A bidder can purchase inventory for multiple buyers in a single bid response. For example, a demand-side platform (DSP) might use its bidding application to purchase inventory for several marketers or agencies who are buyers. This guide explains how to code your bidder to process a single request sent on behalf of multiple buyers. ## Background In some scenarios, an ad network or agency trading desk may choose to work with one or more DSPs. There are two options available for buyers who work through a DSP: - **The DSP purchases inventory for marketers or agencies that are *not* buyers**. In this case, the DSP receives one bid request and responds with one bid. Google bills the DSP directly. - **The DSP purchases inventory for marketers or agencies that are buyers**. The DSP receives one bid request including multiple billing IDs associated with eligible buyers, and can place distinct bids for each buyer they intend to bid on behalf of. In this model, Google bills the buyer, not the DSP. The rest of this guide focuses on this scenario. ## Setup and pretargeting Google will send a bid request containing one or more billing IDs associated with buyers and pretargeting configurations that targeted the impression. These can be found with the `BidRequest.imp.ext.billing_id` field. When responding to a `BidRequest` that contains billing IDs from multiple buyers, `BidResponse.seatbid.bid.ext.billing_id` is required so that Google knows which account to associate with the bid. Any response that does not set the field is filtered. The field remains optional for any `BidRequest` that only includes a single billing ID. ### Pretargeting example A bidder bids on behalf of two buyers, one having a billing ID of 123, and the other with billing ID 124. The bidder configures one pretargeting configuration with billing ID 213 to target the English language, and another with billing ID 231 to target personal computers. The following describes the billing IDs that appear in bid requests for different kinds of impressions. | Impression description | Billing IDs in bid request | |---|---| | Japanese language content on a personal computer. | 123, 124, 231 | | English language content on a mobile phone. | 123, 124, 213 | | English language content on a personal computer. | 123, 124, 213, 231 | > [!IMPORTANT] > **Important:** If these were your only active pretargeting configurations, you wouldn't receive bid requests for impressions that didn't originate from a personal computer and include non-English content. ## Example BidRequests Below are examples of a `BidRequest`. You'll note that there are multiple billing IDs in these requests because the requests are applicable to multiple accounts. ### OpenRTB Protobuf #### Show me the example [Serialized request](https://developers.google.com/authorized-buyers/rtb/data/request-response/openrtb_protobuf_bid_request_for_multiple_accounts_request.bin) ``` id: "a7gs668pOD71593174WD18" imp { id: "1" banner { w: 320 h: 50 pos: ABOVE_THE_FOLD battr: VIDEO_IN_BANNER_AUTO_PLAY battr: VIDEO_IN_BANNER_USER_INITIATED api: MRAID_1 api: MRAID_2 format { w: 320 h: 50 } } displaymanager: "GoogleMobileAds-iOS" displaymanagerver: "12.11.0" tagid: "1775995363" bidfloor: 10.0 bidfloorcur: "JPY" pmp { deals { id: "28061984" bidfloor: 10.0 bidfloorcur: "JPY" [com.google.doubleclick.deal] { deal_type: MARKETPLACE_PACKAGE } } } secure: true exp: 3600 clickbrowser: true metric { type: "click_through_rate" value: 0.0007115462212823331 vendor: "EXCHANGE" } metric { type: "viewability" value: 0.83 vendor: "EXCHANGE" } [com.google.doubleclick.imp] { billing_id: 25077279506 billing_id: 81842042446 publisher_settings_list_id: 9245119909902343598 