diff --git a/src/content-gate/gate.js b/src/content-gate/gate.js
index 6a17bae8b4..3d4366dacb 100644
--- a/src/content-gate/gate.js
+++ b/src/content-gate/gate.js
@@ -160,9 +160,19 @@ function getGateEventPayload( payload, gate ) {
 /**
  * Handle when the gate is seen.
  *
- * @param {HTMLElement} gate The gate element.
+ * @param {HTMLElement} gate            The gate element.
+ * @param {boolean}     shouldRecordHit Whether to record a hit in RAS for this seen event. Defaults to false.
  */
-function handleSeen( gate ) {
+function handleSeen( gate, shouldRecordHit = false ) {
+	if ( shouldRecordHit ) {
+		// paywall_hits - Number of times reader has reached a paywall.
+		window.newspackRAS = window.newspackRAS || [];
+		window.newspackRAS.push( function ( ras ) {
+			const currentHits = ras.store.get( 'paywall_hits' ) || 0;
+			ras.store.set( 'paywall_hits', currentHits + 1 );
+		} );
+	}
+
 	if ( 'function' !== typeof window.gtag ) {
 		return;
 	}
@@ -314,14 +324,16 @@ domReady( function () {
 	} else {
 		window.addEventListener( 'resize', handleFloatingElements );
 		handleFloatingElements();
+		let seen = false;
 		// Seen event for inline gate.
 		const detectSeen = () => {
 			const delta = ( gate?.getBoundingClientRect().top || 0 ) - window.innerHeight / 2;
 			if ( delta < 0 ) {
+				handleSeen( gate, ! seen );
 				if ( 'function' === typeof window.gtag ) {
-					handleSeen( gate );
 					document.removeEventListener( 'scroll', detectSeen );
 				}
+				seen = true;
 			}
 		};
 		document.addEventListener( 'scroll', detectSeen );
diff --git a/src/reader-activation/article-view.js b/src/reader-activation/article-view.js
index b932ed2dbd..0b4893ac3a 100644
--- a/src/reader-activation/article-view.js
+++ b/src/reader-activation/article-view.js
@@ -36,5 +36,25 @@ export default function setupArticleViewsAggregates( ras ) {
 		}
 		per_month[ month ][ data.post_id ] = true;
 		ras.store.set( 'article_view_per_month', per_month );
+
+		// articles_read — A cumulative count of articles the reader has read.
+		const uniqueViews = ras.getUniqueActivitiesBy( 'article_view', 'post_id' );
+		ras.store.set( 'articles_read', uniqueViews.length );
+
+		// favorite_categories — A list of the reader's most-engaged content categories, ordered by frequency.
+		const allActivities = ras.getActivities( 'article_view' );
+		const catCounts = {};
+		for ( const activity of allActivities ) {
+			const cats = activity.data?.categories || [];
+			for ( const cat of cats ) {
+				catCounts[ cat ] = ( catCounts[ cat ] || 0 ) + 1;
+			}
+		}
+		const topCategories = Object.entries( catCounts )
+			.filter( ( [ , count ] ) => count >= 2 )
+			.sort( ( a, b ) => b[ 1 ] - a[ 1 ] )
+			.slice( 0, 5 )
+			.map( ( [ id ] ) => Number( id ) );
+		ras.store.set( 'favorite_categories', topCategories );
 	} );
 }
diff --git a/src/reader-activation/article-view.test.js b/src/reader-activation/article-view.test.js
new file mode 100644
index 0000000000..95e6e00244
--- /dev/null
+++ b/src/reader-activation/article-view.test.js
@@ -0,0 +1,76 @@
+import setupArticleViewsAggregates from './article-view';
+import { createMockRAS } from './mocks/ras';
+
+describe( 'setupArticleViewsAggregates', () => {
+	let mock;
+
+	beforeEach( () => {
+		mock = createMockRAS();
+		setupArticleViewsAggregates( mock.ras );
+	} );
+
+	afterEach( () => {
+		mock.reset();
+	} );
+
+	function simulateArticleView( data, timestamp = Date.now() ) {
+		mock.trigger( 'activity', { action: 'article_view', data, timestamp } );
+	}
+
+	it( 'should register an activity listener', () => {
+		expect( mock.ras.on ).toHaveBeenCalledWith( 'activity', expect.any( Function ) );
+	} );
+
+	it( 'should ignore non-article_view actions', () => {
+		mock.trigger( 'activity', { action: 'other_action', data: {}, timestamp: Date.now() } );
+		expect( mock.ras.store.set ).not.toHaveBeenCalled();
+	} );
+
+	describe( 'articles_read', () => {
+		it( 'should set articles_read to count of unique post IDs', () => {
+			mock.addActivity( 'article_view', { post_id: 1, categories: [] } );
+			mock.addActivity( 'article_view', { post_id: 2, categories: [] } );
+			simulateArticleView( { post_id: 2, categories: [] } );
+			expect( mock.storeData.articles_read ).toBe( 2 );
+		} );
+
+		it( 'should not increment for duplicate post IDs', () => {
+			mock.addActivity( 'article_view', { post_id: 1, categories: [] } );
+			mock.addActivity( 'article_view', { post_id: 1, categories: [] } );
+			simulateArticleView( { post_id: 1, categories: [] } );
+			expect( mock.storeData.articles_read ).toBe( 1 );
+		} );
+	} );
+
+	describe( 'favorite_categories', () => {
+		it( 'should contain category IDs sorted by frequency', () => {
+			mock.addActivity( 'article_view', { post_id: 1, categories: [ 10, 20 ] } );
+			mock.addActivity( 'article_view', { post_id: 2, categories: [ 10 ] } );
+			mock.addActivity( 'article_view', { post_id: 3, categories: [ 20, 30 ] } );
+			simulateArticleView( { post_id: 3, categories: [ 20, 30 ] } );
+			// 10 appears 2x, 20 appears 2x, 30 appears 1x (excluded — needs >= 2).
