MMP measurement URLs for app advertising

This document defines the requirements for Amazon-managed app advertisers to provide Amazon with proper measurement URLs.

Third party Mobile Measurement Platforms

Amazon Advertising for Apps has integrated with several mobile measurement platforms (MMPs). So app advertisers with Amazon-managed ad campaigns who have also integrated their app with one of these MMPs can send install and in-app events to Amazon. This event data can help Amazon campaign managers identify quality installs and apply optimization strategies that drive toward goals based on advertising cost-per-action (CPA) or return-on-investment (ROI).

Amazon has reserved some of the MMP data parameters to pass identifying information for devices, apps, impressions, and ad campaigns. Advertisers need to follow the parameter specs below so that these identifiers can be transmitted to Amazon systems. The following table is a list of all currently certified MMPs and the supported event types for each territory.

MMPTypeUSCAUKDE
AdjustinstallXXXX
in-appX
AppsFlyerinstallXXXX
in-appX
KochavainstallXXXX
in-appX
TuneinstallXXXX
in-appX

What are the data pathways?

Impressions
As ads are served, Amazon embeds click measurement information in the creative and sends the impression notification to the MMP. View-through attribution (if desired) is managed directly by the advertiser in the MMP portal.

Clicks
When the user clicks on the ad, Amazon records the click and forwards the data to the MMP using the measurement URL.

Installs
When the user loads the app, the MMP SDK in the advertised app notifies the MMP. When the MMP determines an install is credited to Amazon, it can notify Amazon via postback (callback). Amazon strongly encourages advertisers to enable notifications to Amazon for Amazon-attributed installs and non-attributed installs to help optimize ad campaigns (portal settings vary per MMP).

In-app Events
If available and configured properly, when the user completes a desired action in an app, the MMP SDK in the app can report that to the MMP. The MMP can notify Amazon of in-app events (features and settings vary per MMP). Amazon strongly encourages all notifications to help in ad optimization.

Policy and Instructions

Advertising clients working with Amazon Advertising for Apps managed services can send event data to Amazon by enabling postbacks (callbacks) in the MMP portal. Of course this first requires proper integration of the MMP SDK in the advertised app. Failing to comply with the policy and instructions may disrupt data flowing to the MMP and/or to Amazon.

1. Create campaign, enable events
In the MMP campaign screen, create the campaign and enable event “postbacks” or “callbacks” to be sent to Amazon.

2. Get measurement URLs (trackers)
The MMP portal will generate measurement URLs with Amazon data macros embedded. Advertisers should provide these trackers to Amazon that comply with these parameter specs. Advertisers can insert Amazon macros in any of the parameters available to them (i.e. parameters not reserved for Amazon use). Amazon supports one impression tracker and one click tracker per creative. An impression tracker can be used for view-through conversion measurement, but it is optional.

3. Resolve any parameter conflicts
Amazon uses some of the MMP parameters to pipe certain identifiers (details below). If there is an unavoidable parameter conflict, communicate that to the Amazon account contact. Using Amazon- reserved parameters will disrupt the data that Amazon campaign managers use to optimize performance.

4. Additional parameters
Advertisers can add MMP-expanded parameters (as well as their own parameters) to the measurement URL. Other than Amazon macros and MMP macro/placeholder expansion, there is no capability to support different measurement URLs per ad line or group of ad lines.

5. URL modification
Amazon will encode the advertiser-provided measurement URL when the ad is trafficked to preserve it as embedded payload within the ad creative. Amazon may also add data macros or modify other aspects of the URL to comply with the policy and instructions.

