Merge branch 'slice/0.8.5-reputation-gated-merchant-offers'

apps/api/src/conditions/game-condition.service.spec.ts

@@ -280,4 +280,38 @@ describe('GameConditionService', () => {
 
     expect(outcomes.map((outcome) => outcome.met)).toEqual([true, false]);
   });
+
+  it('reports the current value behind each requirement', async () => {
+    const service = createService({ renown: 1, reputation: 14 });
+
+    const outcomes = await service.describe({ characterId: CHARACTER_ID }, [
+      {
+        type: GameConditionType.REGION_REPUTATION,
+        key: 'border-guard',
+        operator: ComparisonOperator.GTE,
+        value: 25,
+      },
+      {
+        type: GameConditionType.WORLD_RENOWN,
+        operator: ComparisonOperator.GTE,
+        value: 3,
+      },
+    ]);
+
+    // "Current: 14" against "Requires 25" is the whole point of showing a
+    // locked offer rather than hiding it (slice §5).
+    expect(outcomes[0]).toMatchObject({ met: false, actual: 14 });
+    expect(outcomes[1]).toMatchObject({ met: false, actual: 1 });
+  });
+
+  it('reports a null current value for a condition with no scale', async () => {
+    const service = createService({ renown: 1, reputation: 100 });
+
+    const outcomes = await service.describe(
+      { characterId: CHARACTER_ID, npcId: NPC_ID },
+      [{ type: GameConditionType.FLAG_SET, key: 'met', value: true }],
+    );
+
+    expect(outcomes[0].actual).toBeNull();
+  });
 });

apps/api/src/conditions/game-condition.service.ts

@@ -27,9 +27,21 @@ export interface ConditionContext {
 
 type RepositoryScope = Pick<DataSource, 'getRepository'>;
 
+/**
+ * One condition's result, plus the number it was measured against.
+ *
+ * `actual` is null for conditions with no scale -- a flag is set or it is not,
+ * and "Current: 0" would be a lie about a boolean.
+ */
+interface ConditionEvaluation {
+  met: boolean;
+  actual: number | null;
+}
+
 export interface ConditionOutcome {
   condition: GameCondition;
   met: boolean;
+  actual: number | null;
 }
 
 /**
@@ -59,7 +71,8 @@ export class GameConditionService {
 
     const scope: RepositoryScope = manager ?? this.dataSource;
     for (const condition of conditions) {
-      if (!(await this.evaluateOne(context, condition, scope))) {
+      const evaluation = await this.evaluateOne(context, condition, scope);
+      if (!evaluation.met) {
         return false;
       }
     }
@@ -83,9 +96,11 @@ export class GameConditionService {
     const scope: RepositoryScope = manager ?? this.dataSource;
     const outcomes: ConditionOutcome[] = [];
     for (const condition of conditions) {
+      const evaluation = await this.evaluateOne(context, condition, scope);
       outcomes.push({
         condition,
-        met: await this.evaluateOne(context, condition, scope),
+        met: evaluation.met,
+        actual: evaluation.actual,
       });
     }
     return outcomes;
@@ -95,9 +110,9 @@ export class GameConditionService {
     context: ConditionContext,
     condition: GameCondition,
     scope: RepositoryScope,
-  ): Promise<boolean> {
+  ): Promise<ConditionEvaluation> {
     if (!SUPPORTED_CONDITION_TYPES.has(condition.type)) {
-      return false;
+      return { met: false, actual: null };
     }
 
     switch (condition.type) {
@@ -110,7 +125,7 @@ export class GameConditionService {
       case GameConditionType.HAS_ITEM:
         return this.evaluateHasItem(context, condition, scope);
       default:
-        return false;
+        return { met: false, actual: null };
     }
   }
 
@@ -118,16 +133,16 @@ export class GameConditionService {
     context: ConditionContext,
     condition: GameCondition,
     scope: RepositoryScope,
-  ): Promise<boolean> {
+  ): Promise<ConditionEvaluation> {
     if (!condition.key) {
-      return false;
+      return { met: false, actual: null };
     }
 
     const faction = await scope
       .getRepository(ReputationFaction)
       .findOneBy({ key: condition.key, enabled: true });
     if (!faction) {
-      return false;
+      return { met: false, actual: null };
     }
 
     const row = await scope.getRepository(CharacterReputation).findOneBy({
@@ -137,32 +152,39 @@ export class GameConditionService {
 
     // A faction the character never interacted with reads as 0, not as absent
     // -- the same rule ReputationService.getCharacterReputation applies.
-    return this.compareNumeric(row?.reputation ?? 0, condition);
+    const reputation = row?.reputation ?? 0;
+    return {
+      met: this.compareNumeric(reputation, condition),
+      actual: reputation,
+    };
   }
 
   private async evaluateWorldRenown(
     context: ConditionContext,
     condition: GameCondition,
     scope: RepositoryScope,
-  ): Promise<boolean> {
+  ): Promise<ConditionEvaluation> {
     const character = await scope
       .getRepository(Character)
       .findOneBy({ id: context.characterId });
     if (!character) {
-      return false;
+      return { met: false, actual: null };
     }
-    return this.compareNumeric(character.renown, condition);
+    return {
+      met: this.compareNumeric(character.renown, condition),
+      actual: character.renown,
+    };
   }
 
   private async evaluateFlag(
     context: ConditionContext,
     condition: GameCondition,
     scope: RepositoryScope,
-  ): Promise<boolean> {
+  ): Promise<ConditionEvaluation> {
     // Flags are per-NPC player state (spec §7). Without an NPC in context
     // there is nothing to read, so the gate stays shut.
     if (!condition.key || !context.npcId) {
-      return false;
+      return { met: false, actual: null };
     }
 
     const state = await scope.getRepository(CharacterNpcState).findOneBy({
@@ -171,23 +193,26 @@ export class GameConditionService {
     });
 
     const expected = condition.value ?? true;
-    return (state?.flags?.[condition.key] ?? false) === expected;
+    return {
+      met: (state?.flags?.[condition.key] ?? false) === expected,
+      actual: null,
+    };
   }
 
   private async evaluateHasItem(
     context: ConditionContext,
     condition: GameCondition,
     scope: RepositoryScope,
-  ): Promise<boolean> {
+  ): Promise<ConditionEvaluation> {
     if (!condition.key) {
-      return false;
+      return { met: false, actual: null };
     }
 
     const definition = await scope
       .getRepository(ItemDefinition)
       .findOneBy({ key: condition.key });
     if (!definition) {
-      return false;
+      return { met: false, actual: null };
     }
 
     const owned = await scope.getRepository(CharacterItem).findOneBy({
@@ -196,11 +221,15 @@ export class GameConditionService {
     });
 
     // "Has item" without an explicit comparison means "at least one".
-    return this.compareNumeric(owned?.quantity ?? 0, {
+    const quantity = owned?.quantity ?? 0;
+    return {
+      met: this.compareNumeric(quantity, {
         ...condition,
         operator: condition.operator ?? ComparisonOperator.GTE,
         value: condition.value ?? 1,
-    });
+      }),
+      actual: quantity,
+    };
   }
 
   private compareNumeric(actual: number, condition: GameCondition): boolean {

apps/api/src/database/migrations/1796000000000-SellableLootBags.ts

@@ -0,0 +1,101 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Lets a shop offer sell a loot bag, and lets one offer carry an exception
+ * (Playable Slice 0.8.5 §4, §7).
+ *
+ * A bag is a `loot_bag_definitions` row, not an item -- deliberately so since
+ * Slice 0.7.5 §6, because a bag is never equipped, never rolls as loot and has
+ * no combat stats. Selling one therefore needs a second target column rather
+ * than a fake item definition, which is exactly the "offer shape" the Slice 0.8
+ * seed said it had no reason to build yet.
+ *
+ * `bypass_conditions` is the minimal exception support Slice 0.9 needs: an
+ * offer opens when `conditions` hold *or* `bypass_conditions` hold. One column,
+ * OR semantics, no rule engine (slice §7, §11).
+ */
+export class SellableLootBags1796000000000 implements MigrationInterface {
+  name = 'SellableLootBags1796000000000';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    // Shop offers are pure content -- nothing references them, and Slice 0.8
+    // inserted its two rows with generated uuids. The seed re-creates every
+    // offer with a stable id (AGENTS.md §8), which needs the old anonymous
+    // rows gone or they would linger as duplicates the upsert never matches.
+    await queryRunner.query(`DELETE FROM "shop_offers"`);
+
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ALTER COLUMN "item_definition_id" DROP NOT NULL
+    `);
+
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ADD COLUMN "loot_bag_definition_id" uuid
+    `);
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ADD CONSTRAINT "FK_shop_offers_loot_bag"
+        FOREIGN KEY ("loot_bag_definition_id")
+        REFERENCES "loot_bag_definitions"("id") ON DELETE RESTRICT
+    `);
+
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ADD COLUMN "bypass_conditions" jsonb NOT NULL DEFAULT '[]'::jsonb
+    `);
+
+    // Exactly one target. An offer selling nothing has no meaning, and one
+    // selling both would make the grant path ambiguous.
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ADD CONSTRAINT "CHK_shop_offers_single_target"
+        CHECK (num_nonnulls("item_definition_id", "loot_bag_definition_id") = 1)
+    `);
+
+    // Partial, because the column each one covers is now nullable and Postgres
+    // treats NULLs as distinct -- a plain unique index over (shop_id,
+    // item_definition_id) would happily accept a hundred bag offers.
+    await queryRunner.query(`DROP INDEX "IDX_shop_offers_shop_item"`);
+    await queryRunner.query(
+      `CREATE UNIQUE INDEX "IDX_shop_offers_shop_item" ON "shop_offers" ("shop_id", "item_definition_id") WHERE "item_definition_id" IS NOT NULL`,
+    );
+    await queryRunner.query(
+      `CREATE UNIQUE INDEX "IDX_shop_offers_shop_bag" ON "shop_offers" ("shop_id", "loot_bag_definition_id") WHERE "loot_bag_definition_id" IS NOT NULL`,
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    // Bag offers cannot survive a rollback: the column that identifies what
+    // they sell is about to disappear, and the restored NOT NULL would reject
+    // them anyway.
+    await queryRunner.query(
+      `DELETE FROM "shop_offers" WHERE "loot_bag_definition_id" IS NOT NULL`,
+    );
+
+    await queryRunner.query(`DROP INDEX "IDX_shop_offers_shop_bag"`);
+    await queryRunner.query(`DROP INDEX "IDX_shop_offers_shop_item"`);
+    await queryRunner.query(
+      `CREATE UNIQUE INDEX "IDX_shop_offers_shop_item" ON "shop_offers" ("shop_id", "item_definition_id")`,
+    );
+
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        DROP CONSTRAINT "CHK_shop_offers_single_target"
+    `);
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers" DROP COLUMN "bypass_conditions"
+    `);
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        DROP CONSTRAINT "FK_shop_offers_loot_bag"
+    `);
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers" DROP COLUMN "loot_bag_definition_id"
+    `);
+    await queryRunner.query(`
+      ALTER TABLE "shop_offers"
+        ALTER COLUMN "item_definition_id" SET NOT NULL
+    `);
+  }
+}