+			expect( mock.storeData.favorite_categories ).toEqual( [ 10, 20 ] );
+		} );
+
+		it( 'should exclude categories with only 1 view', () => {
+			mock.addActivity( 'article_view', { post_id: 1, categories: [ 10 ] } );
+			simulateArticleView( { post_id: 2, categories: [ 20 ] } );
+			// Each category has only 1 view.
+			expect( mock.storeData.favorite_categories ).toEqual( [] );
+		} );
+
+		it( 'should limit to top 5 categories', () => {
+			// Each category needs at least 2 views to be included.
+			mock.addActivity( 'article_view', { post_id: 1, categories: [ 1, 2, 3, 4, 5, 6, 7 ] } );
+			mock.addActivity( 'article_view', { post_id: 2, categories: [ 1, 2, 3, 4, 5, 6, 7 ] } );
+			simulateArticleView( { post_id: 3, categories: [ 1, 2, 3, 4, 5, 6, 7 ] } );
+			expect( mock.storeData.favorite_categories ).toHaveLength( 5 );
+		} );
+
+		it( 'should handle articles with no categories', () => {
+			mock.addActivity( 'article_view', { post_id: 1 } );
+			simulateArticleView( { post_id: 1 } );
+			expect( mock.storeData.favorite_categories ).toEqual( [] );
+		} );
+	} );
+} );
diff --git a/src/reader-activation/engagement.js b/src/reader-activation/engagement.js
new file mode 100644
index 0000000000..040abbf961
--- /dev/null
+++ b/src/reader-activation/engagement.js
@@ -0,0 +1,19 @@
+/* globals newspack_reader_data */
+
+/**
+ * Set up general reader engagement fields.
+ *
+ * @param {Object} ras Reader Activation object.
+ */
+export default function setupEngagement( ras ) {
+	// first_visit_date — preserve the oldest known value (server or client).
+	const serverFirstVisit = newspack_reader_data?.items?.first_visit_date;
+	const serverValue = serverFirstVisit ? JSON.parse( serverFirstVisit ) : null;
+	const clientValue = ras.store.get( 'first_visit_date' );
+	const candidates = [ serverValue, clientValue ].filter( Boolean );
+	const firstVisit = candidates.length ? Math.min( ...candidates ) : Date.now();
+	ras.store.set( 'first_visit_date', firstVisit );
+
+	// last_active — Date reader was last seen on site.