Amazon Macros for All MMPs

When an ad is served, advertisers can send campaign, ad, publisher, and creative size data using a macro in the measurement URL. Amazon Ad servers replace the macro with data. Amazon supports the following macros:

Amazon macrodescription
__CS_CAMPAIGN_NAME__Amazon campaign id + name
__CS_AD_NAME__Amazon ad id + name
__AAX_SOURCE_NAME__Amazon publisher group
__AAX_SITE_NAME__Amazon publisher
__CS_AD_SIZE__Creative size
__CS_CREATIVE_ID__Amazon creative id

MMP Measurement URLs (trackers)

Amazon ad creatives support measurement URLs or “trackers”. On every advertising campaign, the advertiser provides Amazon with impression and click trackers: one of each per ad platform OS (although the impression tracker is optional). These trackers are generated in the MMP portal by the advertiser. There are cases where the advertiser wishes for more granular reporting (by creative or special segments, for example). Since an ad creative has only one impression and click tracker, Amazon has some “macros” available that are automatically replaced in the creative when the ad is rendered. The replaced macros include info such as campaign, ad line, device, and other data embedded in the ad creative for more granularity in summary reports. Occasionally, there may be a technical exception where a measurement URL is not used. Amazon may pass data in unused advertiser parameters.

Adjust Parameters

Amazon uses custom parameters with Adjust, so advertisers may use any of these params below. (See https://docs.adjust.com/en/tracker-generation/ and https://docs.adjust.com/en/special-partners/amazon/)

parameterusagedescription
campaignavailableAvailable for advertiser use
adgroupavailableAvailable for advertiser use
creativeavailableAvailable for advertiser use
labelavailableAvailable for advertiser use (does not breakout data in Adjust dashboard)

Adjust Example Measurement URLs

Impression: iOS / Android / Fire

https://view.adjust.com/impression/abc123?
campaign=__CS_CAMPAIGN_NAME__&adgroup=__AAX_SOURCE_NAME__&creative=__CS_CREATIVE_ID__-
__CS_AD_SIZE__&gps_adid=__AAX_IDFA__&idfa=__AAX_IDFA__&android_id_lower_sha1=__AAX_SHA1
_UDID__&amzn_ad_tracking=__AAX_AD_TRACKING__&referrer=adjust_external_click_id%3d__AAX_
TRACKING_ID__&amzn_ref_id=__AAX_TRACKING_ID__&cost_type=__AAX_COST_MODEL__&cost_amount=
__AAX_COST__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&amzn_app_id
=__CS_APP_ID__&amzn_campaign_name=__CS_CAMPAIGN_NAME__&amzn_ad_name=__CS_AD_NAME__&amzn
_supply_source=__AAX_SOURCE_NAME__&amzn_site_id=__AAX_SITE_NAME__&amzn_creative_id=__CS
_CREATIVE_ID__&amzn_creative_size=__CS_AD_SIZE__&s2s=1

Click: iOS / Android / Fire

https://app.adjust.com/abc123?
campaign=__CS_CAMPAIGN_NAME__&adgroup=__AAX_SOURCE_NAME__&creative=__CS_CREATIVE_ID__-
__CS_AD_SIZE__&gps_adid=__AAX_IDFA__&idfa=__AAX_IDFA__&android_id_lower_sha1=__AAX_SHA1
_UDID__&amzn_ad_tracking=__AAX_AD_TRACKING__&referrer=adjust_external_click_id%3d__AAX_
TRACKING_ID__&amzn_ref_id=__AAX_TRACKING_ID__&cost_type=__AAX_COST_MODEL__&cost_amount=
__AAX_COST__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&amzn_app_id
=__CS_APP_ID__&amzn_campaign_name=__CS_CAMPAIGN_NAME__&amzn_ad_name=__CS_AD_NAME__&amzn
_supply_source=__AAX_SOURCE_NAME__&amzn_site_id=__AAX_SITE_NAME__&amzn_creative_id=__CS
_CREATIVE_ID__&amzn_creative_size=__CS_AD_SIZE__&s2s=1

AppsFlyer Parameters

parameterusagedescription
cavailableDefaults to __CS_CAMPAIGN_NAME__ (Amazon campaign id + name)
af_refreserved__AAX_TRACKING_ID__ (Google referrer)
af_channelreserved__AAX_SOURCE_NAME__ (supply category name)
af_siteidreserved__AAX_SITE_NAME__ (Amazon publisher)
af_adreserved__CS_AD_NAME__ (Amazon ad id + name)
af_ad_typereserved__CS_AD_SIZE__ (creative size)
af_ad_idreserved__CS_CREATIVE_ID__ (Amazon creative id)

