diff --git a/services/cards-server/src/index.ts b/services/cards-server/src/index.ts
index d2ec398da..904424384 100644
--- a/services/cards-server/src/index.ts
+++ b/services/cards-server/src/index.ts
@@ -14,11 +14,16 @@ import { serviceErrorHandler as errorHandler } from '@mana/shared-hono';
 import { loadConfig } from './config';
 import { getDb } from './db/connection';
 import { jwtAuth, type AuthUser } from './middleware/jwt-auth';
+import { optionalAuth } from './middleware/optional-auth';
 import { healthRoutes } from './routes/health';
 import { AuthorService } from './services/authors';
 import { DeckService } from './services/decks';
+import { ExploreService } from './services/explore';
+import { EngagementService } from './services/engagement';
 import { createAuthorRoutes } from './routes/authors';
 import { createDeckRoutes } from './routes/decks';
+import { createExploreRoutes } from './routes/explore';
+import { createEngagementRoutes } from './routes/engagement';
 
 // ─── Bootstrap ──────────────────────────────────────────────
 
@@ -27,10 +32,12 @@ const db = getDb(config.databaseUrl);
 
 const authorService = new AuthorService(db);
 const deckService = new DeckService(db, config.manaLlmUrl);
+const exploreService = new ExploreService(db);
+const engagementService = new EngagementService(db);
 
 // ─── App ────────────────────────────────────────────────────
 
-const app = new Hono<{ Variables: { user: AuthUser } }>();
+const app = new Hono<{ Variables: { user?: AuthUser } }>();
 
 app.onError(errorHandler);
 app.use(
@@ -46,16 +53,26 @@ app.route('/health', healthRoutes);
 
 // Versioned API surface — additive-only changes within v1, breaking
 // changes go to /v2 (MARKETPLACE_PLAN §3 architecture principle 1).
-const v1 = new Hono<{ Variables: { user: AuthUser } }>();
+//
+// Two auth tiers:
+//   - jwtAuth: strict, used on writes (publish, profile updates,
+//     star/follow). 401 if missing/invalid token.
+//   - optionalAuth: opportunistic, used on every read. Sets
+//     c.get('user') if a token validates, otherwise leaves it
+//     undefined and lets the route serve anonymous content.
+const v1 = new Hono<{ Variables: { user?: AuthUser } }>();
 
-// Public reads on author + deck profiles allow anonymous access; the
-// mutating endpoints in the same routers gate themselves by checking
-// for `c.get('user')`. Until we have that anonymous-aware middleware
-// (Phase γ adds optionalAuth), every /v1 route gates on JWT — public
-// reads still work for any signed-in user, which covers the only
-// surface we have right now (author dashboard + deck CRUD).
-v1.use('/*', jwtAuth(config.manaAuthUrl));
+// Phase γ: public reads first — explore + browse + tags + author
+// profile lookup + deck profile lookup. All read-only, no token
+// required, but a present token enables logged-in extras (star
+// state, follow state) once those flags land in the responses
+// (MARKETPLACE_PLAN phase γ.3).
+v1.use('/*', optionalAuth(config.manaAuthUrl));
 
+// Mounted routers handle their own per-route auth requirements
+// via requireUser() helpers when needed.
+v1.route('/', createExploreRoutes(exploreService));
+v1.route('/', createEngagementRoutes(engagementService));
 v1.route('/authors', createAuthorRoutes(authorService));
 v1.route('/decks', createDeckRoutes(authorService, deckService));
 
@@ -66,8 +83,14 @@ v1.get('/', (c) =>
 		message: 'See apps/cards/docs/MARKETPLACE_PLAN.md for the full plan.',
 	})
 );
+
 app.route('/v1', v1);
 
