VAST macros / Ad and pod
[BREAKMAXADS] VAST macro
Short answer: The maximum number of ads allowed in the break. Introduced in VAST 4.1.
What it means
Resolves to the cap on how many ads the break will accept, letting servers fill a pod without overshooting.
Example value
After the player substitutes the macro, [BREAKMAXADS] becomes something like:
4Where it is valid
Ad request URLs.
Macros are case-sensitive and substituted only inside URL fields. A macro written in the wrong case, or placed where it has no defined value, is sent to the server as literal text instead of a value.
Using it in a tag
<Impression><![CDATA[https://t.example.com/i?val=[BREAKMAXADS]&cb=[CACHEBUSTING]]]></Impression>VAST XML fragment only. This excerpt belongs inside a complete VAST document, so standalone validation will fail until it is wrapped in a full <VAST>response.
Related vastlint rules
- VAST-2.0-macro-unknown: URL contains a [MACRO] that is not a recognised IAB VAST macro
- VAST-2.0-macro-lowercase: Recognised macro is not uppercase — players match macro names case-sensitively
Related macros
- [BREAKMINADLENGTH]: The minimum allowed duration of a single ad in the break (seconds).
- [BREAKMAXADLENGTH]: The maximum allowed duration of a single ad in the break (seconds).
- [BREAKPOSITION]: The position of the ad break: pre-roll, mid-roll, or post-roll.
Validate your macros
vastlint flags unknown, mis-cased, deprecated, out-of-context, and unencoded macros in any tracking, click, error, impression, or media URL:
# CLI: exits non-zero on errors, ideal for pipelines
vastlint check creative.xmlUse the right tool for this failure
If you already have the resolved XML, run a pure spec check. If you only have a live tag URL, test that endpoint first. If the failure happens in the wrapper chain, inspect each hop.