apps/api/src/database/migrations/sellable-loot-bags.migration.spec.ts

@@ -0,0 +1,120 @@
+import 'reflect-metadata';
+import { getMetadataArgsStorage, QueryRunner } from 'typeorm';
+import { SellableLootBags1796000000000 } from './1796000000000-SellableLootBags';
+import { ShopOffer } from '../../shops/entities/shop-offer.entity';
+
+async function runUp(): Promise<string[]> {
+  const query = jest.fn().mockResolvedValue(undefined);
+  const queryRunner = { query } as unknown as QueryRunner;
+  await new SellableLootBags1796000000000().up(queryRunner);
+  return query.mock.calls.map(([sql]) => sql as string);
+}
+
+async function runDown(): Promise<string[]> {
+  const query = jest.fn().mockResolvedValue(undefined);
+  const queryRunner = { query } as unknown as QueryRunner;
+  const migration = new SellableLootBags1796000000000();
+  await migration.up(queryRunner);
+  const upCount = query.mock.calls.length;
+  await migration.down(queryRunner);
+  return query.mock.calls.slice(upCount).map(([sql]) => sql as string);
+}
+
+describe('SellableLootBags1796000000000', () => {
+  it('adds the bag target and bypass columns', async () => {
+    const joined = (await runUp()).join('\n');
+
+    expect(joined).toContain('"loot_bag_definition_id" uuid');
+    expect(joined).toContain('"bypass_conditions" jsonb');
+    expect(joined).toContain('FK_shop_offers_loot_bag');
+  });
+
+  it('makes the item target nullable so a bag offer can exist', async () => {
+    const joined = (await runUp()).join('\n');
+
+    expect(joined).toContain('ALTER COLUMN "item_definition_id" DROP NOT NULL');
+  });
+
+  it('requires exactly one target per offer', async () => {
+    const joined = (await runUp()).join('\n');
+
+    // An offer that sells nothing, or sells both an item and a bag, is a
+    // content bug the database must not store.
+    expect(joined).toContain('CHK_shop_offers_single_target');
+    expect(joined).toContain('num_nonnulls');
+  });
+
+  it('keeps both target kinds unique per shop via partial indexes', async () => {
+    const joined = (await runUp()).join('\n');
+
+    // A plain unique index over a nullable column would let a shop hold
+    // unlimited bag offers, because Postgres treats NULLs as distinct.
+    expect(joined).toContain(
+      'CREATE UNIQUE INDEX "IDX_shop_offers_shop_item" ON "shop_offers" ("shop_id", "item_definition_id") WHERE "item_definition_id" IS NOT NULL',
+    );
+    expect(joined).toContain(
+      'CREATE UNIQUE INDEX "IDX_shop_offers_shop_bag" ON "shop_offers" ("shop_id", "loot_bag_definition_id") WHERE "loot_bag_definition_id" IS NOT NULL',
+    );
+  });
+
+  it('clears content offers so the seed can own stable ids', async () => {
+    const joined = (await runUp()).join('\n');
+
+    expect(joined).toContain('DELETE FROM "shop_offers"');
+  });
+
+  it('drops what it added and restores the original index on rollback', async () => {
+    const joined = (await runDown()).join('\n');
+
+    expect(joined).toContain('DROP COLUMN "loot_bag_definition_id"');
+    expect(joined).toContain('DROP COLUMN "bypass_conditions"');
+    expect(joined).toContain('ALTER COLUMN "item_definition_id" SET NOT NULL');
+    expect(joined).toContain(
+      'CREATE UNIQUE INDEX "IDX_shop_offers_shop_item" ON "shop_offers" ("shop_id", "item_definition_id")',
+    );
+  });
+});
+
+describe('slice 0.8.5 entity schema', () => {
+  function column(target: unknown, propertyName: string) {
+    return getMetadataArgsStorage().columns.find(
+      (candidate) =>
+        candidate.target === target && candidate.propertyName === propertyName,
+    );
+  }
+
+  it('lets the item target sit empty when the offer sells a bag instead', () => {
+    expect(column(ShopOffer, 'itemDefinitionId')?.options.nullable).toBe(true);
+  });
+
+  it('gives a bag offer its own nullable uuid target', () => {
+    const lootBagDefinitionId = column(ShopOffer, 'lootBagDefinitionId');
+    expect(lootBagDefinitionId?.options.type).toBe('uuid');
+    expect(lootBagDefinitionId?.options.nullable).toBe(true);
+  });
+
+  it('requires every offer to carry its bypass conditions, empty or not', () => {
+    const bypassConditions = column(ShopOffer, 'bypassConditions');
+    expect(bypassConditions?.options.type).toBe('jsonb');
+    expect(bypassConditions?.options.nullable).toBeFalsy();
+  });
+
+  it('declares both partial unique indexes with their WHERE clauses', () => {
+    const indices = getMetadataArgsStorage().indices.filter(
+      (candidate) => candidate.target === ShopOffer,
+    );
+
+    const itemIndex = indices.find(
+      (candidate) => candidate.name === 'IDX_shop_offers_shop_item',
+    );
+    const bagIndex = indices.find(
+      (candidate) => candidate.name === 'IDX_shop_offers_shop_bag',
+    );
+
+    expect(itemIndex?.unique).toBe(true);
+    expect(itemIndex?.where).toBe('"item_definition_id" IS NOT NULL');
+
+    expect(bagIndex?.unique).toBe(true);
+    expect(bagIndex?.where).toBe('"loot_bag_definition_id" IS NOT NULL');
+  });
+});

apps/api/src/database/seeds/npc-content.ts

@@ -9,6 +9,7 @@ import type {
   DialogueResponseContent,
 } from '../../npcs/npc.types';
 import { ITEM_IDS } from './item.constants';
+import { BASIC_HIDE_BAG_ID, BASIC_TROPHY_POUCH_ID } from './loot-bag-content';
 import { BORDER_GUARD_FACTION_ID } from './reputation-content';
 
 export const BORIN_NPC_ID = 'b0000000-0000-4000-8000-000000000001';
@@ -19,6 +20,20 @@ export const BORIN_KEY = 'borin-quartermaster';
 export const BORIN_SHOP_KEY = 'borin-supplies';
 export const BORIN_EXCHANGE_KEY = 'borin-trade-in';
 
+// Stable offer ids so re-seeding re-tunes a price instead of inserting a
+// second row (AGENTS.md §8). Needed here in particular because an offer has
+// two possible targets and no single natural key across both shapes.
+export const BORIN_OFFER_IDS = {
+  potion: 'b4000000-0000-4000-8000-000000000001',
+  shortsword: 'b4000000-0000-4000-8000-000000000002',
+  trophyPouch: 'b4000000-0000-4000-8000-000000000003',
+  hideBag: 'b4000000-0000-4000-8000-000000000004',
+  banditBlade: 'b4000000-0000-4000-8000-000000000005',
+} as const;
+
+/** The flag the Slice 0.9 warden sets when she sends the player to Borin. */
+export const SOUTH_GATE_REFERRAL_FLAG = 'referred-by-south-gate-warden';
+
 /**
  * The Renown 2 milestone (Playable Slice 0.6.5 §6).
  *
@@ -188,49 +203,139 @@ export const NPC_SHOPS: SeedNpcShop[] = [
 ];
 
 export interface SeedShopOffer {
+  id: string;
   shopId: string;
-  itemDefinitionId: string;
+  itemDefinitionId: string | null;
+  lootBagDefinitionId: string | null;
   currencyType: string;
   price: number;
   quantity: number;
   repeatable: boolean;
   sortOrder: number;
   conditions: GameCondition[];
+  bypassConditions: GameCondition[];
   enabled: boolean;
 }
 
 /**
- * Deliberately thin (slice §12: "Avoid adding many new items just to populate
+ * What Borin sells (Playable Slice 0.8 §12, Slice 0.8.5 §4).
- * the shop"). The point of 0.8 is trade-in; the shop exists so Silver has
- * somewhere to go the moment it is earned.
  *
- * No offer carries conditions yet -- reputation-gated offers are Slice 0.8.5
+ * Two open offers so Silver always has somewhere to go, and three gated ones
- * (slice §3). Loot bags are not sold here either: 0.8.5 §4 plans the Basic
+ * so reputation visibly changes what the player can do (0.8.5 §1). The locked
- * Hide Bag as its locked-offer example, and a bag is a `LootBagDefinition`
+ * offers stay listed rather than hidden: a reward you can see is a goal, and a
- * rather than an `ItemDefinition`, so selling one needs an offer shape this
+ * reward you cannot see is nothing (0.8.5 §5).
- * slice has no reason to build.
+ *
+ * Thresholds are balancing data (0.8.5 §4). The exchange pays 2-12 reputation
+ * per trade good, so 25 is three or four good hunts away -- close enough to
+ * pull, far enough to matter -- and 40 is deliberately further out, which is
+ * what makes the Slice 0.9 referral read as a favour rather than a shortcut
+ * around nothing.
+ *
+ * The Bandit Blade sits behind World Renown 3, which today's content cannot
+ * reach: there is exactly one renown milestone, worth +1. That is intentional
+ * and not a balancing oversight -- it is the long-horizon goal on the shelf
+ * until Slice 0.11 adds the milestones that reach it.
  */
 export const SHOP_OFFERS: SeedShopOffer[] = [
   {
+    id: BORIN_OFFER_IDS.potion,
     shopId: BORIN_SHOP_ID,
     itemDefinitionId: ITEM_IDS['small-healing-potion'],
+    lootBagDefinitionId: null,
     currencyType: 'SILVER',
     price: 12,
     quantity: 1,
     repeatable: true,
     sortOrder: 1,
     conditions: [],
+    bypassConditions: [],
     enabled: true,
   },
   {
+    id: BORIN_OFFER_IDS.shortsword,
     shopId: BORIN_SHOP_ID,
     itemDefinitionId: ITEM_IDS['worn-short-sword'],
+    lootBagDefinitionId: null,
     currencyType: 'SILVER',
     price: 30,
     quantity: 1,
     repeatable: true,
     sortOrder: 2,
     conditions: [],
+    bypassConditions: [],
+    enabled: true,
+  },
+  {
+    // The first gate a player meets, and the one 0.8.5 §5 uses as its worked
+    // example: 40 Silver, Ashen Fields reputation 25.
+    id: BORIN_OFFER_IDS.trophyPouch,
+    shopId: BORIN_SHOP_ID,
+    itemDefinitionId: null,
+    lootBagDefinitionId: BASIC_TROPHY_POUCH_ID,
+    currencyType: 'SILVER',
+    price: 40,
+    quantity: 1,
+    repeatable: false,
+    sortOrder: 3,
+    conditions: [
+      {
+        type: GameConditionType.REGION_REPUTATION,
+        key: 'border-guard',
+        operator: ComparisonOperator.GTE,
+        value: 25,
+      },
+    ],
+    bypassConditions: [],
+    enabled: true,
+  },
+  {
+    // Reputation 40 is out of reach for a new character on purpose. Slice 0.9
+    // sends the player here with the warden's word instead, which is the one
+    // exception the offer system supports (0.8.5 §7).
+    id: BORIN_OFFER_IDS.hideBag,
+    shopId: BORIN_SHOP_ID,
+    itemDefinitionId: null,
+    lootBagDefinitionId: BASIC_HIDE_BAG_ID,
+    currencyType: 'SILVER',
+    price: 35,
+    quantity: 1,
+    repeatable: false,
+    sortOrder: 4,
+    conditions: [
+      {
+        type: GameConditionType.REGION_REPUTATION,
+        key: 'border-guard',
+        operator: ComparisonOperator.GTE,
+        value: 40,
+      },
+    ],
+    bypassConditions: [
+      {
+        type: GameConditionType.FLAG_SET,
+        key: SOUTH_GATE_REFERRAL_FLAG,
+        value: true,
+      },
+    ],
+    enabled: true,
+  },
+  {
+    id: BORIN_OFFER_IDS.banditBlade,
+    shopId: BORIN_SHOP_ID,
+    itemDefinitionId: ITEM_IDS['bandit-blade'],
+    lootBagDefinitionId: null,
+    currencyType: 'SILVER',
+    price: 60,
+    quantity: 1,
+    repeatable: true,
+    sortOrder: 5,
+    conditions: [
+      {
+        type: GameConditionType.WORLD_RENOWN,
+        operator: ComparisonOperator.GTE,
+        value: 3,
+      },
+    ],
+    bypassConditions: [],
     enabled: true,
   },
 ];

apps/api/src/database/seeds/vertical-slice.seed.spec.ts

@@ -20,6 +20,10 @@ import { NpcDefinition } from '../../npcs/entities/npc-definition.entity';
 import { NpcShop } from '../../shops/entities/npc-shop.entity';
 import { ShopOffer } from '../../shops/entities/shop-offer.entity';
 import { DEMO_CHARACTER_STARTING_WEAPON_ITEM_ID } from '../../demo/demo-character.constants';
+import {
+  ComparisonOperator,
+  GameConditionType,
+} from '../../conditions/game-condition.types';
 import {
   ASH_RAT_LOOT_TABLE_ID,
   CHARRED_LOOTER_LOOT_TABLE_ID,
@@ -27,6 +31,8 @@ import {
   ROAD_BANDIT_LOOT_TABLE_ID,
   WILD_ROAD_DOG_LOOT_TABLE_ID,
 } from './item.constants';
+import { BASIC_HIDE_BAG_ID } from './loot-bag-content';
+import { BORIN_OFFER_IDS, SHOP_OFFERS } from './npc-content';
 import { seedVisibleVerticalSlice } from './vertical-slice.seed';
 
 type Row = Record<string, unknown>;
@@ -637,7 +643,7 @@ describe('seedVisibleVerticalSlice', () => {
     );
   });
 
-  it('gives the demo character one active bag per category, idempotently', async () => {
+  it('gives the demo character only the Hide Bag, idempotently', async () => {
     const characterLootBagRepository = new InMemoryRepository();
     const dataSource = createDataSource(
       new InMemoryRepository(),
@@ -659,20 +665,18 @@ describe('seedVisibleVerticalSlice', () => {
     await seedVisibleVerticalSlice(dataSource);
     await seedVisibleVerticalSlice(dataSource);
 