AppsFlyer Example Measurement URLs

Impression: iOS

https://impression.appsflyer.com/id123456789?
pid=amazon_int&c=__CS_CAMPAIGN_NAME__&idfa=__AAX_IDFA__&amzn_ad_tracking=__AAX_AD_TRACK
ING__&amzn_ref_id=__AAX_TRACKING_ID__&af_cost_model=__AAX_COST_MODEL__&af_cost_value=__
AAX_COST__&af_channel=__AAX_SOURCE_NAME__&af_siteid=__AAX_SITE_NAME__&amzn_campaign_nam
e=__CS_CAMPAIGN_NAME__&af_ad=__CS_AD_NAME__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=_
_AAX_POSTBACK_URL__&amzn_app_id=__CS_APP_ID__&af_ad_id=__CS_CREATIVE_ID__&af_ad_type=__
CS_AD_SIZE__&redirect=false&af_prt=amazon

Impression: Android / Fire

https://impression.appsflyer.com/com.example.app?
pid=amazon_int&c=network_test&advertising_id=__AAX_IDFA__&sha1_android_id=__AAX_SHA1_UD
ID__&amzn_ad_tracking=__AAX_AD_TRACKING__&af_ref=__AAX_TRACKING_ID__&amzn_ref_id=__AAX_
TRACKING_ID__&af_cost_model=__AAX_COST_MODEL__&af_cost_value=__AAX_COST__&af_channel=__
AAX_SOURCE_NAME__&af_siteid=__AAX_SITE_NAME__&amzn_campaign_name=__CS_CAMPAIGN_NAME__&a
f_ad=__CS_AD_NAME__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&amzn
_app_id=__CS_APP_ID__&af_ad_id=__CS_CREATIVE_ID__&af_ad_type=__CS_AD_SIZE__&redirect=fa
lse&af_prt=amazon

Click: iOS

https://app.appsflyer.com/id123456789?
pid=amazon_int&c=__CS_CAMPAIGN_NAME__&idfa=__AAX_IDFA__&amzn_ad_tracking=__AAX_AD_TRACK
ING__&amzn_ref_id=__AAX_TRACKING_ID__&af_cost_model=__AAX_COST_MODEL__&af_cost_value=__
AAX_COST__&af_channel=__AAX_SOURCE_NAME__&af_siteid=__AAX_SITE_NAME__&amzn_campaign_nam
e=__CS_CAMPAIGN_NAME__&af_ad=__CS_AD_NAME__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=_
_AAX_POSTBACK_URL__&amzn_app_id=__CS_APP_ID__&af_ad_id=__CS_CREATIVE_ID__&af_ad_type=__
CS_AD_SIZE__&redirect=false&af_prt=amazon

Click: Android / Fire

https://app.appsflyer.com/com.example.app?
pid=amazon_int&c=network_test&advertising_id=__AAX_IDFA__&sha1_android_id=__AAX_SHA1_UD
ID__&amzn_ad_tracking=__AAX_AD_TRACKING__&af_ref=__AAX_TRACKING_ID__&amzn_ref_id=__AAX_
TRACKING_ID__&af_cost_model=__AAX_COST_MODEL__&af_cost_value=__AAX_COST__&af_channel=__
AAX_SOURCE_NAME__&af_siteid=__AAX_SITE_NAME__&amzn_campaign_name=__CS_CAMPAIGN_NAME__&a
f_ad=__CS_AD_NAME__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&amzn
_app_id=__CS_APP_ID__&af_ad_id=__CS_CREATIVE_ID__&af_ad_type=__CS_AD_SIZE__&redirect=fa
lse&af_prt=amazon

Kochava Parameters

The following Kochava parameters are reserved for Amazon use. (See http://kochava.freshdesk.com/support/articles/1000072813-integrate-as-a-network-publisher)

parameterusagedescription
site_idreservedAmazon publisher information for Kochava Summary Reporting (network & install) formatted as “__AAX_SITE_NAME__”
creative_idreservedAmazon creative ID for Kochava Summary Reporting (network & install) formatted as “__CS_CREATIVE_ID__”

