ApplQueueDepth (FIX tag 813)

intFIX 4.4

ApplQueueDepth (tag 813) is an int field defined in FIX 4.4. It appears in 2 message types, always optionally.

At a glance

Tag: 813
Name: ApplQueueDepth
Datatype: int
Dialects: FIX 4.4
Messages: 2

What the specification says

Current number of application messages that were queued at the time that the message was created by the counterparty.

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

A real message using tag 813

MarketDataSnapshotFullRefresh · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	81
35	MsgType	W	Market Data-Snapshot/Full Refresh
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
268	NoMDEntries1 entry	1	repeating group
269	MDEntryType	0	Bid
813	ApplQueueDepth	1
10	CheckSum	254

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 813 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
MarketDataIncrementalRefresh	X	Optional	directly on the message body
MarketDataSnapshotFullRefresh	W	Optional	directly on the message body

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 813 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[813];field?.name;   // "ApplQueueDepth"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