-    // Deliberate: 0.7.5 §7 leaves acquisition to the merchant slice, but with
+    // Slice 0.8.5 decision: the Trophy Pouch is now a reputation-gated offer,
-    // no merchant yet a bagless character could never empty a full bag. See
+    // so handing it to the demo character for free would undercut the
-    // the ASSUMPTION note in the seed.
+    // showcase. The Hide Bag stays -- without it, HIDE capacity would drop to
-    expect(characterLootBagRepository.rows).toHaveLength(2);
+    // the bagless default of 1 with no way to raise it before Slice 0.9 grants
+    // it through the warden's referral. See the ASSUMPTION note in the seed.
+    expect(characterLootBagRepository.rows).toHaveLength(1);
     expect(characterLootBagRepository.rows.map((row) => row.active)).toEqual([
       true,
-      true,
     ]);
     expect(
       characterLootBagRepository.rows.map((row) => row.lootBagDefinitionId),
-    ).toEqual([
+    ).toEqual(['a0000000-0000-4000-8000-000000000001']);
-      'a0000000-0000-4000-8000-000000000001',
-      'a0000000-0000-4000-8000-000000000002',
-    ]);
   });
 
   it('seeds the starting sword as a real, equipped CharacterItem idempotently', async () => {
@@ -904,4 +908,149 @@ describe('seedVisibleVerticalSlice', () => {
       enabled: true,
     });
   });
+
+  it('seeds two visibly locked bag offers and one renown-gated weapon', async () => {
+    const gated = SHOP_OFFERS.filter((offer) => offer.conditions.length > 0);
+
+    expect(gated).toHaveLength(3);
+    expect(gated.map((offer) => offer.conditions[0].type).sort()).toEqual([
+      GameConditionType.REGION_REPUTATION,
+      GameConditionType.REGION_REPUTATION,
+      GameConditionType.WORLD_RENOWN,
+    ]);
+  });
+
+  it('gives the Hide Bag a referral bypass for Slice 0.9', async () => {
+    const hideBag = SHOP_OFFERS.find(
+      (offer) => offer.lootBagDefinitionId === BASIC_HIDE_BAG_ID,
+    );
+
+    expect(hideBag?.bypassConditions).toEqual([
+      {
+        type: GameConditionType.FLAG_SET,
+        key: 'referred-by-south-gate-warden',
+        value: true,
+      },
+    ]);
+  });
+
+  it('sells every bag as a one-off', async () => {
+    // A bag is one object; a second copy raises no capacity.
+    for (const offer of SHOP_OFFERS.filter(
+      (candidate) => candidate.lootBagDefinitionId !== null,
+    )) {
+      expect(offer.repeatable).toBe(false);
+    }
+  });
+
+  it('gives every offer exactly one target', async () => {
+    for (const offer of SHOP_OFFERS) {
+      const targets = [
+        offer.itemDefinitionId,
+        offer.lootBagDefinitionId,
+      ].filter((target) => target !== null);
+      expect(targets).toHaveLength(1);
+    }
+  });
+
+  it('gives every offer a stable id so re-seeding cannot duplicate it', async () => {
+    const ids = SHOP_OFFERS.map((offer) => offer.id);
+
+    expect(new Set(ids).size).toBe(ids.length);
+    expect(ids.every((id) => id.length === 36)).toBe(true);
+  });
+
+  it('still holds exactly five offers after a re-seed, at the tuned numbers', async () => {
+    const shopOfferRepository = new InMemoryRepository();
+    const dataSource = createDataSource(
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      new InMemoryRepository(),
+      shopOfferRepository,
+    );
+
+    // Twice, because that is the whole point of the stable ids (NPC spec §32).
+    // Both bag offers carry `itemDefinitionId: null`, so the pre-0.8.5 conflict
+    // target of (shopId, itemDefinitionId) would fold them into a single row
+    // here -- and would blow up outright on Postgres, where NULL never equals
+    // NULL in a unique index.
+    await seedVisibleVerticalSlice(dataSource);
+    await seedVisibleVerticalSlice(dataSource);
+
+    expect(shopOfferRepository.rows).toHaveLength(5);
+    expect(
+      shopOfferRepository.rows.map((row: Row) => String(row.id)).sort(),
+    ).toEqual(
+      [
+        BORIN_OFFER_IDS.potion,
+        BORIN_OFFER_IDS.shortsword,
+        BORIN_OFFER_IDS.trophyPouch,
+        BORIN_OFFER_IDS.hideBag,
+        BORIN_OFFER_IDS.banditBlade,
+      ].sort(),
+    );
+
+    // Prices and thresholds are balancing decisions, not incidentals, so a
+    // refactor must not be able to drift one silently (AGENTS.md §39).
+    const byId = new Map<string, Row>(
+      shopOfferRepository.rows.map((row: Row): [string, Row] => [
+        String(row.id),
+        row,
+      ]),
+    );
+    expect(byId.get(BORIN_OFFER_IDS.potion)).toMatchObject({
+      price: 12,
+      conditions: [],
+    });
+    expect(byId.get(BORIN_OFFER_IDS.shortsword)).toMatchObject({
+      price: 30,
+      conditions: [],
+    });
+    expect(byId.get(BORIN_OFFER_IDS.trophyPouch)).toMatchObject({
+      price: 40,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+      ],
+    });
+    expect(byId.get(BORIN_OFFER_IDS.hideBag)).toMatchObject({
+      price: 35,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 40,
+        },
+      ],
+    });
+    expect(byId.get(BORIN_OFFER_IDS.banditBlade)).toMatchObject({
+      price: 60,
+      conditions: [
+        {
+          type: GameConditionType.WORLD_RENOWN,
+          operator: ComparisonOperator.GTE,
+          value: 3,
+        },
+      ],
+    });
+  });
 });

apps/api/src/database/seeds/vertical-slice.seed.ts

@@ -43,11 +43,7 @@ import {
   BURNED_ROAD_LOCAL_CONTENT,
   SOUTH_GATE_LOCAL_CONTENT,
 } from './local-location.content';
-import {
+import { BASIC_HIDE_BAG_ID, LOOT_BAG_DEFINITIONS } from './loot-bag-content';
-  BASIC_HIDE_BAG_ID,
-  BASIC_TROPHY_POUCH_ID,
-  LOOT_BAG_DEFINITIONS,
-} from './loot-bag-content';
 import { REPUTATION_FACTIONS } from './reputation-content';
 import {
   DIALOGUE_NODES,
@@ -362,34 +358,28 @@ export async function seedVisibleVerticalSlice(
     });
   }
 
-  // ASSUMPTION (Playable Slice 0.7.5 §7 leaves acquisition to the merchant
+  // ASSUMPTION (Slice 0.8.5 decision): the demo character keeps the Hide Bag
-  // and quest slices, so nothing in 0.7.5 hands out a bag).
+  // and no longer starts with the Trophy Pouch.
   //
-  // The demo character starts with both starter bags anyway. Without them the
+  // The pouch is now a reputation-gated offer (0.8.5 §4) and handing it over
-  // bagless default of 1 applies, and since the merchant that empties a bag
+  // for free would make the slice's own showcase pointless. The Hide Bag stays
-  // only arrives in 0.8, the second kill of a hunt would leave its trade good
+  // until Slice 0.9 grants it through the warden's referral -- removing both
-  // behind forever -- the hunting loop would be unplayable between these two
+  // now would drop HIDE capacity to the bagless default of 1 with no way to
-  // slices. Capacity 5 lets the fill-up actually be experienced.
+  // raise it, and the hunting loop would be unplayable in between.
   //
-  // Smallest reversible choice: two seed rows, no acquisition mechanism.
+  // Delete this block once 0.9 hands the Hide Bag over in the quest.
-  // Delete them once the merchant sells bags.
   const characterLootBagRepository = dataSource.getRepository(CharacterLootBag);
-  for (const lootBagDefinitionId of [
-    BASIC_HIDE_BAG_ID,
-    BASIC_TROPHY_POUCH_ID,
-  ]) {
   const existingBag = await characterLootBagRepository.findOneBy({
     characterId: DEMO_CHARACTER_ID,
-      lootBagDefinitionId,
+    lootBagDefinitionId: BASIC_HIDE_BAG_ID,
   });
   if (!existingBag) {
     await characterLootBagRepository.insert({
       characterId: DEMO_CHARACTER_ID,
-        lootBagDefinitionId,
+      lootBagDefinitionId: BASIC_HIDE_BAG_ID,
       active: true,
     });
   }
-  }
 
   // NPC content (NPC Specification V1 §32; Playable Slice 0.8).
   //
@@ -413,7 +403,10 @@ export async function seedVisibleVerticalSlice(
 
   await dialogueNodeRepository.upsert(DIALOGUE_NODES, ['npcId', 'key']);
   await npcShopRepository.upsert(NPC_SHOPS, ['key']);
-  await shopOfferRepository.upsert(SHOP_OFFERS, ['shopId', 'itemDefinitionId']);
+  // By id, not by (shop, item): an offer may now sell a bag instead of an
+  // item, so the old pair is null for half the rows and useless as a conflict
+  // target. Migration 1796 cleared the anonymous 0.8 rows for exactly this.
+  await shopOfferRepository.upsert(SHOP_OFFERS, ['id']);
   await npcExchangeProfileRepository.upsert(NPC_EXCHANGE_PROFILES, ['key']);
   await exchangeRuleRepository.upsert(EXCHANGE_RULES, [
     'profileId',

apps/api/src/shops/entities/shop-offer.entity.ts

@@ -10,6 +10,7 @@ import {
 } from 'typeorm';
 import type { GameCondition } from '../../conditions/game-condition.types';
 import { ItemDefinition } from '../../items/entities/item-definition.entity';
+import { LootBagDefinition } from '../../loot-bags/entities/loot-bag-definition.entity';
 import { NpcShop } from './npc-shop.entity';
 
 /**
@@ -23,6 +24,11 @@ import { NpcShop } from './npc-shop.entity';
 @Entity({ name: 'shop_offers' })
 @Index('IDX_shop_offers_shop_item', ['shopId', 'itemDefinitionId'], {
   unique: true,
+  where: '"item_definition_id" IS NOT NULL',
+})
+@Index('IDX_shop_offers_shop_bag', ['shopId', 'lootBagDefinitionId'], {
+  unique: true,
+  where: '"loot_bag_definition_id" IS NOT NULL',
 })
 export class ShopOffer {
   @PrimaryGeneratedColumn('uuid', { name: 'id' })
@@ -31,8 +37,16 @@ export class ShopOffer {
   @Column({ name: 'shop_id', type: 'uuid' })
   shopId!: string;
 
-  @Column({ name: 'item_definition_id', type: 'uuid' })
+  /**
-  itemDefinitionId!: string;
+   * What the offer sells. Exactly one of these is set, enforced by
+   * `CHK_shop_offers_single_target`: a bag is a `LootBagDefinition` rather
+   * than an item (Slice 0.7.5 §6), so the two cannot share a column.
+   */
+  @Column({ name: 'item_definition_id', type: 'uuid', nullable: true })
+  itemDefinitionId!: string | null;
+
+  @Column({ name: 'loot_bag_definition_id', type: 'uuid', nullable: true })
+  lootBagDefinitionId!: string | null;
 
   /**
    * Which currency `price` is denominated in. Only SILVER exists today; the
@@ -58,6 +72,21 @@ export class ShopOffer {
   @Column({ name: 'conditions', type: 'jsonb', default: () => "'[]'::jsonb" })
   conditions!: GameCondition[];
 
+  /**
+   * An alternative way in (Slice 0.8.5 §7).
+   *
+   * The offer opens when `conditions` hold **or** these do. That is the whole
+   * exception model: it lets one quest referral grant an acquisition that
+   * reputation alone would not yet allow, without a favor engine. Empty on
+   * every offer that has no exception.
+   */
+  @Column({
+    name: 'bypass_conditions',
+    type: 'jsonb',
+    default: () => "'[]'::jsonb",
+  })
+  bypassConditions!: GameCondition[];
+
   @Column({ name: 'enabled', type: 'boolean', default: true })
   enabled!: boolean;
 
@@ -71,7 +100,11 @@ export class ShopOffer {
   @JoinColumn({ name: 'shop_id' })
   shop!: NpcShop;
 
-  @ManyToOne(() => ItemDefinition, { onDelete: 'RESTRICT' })
+  @ManyToOne(() => ItemDefinition, { onDelete: 'RESTRICT', nullable: true })
   @JoinColumn({ name: 'item_definition_id' })
-  itemDefinition!: ItemDefinition;
+  itemDefinition!: ItemDefinition | null;
+
+  @ManyToOne(() => LootBagDefinition, { onDelete: 'RESTRICT', nullable: true })
+  @JoinColumn({ name: 'loot_bag_definition_id' })
+  lootBagDefinition!: LootBagDefinition | null;
 }

apps/api/src/shops/offer-presentation.spec.ts

@@ -0,0 +1,190 @@
+import {
+  ComparisonOperator,
+  GameConditionType,
+} from '../conditions/game-condition.types';
+import { LootCategory } from '../items/loot-category.enum';
+import {
+  describeBagEffect,
+  describeItemEffect,
+  describeRequirement,
+} from './offer-presentation';
+
+const FACTIONS = new Map([['border-guard', 'Border Watch']]);
+
+describe('describeRequirement', () => {
+  it('names the faction and the threshold for a reputation gate', () => {
+    const requirement = describeRequirement(
+      {
+        condition: {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+        met: false,
+        actual: 14,
+      },
+      FACTIONS,
+    );
+
+    expect(requirement).toEqual({
+      label: 'Requires Border Watch Reputation 25',
+      current: 14,
+      required: 25,
+      met: false,
+    });
+  });
+
+  it('describes a World Renown gate', () => {
+    const requirement = describeRequirement(
+      {
+        condition: {
+          type: GameConditionType.WORLD_RENOWN,
+          operator: ComparisonOperator.GTE,
+          value: 3,
+        },
+        met: false,
+        actual: 1,
+      },
+      FACTIONS,
+    );
+
+    expect(requirement).toMatchObject({
+      label: 'Requires World Renown 3',
+      current: 1,
+      required: 3,
+    });
+  });
+
+  it('falls back to the faction key when the faction is unknown', () => {
+    // A gate naming a faction that is not seeded still has to render as
+    // something, and the key is more useful to a player than a blank.
+    const requirement = describeRequirement(
+      {
+        condition: {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'dusk-hunters',
+          operator: ComparisonOperator.GTE,
+          value: 10,
+        },
+        met: false,
+        actual: 0,
+      },
+      FACTIONS,
+    );
+
+    expect(requirement?.label).toBe('Requires dusk-hunters Reputation 10');
+  });
+
+  it('renders no line for a condition type the player is not shown', () => {
+    // A dialogue flag is an internal gate. Naming it would spoil the quest
+    // that sets it, and the offer already renders as locked without it.
+    expect(
+      describeRequirement(
+        {
+          condition: {
+            type: GameConditionType.FLAG_SET,
+            key: 'referred-by-south-gate-warden',
+            value: true,
+          },
+          met: false,
+          actual: null,
+        },
+        FACTIONS,
+      ),
+    ).toBeNull();
+  });
+
+  it('renders no line if the condition has a non-numeric value', () => {
+    // A requirement with no valid threshold is unactionable -- the player
+    // has no goal to work toward. Better to hide the gate than to render
+    // a malformed line.
+    expect(
+      describeRequirement(
+        {
+          condition: {
+            type: GameConditionType.REGION_REPUTATION,
+            key: 'border-guard',
+            operator: ComparisonOperator.GTE,
+            value: NaN,
+          },
+          met: false,
+          actual: 14,
+        },
+        FACTIONS,
+      ),
+    ).toBeNull();
+  });
+
+  it('renders no line for a reputation gate with no faction key', () => {
+    // A gate that names no faction is malformed. The player cannot act on a
+    // requirement that never says which faction. Better to show nothing than
+    // broken content.
+    expect(
+      describeRequirement(
+        {
+          condition: {
+            type: GameConditionType.REGION_REPUTATION,
+            operator: ComparisonOperator.GTE,
+            value: 25,
+          } as any,
+          met: false,
+          actual: 14,
+        },
+        FACTIONS,
+      ),
+    ).toBeNull();
+  });
+});
+
+describe('describeItemEffect', () => {
+  it('summarises a weapon', () => {
+    expect(
+      describeItemEffect({
+        weaponDamage: 11,
+        bonusAttack: 1,
+        bonusHp: 0,
+        bonusArmor: 0,
+      }),
+    ).toBe('11 Weapon Damage, +1 Attack');
+  });
+
+  it('summarises armour', () => {
+    expect(
+      describeItemEffect({
+        weaponDamage: 0,
+        bonusAttack: 0,
+        bonusHp: 5,
+        bonusArmor: 4,
+      }),
+    ).toBe('+5 HP, +4 Armor');
+  });
+
+  it('has nothing to say about an item with no stats', () => {
+    expect(
+      describeItemEffect({
+        weaponDamage: 0,
+        bonusAttack: 0,
+        bonusHp: 0,
+        bonusArmor: 0,
+      }),
+    ).toBeNull();
+  });
+});
+
+describe('describeBagEffect', () => {
+  it('states what the bag carries and how much', () => {
+    expect(
+      describeBagEffect({
+        capacity: 5,
+        lootCategory: LootCategory.RAIDER_TROPHY,
+      }),
+    ).toBe('Capacity: 5 Raider Trophies');
+  });
+
+  it('uses the plural label of the category', () => {
+    expect(
+      describeBagEffect({ capacity: 5, lootCategory: LootCategory.HIDE }),
+    ).toBe('Capacity: 5 Hides');
+  });
+});

