AssignmentUnit (FIX tag 745)

QtyFIX 4.4

AssignmentUnit (tag 745) is a Qty field defined in FIX 4.4. It appears in 1 message type, always optionally.

At a glance

Tag: 745
Name: AssignmentUnit
Datatype: Qty (float)
Dialects: FIX 4.4
Messages: 1

What the specification says

Quantity Increment used in performing assignment.

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

A real message using tag 745

AssignmentReport · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	183
35	MsgType	AW	Assignment Report
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
833	AsgnRptID	EXAMPLE
581	AccountType	1	Account is carried on customer Side of Books
730	SettlPrice	1.09210
731	SettlPriceType	1	Final
732	UnderlyingSettlPrice	1.09210
744	AssignmentMethod	R	Random
745	AssignmentUnit	1000000
746	OpenInterest	125000.00
747	ExerciseMethod	A	Automatic
716	SettlSessID	ITD	Intraday
717	SettlSessSubID	EXAMPLE
715	ClearingBusinessDate	20240101
10	CheckSum	207

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 745 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
AssignmentReport	AW	Optional	directly on the message body

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 745 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[745];field?.name;   // "AssignmentUnit"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