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User-Agent source

User-Agent source says where the structured browser and platform data in a request came from: Client Hints, with or without the high-entropy values, or a parsed User-Agent string. OpenRTB 2.6 sends it in UserAgent.source, the source field of device.sua, with a default of 0. Buyers use it to decide how far to trust versions and device models.

List: User-Agent Source4 valuesUsed by device.sua.source

Values

ValueNameWhat it means
0Unspecified or unknownThe source of the structured user agent data is not known or not reported; this is the default.
1Client Hints, low entropy onlyBuilt from the Client Hints a browser sends by default: brands, major versions, mobile flag and platform.
2Client Hints, with high entropyBuilt from Client Hints including the high-entropy values, such as full versions, platform version and device model.
3Parsed from the User-Agent headerDerived by parsing the same User-Agent string carried in Device.ua, with its frozen and reduced values.

Fields that use this list

How to use it

Set source to describe how you built device.sua, not what the browser could have offered. Low-entropy Client Hints, which browsers send by default, give brands, major versions, a mobile flag and the platform. High-entropy hints, which a site must request, add full versions, platform version, model and architecture. Parsing the UA string works everywhere but inherits the frozen and reduced values that browsers now put in it. Keep sending Device.ua alongside sua for buyers that have not switched.

Common mistakes

  • Leaving source at 0 when you built sua yourself and know exactly how.
  • Marking an sua built from a parsed UA string as 2. Buyers then trust a reduced platform version as if the browser had reported it.
  • Sending an sua with an empty browsers array, which rtblint reports as openrtb.sua.browsers_empty.

Validation

On OpenRTB 2.6 snapshots, RTBlint reports a value outside this list as openrtb.value.invalid. Paste a request into the tester to check the values you send.

Related lists

All lists are on the enumerated lists index.