apps/api/src/shops/offer-presentation.ts

@@ -0,0 +1,104 @@
+import type { ConditionOutcome } from '../conditions/game-condition.service';
+import { GameConditionType } from '../conditions/game-condition.types';
+import { LootCategory } from '../items/loot-category.enum';
+
+/**
+ * One requirement as the player reads it (Playable Slice 0.8.5 §5, §8).
+ *
+ * `current` is what makes a locked offer a goal rather than a wall: seeing
+ * "Requires 25 / Current 14" tells the player how much further to go.
+ */
+export interface ShopOfferRequirementDto {
+  label: string;
+  current: number | null;
+  required: number | null;
+  met: boolean;
+}
+
+/** Plural, because a capacity counts things. Mirrors the web strip's labels. */
+const CATEGORY_LABELS: Readonly<Record<LootCategory, string>> = {
+  [LootCategory.HIDE]: 'Hides',
+  [LootCategory.RAIDER_TROPHY]: 'Raider Trophies',
+};
+
+/**
+ * Turns one evaluated condition into a player-facing line, or into nothing.
+ *
+ * Only the two gate types slice §8 names are rendered. Everything else --
+ * dialogue flags above all -- returns null: the offer still shows as locked,
+ * but an internal gate is not announced, and a quest flag named on a shop row
+ * would spoil the Slice 0.9 tutorial before the quest exists.
+ */
+export function describeRequirement(
+  outcome: ConditionOutcome,
+  factionNames: ReadonlyMap<string, string>,
+): ShopOfferRequirementDto | null {
+  const { condition, met, actual } = outcome;
+  const required = Number(condition.value);
+  if (!Number.isFinite(required)) {
+    return null;
+  }
+
+  switch (condition.type) {
+    case GameConditionType.REGION_REPUTATION: {
+      if (!condition.key) {
+        return null;
+      }
+      // The key is a poor label, but a blank is worse -- a gate on a faction
+      // that is not seeded yet should still read as something.
+      const faction = factionNames.get(condition.key) ?? condition.key;
+      return {
+        label: `Requires ${faction} Reputation ${required}`,
+        current: actual,
+        required,
+        met,
+      };
+    }
+    case GameConditionType.WORLD_RENOWN:
+      return {
+        label: `Requires World Renown ${required}`,
+        current: actual,
+        required,
+        met,
+      };
+    default:
+      return null;
+  }
+}
+
+/**
+ * What an item does, in one line (slice §8 "relevant effect").
+ *
+ * Stats only. The flavour text is already carried separately, and repeating it
+ * here would push the actual numbers off the row.
+ */
+export function describeItemEffect(item: {
+  weaponDamage: number;
+  bonusAttack: number;
+  bonusHp: number;
+  bonusArmor: number;
+}): string | null {
+  const parts: string[] = [];
+  if (item.weaponDamage > 0) {
+    parts.push(`${item.weaponDamage} Weapon Damage`);
+  }
+  if (item.bonusAttack > 0) {
+    parts.push(`+${item.bonusAttack} Attack`);
+  }
+  if (item.bonusHp > 0) {
+    parts.push(`+${item.bonusHp} HP`);
+  }
+  if (item.bonusArmor > 0) {
+    parts.push(`+${item.bonusArmor} Armor`);
+  }
+  return parts.length > 0 ? parts.join(', ') : null;
+}
+
+/** What a bag does: one category, one capacity (Slice 0.7.5 §6). */
+export function describeBagEffect(bag: {
+  capacity: number;
+  lootCategory: LootCategory;
+}): string {
+  const label = CATEGORY_LABELS[bag.lootCategory] ?? bag.lootCategory;
+  return `Capacity: ${bag.capacity} ${label}`;
+}

apps/api/src/shops/shop.errors.ts

@@ -5,6 +5,8 @@ export type ShopErrorCode =
   | 'SHOP_DISABLED'
   | 'SHOP_OFFER_NOT_FOUND'
   | 'SHOP_OFFER_LOCKED'
+  | 'MERCHANT_REPUTATION_TOO_LOW'
+  | 'SHOP_BAG_ALREADY_OWNED'
   | 'SHOP_INVALID_QUANTITY'
   | 'SHOP_INSUFFICIENT_SILVER';
 
@@ -57,6 +59,34 @@ export function shopOfferLocked(): ShopDomainError {
   );
 }
 
+/**
+ * The specific case of `SHOP_OFFER_LOCKED` where reputation is what is short
+ * (Playable Slice 0.8.5 §6).
+ *
+ * Added alongside the generic code rather than replacing it: a gate on a quest
+ * flag or an item is still `SHOP_OFFER_LOCKED`, and telling a player to earn
+ * reputation they do not need would be worse than saying nothing specific.
+ */
+export function merchantReputationTooLow(): ShopDomainError {
+  return new ShopDomainError(
+    'MERCHANT_REPUTATION_TOO_LOW',
+    HttpStatus.FORBIDDEN,
+    'You have not earned enough standing for this yet.',
+  );
+}
+
+/**
+ * Only the roomiest active bag per category counts (Slice 0.7.5 §6), so a
+ * second copy grants nothing. Selling one would be taking Silver for nothing.
+ */
+export function shopBagAlreadyOwned(): ShopDomainError {
+  return new ShopDomainError(
+    'SHOP_BAG_ALREADY_OWNED',
+    HttpStatus.CONFLICT,
+    'You already carry that.',
+  );
+}
+
 export function shopInvalidQuantity(): ShopDomainError {
   return new ShopDomainError(
     'SHOP_INVALID_QUANTITY',

apps/api/src/shops/shop.service.spec.ts

@@ -1,8 +1,17 @@
 import { DataSource, EntityManager } from 'typeorm';
 import { Character } from '../characters/entities/character.entity';
 import { GameConditionService } from '../conditions/game-condition.service';
+import {
+  ComparisonOperator,
+  GameCondition,
+  GameConditionType,
+} from '../conditions/game-condition.types';
 import { CharacterItem } from '../items/entities/character-item.entity';
+import { LootCategory } from '../items/loot-category.enum';
+import { CharacterLootBag } from '../loot-bags/entities/character-loot-bag.entity';
+import { LootBagDefinition } from '../loot-bags/entities/loot-bag-definition.entity';
 import { NpcService } from '../npcs/npc.service';
+import { ReputationFaction } from '../reputation/entities/reputation-faction.entity';
 import { NpcShop } from './entities/npc-shop.entity';
 import { ShopOffer } from './entities/shop-offer.entity';
 import { ShopService } from './shop.service';
@@ -14,12 +23,44 @@ interface Fixture {
   silver?: number;
   shopEnabled?: boolean;
   hasShop?: boolean;
+  /** The fake engine's blanket answer for every condition it is handed. */
   offerUnlocked?: boolean;
+  /**
+   * Condition types the fake engine says do *not* hold, whatever
+   * `offerUnlocked` says. Lets one list mix a met requirement with an unmet
+   * one, which is what distinguishes "reputation is short" from "something
+   * else is".
+   */
+  unmetConditionTypes?: GameConditionType[];
   offerRepeatable?: boolean;
   offerQuantity?: number;
   ownedPotions?: number | null;
+  /** Replaces the single item offer with one that sells the trophy pouch. */
+  bagOffer?: boolean;
+  /** Bag offers are one-off by nature; a test can lift that to reach the
+   * bag-specific quantity rule underneath it. */
+  bagRepeatable?: boolean;
+  /** Whether the character already holds the bag the offer sells. */
+  ownsBag?: boolean;
+  /** Conditions on the offer, so a test can gate it on reputation. */
+  conditions?: GameCondition[];
+  /** The alternative way in (slice §7). */
+  bypassConditions?: GameCondition[];
+  /** Whether the fake engine says the bypass list holds. */
+  bypassPasses?: boolean;
 }
 
+/**
+ * What the fake engine reports as measured, per condition type.
+ *
+ * Only conditions with a scale have one: a flag is set or it is not, and the
+ * real engine reports `actual: null` for it.
+ */
+const FAKE_MEASURED_VALUE: Partial<Record<GameConditionType, number>> = {
+  [GameConditionType.REGION_REPUTATION]: 14,
+  [GameConditionType.WORLD_RENOWN]: 14,
+};
+
 function createWorld(fixture: Fixture = {}) {
   const character = {
     id: CHARACTER_ID,
@@ -36,17 +77,47 @@ function createWorld(fixture: Fixture = {}) {
           quantity: fixture.ownedPotions,
         };
 
+  const bag = {
+    id: 'bag-trophy-pouch',
+    key: 'basic-trophy-pouch',
+    name: 'Basic Trophy Pouch',
+    lootCategory: LootCategory.RAIDER_TROPHY,
+    capacity: 5,
+    iconPath: '/images/items/basic-trophy-pouch.png',
+  };
+
+  const grantedBags: Array<Record<string, unknown>> = [];
+
   const offers = [
-    {
+    fixture.bagOffer
+      ? {
+          id: 'offer-bag',
+          shopId: 'shop-1',
+          itemDefinitionId: null,
+          lootBagDefinitionId: bag.id,
+          currencyType: 'SILVER',
+          price: 40,
+          quantity: 1,
+          repeatable: fixture.bagRepeatable ?? false,
+          sortOrder: 1,
+          conditions: fixture.conditions ?? [],
+          bypassConditions: fixture.bypassConditions ?? [],
+          enabled: true,
+          itemDefinition: null,
+          lootBagDefinition: bag,
+        }
+      : {
           id: 'offer-1',
           shopId: 'shop-1',
           itemDefinitionId: 'item-potion',
+          lootBagDefinitionId: null,
           currencyType: 'SILVER',
           price: 12,
           quantity: fixture.offerQuantity ?? 1,
           repeatable: fixture.offerRepeatable ?? true,
           sortOrder: 1,
-      conditions: [],
+          conditions: fixture.conditions ?? [],
+          bypassConditions: fixture.bypassConditions ?? [],
           enabled: true,
           itemDefinition: {
             id: 'item-potion',
@@ -54,7 +125,12 @@ function createWorld(fixture: Fixture = {}) {
             name: 'Small Healing Potion',
             description: 'A bitter draught.',
             iconPath: '/images/items/potion.png',
+            weaponDamage: 0,
+            bonusAttack: 0,
+            bonusHp: 0,
+            bonusArmor: 0,
           },
+          lootBagDefinition: null,
         },
   ] as unknown as ShopOffer[];
 
@@ -88,9 +164,35 @@ function createWorld(fixture: Fixture = {}) {
       return {
         findOne: () => Promise.resolve(owned),
         create: (row: Record<string, unknown>) => row,
-        save: async (row: Record<string, unknown>) => {
+        save: (row: Record<string, unknown>) => {
           grantedItems.push(row);
-          return row;
+          return Promise.resolve(row);
+        },
+      };
+    }
+    if (entity === ReputationFaction) {
+      return {
+        find: () =>
+          Promise.resolve([
+            { id: 'faction-1', key: 'border-guard', name: 'Border Watch' },
+          ]),
+      };
+    }
+    if (entity === LootBagDefinition) {
+      return { findOneBy: () => Promise.resolve(bag) };
+    }
+    if (entity === CharacterLootBag) {
+      return {
+        findOne: () =>
+          Promise.resolve(
+            fixture.ownsBag
+              ? { characterId: CHARACTER_ID, lootBagDefinitionId: bag.id }
+              : null,
+          ),
+        create: (row: Record<string, unknown>) => row,
+        save: (row: Record<string, unknown>) => {
+          grantedBags.push(row);
+          return Promise.resolve(row);
         },
       };
     }
@@ -104,8 +206,43 @@ function createWorld(fixture: Fixture = {}) {
       run(manager),
   } as unknown as DataSource;
 
