adds manual gpid to prebid ad unit and launch to 99% of users

.changeset/tiny-rats-lay.md

@@ -0,0 +1,5 @@
+---
+'@guardian/commercial': patch
+---
+
+adds gpid for 99% of users to prebid request

src/experiments/ab-tests.ts

@@ -1,4 +1,5 @@
 import type { ABTest } from '@guardian/ab-core';
+import { gpidPrebidAdUnits } from './tests/gpid-prebid';
 import { mpuWhenNoEpic } from './tests/mpu-when-no-epic';
 import { newHeaderBiddingEndpoint } from './tests/new-header-bidding-endpoint';
 import { optOutFrequencyCap } from './tests/opt-out-frequency-cap';
@@ -13,4 +14,5 @@ export const concurrentTests: ABTest[] = [
 	mpuWhenNoEpic,
 	optOutFrequencyCap,
 	newHeaderBiddingEndpoint,
+	gpidPrebidAdUnits,
 ];

src/experiments/tests/gpid-prebid.ts

@@ -0,0 +1,29 @@
+import type { ABTest } from '@guardian/ab-core';
+
+export const gpidPrebidAdUnits: ABTest = {
+	id: 'GpidPrebidAdUnits',
+	author: '@commercial-dev',
+	start: '2024-11-15',
+	expiry: '2024-12-22',
+	audience: 2 / 100,
+	audienceOffset: 0 / 100,
+	audienceCriteria: '',
+	successMeasure: 'Verify GPID is added to Prebid.js ad units',
+	description:
+		'Test to verify that GPID is correctly added to Prebid.js ad units.',
+	variants: [
+		{
+			id: 'control',
+			test: (): void => {
+				/* no-op */
+			},
+		},
+		{
+			id: 'variant',
+			test: (): void => {
+				/* no-op */
+			},
+		},
+	],
+	canRun: () => true,
+};

src/lib/header-bidding/prebid/prebid.ts

@@ -9,6 +9,7 @@ import { EventTimer } from '../../../core/event-timer';
 import type { PageTargeting } from '../../../core/targeting/build-page-targeting';
 import type { Advert } from '../../../define/Advert';
 import { isUserInVariant } from '../../../experiments/ab';
+import { gpidPrebidAdUnits } from '../../../experiments/tests/gpid-prebid';
 import { newHeaderBiddingEndpoint } from '../../../experiments/tests/new-header-bidding-endpoint';
 import { getPageTargeting } from '../../build-page-targeting';
 import { getAdvertById } from '../../dfp/get-advert-by-id';
@@ -163,10 +164,21 @@ type BidderSettings = {
 	magnite?: Partial<BidderSetting>;
 };
 
+const shouldIncludeGpid = !isUserInVariant(gpidPrebidAdUnits, 'control');
+
 class PrebidAdUnit {
 	code: string | null | undefined;
 	bids: PrebidBid[] | null | undefined;
 	mediaTypes: PrebidMediaTypes | null | undefined;
+	gpid?: string;
+	ortb2Imp?: {
+		ext: {
+			gpid: string;
+			data: {
+				pbadslot: string;
+			};
+		};
+	};
 
 	constructor(
 		advert: Advert,
@@ -176,13 +188,31 @@ class PrebidAdUnit {
 		this.code = advert.id;
 		this.bids = bids(advert.id, slot.sizes, pageTargeting);
 		this.mediaTypes = { banner: { sizes: slot.sizes } };
+		if (shouldIncludeGpid) {
+			this.gpid = this.generateGpid(advert, slot);
+			this.ortb2Imp = {
+				ext: {
+					gpid: this.gpid,
+					data: {
+						pbadslot: this.gpid,
+					},
+				},
+			};
+		}
+
 		advert.headerBiddingSizes = slot.sizes;
 		log('commercial', `PrebidAdUnit ${this.code}`, this.bids);
 	}
 
 	isEmpty() {
 		return this.code == null;
 	}
+	private generateGpid(advert: Advert, slot: HeaderBiddingSlot): string {
+		const sectionName = window.guardian.config.page.section;
+		const contentType = window.guardian.config.page.contentType;
+		const slotName = slot.key;
+		return `/59666047/gu/${sectionName}/${contentType}/${slotName}`;
+	}
 }
 
 declare global {