ApplExtID (FIX tag 1156)

intFIX 5.0 SP2session envelope

ApplExtID (tag 1156) is an int field defined in FIX 5.0 SP2. It belongs to the session envelope: every FIX 5.0 SP2 message carries it, so it identifies the session rather than describing the business event.

At a glance

Tag: 1156
Name: ApplExtID
Datatype: int
Dialects: FIX 5.0 SP2
Messages: 115

What the specification says

The extension pack number associated with an application message.

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

A real message using tag 1156

NewOrderSingle · FIX 5.0 SP2

Tag	Field	Wire value	Meaning
8	BeginString	FIXT.1.1
9	BodyLength	118
35	MsgType	D	NewOrderSingle
1156	ApplExtID	1
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
10	CheckSum	129

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.

Where tag 1156 appears

Session envelope field

Tag 1156 appears in every one of the 115 FIX 5.0 SP2 message types, because it is part of the standard header or trailer. Listing them all would say nothing useful — it is present on anything you will ever decode.

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 1156 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 field = message.fields[1156];field?.name;   // "ApplExtID"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-fix50sp2

Try the decoder Source on GitHub