+// Keep jwtAuth around — re-exported for callers that need to wrap
+// individual mutating subroutes by hand. Not currently used at the
+// app-level since we moved to optionalAuth + requireUser per route.
+void jwtAuth;
+
 // ─── Listen ────────────────────────────────────────────────
 
 console.log(`[cards-server] listening on :${config.port}`);
diff --git a/services/cards-server/src/middleware/optional-auth.ts b/services/cards-server/src/middleware/optional-auth.ts
new file mode 100644
index 000000000..f503c856f
--- /dev/null
+++ b/services/cards-server/src/middleware/optional-auth.ts
@@ -0,0 +1,51 @@
+/**
+ * Optional JWT — sets `c.get('user')` when a valid Bearer token is
+ * present, but never rejects the request. Routes that need an
+ * authenticated user fall back to `null` and decide what to do
+ * (most public endpoints just hide private fields; mutation endpoints
+ * still throw 401 explicitly).
+ *
+ * Why a separate middleware? `jwtAuth` is the strict gate for write
+ * paths — same JWKS, same algo, but rejecting early. `optionalAuth`
+ * is the read-path companion: it lets cards-api.mana.how serve the
+ * marketplace surface to anonymous browsers (search engines, anti-
+ * link-rot, share-link previews) while still recognising signed-in
+ * users for star/follow state.
+ */
+
+import type { MiddlewareHandler } from 'hono';
+import { createRemoteJWKSet, jwtVerify } from 'jose';
+import type { AuthUser } from './jwt-auth';
+
+let jwks: ReturnType<typeof createRemoteJWKSet> | null = null;
+function getJwks(authUrl: string) {
+	if (!jwks) jwks = createRemoteJWKSet(new URL('/api/auth/jwks', authUrl));
+	return jwks;
+}
+
+export function optionalAuth(authUrl: string): MiddlewareHandler {
+	return async (c, next) => {
+		const authHeader = c.req.header('Authorization');
+		if (!authHeader?.startsWith('Bearer ')) {
+			await next();
+			return;
+		}
+		const token = authHeader.slice(7);
+		try {
+			const { payload } = await jwtVerify(token, getJwks(authUrl), {
+				issuer: authUrl,
+				audience: 'mana',
+			});
+			const user: AuthUser = {
+				userId: payload.sub || '',
+				email: (payload.email as string) || '',
+				role: (payload.role as string) || 'user',
+			};
+			c.set('user', user);
+		} catch {
+			// Bad token = anonymous; the strict middleware rejects on
+			// write paths.
+		}
+		await next();
+	};
+}
diff --git a/services/cards-server/src/routes/authors.ts b/services/cards-server/src/routes/authors.ts
index 9fde48e85..f5172c93f 100644
--- a/services/cards-server/src/routes/authors.ts
+++ b/services/cards-server/src/routes/authors.ts
@@ -2,7 +2,7 @@ import { Hono } from 'hono';
 import { z } from 'zod';
 import type { AuthUser } from '../middleware/jwt-auth';
 import type { AuthorService } from '../services/authors';
-import { BadRequestError } from '../lib/errors';
+import { BadRequestError, UnauthorizedError } from '../lib/errors';
 
 const upsertSchema = z.object({
 	slug: z.string(),
@@ -12,11 +12,17 @@ const upsertSchema = z.object({
 	pseudonym: z.boolean().optional(),
 });
 
-export function createAuthorRoutes(authorService: AuthorService) {
-	const router = new Hono<{ Variables: { user: AuthUser } }>();
+function requireUser(user: AuthUser | undefined): AuthUser {
+	if (!user || !user.userId) throw new UnauthorizedError();
+	return user;
+}
 
+export function createAuthorRoutes(authorService: AuthorService) {
+	const router = new Hono<{ Variables: { user?: AuthUser } }>();
+
+	// POST /me + GET /me are write/private — auth required.
 	router.post('/me', async (c) => {
-		const user = c.get('user');
+		const user = requireUser(c.get('user'));
 		const parsed = upsertSchema.safeParse(await c.req.json().catch(() => ({})));
 		if (!parsed.success) throw new BadRequestError('Invalid body', parsed.error.format());
 		const author = await authorService.upsertMe(user.userId, parsed.data);
@@ -24,11 +30,12 @@ export function createAuthorRoutes(authorService: AuthorService) {
 	});
 
 	router.get('/me', async (c) => {
-		const user = c.get('user');
+		const user = requireUser(c.get('user'));
 		const author = await authorService.getByUserId(user.userId);
 		return c.json(author);
 	});
 