Kochava Example Measurement URLs

Impression: iOS

https://imp.control.kochava.com/track/impression?campaign_id=abc-def-ghi559d967642dda8c74fb23ae113&network_id=2364&device_id=__AAX_IDFA__&device_id_type=idf
a&amzn_ad_tracking=__AAX_AD_TRACKING__&bid_type=__AAX_COST_MODEL__&bid_value=__AAX_COST_
_&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREATIVE_ID__&cp_0
=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__CS_AD_NAME__&c
p_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_7=__CS_AD_SIZ
E__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Impression: Android

https://imp.control.kochava.com/track/impression?campaign_id=abc-def-ghi559d967642dda8c74fb23ae113&network_id=2365&device_id=__AAX_IDFA__&android_id_sha1=__
AAX_SHA1_UDID__&device_id_type=adid&amzn_ad_tracking=__AAX_AD_TRACKING__&amzn_gp_ref=__
AAX_AD_TRACKING_ID__&append_app_conv_trk_params=1&bid_type=__AAX_COST_MODEL__&bid_value
=__AAX_COST__&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREATIV
E_ID__&cp_0=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__CS_
AD_NAME__&cp_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_7=
__CS_AD_SIZE__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Impression: Fire

https://imp.control.kochava.com/track/impression?campaign_id=abc-def-
ghi559d967642dda8c74fb23ae113&network_id=3501&device_id=__AAX_SHA1_UDID__&android_id_sh
a1=__AAX_SHA1_UDID__&device_id_type=adid&amzn_ad_tracking=__AAX_AD_TRACKING__&amzn_gp_r
ef=__AAX_TRACKING_ID__&append_app_conv_trk_params=1&bid_type=__AAX_COST_MODEL__&bid_va
lue=__AAX_COST__&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREAT
IVE_ID__&cp_0=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__C
S_AD_NAME__&cp_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_
7=__CS_AD_SIZE__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Click: iOS

https://control.kochava.com/v1/cpi/click?campaign_id=abc-def-
ghi559d967642dda8c74fb23ae113&network_id=2364&device_id=__AAX_IDFA__&device_id_type=idf
a&amzn_ad_tracking=__AAX_AD_TRACKING__&bid_type=__AAX_COST_MODEL__&bid_value=__AAX_COST
__&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREATIVE_ID__&cp_0
=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__CS_AD_NAME__&c
p_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_7=__CS_AD_SIZ
E__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Click: Android

https://control.kochava.com/v1/cpi/click?campaign_id=abc-def-
ghi559d967642dda8c74fb23ae113&network_id=2365&device_id=__AAX_IDFA__&android_id_sha1=__
AAX_SHA1_UDID__&device_id_type=adid&amzn_ad_tracking=__AAX_AD_TRACKING__&amzn_gp_ref=__
AAX_AD_TRACKING_ID__&append_app_conv_trk_params=1&bid_type=__AAX_COST_MODEL__&bid_value
=__AAX_COST__&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREATIV
E_ID__&cp_0=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__CS_
AD_NAME__&cp_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_7=
__CS_AD_SIZE__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Click: Fire

https://control.kochava.com/v1/cpi/click?campaign_id=abc-def-
ghi559d967642dda8c74fb23ae113&network_id=3501&device_id=__AAX_SHA1_UDID__&android_id_sh
a1=__AAX_SHA1_UDID__&device_id_type=adid&amzn_ad_tracking=__AAX_AD_TRACKING__&amzn_gp_r
ef=__AAX_TRACKING_ID__&append_app_conv_trk_params=1&bid_type=__AAX_COST_MODEL__&bid_val
ue=__AAX_COST__&cpi_price=__AAX_COST__&site_id=__AAX_SITE_NAME__&creative_id=__CS_CREAT
IVE_ID__&cp_0=__AAX_TRACKING_ID__&cp_1=__CS_APP_ID__&cp_2=__CS_CAMPAIGN_NAME__&cp_3=__C
S_AD_NAME__&cp_4=__AAX_SOURCE_NAME__&cp_5=__AAX_SITE_NAME__&cp_6=__CS_CREATIVE_ID__&cp_
7=__CS_AD_SIZE__&amzn_mmp=__CS_MSR_PARTNER__&amzn_endpoint=__AAX_POSTBACK_URL__&pbr=1

