diff --git a/apps/api/src/app/build-app.js b/apps/api/src/app/build-app.js
index 6ec95ff..af1548f 100644
--- a/apps/api/src/app/build-app.js
+++ b/apps/api/src/app/build-app.js
@@ -21,6 +21,7 @@ import { registerAdminDashboardRoutes } from "../modules/dashboard/routes/admin-
 import { registerAdminPricingRoutes } from "../modules/pricing/routes/admin-pricing-routes.js";
 import { registerAdminProviderMappingRoutes } from "../modules/pricing/routes/admin-provider-mapping-routes.js";
 import { registerAdminExportRoutes } from "../modules/exports/routes/admin-export-routes.js";
+import { registerAdminSettingsRoutes } from "../modules/settings/routes/admin-settings-routes.js";
 
 export function buildApp(dependencies) {
   const app = Fastify();
@@ -93,6 +94,10 @@ export function buildApp(dependencies) {
     ...dependencies,
     prefix: "/api/v1/admin",
   });
+  app.register(registerAdminSettingsRoutes, {
+    ...dependencies,
+    prefix: "/api/v1/admin",
+  });
   app.register(registerPublicSearchRoutes, {
     ...dependencies,
     prefix: "/api/v1",
diff --git a/apps/api/src/app/server.js b/apps/api/src/app/server.js
index eaa261f..60b3c38 100644
--- a/apps/api/src/app/server.js
+++ b/apps/api/src/app/server.js
@@ -53,6 +53,8 @@ import { createPricingProviderRegistry } from "../modules/pricing/providers/pric
 import { createFixturePricingProvider } from "../modules/pricing/providers/fixture-pricing-provider.js";
 import { createHttpPricingProvider } from "../modules/pricing/providers/http-pricing-provider.js";
 import { createAdminExportService } from "../modules/exports/services/admin-export-service.js";
+import { createSellerSettingsRepository } from "../modules/settings/repositories/seller-settings-repository.js";
+import { createSellerSettingsService } from "../modules/settings/services/seller-settings-service.js";
 
 function parsePort(value) {
   const port = Number.parseInt(value ?? "3000", 10);
@@ -90,6 +92,9 @@ async function startServer() {
   const providerMappingRepository = createProviderMappingRepository(
     database.db,
   );
+  const sellerSettingsService = createSellerSettingsService({
+    sellerSettingsRepository: createSellerSettingsRepository(database.db),
+  });
   const providers = [];
   if (process.env.PRICING_FIXTURE_PROVIDER_ENABLED === "true")
     providers.push(createFixturePricingProvider());
@@ -163,6 +168,7 @@ async function startServer() {
     adminExportService: createAdminExportService({
       inventoryItemService,
     }),
+    sellerSettingsService,
     catalogLookupRepository,
     publicImageService,
     publicInventoryService: createPublicInventoryService({
diff --git a/apps/api/src/infrastructure/database/schema.js b/apps/api/src/infrastructure/database/schema.js
index 979ec46..25136b7 100644
--- a/apps/api/src/infrastructure/database/schema.js
+++ b/apps/api/src/infrastructure/database/schema.js
@@ -61,6 +61,14 @@ export const sellers = pgTable(
   (table) => [uniqueIndex("sellers_user_id_unique").on(table.userId)],
 );
 
+export const sellerSettings = pgTable("seller_settings", {
+  sellerId: uuid("seller_id")
+    .primaryKey()
+    .references(() => sellers.id, { onDelete: "cascade" }),
+  settings: jsonb("settings").default({}).notNull(),
+  ...timestamps,
+});
+
 export const sessions = pgTable(
   "sessions",
   {
diff --git a/apps/api/src/modules/settings/repositories/seller-settings-repository.js b/apps/api/src/modules/settings/repositories/seller-settings-repository.js
new file mode 100644
index 0000000..9df1de4
--- /dev/null
+++ b/apps/api/src/modules/settings/repositories/seller-settings-repository.js
@@ -0,0 +1,24 @@
+import { eq } from 'drizzle-orm';
+
+import { sellerSettings } from '../../../infrastructure/database/schema.js';
+
+export function createSellerSettingsRepository(db) {
+  return {
+    async findBySellerId(sellerId) {
+      const [record] = await db.select().from(sellerSettings).where(eq(sellerSettings.sellerId, sellerId));
+      return record ?? null;
+    },
+
+    async upsert(sellerId, settings) {
+      const [record] = await db
+        .insert(sellerSettings)
+        .values({ sellerId, settings })
+        .onConflictDoUpdate({
+          target: sellerSettings.sellerId,
+          set: { settings, updatedAt: new Date() },
+        })
+        .returning();
+      return record;
+    },
+  };
+}
diff --git a/apps/api/src/modules/settings/routes/admin-settings-routes.js b/apps/api/src/modules/settings/routes/admin-settings-routes.js
new file mode 100644
index 0000000..f78b974
--- /dev/null
+++ b/apps/api/src/modules/settings/routes/admin-settings-routes.js
@@ -0,0 +1,50 @@
+import { sellerSettingsSchema } from '@pokemon-inventory/validation/settings';