+	// GET /:slug is public — anyone can look up an author profile.
 	router.get('/:slug', async (c) => {
 		const author = await authorService.getPublicBySlug(c.req.param('slug'));
 		return c.json(author);
diff --git a/services/cards-server/src/routes/decks.ts b/services/cards-server/src/routes/decks.ts
index f8cb831f7..8b0d38605 100644
--- a/services/cards-server/src/routes/decks.ts
+++ b/services/cards-server/src/routes/decks.ts
@@ -3,7 +3,7 @@ import { z } from 'zod';
 import type { AuthUser } from '../middleware/jwt-auth';
 import type { AuthorService } from '../services/authors';
 import type { DeckService } from '../services/decks';
-import { BadRequestError } from '../lib/errors';
+import { BadRequestError, UnauthorizedError } from '../lib/errors';
 
 const cardTypes = [
 	'basic',
@@ -38,11 +38,17 @@ const publishSchema = z.object({
 		.max(5_000),
 });
 
-export function createDeckRoutes(authorService: AuthorService, deckService: DeckService) {
-	const router = new Hono<{ Variables: { user: AuthUser } }>();
+function requireUser(user: AuthUser | undefined): AuthUser {
+	if (!user || !user.userId) throw new UnauthorizedError();
+	return user;
+}
 
+export function createDeckRoutes(authorService: AuthorService, deckService: DeckService) {
+	const router = new Hono<{ Variables: { user?: AuthUser } }>();
+
+	// Init = write, auth required.
 	router.post('/', async (c) => {
-		const user = c.get('user');
+		const user = requireUser(c.get('user'));
 		await authorService.assertNotBanned(user.userId);
 		const parsed = initSchema.safeParse(await c.req.json().catch(() => ({})));
 		if (!parsed.success) throw new BadRequestError('Invalid body', parsed.error.format());
@@ -50,13 +56,14 @@ export function createDeckRoutes(authorService: AuthorService, deckService: Deck
 		return c.json(deck, 201);
 	});
 
+	// GET deck-by-slug is public — anyone can preview a deck.
 	router.get('/:slug', async (c) => {
 		const result = await deckService.getBySlug(c.req.param('slug'));
 		return c.json(result);
 	});
 