Tune Parameters

Tune provides a way to add customer parameters to the measurement URL in the “My Parameters” section. Amazon reserves the following “Partner Parameters”. (See https://help.tune.com/marketing-console/attribution-analytics/measurement/measurement-urls/)

parameterusagedescription
sub_publisherreserved__AAX_SOURCE_NAME__ (supply category name)
sub_sitereserved__AAX_SITE_NAME__ (Amazon publisher)
sub_campaignreserved__CS_CAMPAIGN_NAME__ (Amazon campaign id + name)
sub_adreserved__CS_AD_NAME__ (Amazon ad id + name)
sub1reserved__CS_MSR_PARTNER__ (MMP id, “tune.com” in this case)
sub2reserved__AAX_POSTBACK_URL__ (postback URL for regional endpoint, can be empty, default is US endpoint)
sub3reserved__CS_APP_ID__ (Amazon app id for the promoted app)
sub4reserved__CS_AD_SIZE__ (creative size)
sub5reserved__CS_CREATIVE_ID__ (Amazon creative id)

Tune Example Tracking URLs

Impression: iOS

https://12345.tlnk.io/serve?
action=impression&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&ios
_ifa=__AAX_IDFA__&ios_ad_tracking=__AAX_AD_TRACKING__&ref_id=__AAX_TRACKING_ID__&cost_mo
del=__AAX_COST_MODEL__&cost=__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_site=__A
AX_SITE_NAME__&sub_campaign=__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_MSR_PA
RTNER__&sub2=__AAX_POSTBACK_URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response_forma
t=json

Impression: Android

https://12345.tlnk.io/serve?
action=impression&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&goog
le_aid=__AAX_IDFA__&google_ad_tracking=__AAX_AD_TRACKING__&ref_id=__AAX_TRACKING_ID__&c
ost_model=__AAX_COST_MODEL__&cost=__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_si
te=__AAX_SITE_NAME__&sub_campaign=__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_
MSR_PARTNER__&sub2=__AAX_POSTBACK_URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response
_format=json

Impression: Fire

https://12345.tlnk.io/serve?
action=impression&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&andr
oid_id_sha1=__AAX_SHA1_UDID__&ref_id=__AAX_TRACKING_ID__&cost_model=__AAX_COST_MODEL__&
cost=__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_site=__AAX_SITE_NAME__&sub_camp
aign=__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_MSR_PARTNER__&sub2=__AAX_POST
BACK_URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response_format=json

Click: iOS

https://12345.tlnk.io/serve?
action=click&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&ios_ifa=_
_AAX_IDFA__&ios_ad_tracking=__AAX_AD_TRACKING__&ref_id=__AAX_TRACKING_ID__&cost_model=_
_AAX_COST_MODEL__&cost=__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_site=__AAX_SI
TE_NAME_&sub_campaign=__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_MSR_PARTNER_
_&sub2=__AAX_POSTBACK_URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response_format=json

Click: Android

https://12345.tlnk.io/serve?
action=click&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&google_ai
d=__AAX_IDFA__&google_ad_tracking=__AAX_AD_TRACKING__&ref_id=__AAX_TRACKING_ID__&cost_m
odel=__AAX_COST_MODEL__&cost=__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_site=__
AAX_SITE_NAME__&sub_campaign=__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_MSR_P
ARTNER__&sub2=__AAX_POSTBACK_URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response_form
at=json

Click: Fire

https://12345.tlnk.io/serve?
action=click&integration_id=1118&site_id=2962&tracking_id=__AAX_TRACKING_ID__&android_i
d_sha1=__AAX_SHA1_UDID__&ref_id=__AAX_TRACKING_ID__&cost_model=__AAX_COST_MODEL__&cost=
__AAX_COST__&sub_publisher=__AAX_SOURCE_NAME__&sub_site=__AAX_SITE_NAME__&sub_campaign=
__CS_CAMPAIGN_NAME__&sub_ad=__CS_AD_NAME__&sub1=__CS_MSR_PARTNER__&sub2=__AAX_POSTBACK_
URL__&sub3=__CS_APP_ID__&sub4=__CS_AD_SIZE__&response_format=json