ApplVerID (FIX tag 1128)

StringFIX 5.0 SP2session envelope

ApplVerID (tag 1128) is a String 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. It is an enumerated field with 11 defined values.

At a glance

Tag
1128
Name
ApplVerID
Datatype
String
Dialects
FIX 5.0 SP2
Messages
115
Valid values
11

What the specification says

Specifies application version.

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

A real message using tag 1128

NewOrderSingle · FIX 5.0 SP2
TagFieldWire valueMeaning
8BeginStringFIXT.1.1
9BodyLength118
35MsgTypeDNewOrderSingle
1128ApplVerID9FIX50SP2
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
11ClOrdIDORD-10042
54Side1Buy
60TransactTime20240101-12:00:00.000
40OrdType1Market
10CheckSum136
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.

ValueMeaningSymbolic name
0FIX27FIX27
1FIX30FIX30
2FIX40FIX40
3FIX41FIX41
4FIX42FIX42
5FIX43FIX43
6FIX44FIX44
7FIX50FIX50
8FIX50SP1FIX50SP1
9FIX50SP2FIX50SP2
10FIXLatestFIXLatest

Where tag 1128 appears

Session envelope field
Tag 1128 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

Free-form text. Any byte except the SOH separator is legal, so values are not trimmed or case-folded on the wire. @boarteam/fix keeps the value as a string; format rules are checked by validate(), which reports validate/invalid-value rather than throwing.

Read tag 1128 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 applVerID = message.fields[1128]?.raw;// e.g. "0" — FIX27// The dictionary also carries the labels:const label = fix.dictionary  .fieldByTag(1128)  ?.enumValues?.find((e) => e.value === applVerID)  ?.description;

Other String fields

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