VAST macros / Player and device
[DEVICEUA] VAST macro
Short answer: The user agent of the end-user device. Introduced in VAST 4.1.
What it means
Resolves to the device user-agent string. On many platforms this matches [CLIENTUA]; it is provided separately for cases where the device and player user agents differ.
Example value
After the player substitutes the macro, [DEVICEUA] becomes something like:
Mozilla%2F5.0%20(Linux%3B%20Android%2014)Where it is valid
Impression, tracking, and click 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=[DEVICEUA]&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
- VAST-2.0-macro-uri-unencoded: Macro-bearing URL contains characters that must be percent-encoded per RFC 3986
Related macros
- [CLIENTUA]: The user agent of the client player making the request.
- [SERVERUA]: The user agent of the server making a server-side request.
- [DEVICEIP]: The IP address of the end-user device.
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.