Bid Response Specification

Attribute	Type	Description	Example
`id`	string; required	ID of the bid request to which this is a response.	`"eb85349d-03c3-44f4-a77b-824f7221d116"`
`seatbid`	object array	Array of seatbid objects; 1+ required if a bid is to be made.	(empty)
`bidid`	string	Bidder generated response ID to assist with logging/tracking.	`"1asd24ht3hg0-fk1pmfflkdmsfk-12flkfdfd"`
`cur`	string; default "USD"	Bid currency using ISO-4217 alpha codes.	`"USD"`
`nbr`	integer	Reason for not bidding.	`1`

Seatbid Object

Attribute	Type	Description	Example
`bid`	object array; required	Array of 1+ Bid objects each related to an impression. Multiple bids can relate to the same impression.	(empty)
`seat`	string	ID of the bidder seat on whose behalf this bid is made.	`"123"`
`group`	integer; default 0	`0` = impressions can be won individually; `1` = impressions must be won or lost as a group.	`0`

Bid Object

Attribute	Type	Description	Example
`id`	string; required	Bidder generated bid ID to assist with logging/tracking.	`"1fwdsg1gdsgwfdb"`
`impid`	string; required	ID of the Imp object in the related bid request.	`"23fsdfsdg-12312fds-44f4-12dfsfa-824f7221d116"`
`price`	float; required	Bid price expressed as CPM. Integer math is recommended for currencies.	`1.15`
`adid`	string	ID of a preloaded ad to be served if the bid wins.	`"1378ygfvn928ouyghf19oiuhg03r"`
`nurl`	string	Win notice URL called if the bid wins.	`http://example.com/win/...?won=${AUCTION_PRICE}`
`lurl`	string	Loss notice URL called when a bid is lost.	`http://example.com/loss/...?final_price=${AUCTION_PRICE}`
`adm`	string	Ad markup in case of win (supersedes nurl if both present).	`"AD"`
`adomain`	string array; required	Advertiser domains (for blocklist checking).	`["test-domain.com"]`
`bundle`	string	App bundle being advertised.	`android: "com.test.app", iOS: "8120398"`
`iurl`	string	Image URL for ad quality/safety checking.	`http://example.com/i/...`
`cid`	string	Campaign ID.	`"12341"`
`crid`	string	Creative ID.	`"231"`
`cat`	string array	IAB content categories of the creative.	`["IAB3-1"]`
`attr`	integer array	Creative attributes.	`[1,2,13]`
`h`	integer	Height of the creative in pixels.	`480`
`w`	integer	Width of the creative in pixels.	`320`
`ext`	object; optional	Bidder-specific extensions. `ext.imptrackers` is a BidMachine extension carrying impression tracking URLs.	`{"imptrackers": ["https://..."]}`
`burl`	string; optional	Standard OpenRTB billing notice URL, called by the exchange when the impression occurs.	`http://example.com/bill_imp/...`

note

bid.burl and bid.ext.imptrackers are interchangeable: the exchange reads and processes both, neither is required, and a DSP may send either one or both. Using only one of them does not break tracking.

See nURL and Impression Tracking Schemes for the exact firing order per ad type.

note

BidMachine does not expect and does not accept any rendering-experience confirmation field in the bid response. There is no field for a DSP to report which video experience (placement, plcmt, or linearity) was actually rendered.

crtype is populated by BidMachine itself on the supply-facing side of the exchange and is derived from the placement type. It is not a DSP-facing bid response field: DSPs do not populate it, and the exchange does not read it from a bid response.