LegPrice (FIX tag 566)

PriceFIX 4.4FIX 5.0 SP2

LegPrice (tag 566) is a Price field defined in FIX 4.4 and FIX 5.0 SP2. It appears in 5 message types, always optionally.

At a glance

Tag: 566
Name: LegPrice
Datatype: Price (float)
Dialects: FIX 4.4 and FIX 5.0 SP2
Messages: 5

What the specification says

FIX 4.4

Price for leg of a multileg See Price (44) field for description

FIX 5.0 SP2

Price for leg of a multileg

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 566

ExecutionReport · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	187
35	MsgType	8	Execution Report
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
37	OrderID	ORD-10042
17	ExecID	EXEC-88117
150	ExecType	0	New
39	OrdStatus	0	New
54	Side	1	Buy
151	LeavesQty	0
14	CumQty	1000000
6	AvgPx	1.09215
555	NoLegs2 entries	2	repeating group
600	LegSymbol	EXAMPLE
566	LegPrice	1.09210
600	LegSymbol	EXAMPLE
566	LegPrice	1.09210
10	CheckSum	101

Edit and decode it yourself

Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.

Open in the full decoder →

Generated from the FIX 4.4 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 566 appears

Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.

Message	MsgType	FIX 4.4	FIX 5.0 SP2	Where in the message
Advertisement	7	—	Optional	inside InstrmtLegGrp › InstrumentLeg
AllocationInstruction	J	—	Optional	inside InstrmtLegGrp › InstrumentLeg
AllocationInstructionAlert	BM	—	Optional	inside InstrmtLegGrp › InstrumentLeg
AllocationReport	AS	—	Optional	inside InstrmtLegGrp › InstrumentLeg
AssignmentReport	AW	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralAssignment	AY	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralInquiry	BB	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralInquiryAck	BG	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralReport	BA	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralRequest	AX	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CollateralResponse	AZ	—	Optional	inside InstrmtLegGrp › InstrumentLeg
Confirmation	AK	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CrossOrderCancelReplaceRequest	t	—	Optional	inside InstrmtLegGrp › InstrumentLeg
CrossOrderCancelRequest	u	—	Optional	inside InstrmtLegGrp › InstrumentLeg
DerivativeSecurityList	AA	—	Optional	inside RelSymDerivSecGrp › InstrmtLegGrp › InstrumentLeg
DerivativeSecurityListUpdateReport	BR	—	Optional	inside RelSymDerivSecUpdGrp › InstrmtLegGrp › InstrumentLeg
DontKnowTrade	Q	—	Optional	inside InstrmtLegGrp › InstrumentLeg
Email	C	—	Optional	inside InstrmtLegGrp › InstrumentLeg
ExecutionAcknowledgement	BN	—	Optional	inside InstrmtLegGrp › InstrumentLeg
ExecutionReport	8	Optional	Optional	inside the InstrmtLegExecGrp component
IOI	6	—	Optional	inside InstrmtLegIOIGrp › InstrumentLeg
MarketDataIncrementalRefresh	X	—	Optional	inside MDIncGrp › InstrmtLegGrp › InstrumentLeg
MarketDataRequest	V	—	Optional	inside InstrmtMDReqGrp › InstrmtLegGrp › InstrumentLeg
MarketDataSnapshotFullRefresh	W	—	Optional	inside InstrmtLegGrp › InstrumentLeg
MassQuote	i	—	Optional	inside QuotSetGrp › QuotEntryGrp › InstrmtLegGrp › InstrumentLeg
MassQuoteAcknowledgement	b	—	Optional	inside QuotSetAckGrp › QuotEntryAckGrp › InstrmtLegGrp › InstrumentLeg
MultilegOrderCancelReplace	AC	Optional	Optional	inside the LegOrdGrp component
NewOrderCross	s	—	Optional	inside InstrmtLegGrp › InstrumentLeg
NewOrderMultileg	AB	Optional	Optional	inside the LegOrdGrp component
News	B	—	Optional	inside InstrmtLegGrp › InstrumentLeg
PositionMaintenanceReport	AM	—	Optional	inside InstrmtLegGrp › InstrumentLeg
PositionMaintenanceRequest	AL	—	Optional	inside InstrmtLegGrp › InstrumentLeg
PositionReport	AP	—	Optional	inside InstrmtLegGrp › InstrumentLeg
Quote	S	—	Optional	inside LegQuotGrp › InstrumentLeg
QuoteCancel	Z	—	Optional	inside QuotCxlEntriesGrp › InstrmtLegGrp › InstrumentLeg
QuoteRequest	R	—	Optional	inside QuotReqGrp › QuotReqLegsGrp › InstrumentLeg
QuoteRequestReject	AG	—	Optional	inside QuotReqRjctGrp › QuotReqLegsGrp › InstrumentLeg
QuoteResponse	AJ	—	Optional	inside LegQuotGrp › InstrumentLeg
QuoteStatusReport	AI	—	Optional	inside LegQuotStatGrp › InstrumentLeg
QuoteStatusRequest	a	—	Optional	inside InstrmtLegGrp › InstrumentLeg
RFQRequest	AH	—	Optional	inside RFQReqGrp › InstrmtLegGrp › InstrumentLeg
RequestForPositions	AN	—	Optional	inside InstrmtLegGrp › InstrumentLeg
RequestForPositionsAck	AO	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityDefinition	d	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityDefinitionRequest	c	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityDefinitionUpdateReport	BP	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityList	y	—	Optional	inside SecListGrp › InstrmtLegSecListGrp › InstrumentLeg
SecurityListRequest	x	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityListUpdateReport	BK	—	Optional	inside SecLstUpdRelSymGrp › SecLstUpdRelSymsLegGrp › InstrumentLeg
SecurityStatus	f	—	Optional	inside InstrmtLegGrp › InstrumentLeg
SecurityStatusRequest	e	—	Optional	inside InstrmtLegGrp › InstrumentLeg
TradeCaptureReport	AE	Optional	Optional	inside the TrdInstrmtLegGrp component
TradeCaptureReportAck	AR	Optional	Optional	inside the TrdInstrmtLegGrp component
TradeCaptureReportRequest	AD	—	Optional	inside InstrmtLegGrp › InstrumentLeg
TradeCaptureReportRequestAck	AQ	—	Optional	inside InstrmtLegGrp › InstrumentLeg

Wire format

A decimal price. Precision is a venue convention, not a protocol rule, so compare the raw string when exactness matters. @boarteam/fix parses the value as a number and reports parse/invalid-float when it does not lex as one; the raw string is kept so precision and trailing zeros are never lost.

Read tag 566 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix44";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[566];field?.name;   // "LegPrice"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Decode this in your own code

The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.

npm i @boarteam/fix @boarteam/fix-dict-fix44

Try the decoder Source on GitHub