FIX API

FIX (Financial Information eXchange) is a standard electronic messaging protocol for placing orders, receiving order updates, and cancelling orders. BTSE's FIX API is based on the FIX 4.2 specification.

Connection

Environment	Host	Port
Production	`tcp+ssl://fix.btse.com`	`9876`
Testnet	`tcp+ssl://fix.btse.io`	`9876`

Sessions for Spot and Futures are separated using SenderSubID:

SenderSubID	Market
`SPOT`	Spot trading
`FUTURES`	Futures trading

Rate Limits

Group	Message Types	Limit
Auth	Logon (A), Logout (5)	2 per second
General	All other messages	30 per second

When a rate limit is exceeded, a Business Message Reject (j) is returned with BusinessRejectReason: 4 (application not available).

Common Request Attributes

All client messages must include these fields:

Tag	Name	Description
8	BeginString	Must be `FIX.4.2`
9	BodyLength	Body length in bytes
34	MsgSeqNum	Sequence number — starts at 1, increments per message. Duplicates/out-of-order are rejected. Reset on new connection.
35	MsgType	Message type
49	SenderCompID	Client API key
50	SenderSubID	`SPOT` or `FUTURES`
52	SendingTime	Message send time (e.g. `20220916-07:29:07`)
56	TargetCompID	Must be `<Brand />`
10	CheckSum	Message checksum

Messages

Logon (A)

Initiates a FIX session. Must be the first message sent. Only one session per connection.

Tag	Name	Value	Description
35	MsgType	A
95	RawDataLength	96	Length of RawData field
96	RawData	(hex)	HMAC-SHA384 signature. Concatenate with FIX field separator (`0x01`): `SendingTime` + `MsgType` + `MsgSeqNum` + `SenderCompID` + `TargetCompID`, then HMAC-SHA384 with API secret
98	EncryptMethod	0	Must be `0` (None)
108	HeartBtInt	30	Heartbeat interval in seconds. Send heartbeats every N−5 seconds
141	ResetSeqNumFlag	Y	Must be `Y`
5001	ApplyNewSymbolName	Y	Futures only. Enables new symbol names (e.g. `BTC-PERP`). Without this field, only old names (e.g. `BTCPFC`) are accepted

example

Signature computation

// Concatenate fields with FIX separator (0x01):
// SendingTime + 0x01 + MsgType + 0x01 + MsgSeqNum
//   + 0x01 + SenderCompID + 0x01 + TargetCompID
//
// Then: HMAC-SHA384(apiSecret, dataRaw)
// Hex-encode the result → RawData (tag 96)

Heartbeat (0)

Keeps the session alive. Send every N−5 seconds where N is the heartbeat interval set in Logon.

Tag	Name	Value	Description
35	MsgType	0
112	TestReqID	123	If responding to a TestRequest, copy from the TestRequest

Test Request (1)

Requests a heartbeat response.

Tag	Name	Value	Description
35	MsgType	1
112	TestReqID	123	Arbitrary string — echoed back in a Heartbeat

Logout (5)

Terminates the session. The other side responds with another Logout message; connection closes afterwards.

Tag	Name	Value
35	MsgType	5

New Order Single (D)

Submits a new order. Supports Market and Limit orders.

Tag	Name	Value	Description
35	MsgType	D
21	HandlInst	1	Must be `1` (AutomatedExecutionNoIntervention)
11	ClOrdID	order123	Unique client-selected order identifier
55	Symbol	BTC-USD	Symbol name
40	OrdType	2	`1`: Market · `2`: Limit
38	OrderQty	1.1	Order size in base units (required for Limit and Market sell)
44	Price	18000	Limit or Market buy price (required for Limit and Market buy)
54	Side	1	`1`: Buy · `2`: Sell
59	TimeInForce	1	`1`: GTC · `3`: IOC · `4`: FOK · `a`: 30s · `b`: 5min · `c`: 1h · `d`: 12h · `e`: 1 week · `f`: 1 month
18	ExecInst	6	Optional: `E`: reduce only · `6`: post only
5002	PositionId	BTC-PERP-USDT	Optional. Position to reduce (Futures)
5003	PositionMode	ONEWAY	Optional. `ONEWAY` (default) · `HEDGE` · `ISOLATED`

On acceptance, an Execution Report (8) is returned.

Order Cancel Request (F)

Requests cancellation of an open order. Provide only one of OrderID or OrigClOrdID.