+  /** One condition's verdict, so `evaluate` and `describe` cannot disagree. */
+  const conditionHolds = (condition: GameCondition) => {
+    if (fixture.unmetConditionTypes?.includes(condition.type)) {
+      return false;
+    }
+    return fixture.offerUnlocked ?? true;
+  };
+
   const conditions = {
-    evaluate: jest.fn(() => Promise.resolve(fixture.offerUnlocked ?? true)),
+    evaluate: jest.fn(
+      (_context: unknown, list: GameCondition[] | undefined) => {
+        // Mirrors the real engine (game-condition.service.ts): an AND over
+        // nothing holds, so an empty list is not a gate at all. Keeping this
+        // faithful is what makes the service's `bypass.length > 0` guard
+        // load-bearing rather than decorative.
+        if (!list || list.length === 0) {
+          return Promise.resolve(true);
+        }
+        // The fixture distinguishes the two lists by identity, so a test can say
+        // "the gate is shut but the bypass is open".
+        if (list === fixture.bypassConditions) {
+          return Promise.resolve(fixture.bypassPasses ?? false);
+        }
+        // Answered from the list's own contents, so handing the gate the wrong
+        // list cannot pass unnoticed.
+        return Promise.resolve(list.every(conditionHolds));
+      },
+    ),
+    describe: jest.fn((_context: unknown, list: GameCondition[] | undefined) =>
+      Promise.resolve(
+        (list ?? []).map((condition) => ({
+          condition,
+          met: conditionHolds(condition),
+          actual: FAKE_MEASURED_VALUE[condition.type] ?? null,
+        })),
+      ),
+    ),
   } as unknown as GameConditionService;
 
   const npcs = {
@@ -116,6 +253,7 @@ function createWorld(fixture: Fixture = {}) {
     service: new ShopService(dataSource, conditions, npcs),
     character,
     grantedItems,
+    grantedBags,
     owned,
   };
 }
@@ -190,8 +328,19 @@ describe('ShopService', () => {
   it('refuses a locked offer even when the request asks for it directly', async () => {
     // The gate is enforced server-side, so hiding it in the UI is not the
     // protection (NPC spec §33: "gesperrtes Item kann nicht direkt über API
-    // gekauft werden").
+    // gekauft werden"). Gated on a flag rather than reputation, because a
-    const world = createWorld({ offerUnlocked: false, silver: 1000 });
+    // non-reputation gate is what keeps the generic code in play.
+    const world = createWorld({
+      offerUnlocked: false,
+      silver: 1000,
+      conditions: [
+        {
+          type: GameConditionType.FLAG_SET,
+          key: 'vouched-for-by-the-warden',
+          value: true,
+        },
+      ],
+    });
 
     await expect(
       world.service.purchase(
@@ -203,6 +352,37 @@ describe('ShopService', () => {
     ).rejects.toMatchObject({ code: 'SHOP_OFFER_LOCKED' });
 
     expect(world.character.silver).toBe(1000);
+    expect(world.grantedItems).toHaveLength(0);
+  });
+
+  it('keeps an offer shut when its bypass list is empty', async () => {
+    // An empty condition list is an AND over nothing, so it *holds*. Without
+    // the service's emptiness guard, every offer in the database -- whose
+    // `bypass_conditions` default to '[]' -- would open (slice §7).
+    const world = createWorld({
+      offerUnlocked: false,
+      silver: 1000,
+      conditions: [
+        {
+          type: GameConditionType.FLAG_SET,
+          key: 'vouched-for-by-the-warden',
+          value: true,
+        },
+      ],
+      bypassConditions: [],
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'small-healing-potion',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_OFFER_LOCKED' });
+
+    expect(world.character.silver).toBe(1000);
+    expect(world.grantedItems).toHaveLength(0);
   });
 
   it('refuses an item the shop does not stock', async () => {
@@ -211,6 +391,9 @@ describe('ShopService', () => {
     await expect(
       world.service.purchase(CHARACTER_ID, MERCHANT_KEY, 'ash-blade', 1),
     ).rejects.toMatchObject({ code: 'SHOP_OFFER_NOT_FOUND' });
+
+    expect(world.character.silver).toBe(100);
+    expect(world.grantedItems).toHaveLength(0);
   });
 
   it('refuses a non-positive quantity', async () => {
@@ -224,6 +407,9 @@ describe('ShopService', () => {
         0,
       ),
     ).rejects.toMatchObject({ code: 'SHOP_INVALID_QUANTITY' });
+
+    expect(world.character.silver).toBe(100);
+    expect(world.grantedItems).toHaveLength(0);
   });
 
   it('refuses to buy a one-off offer more than once in a request', async () => {
@@ -237,6 +423,9 @@ describe('ShopService', () => {
         2,
       ),
     ).rejects.toMatchObject({ code: 'SHOP_INVALID_QUANTITY' });
+
+    expect(world.character.silver).toBe(100);
+    expect(world.grantedItems).toHaveLength(0);
   });
 
   it('refuses a closed shop', async () => {
@@ -261,4 +450,282 @@ describe('ShopService', () => {
     expect(result.quantity).toBe(6);
     expect(result.silverSpent).toBe(24);
   });
+
+  it('shows the requirement and the current value on a locked offer', async () => {
+    const world = createWorld({
+      offerUnlocked: false,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+      ],
+    });
+
+    const view = await world.service.getShopView(CHARACTER_ID, MERCHANT_KEY);
+
+    // Locked, but still listed: a visible reward is a goal (slice §5).
+    expect(view.offers).toHaveLength(1);
+    expect(view.offers[0].unlocked).toBe(false);
+    expect(view.offers[0].requirements).toEqual([
+      {
+        label: 'Requires Border Watch Reputation 25',
+        current: 14,
+        required: 25,
+        met: false,
+      },
+    ]);
+  });
+
+  it('lists a bag offer with its capacity as the effect', async () => {
+    const world = createWorld({ bagOffer: true, silver: 100 });
+
+    const view = await world.service.getShopView(CHARACTER_ID, MERCHANT_KEY);
+
+    expect(view.offers[0]).toMatchObject({
+      itemKey: 'basic-trophy-pouch',
+      itemName: 'Basic Trophy Pouch',
+      price: 40,
+      effectSummary: 'Capacity: 5 Raider Trophies',
+      unlocked: true,
+    });
+    // The capacity line is sent once, as the effect. Repeating it as the
+    // description makes the row render it twice (slice §5).
+    expect(view.offers[0].itemDescription).toBe('');
+  });
+
+  it('grants a bag rather than stacking it as an item', async () => {
+    // Slice §10 case 3: the reputation gate is present *and* satisfied, so the
+    // purchase goes through. A fixture with no conditions at all would pass
+    // without the gate ever being consulted.
+    const world = createWorld({
+      bagOffer: true,
+      silver: 100,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+      ],
+    });
+
+    const result = await world.service.purchase(
+      CHARACTER_ID,
+      MERCHANT_KEY,
+      'basic-trophy-pouch',
+      1,
+    );
+
+    expect(result.silverSpent).toBe(40);
+    expect(world.grantedItems).toHaveLength(0);
+    expect(world.grantedBags[0]).toMatchObject({
+      characterId: CHARACTER_ID,
+      lootBagDefinitionId: 'bag-trophy-pouch',
+      active: true,
+    });
+  });
+
+  it('refuses to sell a bag the character already carries', async () => {
+    // A second copy grants nothing (only the roomiest active bag per category
+    // counts) so charging for it would be taking Silver for nothing.
+    const world = createWorld({ bagOffer: true, ownsBag: true, silver: 100 });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'basic-trophy-pouch',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_BAG_ALREADY_OWNED' });
+
+    expect(world.character.silver).toBe(100);
+    expect(world.grantedBags).toHaveLength(0);
+  });
+
+  it('refuses to sell two of the same bag in one request', async () => {
+    // A bag is one object, not a stack: the second grants nothing. The offer
+    // is made repeatable here so the bag rule is what answers, not the
+    // one-off rule that normally sits in front of it.
+    const world = createWorld({
+      bagOffer: true,
+      bagRepeatable: true,
+      silver: 1000,
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'basic-trophy-pouch',
+        2,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_INVALID_QUANTITY' });
+
+    expect(world.character.silver).toBe(1000);
+    expect(world.grantedBags).toHaveLength(0);
+  });
+
+  it('names reputation as the reason when a reputation gate is what blocks', async () => {
+    const world = createWorld({
+      offerUnlocked: false,
+      silver: 1000,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+      ],
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'small-healing-potion',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'MERCHANT_REPUTATION_TOO_LOW' });
+
+    expect(world.character.silver).toBe(1000);
+    expect(world.grantedItems).toHaveLength(0);
+  });
+
+  it('does not blame reputation when reputation is not what is short', async () => {
+    // The standing is already earned; a quest flag is the thing missing.
+    // Telling this player to go and earn reputation would send them after
+    // something they already have (slice §6).
+    const world = createWorld({
+      silver: 1000,
+      unmetConditionTypes: [GameConditionType.FLAG_SET],
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 10,
+        },
+        {
+          type: GameConditionType.FLAG_SET,
+          key: 'vouched-for-by-the-warden',
+          value: true,
+        },
+      ],
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'small-healing-potion',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_OFFER_LOCKED' });
+
+    expect(world.character.silver).toBe(1000);
+    expect(world.grantedItems).toHaveLength(0);
+  });
+
+  it('blocks a renown-gated offer without blaming merchant reputation', async () => {
+    // Slice §10 case 4, and the discrimination this branch introduced: World
+    // Renown is not the merchant's regard, so a renown block must read as a
+    // plain lock. Sending this player off to trade pelts with Borin would be
+    // pointing at the wrong bar entirely.
+    const world = createWorld({
+      silver: 1000,
+      unmetConditionTypes: [GameConditionType.WORLD_RENOWN],
+      conditions: [
+        {
+          type: GameConditionType.WORLD_RENOWN,
+          operator: ComparisonOperator.GTE,
+          value: 3,
+        },
+      ],
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'small-healing-potion',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_OFFER_LOCKED' });
+
+    expect(world.character.silver).toBe(1000);
+    expect(world.grantedItems).toHaveLength(0);
+  });
+
+  it('opens an offer whose bypass holds even though its conditions do not', async () => {
+    // The Slice 0.9 referral: the warden's word is worth more than the
+    // reputation the player has not earned yet (slice §7).
+    const bypassConditions: GameCondition[] = [
+      {
+        type: GameConditionType.FLAG_SET,
+        key: 'referred-by-south-gate-warden',
+        value: true,
+      },
+    ];
+    const world = createWorld({
+      bagOffer: true,
+      silver: 100,
+      offerUnlocked: false,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 40,
+        },
+      ],
+      bypassConditions,
+      bypassPasses: true,
+    });
+
+    const result = await world.service.purchase(
+      CHARACTER_ID,
+      MERCHANT_KEY,
+      'basic-trophy-pouch',
+      1,
+    );
+
+    expect(result.silverSpent).toBe(40);
+    expect(world.grantedBags).toHaveLength(1);
+  });
+
+  it('still charges the price when a requirement is met', async () => {
+    // Reputation opens the offer; it does not pay for it (slice §10). The
+    // requirement has to actually exist and hold for that to be the thing
+    // under test.
+    const world = createWorld({
+      bagOffer: true,
+      silver: 10,
+      conditions: [
+        {
+          type: GameConditionType.REGION_REPUTATION,
+          key: 'border-guard',
+          operator: ComparisonOperator.GTE,
+          value: 25,
+        },
+      ],
+    });
+
+    await expect(
+      world.service.purchase(
+        CHARACTER_ID,
+        MERCHANT_KEY,
+        'basic-trophy-pouch',
+        1,
+      ),
+    ).rejects.toMatchObject({ code: 'SHOP_INSUFFICIENT_SILVER' });
+
+    expect(world.character.silver).toBe(10);
+    expect(world.grantedBags).toHaveLength(0);
+  });
 });

apps/api/src/shops/shop.service.ts

@@ -1,13 +1,24 @@
 import { Injectable } from '@nestjs/common';
-import { DataSource } from 'typeorm';
+import { DataSource, EntityManager } from 'typeorm';
 import { Character } from '../characters/entities/character.entity';
 import { GameConditionService } from '../conditions/game-condition.service';
+import { GameConditionType } from '../conditions/game-condition.types';
 import { CharacterItem } from '../items/entities/character-item.entity';
+import { CharacterLootBag } from '../loot-bags/entities/character-loot-bag.entity';
 import { NpcService } from '../npcs/npc.service';
+import { ReputationFaction } from '../reputation/entities/reputation-faction.entity';
 import { NpcShop } from './entities/npc-shop.entity';
 import { ShopOffer } from './entities/shop-offer.entity';
+import {
+  describeBagEffect,
+  describeItemEffect,
+  describeRequirement,
+  ShopOfferRequirementDto,
+} from './offer-presentation';
 import {
   characterNotFound,
+  merchantReputationTooLow,
+  shopBagAlreadyOwned,
   shopDisabled,
   shopInsufficientSilver,
   shopInvalidQuantity,
@@ -26,12 +37,34 @@ export interface ShopOfferDto {
   currencyType: string;
   price: number;
   quantity: number;
+  /** What buying it does: weapon stats, or a bag's capacity (slice §8). */
+  effectSummary: string | null;
+  /** Why it is locked, and how close the player is (slice §5). Empty when open. */
+  requirements: ShopOfferRequirementDto[];
   /** False when the offer's conditions are not met (Slice 0.8.5 content). */
   unlocked: boolean;
   /** True when the character simply cannot afford an otherwise open offer. */
   affordable: boolean;
 }
 
