOrderSingle messages to Bakkt. The system allows clients to quote cryptocurrency orders in two ways:

• Notional – Use Tag 152 in the CashOrderQty field (e.g., the customer buys $100 of BTCUSD by entering 100 for Tag 152 in the CashOrderQty field)
• Absolute – Use Tag 38 in the OrderQty field (e.g., the customer sells .05 BTCUSD by entering .05 for Tag 38 in the OrderQty field)

NOTE: The asterisk (*) indicates a conditionally-required field.

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = D	Required
1	Account	String	The Bakkt client account identifier (e.g., ABC12345)	Required
11	ClOrdID	String	The client-specified unique order identifier; The ClOrdID must not exceed 64 characters in length	Required
15	Currency	String	For NFT sell orders, the currency of Price (must be the same as the NFT's native cryptocurrency); for NFT buy orders, the currency is implicitly USD, so do not specify this field	*Optional
21	HandlInst	Char	Must always be '1' (for automatic execution, private, and no broker)	Required
55	Symbol	String	The Bakkt-tradeable symbol identifier	Required
54	Side	Char	The market side of the order; acceptable values include '1' (for Buy) and '2' (for Sell)	Required
44	Price	Float	This field is for the price (e.g., “23.0”=”23.0000”=”23”); all float fields must accommodate up to fifteen significant digits	Required
38	OrderQty	Float	The order size in number of product units; Bakkt requires either OrderQty<3> or CashOrderQty<152>	*Optional
40	OrdType	Char	The type of order (market or limit); acceptable values are: 1 (Market Order) 2 (Limit Order)	Required
59	TimeInForce	Char	Time-in-Force is the life expectancy of an order; the platform currently supports the following: 0 (Day) 1 (Good til Cancel) 3 (Immediate or Cancel)	Required
60	TransactTime	Utctimestamp	The UTC/GMT time that the source system submits the order in millisecond precision	Required
152	CashOrderQty	Float	The order size quoted as a notional cash quantity; Bakkt requires either OrderQty<3> or CashOrderQty<152>	*Optional
	Standard Trailer			Required

Order Cancel Request

This message requests the cancellation of an order.

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = F	Required
41	OrigClOrdID	String	The client-specified unique order identifier	Required
11	ClOrdID	String	The client-specified unique cancel request identifier	Required
37	OrderID	String	The Bakkt-generated order identifier returned in the acknowledgement	Required
55	Symbol	String	The Bakkt-tradeable symbol identifier from NewOrderSingle	Required
54	Side	Char	The market side of original order per NewOrderSingle; acceptable values include '1' (for Buy) and '2' (for Sell)	Required
60	TransactTime	Utctimestamp	The time the client generates the cancel request	Required
	Standard Trailer			Required

Order Cancel Reject

Bakkt may reject a cancel request by responding to the Order Cancel Request with an Order Cancel Reject message.

Tag	Field Name	Type	Definition	Optional/Required
	Standard Header		MsgType = 9	Required
41	OrigClOrdID	String	The ClOrdID of the order to cancel	Required
11	ClOrdID	String	The client-specified unique cancel request identifier	Required
37	OrderID	String	The Bakkt-generated order identifier returned in the acknowledgment	Required
39	OrdStatus	Char	The current status of the order	Required
58	Text	String	This field offers text explaining the rejection	Required
60	TransactTime	Utctimestamp	The time that Bakkt generates the rejection of the order cancellation request	Required
	Standard Trailer			Required