+
+import { createApplicationError } from '../../../shared/errors/application-error.js';
+
+export async function registerAdminSettingsRoutes(app, options) {
+  const {
+    authenticateAdmin = async () => {
+      throw createApplicationError('UNAUTHORIZED', 'Authentication is required.', 401);
+    },
+    authorizeUnsafeRequest,
+    sessionCookieName = 'pokemon_inventory_session',
+    sellerSettingsService,
+  } = options;
+
+  app.addHook('preHandler', async (request) => {
+    const admin = await authenticateAdmin(request);
+    if (!admin?.sellerId) {
+      throw createApplicationError('UNAUTHORIZED', 'Authentication is required.', 401);
+    }
+    request.admin = admin;
+  });
+
+  app.get('/settings', async (request) => ({
+    data: await sellerSettingsService.get({ sellerId: request.admin.sellerId }),
+  }));
+
+  app.patch('/settings', async (request, reply) => {
+    await authorizeUnsafeRequest?.(
+      request.cookies[sessionCookieName],
+      request.headers['x-csrf-token'],
+    );
+    const result = sellerSettingsSchema.safeParse(request.body);
+    if (!result.success) {
+      return reply.code(400).send({
+        error: {
+          code: 'VALIDATION_ERROR',
+          message: 'Request validation failed.',
+          details: result.error.issues.map(({ message, path }) => ({ message, path })),
+        },
+      });
+    }
+
+    return reply.send({
+      data: await sellerSettingsService.update({
+        sellerId: request.admin.sellerId,
+        settings: result.data,
+      }),
+    });
+  });
+}
diff --git a/apps/api/src/modules/settings/services/seller-settings-service.js b/apps/api/src/modules/settings/services/seller-settings-service.js
new file mode 100644
index 0000000..f3fe851
--- /dev/null
+++ b/apps/api/src/modules/settings/services/seller-settings-service.js
@@ -0,0 +1,27 @@
+import { sellerSettingsSchema } from '@pokemon-inventory/validation/settings';
+
+export function createSellerSettingsService({ sellerSettingsRepository }) {
+  return {
+    async get({ sellerId }) {
+      const record = await sellerSettingsRepository.findBySellerId(sellerId);
+      return record?.settings ?? {};
+    },
+
+    async update({ sellerId, settings }) {
+      const validated = sellerSettingsSchema.parse(settings);
+      const current = await this.get({ sellerId });
+      const merged = mergeSettings(current, validated);
+      const record = await sellerSettingsRepository.upsert(sellerId, merged);
+      return record.settings;
+    },
+  };
+}
+
+function mergeSettings(current, update) {
+  return Object.fromEntries(
+    Object.entries({ ...current, ...update }).map(([category, values]) => [
+      category,
+      { ...(current[category] ?? {}), ...values },
+    ]),
+  );
+}
diff --git a/apps/api/tests/application/seller-settings-service.test.js b/apps/api/tests/application/seller-settings-service.test.js
new file mode 100644
index 0000000..892e326
--- /dev/null
+++ b/apps/api/tests/application/seller-settings-service.test.js
@@ -0,0 +1,42 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { createSellerSettingsService } from '../../src/modules/settings/services/seller-settings-service.js';
+
+test('merges validated seller settings without replacing other categories', async () => {
+  let stored = null;
+  const service = createSellerSettingsService({
+    sellerSettingsRepository: {
+      async findBySellerId() { return stored; },
+      async upsert(sellerId, settings) {
+        stored = { sellerId, settings };
+        return stored;
+      },
+    },
+  });
+
+  await service.update({
+    sellerId: 'seller-1',
+    settings: { pricing: { defaultStrategy: 'median' }, general: { publicContactEmail: 'owner@example.test' } },
+  });
+  const result = await service.update({
+    sellerId: 'seller-1',
+    settings: { inventory: { maxImagesPerItem: 12 } },
+  });
+
+  assert.deepEqual(result, {
+    pricing: { defaultStrategy: 'median' },
+    general: { publicContactEmail: 'owner@example.test' },
+    inventory: { maxImagesPerItem: 12 },
+  });
+});
+
+test('rejects unknown or invalid settings', async () => {
+  const service = createSellerSettingsService({
+    sellerSettingsRepository: { async findBySellerId() { return null; } },
+  });
+
+  await assert.rejects(
+    () => service.update({ sellerId: 'seller-1', settings: { secrets: { token: 'nope' } } }),
+  );
+});
diff --git a/apps/api/tests/http/admin-settings-routes.test.js b/apps/api/tests/http/admin-settings-routes.test.js
new file mode 100644
index 0000000..f33556b
--- /dev/null
+++ b/apps/api/tests/http/admin-settings-routes.test.js
