Source§3.2.2 · Bid Request
This object describes the nature and behavior of the entity that is the source of the bid request upstream from the exchange. The primary purpose of this object is to define post-auction or upstream decisioning when the exchange itself does not control the final decision. A common example of this is header bidding, but it can also apply to upstream server entities such as another RTB exchange, a mediation platform, or an ad server combines direct campaigns with 3rd party demand in decisioning.
| Attribute | Type | Description |
|---|---|---|
| fd | integer | Entity responsible for the final impression sale decision, where 0 = exchange, 1 = upstream source. |
| tid | string | Transaction ID that must be common across all participants in this bid request (e.g., potentially multiple exchanges). |
| pchain | string | Payment ID chain string containing embedded syntax described in the TAG payment ID Protocol v1.0. |
| ext | object | Placeholder for exchange-specific extensions to OpenRTB. |
Field descriptions reconciled against the official 2.6 draft; 2.5-specific fields come from a third-party Go implementation source (Apache 2.0), proofread against the official PDF · first-draft proofreading