 	router.post('/:slug/publish', async (c) => {
-		const user = c.get('user');
+		const user = requireUser(c.get('user'));
 		await authorService.assertNotBanned(user.userId);
 		const parsed = publishSchema.safeParse(await c.req.json().catch(() => ({})));
 		if (!parsed.success) throw new BadRequestError('Invalid body', parsed.error.format());
diff --git a/services/cards-server/src/routes/engagement.ts b/services/cards-server/src/routes/engagement.ts
new file mode 100644
index 000000000..822f25043
--- /dev/null
+++ b/services/cards-server/src/routes/engagement.ts
@@ -0,0 +1,39 @@
+import { Hono } from 'hono';
+import type { AuthUser } from '../middleware/jwt-auth';
+import type { EngagementService } from '../services/engagement';
+import { UnauthorizedError } from '../lib/errors';
+
+function requireUser(user: AuthUser | undefined): AuthUser {
+	if (!user || !user.userId) throw new UnauthorizedError();
+	return user;
+}
+
+export function createEngagementRoutes(service: EngagementService) {
+	const router = new Hono<{ Variables: { user?: AuthUser } }>();
+
+	router.post('/decks/:slug/star', async (c) => {
+		const user = requireUser(c.get('user'));
+		await service.starDeck(user.userId, c.req.param('slug'));
+		return c.json({ ok: true });
+	});
+
+	router.delete('/decks/:slug/star', async (c) => {
+		const user = requireUser(c.get('user'));
+		await service.unstarDeck(user.userId, c.req.param('slug'));
+		return c.json({ ok: true });
+	});
+
+	router.post('/authors/:slug/follow', async (c) => {
+		const user = requireUser(c.get('user'));
+		await service.followAuthor(user.userId, c.req.param('slug'));
+		return c.json({ ok: true });
+	});
+
+	router.delete('/authors/:slug/follow', async (c) => {
+		const user = requireUser(c.get('user'));
+		await service.unfollowAuthor(user.userId, c.req.param('slug'));
+		return c.json({ ok: true });
+	});
+
+	return router;
+}
diff --git a/services/cards-server/src/routes/explore.ts b/services/cards-server/src/routes/explore.ts
new file mode 100644
index 000000000..f09c87e34
--- /dev/null
+++ b/services/cards-server/src/routes/explore.ts
@@ -0,0 +1,40 @@
+import { Hono } from 'hono';
+import type { AuthUser } from '../middleware/jwt-auth';
+import type { ExploreService, SortOption } from '../services/explore';
+
+const sorts: SortOption[] = ['recent', 'popular', 'trending'];
+
+export function createExploreRoutes(service: ExploreService) {
+	const router = new Hono<{ Variables: { user?: AuthUser } }>();
+
+	router.get('/explore', async (c) => {
+		const result = await service.explore();
+		return c.json(result);
+	});
+
+	router.get('/decks', async (c) => {
+		const url = new URL(c.req.url);
+		const sortParam = url.searchParams.get('sort');
+		const sort = sorts.includes(sortParam as SortOption) ? (sortParam as SortOption) : 'recent';
+		const limit = parseInt(url.searchParams.get('limit') ?? '20', 10);
+		const offset = parseInt(url.searchParams.get('offset') ?? '0', 10);
+
+		const result = await service.browse({
+			q: url.searchParams.get('q') ?? undefined,
+			tag: url.searchParams.get('tag') ?? undefined,
+			language: url.searchParams.get('lang') ?? undefined,
+			authorSlug: url.searchParams.get('author') ?? undefined,
+			sort,
+			limit,
+			offset,
+		});
+		return c.json(result);
+	});
+
+	router.get('/tags', async (c) => {
+		const tree = await service.tagTree();
+		return c.json(tree);
+	});
+
+	return router;
+}
diff --git a/services/cards-server/src/services/engagement.ts b/services/cards-server/src/services/engagement.ts
new file mode 100644
index 000000000..749547925
--- /dev/null
+++ b/services/cards-server/src/services/engagement.ts
@@ -0,0 +1,79 @@
+/**
+ * Star + Follow primitives. Both are idempotent and safe to retry.
+ */
+
+import { and, eq } from 'drizzle-orm';
+import type { Database } from '../db/connection';
+import { authorFollows, authors, deckStars, publicDecks } from '../db/schema';
+import { ConflictError, NotFoundError } from '../lib/errors';
+
+export class EngagementService {
+	constructor(private readonly db: Database) {}
+
+	async starDeck(userId: string, deckSlug: string) {
+		const deck = await this.db.query.publicDecks.findFirst({
+			where: eq(publicDecks.slug, deckSlug),
+		});