+/**
+ * What an offer sells, flattened out of whichever target it points at.
+ *
+ * Both shapes reduce to a key, a name, an icon and an effect, which is all the
+ * presentation layer needs -- and `kind` plus `definitionId` is all the grant
+ * needs, so the branch on offer kind lives in one place instead of being spread
+ * across the view and the purchase path.
+ */
+interface OfferTarget {
+  kind: 'item' | 'bag';
+  definitionId: string;
+  key: string;
+  name: string;
+  description: string;
+  iconPath: string;
+  effectSummary: string | null;
+}
+
 export interface ShopViewDto {
   shopKey: string;
   shopName: string;
@@ -79,26 +112,58 @@ export class ShopService {
 
     const offers = await this.dataSource.getRepository(ShopOffer).find({
       where: { shopId: shop.id, enabled: true },
-      relations: { itemDefinition: true },
+      relations: { itemDefinition: true, lootBagDefinition: true },
       order: { sortOrder: 'ASC' },
     });
 
+    // One read for the whole view: every reputation requirement needs a
+    // display name, and offers commonly gate on the same faction. Restricted
+    // to enabled factions because that is what the condition engine evaluates
+    // against -- naming a faction the engine treats as absent would describe a
+    // requirement that can never be met.
+    const factionNames = new Map(
+      (
+        await this.dataSource
+          .getRepository(ReputationFaction)
+          .find({ where: { enabled: true } })
+      ).map((faction) => [faction.key, faction.name]),
+    );
+
+    const context = { characterId, npcId };
     const view: ShopOfferDto[] = [];
     for (const offer of offers) {
-      const unlocked = await this.conditions.evaluate(
+      const target = this.resolveTarget(offer);
-        { characterId, npcId },
+      if (!target) {
+        continue;
+      }
+
+      const gate = await this.evaluateGate(context, offer);
+      // Described even when open, so the UI can show a requirement the player
+      // has already met rather than having it vanish on unlock. Only
+      // `conditions` are described: a bypass is content's private exception,
+      // not something the player is told to go and satisfy.
+      const outcomes = await this.conditions.describe(
+        context,
         offer.conditions,
       );
+      const requirements = outcomes
+        .map((outcome) => describeRequirement(outcome, factionNames))
+        .filter(
+          (requirement): requirement is ShopOfferRequirementDto =>
+            requirement !== null,
+        );
 
       view.push({
-        itemKey: offer.itemDefinition.key,
+        itemKey: target.key,
-        itemName: offer.itemDefinition.name,
+        itemName: target.name,
-        itemDescription: offer.itemDefinition.description,
+        itemDescription: target.description,
-        iconPath: offer.itemDefinition.iconPath,
+        iconPath: target.iconPath,
         currencyType: offer.currencyType,
         price: offer.price,
         quantity: offer.quantity,
-        unlocked,
+        effectSummary: target.effectSummary,
+        requirements,
+        unlocked: gate.open,
         affordable: character.silver >= offer.price,
       });
     }
@@ -141,51 +206,83 @@ export class ShopService {
       }
 
       // Matched on the joined definition's business key: the offer table is
-      // keyed by item definition id, while the request carries the stable key.
+      // keyed by definition id, while the request carries the stable key.
       const offers = await manager.getRepository(ShopOffer).find({
         where: { shopId: shop.id, enabled: true },
-        relations: { itemDefinition: true },
+        relations: { itemDefinition: true, lootBagDefinition: true },
+        // Same order as the view: both paths answer "which offer does this key
+        // mean", so neither may answer it from an arbitrary row order.
+        order: { sortOrder: 'ASC' },
       });
-      const match = offers.find(
+      let match: ShopOffer | undefined;
-        (candidate) => candidate.itemDefinition.key === itemKey,
+      let target: OfferTarget | undefined;
-      );
+      for (const candidate of offers) {
+        const candidateTarget = this.resolveTarget(candidate);
+        if (candidateTarget?.key === itemKey) {
+          match = candidate;
+          target = candidateTarget;
+          break;
+        }
+      }
 
-      if (!match) {
+      if (!match || !target) {
         throw shopOfferNotFound();
       }
 
-      const unlocked = await this.conditions.evaluate(
+      const gate = await this.evaluateGate(
         { characterId, npcId },
-        match.conditions,
+        match,
         manager,
       );
-      if (!unlocked) {
+      if (!gate.open) {
-        throw shopOfferLocked();
+        throw gate.reputationBlocked
+          ? merchantReputationTooLow()
+          : shopOfferLocked();
       }
 
       if (!match.repeatable && quantity > 1) {
         throw shopInvalidQuantity();
       }
+      // A bag is one object, not a stack: buying two grants nothing extra.
+      if (target.kind === 'bag' && quantity > 1) {
+        throw shopInvalidQuantity();
+      }
 
       const silverSpent = match.price * quantity;
       if (character.silver < silverSpent) {
         throw shopInsufficientSilver();
       }
 
+      // Checked before the debit: the transaction would roll the Silver back
+      // anyway, but failing on the cheap read keeps the error honest about
+      // what went wrong.
+      if (target.kind === 'bag') {
+        const owned = await manager.getRepository(CharacterLootBag).findOne({
+          where: { characterId, lootBagDefinitionId: target.definitionId },
+        });
+        if (owned) {
+          throw shopBagAlreadyOwned();
+        }
+      }
+
       character.silver -= silverSpent;
       await characters.save(character);
 
+      if (target.kind === 'bag') {
+        await this.grantLootBag(manager, characterId, target.definitionId);
+      } else {
         await this.grantItem(
           manager,
           characterId,
-        match.itemDefinitionId,
+          target.definitionId,
           match.quantity * quantity,
         );
+      }
 
       return {
         shopKey: shop.key,
         itemKey,
-        itemName: match.itemDefinition.name,
+        itemName: target.name,
         quantity: match.quantity * quantity,
         silverSpent,
         silverBalance: character.silver,
@@ -193,6 +290,112 @@ export class ShopService {
     });
   }
 
+  /**
+   * What an offer sells, whichever kind of thing that is.
+   *
+   * The two targets are mutually exclusive by `CHK_shop_offers_single_target`,
+   * so resolving them here lets the view and the purchase path agree on what an
+   * offer *is* without either of them branching on offer kind itself.
+   */
+  private resolveTarget(offer: ShopOffer): OfferTarget | null {
+    if (offer.itemDefinition) {
+      return {
+        kind: 'item',
+        definitionId: offer.itemDefinition.id,
+        key: offer.itemDefinition.key,
+        name: offer.itemDefinition.name,
+        description: offer.itemDefinition.description,
+        iconPath: offer.itemDefinition.iconPath,
+        effectSummary: describeItemEffect(offer.itemDefinition),
+      };
+    }
+    if (offer.lootBagDefinition) {
+      return {
+        kind: 'bag',
+        definitionId: offer.lootBagDefinition.id,
+        key: offer.lootBagDefinition.key,
+        name: offer.lootBagDefinition.name,
+        // A bag definition carries no flavour text of its own. The capacity
+        // line is the whole of what there is to say about it, and it is already
+        // carried by `effectSummary`; repeating it here would render it twice
+        // (slice §5 shows the line once).
+        description: '',
+        iconPath: offer.lootBagDefinition.iconPath,
+        effectSummary: describeBagEffect(offer.lootBagDefinition),
+      };
+    }
+    // CHK_shop_offers_single_target makes this unreachable through the
+    // database. Skipping the row beats rendering an offer that sells nothing.
+    return null;
+  }
+
+  /**
+   * Whether an offer is open, and why not when it is shut.
+   *
+   * `conditions` OR `bypassConditions` -- the whole exception model (slice §7).
+   * A referral does not lower the requirement; it provides a second, narrower
+   * door that content opens deliberately.
+   */
+  private async evaluateGate(
+    context: { characterId: string; npcId: string },
+    offer: ShopOffer,
+    manager?: EntityManager,
+  ): Promise<{ open: boolean; reputationBlocked: boolean }> {
+    if (await this.conditions.evaluate(context, offer.conditions, manager)) {
+      return { open: true, reputationBlocked: false };
+    }
+
+    const bypass = offer.bypassConditions ?? [];
+    if (
+      bypass.length > 0 &&
+      (await this.conditions.evaluate(context, bypass, manager))
+    ) {
+      return { open: true, reputationBlocked: false };
+    }
+
+    // Which error to raise depends on what is actually short, so the player is
+    // told to earn reputation only when reputation is the thing missing.
+    const outcomes = await this.conditions.describe(
+      context,
+      offer.conditions,
+      manager,
+    );
+    const reputationBlocked = outcomes.some(
+      (outcome) =>
+        !outcome.met &&
+        outcome.condition.type === GameConditionType.REGION_REPUTATION,
+    );
+
+    return { open: false, reputationBlocked };
+  }
+
+  /**
+   * Hands over a bag, once.
+   *
+   * A second copy of the same bag grants nothing -- only the roomiest active
+   * bag per category counts (Slice 0.7.5 §6) -- so a repeat purchase is
+   * refused rather than silently charged. The unique index on
+   * (character_id, loot_bag_definition_id) is the real guarantee; this check
+   * is what turns a constraint violation into an explainable domain error.
+   */
+  private async grantLootBag(
+    manager: { getRepository: DataSource['getRepository'] },
+    characterId: string,
+    lootBagDefinitionId: string,
+  ): Promise<void> {
+    const bags = manager.getRepository(CharacterLootBag);
+    const existing = await bags.findOne({
+      where: { characterId, lootBagDefinitionId },
+    });
+    if (existing) {
+      throw shopBagAlreadyOwned();
+    }
+
+    await bags.save(
+      bags.create({ characterId, lootBagDefinitionId, active: true }),
+    );
+  }
+
   /**
    * Adds to an existing stack or starts a new one.
    *

apps/api/src/shops/shops.module.ts

@@ -3,7 +3,10 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { Character } from '../characters/entities/character.entity';
 import { ConditionsModule } from '../conditions/conditions.module';
 import { CharacterItem } from '../items/entities/character-item.entity';
+import { CharacterLootBag } from '../loot-bags/entities/character-loot-bag.entity';
+import { LootBagDefinition } from '../loot-bags/entities/loot-bag-definition.entity';
 import { NpcsModule } from '../npcs/npcs.module';
+import { ReputationFaction } from '../reputation/entities/reputation-faction.entity';
 import { NpcShop } from './entities/npc-shop.entity';
 import { ShopOffer } from './entities/shop-offer.entity';
 import { ShopController } from './shop.controller';
@@ -12,7 +15,15 @@ import { ShopService } from './shop.service';
 /** Buying things for Silver (NPC spec §15, §29). */
 @Module({
   imports: [
-    TypeOrmModule.forFeature([Character, CharacterItem, NpcShop, ShopOffer]),
+    TypeOrmModule.forFeature([
+      Character,
+      CharacterItem,
+      CharacterLootBag,
+      LootBagDefinition,
+      NpcShop,
+      ReputationFaction,
+      ShopOffer,
+    ]),
     ConditionsModule,
     NpcsModule,
   ],

apps/web/src/app/core/api/game-api.models.ts

@@ -430,6 +430,14 @@ export interface ExchangeResult {
   capacities: LootCapacity[];
 }
 
+/** One gate on an offer, as the server phrased it (slice 0.8.5 §5, §8). */
+export interface ShopOfferRequirement {
+  label: string;
+  current: number | null;
+  required: number | null;
+  met: boolean;
+}
+
 export interface ShopOfferView {
   itemKey: string;
   itemName: string;
@@ -438,6 +446,8 @@ export interface ShopOfferView {
   currencyType: string;
   price: number;
   quantity: number;
+  effectSummary: string | null;
+  requirements: ShopOfferRequirement[];
   unlocked: boolean;
   affordable: boolean;
 }

apps/web/src/app/features/npc/merchant-page.component.html

@@ -208,6 +208,21 @@
         <h2 class="merchant__panel-title">{{ shop.shopName }}</h2>
         <p class="merchant__purse" data-purse>{{ shop.silver }} Silver</p>
 
+        @if (store.newlyUnlocked().length > 0) {
+          <p class="shop-unlocked" data-unlocked aria-live="polite">
+            @for (name of store.newlyUnlocked(); track name) {
+              <span>New merchant offer unlocked: {{ name }}</span>
+            }
+            <button
+              type="button"
+              class="merchant__link"
+              (click)="store.dismissUnlocked()"
+            >
+              Dismiss
+            </button>
+          </p>
+        }
+
         <ul class="shop-list">
           @for (offer of shop.offers; track offer.itemKey) {
             <li class="shop-row" [attr.data-shop-item]="offer.itemKey">
@@ -219,9 +234,33 @@
               />
               <div class="shop-row__naming">
                 <span class="shop-row__name">{{ offer.itemName }}</span>
+                @if (offer.itemDescription) {
                   <span class="shop-row__description">{{
                     offer.itemDescription
                   }}</span>
+                }
+                @if (offer.effectSummary) {
+                  <span class="shop-row__effect" data-effect>{{
+                    offer.effectSummary
+                  }}</span>
+                }
+                @for (
+                  requirement of offer.requirements;
+                  track requirement.label
+                ) {
+                  <span
+                    class="shop-row__requirement"
+                    [class.shop-row__requirement--met]="requirement.met"
+                    data-requirement
+                  >
+                    {{ requirement.label }}
+                    @if (!requirement.met && requirement.current !== null) {
+                      <span class="shop-row__current"
+                        >· Current: {{ requirement.current }}</span
+                      >
+                    }
+                  </span>
+                }
               </div>
               <span class="shop-row__price">{{ offer.price }} Silver</span>
               <button

apps/web/src/app/features/npc/merchant-page.component.scss

@@ -351,6 +351,26 @@
   font-size: var(--ar-font-sm);
 }
 
+.shop-row__effect {
+  color: var(--ar-text);
+  font-size: 0.75rem;
+}
+
+/* A lock the player can measure themselves against, not a dead end
+   (slice 0.8.5 §5). */
+.shop-row__requirement {
+  color: var(--ar-gold);
+  font-size: 0.75rem;
+}
+
+.shop-row__requirement--met {
+  color: var(--ar-text-muted);
+}
+
+.shop-row__current {
+  color: var(--ar-text-muted);
+}
+
 .shop-receipt {
   display: flex;
   gap: var(--ar-space-2);
@@ -360,6 +380,17 @@
   font-size: var(--ar-font-sm);
 }
 
