Expected s2s Behavior | Criteo Commerce Grid Documentation

Overview

Commerce Grid expects HTTP 200, 204, or 302 responses to s2s calls, if you have recorded a valid impression.
If Commerce Gridreceives a response code > 399, i.e. HTTP 4xx, or 5xx, it denotes the impression as not properly recorded on the Buyer side, and will lead to discrepancies between Commerce Grid and the Buyer.
If the response code is >= 400, or there was a timeout, Commerce Grid makes 1 retry to check if a valid impression was recorded on the Buyer side.

s2s Headers

When sending s2s impression calls, Commerce Grid uses the following headers.

User-Agent: Indicates that the impression call is relayed by Commerce Grid, this is always BidSwitch/1.0.
X-User-Agent: Specifies the application type, operating system, software vendor or software version of the original request.
X-Forwarded-For: Identifies the originating IP address.
X-TMG-ServerUpstream: A value of 1 indicates that the original impression call to Commerce Grid was from a server.

Use the following table to compare the s2s vs u2s headers Commerce Grid applies in each circumstance.

BidSwitch s2s and u2s HTTP Headers
SSP to DSP	s2s:s2s_nurl in request or adslot	s2s:burl in response	u2s
s2s	`User-Agent: BidSwitch/1.0 X-TMG-ServerUpstream: 1`	`User-Agent: BidSwitch/1.0 X-TMG-ServerUpstream: 1 X-User-Agent: (applied from user in most cases) X-Forwarded-For:`	n/a; s2s forwarded as s2s only
u2s	`User-Agent: BidSwitch/1.0 X-Forwarded-For: X-User-Agent: (applied from user)`	`User-Agent: BidSwitch/1.0 X-Forwarded-For: X-User-Agent: (applied from user)`	`X-Forwarded-For: X-User-Agent: See u2s note`

Note

u2s: In all other scenarios which the table outlines, Commerce Grid applies its own headers. Except in the u2s case, where it forwards the initial u2s call without any alteration.