MultilegModel (FIX tag 1377)

intFIX 5.0 SP2

MultilegModel (tag 1377) is an int field defined in FIX 5.0 SP2. It appears in 10 message types, always optionally. It is an enumerated field with 3 defined values.

At a glance

Tag: 1377
Name: MultilegModel
Datatype: int
Dialects: FIX 5.0 SP2
Messages: 10
Valid values: 3

What the specification says

Specifies the type of multileg order. Defines whether the security is pre-defined or user-defined. Note that MultilegModel(1377)=2(User-defined, Non-Securitized, Multileg) does not apply for Securities.

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

A real message using tag 1377

NewOrderMultileg · FIX 5.0 SP2

Tag	Field	Wire value	Meaning
8	BeginString	FIXT.1.1
9	BodyLength	137
35	MsgType	AB	NewOrderMultileg
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
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
1377	MultilegModel	0	Predefined Multileg Security
10	CheckSum	179

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 5.0 SP2 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Valid values

A value outside this list is not a parse error — the message still decodes — but validate() reports it as validate/value-not-in-enum.

Value	Meaning	Symbolic name
0	Predefined Multileg Security	PREDEFINED_MULTILEG_SECURITY
1	User-defined Multileg Security	USER_DEFINED_MULTLEG_SECURITY
2	User-defined, Non-Securitized, Multileg	USER_DEFINED_NON_SECURITIZED_MULTILEG

Where tag 1377 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	Requiredness	Where in the message
DerivativeSecurityList	AA	Optional	inside DerivativeSecurityDefinition › MarketSegmentGrp › SecurityTradingRules › BaseTradingRules
DerivativeSecurityListUpdateReport	BR	Optional	inside DerivativeSecurityDefinition › MarketSegmentGrp › SecurityTradingRules › BaseTradingRules
MarketDefinition	BU	Optional	inside the BaseTradingRules component
MarketDefinitionUpdateReport	BV	Optional	inside the BaseTradingRules component
MultilegOrderCancelReplace	AC	Optional	directly on the message body
NewOrderMultileg	AB	Optional	directly on the message body
SecurityDefinition	d	Optional	inside MarketSegmentGrp › SecurityTradingRules › BaseTradingRules
SecurityDefinitionUpdateReport	BP	Optional	inside MarketSegmentGrp › SecurityTradingRules › BaseTradingRules
SecurityList	y	Optional	inside SecListGrp › SecurityTradingRules › BaseTradingRules
SecurityListUpdateReport	BK	Optional	inside SecLstUpdRelSymGrp › SecurityTradingRules › BaseTradingRules

Wire format

A whole number, optionally signed. Leading zeros are legal on the wire and are preserved in the raw value. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 1377 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix50sp2";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const multilegModel = message.fields[1377]?.raw;// e.g. "0" — Predefined Multileg Security// The dictionary also carries the labels:const label = fix.dictionary  .fieldByTag(1377)  ?.enumValues?.find((e) => e.value === multilegModel)  ?.description;

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-fix50sp2

Try the decoder Source on GitHub