+/* A line, not a modal (slice 0.8.5 §9). */
+.shop-unlocked {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--ar-space-2);
+  align-items: center;
+  margin: 0;
+  color: var(--ar-gold);
+  font-size: var(--ar-font-sm);
+}
+
 @media (max-width: 40rem) {
   .merchant__identity {
     grid-template-columns: 1fr;

apps/web/src/app/features/npc/merchant-page.component.spec.ts

@@ -83,6 +83,8 @@ const SHOP: ShopView = {
       currencyType: 'SILVER',
       price: 12,
       quantity: 1,
+      effectSummary: null,
+      requirements: [],
       unlocked: true,
       affordable: true,
     },
@@ -94,6 +96,8 @@ const SHOP: ShopView = {
       currencyType: 'SILVER',
       price: 400,
       quantity: 1,
+      effectSummary: null,
+      requirements: [],
       unlocked: false,
       affordable: false,
     },
@@ -160,6 +164,79 @@ async function render(): Promise<{
   return { fixture, element: fixture.nativeElement as HTMLElement, store };
 }
 
+/**
+ * Renders the merchant page with a caller-supplied shop and opens the shop
+ * panel, so requirement/effect tests don't need to repeat the NPC and
+ * exchange fixtures they don't care about.
+ */
+async function renderMerchantWithShop(
+  shopOverrides: Partial<ShopView>,
+): Promise<{
+  fixture: ComponentFixture<MerchantPageComponent>;
+  element: HTMLElement;
+  store: MerchantStore;
+}> {
+  const shop: ShopView = {
+    shopKey: 'borin-supplies',
+    shopName: "Quartermaster's Supplies",
+    npcKey: 'borin-quartermaster',
+    silver: 100,
+    offers: [],
+    ...shopOverrides,
+  };
+
+  const api = {
+    getNpcInteraction: vi.fn(() => of(INTERACTION)),
+    getTradeIn: vi.fn(() => of(EXCHANGE)),
+    getShop: vi.fn(() => of(shop)),
+    tradeIn: vi.fn(() => of(TRADE_RESULT)),
+    purchase: vi.fn(() =>
+      of({
+        shopKey: 'borin-supplies',
+        itemKey: 'small-healing-potion',
+        itemName: 'Small Healing Potion',
+        quantity: 1,
+        silverSpent: 12,
+        silverBalance: 88,
+      }),
+    ),
+  };
+
+  await TestBed.configureTestingModule({
+    imports: [MerchantPageComponent],
+    providers: [
+      provideZonelessChangeDetection(),
+      { provide: GameApiService, useValue: api },
+      {
+        provide: ActivatedRoute,
+        useValue: {
+          snapshot: { paramMap: { get: () => 'borin-quartermaster' } },
+        },
+      },
+    ],
+  }).compileComponents();
+
+  const fixture = TestBed.createComponent(MerchantPageComponent);
+  const store = TestBed.inject(MerchantStore);
+
+  fixture.detectChanges();
+  await new Promise((resolve) => setTimeout(resolve, 0));
+  fixture.detectChanges();
+
+  const element = fixture.nativeElement as HTMLElement;
+  element
+    .querySelector<HTMLButtonElement>('[data-action="OPEN_SHOP"]')
+    ?.click();
+  fixture.detectChanges();
+
+  return { fixture, element, store };
+}
+
+/** How many times `needle` shows up in `haystack` -- `toContain` cannot say. */
+function countOccurrences(haystack: string, needle: string): number {
+  return haystack.split(needle).length - 1;
+}
+
 describe('MerchantPageComponent', () => {
   afterEach(() => TestBed.resetTestingModule());
 
@@ -308,4 +385,147 @@ describe('MerchantPageComponent', () => {
 
     expect(element.querySelector('[data-purse]')?.textContent).toContain('100');
   });
+
+  it('shows the requirement and the current value on a locked offer', async () => {
+    // A visible lock with a number attached is a goal; a hidden offer is not
+    // (slice §5). Shaped like the real Trophy Pouch offer: a bag definition
+    // carries no flavour text, so the API sends an empty description and the
+    // capacity line arrives once, as the effect.
+    const { fixture } = await renderMerchantWithShop({
+      offers: [
+        {
+          itemKey: 'basic-trophy-pouch',
+          itemName: 'Basic Trophy Pouch',
+          itemDescription: '',
+          iconPath: '/images/items/basic-trophy-pouch.png',
+          currencyType: 'SILVER',
+          price: 40,
+          quantity: 1,
+          effectSummary: 'Capacity: 5 Raider Trophies',
+          requirements: [
+            {
+              label: 'Requires Border Watch Reputation 25',
+              current: 14,
+              required: 25,
+              met: false,
+            },
+          ],
+          unlocked: false,
+          affordable: true,
+        },
+      ],
+    });
+
+    const row = fixture.nativeElement.querySelector(
+      '[data-shop-item="basic-trophy-pouch"]',
+    );
+    expect(row.textContent).toContain('Requires Border Watch Reputation 25');
+    expect(row.textContent).toContain('Current: 14');
+    // Once, not twice: slice §5's worked example shows the capacity line a
+    // single time.
+    expect(
+      countOccurrences(row.textContent, 'Capacity: 5 Raider Trophies'),
+    ).toBe(1);
+    // An empty description renders nothing at all, rather than an empty span
+    // that would let a duplicated capacity line back in unnoticed.
+    expect(row.querySelector('.shop-row__description')).toBeNull();
+    expect(row.querySelector('button').disabled).toBe(true);
+  });
+
+  it('shows what a purchase does', async () => {
+    const { fixture } = await renderMerchantWithShop({
+      offers: [
+        {
+          itemKey: 'bandit-blade',
+          itemName: 'Bandit Blade',
+          itemDescription: 'A roughly serrated blade, forged for quick raids.',
+          iconPath: '/images/items/bandit-blade.png',
+          currencyType: 'SILVER',
+          price: 60,
+          quantity: 1,
+          effectSummary: '11 Weapon Damage, +1 Attack',
+          requirements: [
+            {
+              label: 'Requires World Renown 3',
+              current: 1,
+              required: 3,
+              met: false,
+            },
+          ],
+          unlocked: false,
+          affordable: true,
+        },
+      ],
+    });
+
+    const row = fixture.nativeElement.querySelector(
+      '[data-shop-item="bandit-blade"]',
+    );
+    expect(row.textContent).toContain('11 Weapon Damage, +1 Attack');
+  });
+
+  it('does not label an open offer as requiring anything unmet', async () => {
+    const { fixture } = await renderMerchantWithShop({
+      offers: [
+        {
+          itemKey: 'small-healing-potion',
+          itemName: 'Small Healing Potion',
+          itemDescription: 'A bitter draught.',
+          iconPath: '/images/items/potion.png',
+          currencyType: 'SILVER',
+          price: 12,
+          quantity: 1,
+          effectSummary: null,
+          requirements: [],
+          unlocked: true,
+          affordable: true,
+        },
+      ],
+    });
+
+    const row = fixture.nativeElement.querySelector(
+      '[data-shop-item="small-healing-potion"]',
+    );
+    expect(row.querySelector('[data-requirement]')).toBeNull();
+    expect(row.querySelector('button').disabled).toBe(false);
+  });
+
+  it('renders a bypassed offer as buyable even with an unmet requirement shown', async () => {
+    // A later slice opens an offer through a quest bypass rather than by
+    // meeting the stated requirement. The server still describes the
+    // requirement it evaluated, but `unlocked` is what actually gates the
+    // button -- an unmet requirement must not re-lock a bypassed offer.
+    const { fixture } = await renderMerchantWithShop({
+      offers: [
+        {
+          itemKey: 'referred-trinket',
+          itemName: 'Referred Trinket',
+          itemDescription: 'A favour, called in.',
+          iconPath: '/images/items/referred-trinket.png',
+          currencyType: 'SILVER',
+          price: 20,
+          quantity: 1,
+          effectSummary: null,
+          requirements: [
+            {
+              label: 'Requires Border Watch Reputation 25',
+              current: 14,
+              required: 25,
+              met: false,
+            },
+          ],
+          unlocked: true,
+          affordable: true,
+        },
+      ],
+    });
+
+    const row = fixture.nativeElement.querySelector(
+      '[data-shop-item="referred-trinket"]',
+    );
+    expect(row.textContent).toContain('Requires Border Watch Reputation 25');
+    const button = row.querySelector('button');
+    expect(button.disabled).toBe(false);
+    expect(button.textContent).toContain('Buy');
+  });
 });

apps/web/src/app/features/npc/merchant.store.spec.ts

@@ -6,6 +6,7 @@ import type {
   ExchangeResult,
   ExchangeView,
   NpcInteraction,
+  ShopOfferView,
   ShopView,
 } from '../../core/api/game-api.models';
 import { GameApiService } from '../../core/api/game-api.service';
@@ -74,24 +75,35 @@ function exchangeView(overrides: Partial<ExchangeView> = {}): ExchangeView {
   };
 }
 
-function shopView(): ShopView {
+/** A single shop offer, defaulting to the fields no test in this file varies. */
+function offer(
+  itemKey: string,
+  itemName: string,
+  unlocked: boolean,
+): ShopOfferView {
   return {
-    shopKey: 'borin-supplies',
+    itemKey,
-    shopName: "Quartermaster's Supplies",
+    itemName,
-    npcKey: 'borin-quartermaster',
-    silver: 100,
-    offers: [
-      {
-        itemKey: 'small-healing-potion',
-        itemName: 'Small Healing Potion',
     itemDescription: 'A bitter draught.',
     iconPath: '/images/items/potion.png',
     currencyType: 'SILVER',
     price: 12,
     quantity: 1,
-        unlocked: true,
+    effectSummary: null,
+    requirements: [],
+    unlocked,
     affordable: true,
-      },
+  };
+}
+
+function shopView(offers?: ShopOfferView[]): ShopView {
+  return {
+    shopKey: 'borin-supplies',
+    shopName: "Quartermaster's Supplies",
+    npcKey: 'borin-quartermaster',
+    silver: 100,
+    offers: offers ?? [
+      offer('small-healing-potion', 'Small Healing Potion', true),
     ],
   };
 }
@@ -109,11 +121,23 @@ function tradeResult(): ExchangeResult {
   };
 }
 
-function createApi(overrides: Partial<Record<string, unknown>> = {}) {
+function createApi(
+  overrides: Partial<Record<string, unknown>> & { shopSequence?: ShopView[] } = {},
+) {
+  // `shopSequence` lets a test hand back a different shop view on each call to
+  // `getShop`, so before/after `unlocked` flags can be observed across a trade
+  // without needing a real server round-trip.
+  const { shopSequence, ...rest } = overrides;
+  let shopCallIndex = 0;
+
   return {
     getNpcInteraction: vi.fn(() => of(interaction())),
     getTradeIn: vi.fn(() => of(exchangeView())),
-    getShop: vi.fn(() => of(shopView())),
+    getShop: vi.fn(() =>
+      shopSequence
+        ? of(shopSequence[Math.min(shopCallIndex++, shopSequence.length - 1)])
+        : of(shopView()),
+    ),
     tradeIn: vi.fn(() => of(tradeResult())),
     getCharacter: vi.fn(() =>
       of({
@@ -135,7 +159,7 @@ function createApi(overrides: Partial<Record<string, unknown>> = {}) {
         silverBalance: 88,
       }),
     ),
-    ...overrides,
+    ...rest,
   };
 }
 
@@ -359,4 +383,75 @@ describe('MerchantStore', () => {
     store.showPanel('EXCHANGE');
     expect(store.panel()).toBe('EXCHANGE');
   });
+
+  it('announces an offer that a trade just unlocked', async () => {
+    // Reputation earned by the trade opened the pouch. The player should learn
+    // that without hunting for it (slice §9).
+    const api = createApi({
+      shopSequence: [
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', false)]),
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', true)]),
+      ],
+    });
+    const store = createStore(api);
+
+    await store.load('borin-quartermaster');
+    store.setQuantity('ash-pelt', 1);
+    await store.tradeSelected();
+
+    expect(store.newlyUnlocked()).toEqual(['Basic Trophy Pouch']);
+  });
+
+  it('says nothing when a trade unlocks nothing', async () => {
+    const api = createApi({
+      shopSequence: [
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', false)]),
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', false)]),
+      ],
+    });
+    const store = createStore(api);
+
+    await store.load('borin-quartermaster');
+    store.setQuantity('ash-pelt', 1);
+    await store.tradeSelected();
+
+    expect(store.newlyUnlocked()).toEqual([]);
+  });
+
+  it('does not re-announce an offer that was already open', async () => {
+    const api = createApi({
+      shopSequence: [
+        shopView([offer('small-healing-potion', 'Small Healing Potion', true)]),
+        shopView([offer('small-healing-potion', 'Small Healing Potion', true)]),
+      ],
+    });
+    const store = createStore(api);
+
+    await store.load('borin-quartermaster');
+    store.setQuantity('ash-pelt', 1);
+    await store.tradeSelected();
+
+    expect(store.newlyUnlocked()).toEqual([]);
+  });
+
+  it('clears the unlock banner on a fresh load and at the start of a purchase', async () => {
+    // A stale banner from a previous merchant visit, or from before a buy
+    // click resolves, would misattribute an unlock to the wrong action.
+    const api = createApi({
+      shopSequence: [
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', false)]),
+        shopView([offer('basic-trophy-pouch', 'Basic Trophy Pouch', true)]),
+      ],
+    });
+    const store = createStore(api);
+
+    await store.load('borin-quartermaster');
+    store.setQuantity('ash-pelt', 1);
+    await store.tradeSelected();
+    expect(store.newlyUnlocked()).toEqual(['Basic Trophy Pouch']);
+
+    await store.buy('basic-trophy-pouch');
+
+    expect(store.newlyUnlocked()).toEqual([]);
+  });
 });

apps/web/src/app/features/npc/merchant.store.ts

@@ -30,6 +30,8 @@ const ERROR_MESSAGES: Readonly<Record<string, string>> = {
   SHOP_OFFER_LOCKED: 'You have not earned the right to buy this yet.',
   SHOP_INSUFFICIENT_SILVER: 'You cannot afford that.',
   SHOP_INVALID_QUANTITY: 'That quantity cannot be bought.',
+  MERCHANT_REPUTATION_TOO_LOW: 'You have not earned enough standing for this yet.',
+  SHOP_BAG_ALREADY_OWNED: 'You already carry that.',
   CHARACTER_NOT_FOUND: 'Your character could not be found.',
 };
 