Tag	Name	Value	Description
35	MsgType	F
37	OrderID	order123	System-assigned order ID
41	OrigClOrdID	order123	Client-assigned order ID
55	Symbol	BTC-USD	Symbol name

Returns an Execution Report (8) on success, or Order Cancel Reject (9) on failure.

Order Cancel Reject (9)

Sent by the server when an Order Cancel Request fails.

Tag	Name	Value	Description
35	MsgType	9
37	OrderID	order123	Copied from cancel request (if provided)
41	OrigClOrdID	order123	Copied from cancel request (if provided)
39	OrdStatus	4	`4`: Already cancelled · `8`: Rejection
102	CxlRejReason	1	`1`: Unknown order · `99`: Other
434	CxlRejResponseTo	1	Always `1`

Order Status Request (H)

Queries order status. Provide only one of OrderID or OrigClOrdID. Use OrderID = * to request all pending orders.

Tag	Name	Value	Description
35	MsgType	H
37	OrderID	order123	Order to query, or `*` for all open orders
41	OrigClOrdID	order123	Client order ID
54	Side	1	`1`: Buy · `2`: Sell
55	Symbol	BTC-USD	Symbol name

Returns an Execution Report (8) with ExecType=I. When no open orders exist, Text (58) returns "No open orders".

Execution Report (8)

Sent by the server when: an order is filled, the order status changes, or in response to New Order Single, Order Cancel Request, or Order Status Request.

Tag	Name	Value	Description
11	ClOrdID	order123	Client order ID
12	Commission	0.002	Trade fee (fill only)
13	CommType	3	Always `3`
14	CumQty	0.4	Cumulative filled quantity
17	ExecID	d840c8…	Execution ID
31	LastPx	7999.25	Fill price (fill only)
32	LastShares	0.4	Fill quantity (fill only)
35	MsgType	8
37	OrderID	d840c8…	System order ID
38	OrderQty	1.2	Original order quantity
39	OrdStatus	0	Current order status (see table below)
44	Price	8000	Original order price
54	Side	1	`1`: Buy · `2`: Sell
55	Symbol	BTC-USD	Symbol name
58	Text	text	Rejection reason description
59	TimeInForce	6	`1`: GTC · `3`: IOC · `4`: FOK · `6`: GTD · `a`–`f`: custom durations
60	TransactTime	20190525-08:26:38.989	Order update timestamp
103	OrdRejReason	11	`11`: UNSUPPORTED_ORDER_CHARACTERISTIC — see Text(58) for details
126	ExpireTime	20190525-08:26:38.989	Required when TimeInForce=GTD and ExpireDate not set
150	ExecType	1	Reason for this message (see table below)
151	LeavesQty	0.8	Remaining open quantity
1057	AggressorIndicator	Y	`Y`: taker · `N`: maker (fill only)
5000	Liquidation	Y	`Y`: on-market liquidation order

ExecType values:

ExecType	Description
0	New order
1	Partially filled
3	Fully filled
4	Order cancelled
5	Order amended
7	Order refund (self-trade)
8	Rejected (response to New Order Single)
I	Order status (response to Order Status Request)

OrdStatus values:

OrdStatus	Description
0	New order
1	Partially filled
3	Fully filled
4	Cancelled
5	Amended
7	Refunded
8	Rejected

Reject (3)

Sent by the server in response to an invalid message.

Tag	Name	Value	Description
35	MsgType	3
45	RefSeqNum	2	Sequence number of rejected message
371	RefTagID	38	Tag number of the rejected field
372	RefMsgType	D	Message type of the rejected message
58	Text	Missing quantity	Human-readable rejection reason
373	SessionRejectReason	1	Code identifying rejection reason

Business Message Reject (j)

Sent when a rate limit is exceeded.

Tag	Name	Example	Description
35	MsgType	j
45	RefSeqNum	11	Sequence number of rejected message
49	SenderCompID	BTSE	Always `<Brand />`
56	TargetCompID	c123...05a	Client API key
57	TargetSubID	SPOT	`SPOT` or `FUTURES`
58	Text	exceeding rate limit	Details
372	RefMsgType	F	Message type of rejected message
380	BusinessRejectReason	4	Always `4`: application not available

Connection​

Rate Limits​

Common Request Attributes​

Messages​

Logon (A)​

Heartbeat (0)​

Test Request (1)​

Logout (5)​

New Order Single (D)​

Order Cancel Request (F)​

Order Cancel Reject (9)​

Order Status Request (H)​

Execution Report (8)​

Reject (3)​

Business Message Reject (j)​