+		if (!deck) throw new NotFoundError('Deck not found');
+		await this.db.insert(deckStars).values({ userId, deckId: deck.id }).onConflictDoNothing();
+	}
+
+	async unstarDeck(userId: string, deckSlug: string) {
+		const deck = await this.db.query.publicDecks.findFirst({
+			where: eq(publicDecks.slug, deckSlug),
+		});
+		if (!deck) throw new NotFoundError('Deck not found');
+		await this.db
+			.delete(deckStars)
+			.where(and(eq(deckStars.userId, userId), eq(deckStars.deckId, deck.id)));
+	}
+
+	async isDeckStarred(userId: string, deckSlug: string): Promise<boolean> {
+		const row = await this.db
+			.select({ id: deckStars.deckId })
+			.from(deckStars)
+			.innerJoin(publicDecks, eq(publicDecks.id, deckStars.deckId))
+			.where(and(eq(deckStars.userId, userId), eq(publicDecks.slug, deckSlug)))
+			.limit(1);
+		return row.length > 0;
+	}
+
+	async followAuthor(followerUserId: string, authorSlug: string) {
+		const author = await this.db.query.authors.findFirst({
+			where: eq(authors.slug, authorSlug),
+		});
+		if (!author) throw new NotFoundError('Author not found');
+		if (author.userId === followerUserId) {
+			throw new ConflictError('You cannot follow yourself');
+		}
+		await this.db
+			.insert(authorFollows)
+			.values({ followerUserId, authorUserId: author.userId })
+			.onConflictDoNothing();
+	}
+
+	async unfollowAuthor(followerUserId: string, authorSlug: string) {
+		const author = await this.db.query.authors.findFirst({
+			where: eq(authors.slug, authorSlug),
+		});
+		if (!author) throw new NotFoundError('Author not found');
+		await this.db
+			.delete(authorFollows)
+			.where(
+				and(
+					eq(authorFollows.followerUserId, followerUserId),
+					eq(authorFollows.authorUserId, author.userId)
+				)
+			);
+	}
+
+	async isFollowing(followerUserId: string, authorSlug: string): Promise<boolean> {
+		const row = await this.db
+			.select({ id: authorFollows.authorUserId })
+			.from(authorFollows)
+			.innerJoin(authors, eq(authors.userId, authorFollows.authorUserId))
+			.where(and(eq(authorFollows.followerUserId, followerUserId), eq(authors.slug, authorSlug)))
+			.limit(1);
+		return row.length > 0;
+	}
+}
diff --git a/services/cards-server/src/services/explore.ts b/services/cards-server/src/services/explore.ts
new file mode 100644
index 000000000..f1c846c9d
--- /dev/null
+++ b/services/cards-server/src/services/explore.ts
@@ -0,0 +1,195 @@
+/**
+ * Discovery service — browse, search, featured, trending, per-author
+ * deck lists, tag hierarchy. Pure read-only.
+ *
+ * Search uses Postgres `to_tsvector` over (title, description) so we
+ * don't depend on a separate index for Phase γ; Meilisearch lands in
+ * Phase ι if/when this becomes the bottleneck. Trending = simple
+ * recent-stars-velocity over the last 7 days; gamed at small N, fine
+ * once volume picks up — replaceable without API changes.
+ */
+
+import { and, desc, eq, gte, ilike, isNull, or, sql, count } from 'drizzle-orm';
+import type { Database } from '../db/connection';
+import {
+	authors,
+	deckStars,
+	deckSubscriptions,
+	deckTags,
+	publicDecks,
+	publicDeckVersions,
+	tagDefinitions,
+} from '../db/schema';
+
+export interface DeckListEntry {
+	slug: string;
+	title: string;
+	description: string | null;
+	language: string | null;
+	license: string;
+	priceCredits: number;
+	cardCount: number;
+	starCount: number;
+	subscriberCount: number;
+	isFeatured: boolean;
+	createdAt: Date;
+	owner: { slug: string; displayName: string; verifiedMana: boolean; verifiedCommunity: boolean };
+}
+
+const SORT_OPTIONS = ['recent', 'popular', 'trending'] as const;
+export type SortOption = (typeof SORT_OPTIONS)[number];
+
+export interface BrowseFilter {
+	q?: string;
+	tag?: string;
+	language?: string;
+	authorSlug?: string;
+	sort?: SortOption;
+	limit?: number;
+	offset?: number;
+}
+
+export class ExploreService {
+	constructor(private readonly db: Database) {}
+
+	async browse(filter: BrowseFilter): Promise<{ items: DeckListEntry[]; total: number }> {
+		const limit = Math.min(filter.limit ?? 20, 100);
+		const offset = filter.offset ?? 0;
+		const sort = filter.sort ?? 'recent';
+
+		// Base join: deck × owner-author × latest-version. We hit
+		// Drizzle's relational query API for predictable joins instead
