LegAllocQty (FIX tag 673)

QtyFIX 4.4FIX 5.0 SP2

LegAllocQty (tag 673) is a Qty field defined in FIX 4.4 and FIX 5.0 SP2. It appears in 2 message types, always optionally.

At a glance

Tag: 673
Name: LegAllocQty
Datatype: Qty (float)
Dialects: FIX 4.4 and FIX 5.0 SP2
Messages: 2

What the specification says

FIX 4.4

Leg allocation quantity. See AllocQty (80) for description and valid values.

FIX 5.0 SP2

Leg allocation quantity.

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

A real message using tag 673

NewOrderMultileg · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	184
35	MsgType	AB	New Order - Multileg
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
54	Side	1	Buy
555	NoLegs1 entry	1	repeating group
600	LegSymbol	EXAMPLE
670	NoLegAllocs2 entries	2	repeating group
671	LegAllocAccount	EXAMPLE
673	LegAllocQty	1000000
671	LegAllocAccount	EXAMPLE
673	LegAllocQty	1000000
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
10	CheckSum	098

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 673 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
ExecutionReport	8	—	Optional	inside InstrmtLegExecGrp › LegPreAllocGrp
MultilegOrderCancelReplace	AC	Optional	Optional	inside LegOrdGrp › LegPreAllocGrp
NewOrderMultileg	AB	Optional	Optional	inside LegOrdGrp › LegPreAllocGrp

Wire format

A decimal quantity. Fractional quantities are legal, which is why this is a float family rather than an integer. @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 673 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[673];field?.name;   // "LegAllocQty"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