+	ras.store.set( 'last_active', Date.now() );
+}
diff --git a/src/reader-activation/engagement.test.js b/src/reader-activation/engagement.test.js
new file mode 100644
index 0000000000..d09487a0ad
--- /dev/null
+++ b/src/reader-activation/engagement.test.js
@@ -0,0 +1,62 @@
+import setupEngagement from './engagement';
+import { createMockRAS } from './mocks/ras';
+
+describe( 'setupEngagement', () => {
+	let mock;
+
+	beforeEach( () => {
+		mock = createMockRAS();
+		window.newspack_reader_data = {};
+	} );
+
+	afterEach( () => {
+		mock.reset();
+		delete window.newspack_reader_data;
+	} );
+
+	it( 'should set first_visit_date on first call', () => {
+		setupEngagement( mock.ras );
+		expect( mock.ras.store.set ).toHaveBeenCalledWith( 'first_visit_date', expect.any( Number ) );
+	} );
+
+	it( 'should preserve existing client first_visit_date when no server value', () => {
+		mock.storeData.first_visit_date = 1000;
+		setupEngagement( mock.ras );
+		expect( mock.storeData.first_visit_date ).toBe( 1000 );
+	} );
+
+	it( 'should prefer older server value over newer client value', () => {
+		const oldServerValue = 1000;
+		const newClientValue = 9999;
+		mock.storeData.first_visit_date = newClientValue;
+		window.newspack_reader_data = {
+			items: { first_visit_date: JSON.stringify( oldServerValue ) },
+		};
+		setupEngagement( mock.ras );
+		expect( mock.storeData.first_visit_date ).toBe( oldServerValue );
+	} );
+
+	it( 'should prefer older client value over newer server value', () => {
+		const oldClientValue = 1000;
+		const newServerValue = 9999;
+		mock.storeData.first_visit_date = oldClientValue;
+		window.newspack_reader_data = {
+			items: { first_visit_date: JSON.stringify( newServerValue ) },
+		};
+		setupEngagement( mock.ras );
+		expect( mock.storeData.first_visit_date ).toBe( oldClientValue );
+	} );
+
+	it( 'should always set last_active', () => {
+		setupEngagement( mock.ras );
+		expect( mock.ras.store.set ).toHaveBeenCalledWith( 'last_active', expect.any( Number ) );
+	} );
+
+	it( 'should set last_active to a recent timestamp', () => {
+		const before = Date.now();
+		setupEngagement( mock.ras );
+		const after = Date.now();
+		expect( mock.storeData.last_active ).toBeGreaterThanOrEqual( before );
+		expect( mock.storeData.last_active ).toBeLessThanOrEqual( after );
+	} );
+} );
diff --git a/src/reader-activation/index.js b/src/reader-activation/index.js
index 7a06913d6a..68e512c9d7 100644
--- a/src/reader-activation/index.js
+++ b/src/reader-activation/index.js
@@ -9,6 +9,7 @@ import { getCookie, setCookie, generateID, debugLog } from './utils.js';
 import overlays from './overlays.js';
 import initAnalytics from './analytics.js';
 import setupArticleViewsAggregates from './article-view.js';
+import setupEngagement from './engagement.js';
 import initSubscriptionTiersForm from './subscription-tiers-form.js';
 import { openAuthModal as _openAuthModal } from '../reader-activation-auth/auth-modal.js';
 
@@ -490,6 +491,7 @@ function init() {
 	initSubscriptionTiersForm( readerActivation );
 	fixClientID();
 	setupArticleViewsAggregates( readerActivation );
+	setupEngagement( readerActivation );
 	attachAuthCookiesListener();
 	attachNewsletterFormListener();
 	pushActivities();
diff --git a/src/reader-activation/mocks/ras.js b/src/reader-activation/mocks/ras.js
new file mode 100644
index 0000000000..9a42c958d3
--- /dev/null
+++ b/src/reader-activation/mocks/ras.js
@@ -0,0 +1,75 @@
+/**
+ * Creates a mock RAS (Reader Activation System) object for testing.
+ *
+ * @return {Object} Mock RAS with store, event handlers, and activity helpers.
+ */
+export function createMockRAS() {
+	const storeData = {};
+	const activities = [];
+	const handlers = {};
+
+	const ras = {
+		store: {
+			get: jest.fn( key => storeData[ key ] ?? null ),
+			set: jest.fn( ( key, value ) => {
+				storeData[ key ] = value;
+			} ),
+		},
+		on: jest.fn( ( event, callback ) => {
+			handlers[ event ] = callback;
+		} ),
+		getActivities: jest.fn( () => activities ),
+		getUniqueActivitiesBy: jest.fn( () => {
+			const seen = {};
+			return activities.filter( a => {
+				if ( seen[ a.data.post_id ] ) {
+					return false;
+				}
+				seen[ a.data.post_id ] = true;
+				return true;
+			} );
+		} ),
+	};
+
+	return {
+		ras,
+		/**
+		 * Get the current store data.
+		 */
+		storeData,
+		/**
+		 * Add an activity to the internal activities array.
+		 *
+		 * @param {string} action    Activity action name.
+		 * @param {Object} data      Activity data.
+		 * @param {number} timestamp Optional timestamp.
+		 */
+		addActivity( action, data, timestamp = Date.now() ) {
+			activities.push( { action, data, timestamp } );
+		},
+		/**
+		 * Trigger a registered event handler.
+		 *
+		 * @param {string} event  Event name.
+		 * @param {Object} detail Event detail payload.
+		 */
+		trigger( event, detail ) {
+			if ( handlers[ event ] ) {
+				handlers[ event ]( { detail } );
+			}
+		},
+		/**
+		 * Reset all state between tests.
+		 */
+		reset() {
+			for ( const key in storeData ) {
+				delete storeData[ key ];
+			}
+			for ( const event in handlers ) {
+				delete handlers[ event ];
+			}
+			activities.length = 0;
+			jest.clearAllMocks();
+		},
+	};
+}