@@ -59,6 +61,7 @@ export class MerchantStore {
   private readonly lastTradeState = signal<ExchangeResult | null>(null);
   private readonly lastPurchaseState = signal<ShopPurchaseResult | null>(null);
   private readonly selectionState = signal<Record<string, number>>({});
+  private readonly newlyUnlockedState = signal<string[]>([]);
 
   readonly interaction = this.interactionState.asReadonly();
   readonly exchange = this.exchangeState.asReadonly();
@@ -71,6 +74,7 @@ export class MerchantStore {
   readonly lastTrade = this.lastTradeState.asReadonly();
   readonly lastPurchase = this.lastPurchaseState.asReadonly();
   readonly selection = this.selectionState.asReadonly();
+  readonly newlyUnlocked = this.newlyUnlockedState.asReadonly();
 
   /** True once anything is selected, so the trade button can enable. */
   readonly hasSelection = computed(() =>
@@ -110,6 +114,7 @@ export class MerchantStore {
     this.lastTradeState.set(null);
     this.lastPurchaseState.set(null);
     this.selectionState.set({});
+    this.newlyUnlockedState.set([]);
     this.panelState.set('DIALOGUE');
 
     try {
@@ -207,8 +212,13 @@ export class MerchantStore {
       // capacity, Silver and possibly renown at once, and the server is the
       // only place that knows all of it.
       this.exchangeState.set(await firstValueFrom(this.api.getTradeIn(npcKey)));
-      this.shopState.set(
+      const previousShop = this.shopState();
-        this.shopState() ? await firstValueFrom(this.api.getShop(npcKey)) : null,
+      const refreshedShop = previousShop
+        ? await firstValueFrom(this.api.getShop(npcKey))
+        : null;
+      this.shopState.set(refreshedShop);
+      this.newlyUnlockedState.set(
+        this.unlockedSince(previousShop, refreshedShop),
       );
 
       // The purse in the top bar comes from the shared character state, so a
@@ -230,6 +240,9 @@ export class MerchantStore {
 
     this.pendingState.set(itemKey);
     this.actionErrorState.set(null);
+    // A purchase re-reads the shop below, so a banner from an earlier trade
+    // must not linger and be misread as caused by this buy.
+    this.newlyUnlockedState.set([]);
 
     try {
       this.lastPurchaseState.set(
@@ -252,6 +265,37 @@ export class MerchantStore {
     this.lastPurchaseState.set(null);
   }
 
+  dismissUnlocked(): void {
+    this.newlyUnlockedState.set([]);
+  }
+
+  /**
+   * Offer names that went from locked to open (slice §9).
+   *
+   * Derived from two shop reads the store already performs rather than from a
+   * server event: the trade re-fetches the shop anyway, so the before/after
+   * state is in hand, and a notification the server has to remember would be
+   * more machinery than a one-line message is worth.
+   */
+  private unlockedSince(
+    before: ShopView | null,
+    after: ShopView | null,
+  ): string[] {
+    if (!before || !after) {
+      return [];
+    }
+
+    const wasLocked = new Set(
+      before.offers
+        .filter((offer) => !offer.unlocked)
+        .map((offer) => offer.itemKey),
+    );
+
+    return after.offers
+      .filter((offer) => offer.unlocked && wasLocked.has(offer.itemKey))
+      .map((offer) => offer.itemName);
+  }
+
   private toMessage(error: unknown): string {
     if (error instanceof HttpErrorResponse) {
       const code = (error.error as { code?: string } | null)?.code;

docs/playable-slices/0.8.5-Reputation-Gated-Merchant-Offers.md

@@ -223,14 +223,20 @@ No large modal is required.
 
 ## 11. Acceptance Criteria
 
-- [ ] Merchant offers can define reputation/unlock requirements.
+- [x] Merchant offers can define reputation/unlock requirements.
-- [ ] At least two offers visibly demonstrate locked states.
+- [x] At least two offers visibly demonstrate locked states.
-- [ ] Requirements are shown to the player in English.
+- [x] Requirements are shown to the player in English.
-- [ ] Server rejects purchases when requirements are not met.
+- [x] Server rejects purchases when requirements are not met.
-- [ ] New progression offers do not depend on level gates.
+- [x] New progression offers do not depend on level gates.
-- [ ] Quest/referral unlock support exists for Slice 0.9.
+- [x] Quest/referral unlock support exists for Slice 0.9.
-- [ ] Reputation increase can visibly unlock a previously locked offer.
+- [x] Reputation increase can visibly unlock a previously locked offer.
-- [ ] No generalized rules engine was added unnecessarily.
+- [x] No generalized rules engine was added unnecessarily.
+
+> **Note (implementation):** The Bandit Blade offer is gated on World Renown 3,
+> which current content cannot reach — there is one renown milestone, worth +1.
+> It is deliberately left visible and locked as a long-horizon goal until
+> Slice 0.11 adds the milestones that reach it (§5: visible rewards create
+> goals).
 
 ---
 

docs/playable-slices/0.9-First-Quest-and-Bag-Tutorial.md

@@ -133,7 +133,16 @@ Category: HIDE
 Capacity: 5
 ```
 
-The grant should use the quest/referral exception supported by Slice 0.8.5.
+The grant uses the referral exception built in Slice 0.8.5: the Basic Hide Bag
+offer (`BORIN_OFFER_IDS.hideBag`) carries
+
+```text
+bypassConditions: [{ type: FLAG_SET, key: 'referred-by-south-gate-warden' }]
+```
+
+so setting that flag on the character's Borin state opens the offer without
+changing any reputation. The offer's own gate stays at Border Watch
+Reputation 40.
 
 ---
 

docs/superpowers/plans/2026-08-22-slice-0.8.5-research-notes.md

@@ -0,0 +1,103 @@
+# Slice 0.8.5 — Research Findings (Preliminary to the Plan)
+
+**Spec:** `docs/playable-slices/0.8.5-Reputation-Gated-Merchant-Offers.md`
+**Branch/Worktree:** `slice/0.8.5-reputation-gated-merchant-offers` in `.claude/worktrees/slice-0.8.5-reputation-gated-offers`
+**Baseline:** API 410 tests / 49 suites green, Web 292 tests / 27 suites green.
+
+## What Slice 0.8 Already Delivered
+
+Most of the mechanics already exist — 0.8.5 is largely content plus
+presentation, not new construction.
+
+- `apps/api/src/conditions/game-condition.types.ts` — `GameConditionType` with
+  `REGION_REPUTATION`, `WORLD_RENOWN`, `FLAG_SET`, `HAS_ITEM` as
+  `SUPPORTED_CONDITION_TYPES`; `ComparisonOperator` + `compare()`.
+- `apps/api/src/conditions/game-condition.service.ts` — `evaluate()` (AND logic,
+  fail-closed) and `describe()` (per condition `{condition, met}`). `describe()`
+  has **no caller yet** other than its own spec — it was built explicitly for
+  0.8.5.
+- `shop_offers.conditions` (jsonb) exists in migration
+  `1795000000000-CreateNpcSystem.ts`; the seed sets `conditions: []` everywhere.
+- `ShopService.getShopView()` already returns `unlocked` + `affordable`;
+  `purchase()` throws `SHOP_OFFER_LOCKED` (403) server-side. The frontend renders
+  "Locked"/"Too costly" and maps `SHOP_OFFER_LOCKED` in `merchant.store.ts`.
+
+Conclusion: "Server rejects purchases when requirements are not met" (§11) is in
+practice already satisfied and covered by `shop.service.spec.ts`. What is missing
+is content, the requirement text/progress in the UI, the bag sales format, the
+referral bypass and the unlock feedback.
+
+## Central Architectural Obstacle: Bags Are Not Items
+
+`shop_offers.item_definition_id` is NOT NULL with an FK onto `item_definitions`.
+The spec's two flagship offers (§4), however, are `LootBagDefinition` rows
+(`apps/api/src/loot-bags/entities/loot-bag-definition.entity.ts`) — deliberately
+not items (0.7.5 §6: never equipped, no loot, no combat stats). The 0.8 seed
+predicts this verbatim:
+
+> "a bag is a `LootBagDefinition` rather than an `ItemDefinition`, so selling
+> one needs an offer shape this slice has no reason to build."
+
+**Migration required:** make `item_definition_id` nullable, add
+`loot_bag_definition_id` (nullable, FK → `loot_bag_definitions`, ON DELETE
+RESTRICT), a CHECK for "exactly one of the two is set", and the unique index
+`IDX_shop_offers_shop_item` needs a counterpart for bags. On buying a bag,
+`ShopService` must create a `CharacterLootBag` row instead of stacking a
+`CharacterItem` — idempotently, because
+`IDX_character_loot_bags_character_definition` is unique and 0.9 §11 requires
+"bag grant is idempotent".
+
+## Decisions Taken (Confirmed by the User)
+
+1. **Starter bags in the seed:** Remove only the Trophy Pouch from the demo seed
+   (`vertical-slice.seed.ts:376-392`). The Hide Bag stays seeded for now, until
+   0.9 hands it over through the quest referral.
+2. **Hide Bag gate:** Reputation gate **or** referral flag
+   (`referred-by-south-gate-warden`, 0.9 §5). Needs a clearly named bypass field
+   on the offer — expressly *not* a generic rules engine (§3, §7, §11 "No
+   generalized rules engine"). Proposal: `shop_offers.bypass_conditions` (jsonb)
+   with OR semantics against `conditions` — the smallest extension that carries
+   the exception case.
+3. **Third offer:** Bandit Blade (already exists as an ItemDefinition,
+   `ITEM_IDS['bandit-blade']`, weaponDamage 11 / +1 Attack) behind
+   `WORLD_RENOWN >= 3`.
+
+## Balancing Reference Points
+
+- The exchange pays 2/3/5/12 reputation per trade good (`npc-content.ts`
+  `EXCHANGE_RULES`).
+- Reputation ranks: 0 Stranger, 100 Tolerated, 250 Known, 500 Recognized,
+  800 Trusted, 1200 Esteemed (`reputation-rank.ts`). The gates are numeric, not
+  rank-based — the spec examples say "Reputation 25".
+- Renown: `Character.renown`, currently only one milestone
+  (`first-goods-returned`, +1). **Open:** Renown 3 is unreachable with today's
+  content — either a lower threshold, or the offer stays visibly locked until
+  0.11 (which actually matches §5, "visible rewards create goals").
+- Spec example §5, verbatim: Trophy Pouch, 40 Silver, Requires Ashen Fields
+  Reputation 25.
+
+## Files Affected
+
+| File | Role |
+|---|---|
+| `apps/api/src/database/migrations/1796*-SellableLootBags.ts` | new: bag offers + bypass column |
+| `apps/api/src/shops/entities/shop-offer.entity.ts` | nullable item FK, bag FK, `bypassConditions` |
+| `apps/api/src/shops/shop.service.ts` | bag grant, OR bypass, requirement description via `describe()` |
+| `apps/api/src/shops/shop.errors.ts` | `MERCHANT_REPUTATION_TOO_LOW` (§6) instead of / alongside `SHOP_OFFER_LOCKED` |
+| `apps/api/src/database/seeds/npc-content.ts` | three locked offers |
+| `apps/api/src/database/seeds/vertical-slice.seed.ts:376` | take the Trophy Pouch out of the demo seed |
+| `apps/web/src/app/core/api/game-api.models.ts:433` | `requirements` on `ShopOfferView` |
+| `apps/web/src/app/features/npc/merchant-page.component.{html,scss}` | requirement + current value per row |
+| `apps/web/src/app/features/npc/merchant.store.ts` | unlock feedback after a trade (§9) |
+
+## Still Open Before the Plan
+
+- The wording and carrier of the unlock feedback (§9): the store reloads the shop
+  after a trade anyway (`merchant.store.ts:209-212`), so a before/after
+  comparison of the `unlocked` flags can be drawn locally — with no new server
+  event. That is the smallest solution and needs no endpoint.
+- Whether `MERCHANT_REPUTATION_TOO_LOW` replaces the existing
+  `SHOP_OFFER_LOCKED` or supplements it. Replacing it breaks the existing
+  frontend mapping entry and one test; supplementing it (a more specific code
+  when the violated condition is a reputation condition) satisfies §6 verbatim
+  without a regression.