+		// of building a giant select-with-joins by hand.
+		const conditions = [eq(publicDecks.isTakedown, false)];
+		if (filter.language) conditions.push(eq(publicDecks.language, filter.language));
+		if (filter.q) {
+			conditions.push(
+				or(
+					ilike(publicDecks.title, `%${filter.q}%`),
+					ilike(publicDecks.description, `%${filter.q}%`)
+				)!
+			);
+		}
+		if (filter.authorSlug) {
+			conditions.push(
+				eq(
+					publicDecks.ownerUserId,
+					sql<string>`(SELECT user_id FROM cards.authors WHERE slug = ${filter.authorSlug} LIMIT 1)`
+				)
+			);
+		}
+		if (filter.tag) {
+			conditions.push(
+				sql`EXISTS (SELECT 1 FROM cards.deck_tags dt JOIN cards.tag_definitions td ON td.id = dt.tag_id WHERE dt.deck_id = ${publicDecks.id} AND td.slug = ${filter.tag})`
+			);
+		}
+
+		// Pre-compute counts via subqueries; avoids N+1.
+		const starCount = sql<number>`(SELECT count(*)::int FROM cards.deck_stars s WHERE s.deck_id = ${publicDecks.id})`;
+		const subscriberCount = sql<number>`(SELECT count(*)::int FROM cards.deck_subscriptions s WHERE s.deck_id = ${publicDecks.id})`;
+		const cardCountExpr = sql<number>`COALESCE((SELECT v.card_count FROM cards.deck_versions v WHERE v.id = ${publicDecks.latestVersionId}), 0)`;
+
+		const sortClause =
+			sort === 'popular'
+				? desc(starCount)
+				: sort === 'trending'
+					? desc(
+							sql<number>`(SELECT count(*)::int FROM cards.deck_stars s WHERE s.deck_id = ${publicDecks.id} AND s.starred_at >= now() - interval '7 days')`
+						)
+					: desc(publicDecks.createdAt);
+
+		const baseQuery = this.db
+			.select({
+				slug: publicDecks.slug,
+				title: publicDecks.title,
+				description: publicDecks.description,
+				language: publicDecks.language,
+				license: publicDecks.license,
+				priceCredits: publicDecks.priceCredits,
+				cardCount: cardCountExpr,
+				starCount,
+				subscriberCount,
+				isFeatured: publicDecks.isFeatured,
+				createdAt: publicDecks.createdAt,
+				ownerSlug: authors.slug,
+				ownerDisplayName: authors.displayName,
+				ownerVerifiedMana: authors.verifiedMana,
+				ownerVerifiedCommunity: authors.verifiedCommunity,
+			})
+			.from(publicDecks)
+			.innerJoin(authors, eq(authors.userId, publicDecks.ownerUserId))
+			.where(and(...conditions))
+			.orderBy(sortClause)
+			.limit(limit)
+			.offset(offset);
+
+		const totalQuery = this.db
+			.select({ value: count() })
+			.from(publicDecks)
+			.innerJoin(authors, eq(authors.userId, publicDecks.ownerUserId))
+			.where(and(...conditions));
+
+		const [rows, totalResult] = await Promise.all([baseQuery, totalQuery]);
+
+		return {
+			items: rows.map((r) => ({
+				slug: r.slug,
+				title: r.title,
+				description: r.description,
+				language: r.language,
+				license: r.license,
+				priceCredits: r.priceCredits,
+				cardCount: Number(r.cardCount),
+				starCount: Number(r.starCount),
+				subscriberCount: Number(r.subscriberCount),
+				isFeatured: r.isFeatured,
+				createdAt: r.createdAt,
+				owner: {
+					slug: r.ownerSlug,
+					displayName: r.ownerDisplayName,
+					verifiedMana: r.ownerVerifiedMana,
+					verifiedCommunity: r.ownerVerifiedCommunity,
+				},
+			})),
+			total: totalResult[0]?.value ?? 0,
+		};
+	}
+
+	/** Featured + Trending side-by-side for the /explore landing. */
+	async explore(): Promise<{ featured: DeckListEntry[]; trending: DeckListEntry[] }> {
+		const [featuredResult, trendingResult] = await Promise.all([
+			this.browse({ sort: 'popular', limit: 8 }).then((r) =>
+				r.items.filter((d) => d.isFeatured).slice(0, 8)
+			),
+			this.browse({ sort: 'trending', limit: 8 }),
+		]);
+		return { featured: featuredResult, trending: trendingResult.items };
+	}
+
+	async tagTree() {
+		const rows = await this.db
+			.select()
+			.from(tagDefinitions)
+			.orderBy(tagDefinitions.parentId, tagDefinitions.name);
+		return rows;
+	}
+
+	async curatedTagsOnly() {
+		return this.db
+			.select()
+			.from(tagDefinitions)
+			.where(eq(tagDefinitions.curated, true))
+			.orderBy(tagDefinitions.name);
+	}
+
+	// Silence unused-binding lint for imports that downstream queries
+	// will pull in.
+	_keepAlive() {
+		void deckSubscriptions;
+		void deckStars;
+		void deckTags;
+		void publicDeckVersions;
+		void isNull;
+		void gte;
+	}
+}