publisher_settings_list_id: 7060632308909145426 allowed_vendor_type: 0 ampad: AMP_AD_NOT_ALLOWED buyer_generated_request_data { source_app { id: "com.google.ads.mediation.test.TestAdapter" } data: "Test Data" } excluded_creatives { buyer_creative_id: "EXCLUDED_BUYER_CREATIVE_ID" } excluded_creatives { buyer_creative_id: "EXCLUDED_BUYER_CREATIVE_ID" } skadn { sourceapp: "com.google.testapp" skadnetids: "3Y4W2r13" skadnetids: "D2b9v6eq" versions: "2.0" versions: "2.1" fidelities: STOREKIT_RENDERED_ADS fidelities: VIEW_THROUGH_ADS } creative_enforcement_settings { policy_enforcement: POLICY_ENFORCEMENT_NETWORK_AND_PLATFORM_POLICY publisher_blocks_enforcement: PUBLISHER_BLOCKS_ENFORCEMENT_APPLIES } billable_event_rate_bid_adjustment { bid_adjustment: 1.0 creative_type: HTML_SNIPPET } jsver: "test-sdk_123456789" } } app { name: "Test App" cat: "IAB19-15" pagecat: "IAB19-15" ver: "26.39.0" bundle: "com.google.testapp" publisher { id: "pub-3006071972218254" [com.google.doubleclick.publisher] { country: "US" } } content { url: "https://www.google.com" language: "en" genre: "Business Banking & Finance,Financial Regulation,Automotive Industry,News and Politics,Government Business,Job Market,Personal Finance,Economy,Private Equity,Logistics and Transportation Industry,Crossover,Smart Home,Business and Finance,Celebrity Style,Minivan,Careers,Women\'s Fashion,Consumer Banking,Job Search,Apprenticeships" data { id: "0" segment { id: "OMITTED" } segment { id: "OMITTED" } [com.google.doubleclick.data] { segtax: 6 } } } storeurl: "https://www.google.com" cattax: IAB_CONTENT_1_0 [com.google.doubleclick.app] { installed_sdk { id: "com.google.ads.mediation.test.TestAdapter" sdk_version { major: 8 minor: 16 micro: 0 } adapter_version { major: 8 minor: 16 micro: 0 } } } } device { ua: "OMITTED" geo { lat: 0.0 lon: 0.0 country: "USA" region: "TX" metro: "623" city: "Grand Prairie" zip: "75052" type: IP utcoffset: -300 accuracy: 4812 [com.google.doubleclick.geo] { geo_criteria_id: 9026819 } } ipv6: "2607:fb91:97c:3624:b9ba:48ef:bbc3:ea22" carrier: "70093" language: "en" make: "Apple" model: "iPhone13,4" os: "iOS" osv: "26.7.1" connectiontype: CELL_4G devicetype: HIGHEND_PHONE ifa: "d2ee7c9c-d000-4abb-9fe3-b6f9891f59af" hwv: "iPhone13,4" w: 428 h: 926 pxratio: 3.0 sua { browsers { brand: "Mozilla" version: "5" version: "0" } browsers { brand: "AppleWebKit" version: "605" version: "1" } platform { brand: "iPhone" version: "26" version: "7" } mobile: true bitness: "64" model: "iPhone" source: USER_AGENT_STRING } [com.google.doubleclick.device] { atts: 3 audioout: AUDIO_SPEAKER ifa_type: "idfa" scrollposx: 0 scrollposy: 0 } } user { [com.google.doubleclick.user] { eids { source: "OMITTED_SOURCE" uids { id: "OMITTED_ID" } } session { duration: 94 depth: 8 requestssinceappopen: 11 } } } at: FIRST_PRICE tmax: 700 cur: "AUD" cur: "KRW" bcat: "5" bcat: "10" regs { gpp: "OMITTED" gpp_sid: USNAT } source { schain { complete: true nodes { asi: "testssp.com" sid: "pub-1111111111111111" hp: true } ver: "1.0" } [com.google.doubleclick.source] { omidpn: "Google" omidpv: "afma-sdk-i-v12.11.0" } } cattax: GOOGLE_CATEGORIES [com.google.doubleclick.bid_request] { google_query_id: "ANy-zL23dM-K888C926iz54pL02I4wa4sXX04N9233701g8h787afvX78G815DcjFi573537" fcap_scope: FREQUENCY_CAPPING_SCOPE_NONE privacy_treatments { ip: IP_FULL allow_user_data_collection: true } } ``` ### OpenRTB JSON #### Show me the example ``` { "id": "a7gs668pOD71593174WD18", "imp": [ { "id": "1", "banner": { "w": 320, "h": 50, "pos": 1, "battr": [ 6, 7 ], "api": [ 3, 5 ], "format": [ { "w": 320, "h": 50 } ] }, "displaymanager": "GoogleMobileAds-iOS", "displaymanagerver": "12.11.0", "tagid": "1775995363", "bidfloor": 