Prebid Server | Endpoints | /openrtb2/amp

• GET /openrtb2/amp
  • Request
    • First Party Data
  • Response
  • Error Messages
  • Resolving Sizes
• Configuration Options
• Further Reading

This document describes the behavior of the Prebid Server AMP endpoint in detail. For a more general reference, see the Prebid AMP Implementation Guide .

GET /openrtb2/amp

Parameters

To be compatible with AMP, this endpoint behaves different from normal /openrtb2/auction requests.

1. The ‘tag_id’ parameter points to a stored request.
2. The stored request must have exactly one imp element.
3. The request imp[0].secure will be always be set to 1, because AMP requires all content to be https.
4. AMP query params will overwrite parts of your Stored Request. See the table above.

Request

Valid Stored Requests for AMP pages must contain an imp array with exactly one element. It is not necessary to include a tmax field in the Stored Request, as Prebid Server will always use the smaller of the AMP default timeout (1000ms) and the value passed via the timeoutMillis field of the amp-ad.rtc-config.

An example Stored Request is given below:

{
    "id": "some-request-id",
    "site": {
        "page": "prebid.org"
    },
    "ext": {
        "prebid": {
            "targeting": {
                "pricegranularity": {  // This is equivalent to the deprecated "pricegranularity": "medium"
                    "precision": 2,
                    "ranges": [{
                        "max": 20.00,
                        "increment": 0.10
                    }]
                }
            }
        }
    },
    "imp": [{
      "id": "some-impression-id",
      "banner": {}, // The sizes are defined by your AMP tag query params settings
      "ext": {
        "prebid": {
            "bidder": {
                "bidderA": {
                    // Insert parameters here
                },
                "bidderB": {
                    // Insert parameters here
                }
            }
         }
      }
    }]
}

Note that other ext.prebid extensions can be specified in the stored request such as:

• ext.prebid.currency
• ext.prebid.aliases
• ext.prebid.multibid
• etc.

First Party Data

The nature of AMP is that user-level FPD is difficult or impossible. All of the pages are cached on a CDN and page javascript that can modify RTC calls is severely limited.

Contextual First Party Data must be defined in the stored request entries.

The only field that PBS supports in the AMP call that can be considered FPD is the ‘targeting’ block. These are key-value pairs that are sent to the ad server. They are also copied to the ORTB JSON in imp[].ext.data.

For example, if the AMP JSON targeting provided is:

  <amp-ad width="300" height="50"
    type="doubleclick"
    data-slot="/1111/amp_test"
    rtc-config='{"vendors": {"prebidrubicon": {"REQUEST_ID": "1001-my-test"}}}'
    json='{ "targeting": {"attr1": "val1", "attr2": "val2"}}' >
  </amp-ad>

The AMP URL would be something like this:

GET /openrtb2/amp?tag_id=1001-my-test&w=300&h=250&ow=&oh=&ms=&slot=%2F1111%2Famp_test&targeting=%7B%22attr1%22%3A%22val1%22%2C%22attr2%22%3A%22val2%22%7D&...

And the resulting OpenRTB would merge these targeting values as FPD on imp.ext.data:

{
  "imp": [{
    ...
    "ext": {
      "data": {
        "attr1": "val1",
        "attr2": "val2"
      }
    }
  }],
  ...
}

Response

A sample response payload looks like this:

{
    "targeting": {
        "hb_bidder": "appnexus",
        "hb_bidder_appnexus": "appnexus",
        "hb_cache_id": "420d7329-30e8-4c4e-8eaa-fe937172e4e0",
        "hb_cache_id_appnexus": "420d7329-30e8-4c4e-8eaa-fe937172e4e0",
        "hb_creative_loadtype": "html",
        "hb_pb": "0.50",
        "hb_pb_appnexus": "0.50",
        "hb_size": "300x250",
        "hb_size_appnexus": "300x250"
    }
    "errors": {
        "openx":[
            {
               "code": 1,
               "message": "The request exceeded the timeout allocated"
            }
        ]
    }
}

In the typical AMP setup, these targeting params will be sent to Google Ad Manager.

Error Messages

If any errors were generated they will appear within response.ext.errors.{bidderName}. There are five error codes that could be returned:

0   NoErrorCode
1   TimeoutCode
2   BadInputCode
3   BadServerResponseCode
999 UnknownErrorCode

See the /openrtb2/auction endpoint for a description of some common OpenRTB errors. The following is a list of AMP specific errors that could be returned:

The following errors can occur when loading a stored OpenRTB request for an incoming AMP request.

Resolving Sizes

We strive to return ads with sizes which are valid for the amp-ad on your page. This logic intends to track the logic used by doubleclick when resolving sizes used to fetch ads from their ad server.

Specifically:

1. If ow and oh exist, imp[0].banner.format will be a single element with w: ow and h: oh
2. If ow and h exist, imp[0].banner.format will be a single element with w: ow and h: h
3. If oh and w exist, imp[0].banner.format will be a single element with w: w and h: oh
4. If ms exists, imp[0].banner.format will contain an element for every size it uses.
5. If w and h exist, imp[0].banner.format will be a single element with w: w and h: h
6. If w or h exist, it will be used to override one of the dimensions inside each element of imp[0].banner.format
7. If none of these exist then the Stored Request values for imp[0].banner.format will be used without modification.

Configuration Options

• settings.generate-storedrequest-bidrequest-id: replace the stored request id with a UUID
• amp.default-timeout-ms: default operation timeout for AMP requests
• amp.timeout-adjustment-ms: reduces timeout value passed in AMP request. Can be used to account for estimated latency so that Prebid Server can respond to the AMP RTC request before it times out.
• amp.max-timeout-ms: maximum operation timeout for AMP requests

Further Reading

• Prebid and AMP
• Prebid Server AMP Use Case Overview
• Prebid Server First Party Data
• Stored Requests