Open RTB 2.4 Bid Response

The response for a bid request will have the following structure:

Bid Response Object

Attribute	Description
id	ID of the bid request (string)
seatbid	Collection of bids made by the bidder on behalf of a specific seat.

seatbid

Attribute	Description
bid	ID of the impression object to which this bid applies (string)

seatbid.bid

Attribute	Description
id	ID for the bid object chosen by the bidder (string)
impid	ID of the impression object to which this bid applies (string)
price	Bid price in CPM or CPC (float)
adm	ExoClick XML/JSON Ad Markup (string)
nurl	Win notification URL
cid	Campaign ID to assist with ad quality checking (string)
crid	Creative ID to assist with ad quality checking (string)
iurl	URL of creative
ext	ExoClick specific extension (object)

The nURL must be notified in order to ensure campaign capping and avoid getting the same response every time.

seatbid.bid.ext

Attribute	Description
btype	Pricing Model. Values: 1 = CPM, 2 = CPC*. Default = 1 (int). Note: When response is for an Email Clicks zone request, 1 = Smart CPC.
	Note: Only Push Notification, Native ads, Direct Link, and Email Clicks may bid with the CPC pricing model.

No Bid Response

To answer a bid request without making an actual bid, an HTTP response code 204 "No Content" will be sent.

Win Notification

When the parameter Bid Response Object > Seat Bid Object > Bid Object > nurl is in the bid response, a GET request must be performed to such URL.

Billing Notification

When the parameter Bid Response Object > Seat Bid Object > Bid Object > burl is in the bid response, a GET request is performed to that URL when the impression or click becomes billable (CPM or CPC, per the btype field). This allows the impression or click to be counted from the billable event rather than from Client-side-based tracking, and provides parallel "Served" metrics in the RTB Statistics. that show the gap between what was rendered and what was billed.

If both nurl and burl are present, both should be called.

Count Logic

• When BURL is disabled — The Impression or Click rely entirely on client-side tracker fired by the rendered ad. Today's default for counting impressions and clicks.
• When BURL is enabled — The Impression or Click is counted from the burl call instead of the client-side tracking.
• When BURL enabled but partner fails to fire — The Impression or Click count drops to zero for billing purposes, while served impressions (what the browser logged) remain. This discrepancy flags a technical integration issue.

What stays on Client-side tracking

• Frequency Capping. FC continues to rely on impression events regardless of the BURL toggle.
• All "Served" metrics, by definition.
• Direct (non-RTB) zones, which have no BURL concept.

Examples

You can find detailed examples of the Responses you can receive in the example page.