10.0, "bidfloorcur": "JPY", "pmp": { "deals": [ { "id": "28061984", "bidfloor": 10.0, "bidfloorcur": "JPY", "ext": { "deal_type": 5 } } ] }, "secure": 1, "exp": 3600, "clickbrowser": 1, "metric": [ { "type": "click_through_rate", "value": 0.0007115462212823331, "vendor": "EXCHANGE" }, { "type": "viewability", "value": 0.83, "vendor": "EXCHANGE" } ], "ext": { "billing_id": [ "25077279506", "81842042446" ], "publisher_settings_list_id": [ "9245119909902343598", "7060632308909145426" ], "allowed_vendor_type": [ 0 ], "ampad": 2, "buyer_generated_request_data": [ { "source_app": { "id": "com.google.ads.mediation.test.TestAdapter" }, "data": "Test Data" } ], "excluded_creatives": [ { "buyer_creative_id": "EXCLUDED_BUYER_CREATIVE_ID" }, { "buyer_creative_id": "EXCLUDED_BUYER_CREATIVE_ID" } ], "skadn": { "sourceapp": "com.google.testapp", "skadnetids": [ "3Y4W2r13", "D2b9v6eq" ], "versions": [ "2.0", "2.1" ], "fidelities": [ 1, 0 ] }, "creative_enforcement_settings": { "policy_enforcement": 2, "publisher_blocks_enforcement": 1 }, "billable_event_rate_bid_adjustment": [ { "bid_adjustment": 1.0, "creative_type": 1 } ], "jsver": "test-sdk_123456789" } } ], "app": { "name": "Test App", "cat": [ "IAB19-15" ], "pagecat": [ "IAB19-15" ], "ver": "26.39.0", "bundle": "com.google.testapp", "publisher": { "id": "pub-3006071972218254", "ext": { "country": "US" } }, "content": { "url": "https://www.google.com", "language": "en", "genre": "Business Banking & Finance,Financial Regulation,Automotive Industry,News and Politics,Government Business,Job Market,Personal Finance,Economy,Private Equity,Logistics and Transportation Industry,Crossover,Smart Home,Business and Finance,Celebrity Style,Minivan,Careers,Women's Fashion,Consumer Banking,Job Search,Apprenticeships", "data": [ { "id": "0", "segment": [ { "id": "OMITTED" }, { "id": "OMITTED" } ], "ext": { "segtax": 6 } } ] }, "storeurl": "https://www.google.com", "cattax": 1, "ext": { "installed_sdk": [ { "id": "com.google.ads.mediation.test.TestAdapter", "sdk_version": { "major": 8, "minor": 16, "micro": 0 }, "adapter_version": { "major": 8, "minor": 16, "micro": 0 } } ] } }, "device": { "ua": "OMITTED", "geo": { "lat": 0.0, "lon": 0.0, "country": "USA", "region": "TX", "metro": "623", "city": "Grand Prairie", "zip": "75052", "type": 2, "utcoffset": -300, "accuracy": 4812, "ext": { "geo_criteria_id": 9026819 } }, "ipv6": "2607:fb91:97c:3624:b9ba:48ef:bbc3:ea22", "carrier": "70093", "language": "en", "make": "Apple", "model": "iPhone13,4", "os": "iOS", "osv": "26.7.1", "connectiontype": 6, "devicetype": 4, "ifa": "d2ee7c9c-d000-4abb-9fe3-b6f9891f59af", "hwv": "iPhone13,4", "w": 428, "h": 926, "pxratio": 3.0, "sua": { "browsers": [ { "brand": "Mozilla", "version": [ "5", "0" ] }, { "brand": "AppleWebKit", "version": [ "605", "1" ] } ], "platform": { "brand": "iPhone", "version": [ "26", "7" ] }, "mobile": 1, "bitness": "64", "model": "iPhone", "source": 3 }, "ext": { "atts": 3, "audioout": 1, "ifa_type": "idfa", "scrollposx": 0, "scrollposy": 0 } }, "user": { "ext": { "eids": [ { "source": "OMITTED_SOURCE", "uids": [ { "id": "OMITTED_ID" } ] } ], "session": { "duration": 94, "depth": 8, "requestssinceappopen": 11 } } }, "at": 1, "tmax": 700, "cur": [ "AUD", "KRW" ], "bcat": [ "5", "10" ], "regs": { "gpp": "OMITTED", "gpp_sid": [ 7 ] }, "source": { "schain": { "complete": 1, "nodes": [ { "asi": "testssp.com", "sid": "pub-1111111111111111", "hp": 1 } ], "ver": "1.0" }, "ext": { "omidpn": "Google", "omidpv": "afma-sdk-i-v12.11.0" } }, "cattax": 500, "ext": { "google_query_id": "ANy-zL23dM-K888C926iz54pL02I4wa4sXX04N9233701g8h787afvX78G815DcjFi573537", "fcap_scope": 1, "privacy_treatments": { "ip": 1, "allow_user_data_collection": 1 } } } ```