@@ -0,0 +1,60 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { buildApp } from '../../src/app/build-app.js';
+
+function createTestApp({ authorizeUnsafeRequest } = {}) {
+  let settings = { pricing: { defaultStrategy: 'median' } };
+  return buildApp({
+    authenticateAdmin: async () => ({ sellerId: 'seller-1' }),
+    authorizeUnsafeRequest,
+    sellerSettingsService: {
+      async get() { return settings; },
+      async update({ settings: nextSettings }) {
+        settings = { ...settings, ...nextSettings };
+        return settings;
+      },
+    },
+  });
+}
+
+test('reads and updates seller settings', async (testContext) => {
+  const app = createTestApp();
+  testContext.after(() => app.close());
+
+  const readResponse = await app.inject({ method: 'GET', url: '/api/v1/admin/settings' });
+  const updateResponse = await app.inject({
+    method: 'PATCH',
+    url: '/api/v1/admin/settings',
+    payload: { inventory: { maxImagesPerItem: 12 } },
+  });
+
+  assert.equal(readResponse.statusCode, 200);
+  assert.deepEqual(readResponse.json().data, { pricing: { defaultStrategy: 'median' } });
+  assert.equal(updateResponse.statusCode, 200);
+  assert.deepEqual(updateResponse.json().data, {
+    pricing: { defaultStrategy: 'median' },
+    inventory: { maxImagesPerItem: 12 },
+  });
+});
+
+test('protects settings updates with CSRF validation', async (testContext) => {
+  const app = createTestApp({
+    authorizeUnsafeRequest: async () => {
+      const error = new Error('CSRF validation failed.');
+      error.code = 'FORBIDDEN';
+      error.statusCode = 403;
+      throw error;
+    },
+  });
+  testContext.after(() => app.close());
+
+  const response = await app.inject({
+    method: 'PATCH',
+    url: '/api/v1/admin/settings',
+    payload: { pricing: { defaultStrategy: 'median' } },
+  });
+
+  assert.equal(response.statusCode, 403);
+  assert.equal(response.json().error.code, 'FORBIDDEN');
+});
diff --git a/apps/web/src/pages/AdminSettingsPage.stories.js b/apps/web/src/pages/AdminSettingsPage.stories.js
new file mode 100644
index 0000000..c1d9ea6
--- /dev/null
+++ b/apps/web/src/pages/AdminSettingsPage.stories.js
@@ -0,0 +1,5 @@
+import AdminSettingsPage from './AdminSettingsPage.vue';
+
+export default { title: 'Pages/AdminSettingsPage', component: AdminSettingsPage };
+
+export const SettingsForm = {};
diff --git a/apps/web/src/pages/AdminSettingsPage.vue b/apps/web/src/pages/AdminSettingsPage.vue
new file mode 100644
index 0000000..7130741
--- /dev/null
+++ b/apps/web/src/pages/AdminSettingsPage.vue
@@ -0,0 +1,85 @@
+<script setup>
+import { onMounted, reactive, ref } from 'vue';
+
+import { getAdminSettings, updateAdminSettings } from '@/services/admin-settings-service.js';
+
+const settings = reactive({
+  general: { publicContactEmail: '', publicContactPhone: '' },
+  inventory: { maxImagesPerItem: 10 },
+  pricing: { defaultStrategy: 'median' },
+  security: { sessionIdleMinutes: 60 },
+});
+const isLoading = ref(true);
+const isSaving = ref(false);
+const message = ref('');
+const error = ref('');
+
+function csrfToken() {
+  return document.cookie.split('; ').find((value) => value.startsWith('pokemon_inventory_csrf='))?.split('=')[1] ?? '';
+}
+
+async function load() {
+  try {
+    Object.assign(settings, await getAdminSettings());
+  } catch (requestError) {
+    error.value = requestError.message;
+  } finally {
+    isLoading.value = false;
+  }
+}
+
+async function save() {
+  isSaving.value = true;
+  message.value = '';
+  error.value = '';
+  try {
+    Object.assign(settings, await updateAdminSettings(settings, csrfToken()));
+    message.value = 'Settings saved.';
+  } catch (requestError) {
+    error.value = requestError.message;
+  } finally {
+    isSaving.value = false;
+  }
+}
+
+onMounted(load);
+</script>
+
+<template>
+  <section class="admin-page">
+    <p class="catalog-kicker">Configuration</p>
+    <h1>Settings</h1>
+    <p v-if="isLoading" class="state state--loading" role="status">Loading settings...</p>
+    <p v-if="message" class="state" role="status">{{ message }}</p>
+    <p v-if="error" class="state state--error" role="alert">{{ error }}</p>
+    <form v-if="!isLoading" class="admin-workspace-grid" @submit.prevent="save">
+      <fieldset class="showcase-panel">
+        <legend>General</legend>
+        <label class="fixture-label" for="settings-email">Public contact email</label>
+        <input id="settings-email" v-model="settings.general.publicContactEmail" class="fixture-input" type="email" />
+        <label class="fixture-label" for="settings-phone">Public contact phone</label>
+        <input id="settings-phone" v-model="settings.general.publicContactPhone" class="fixture-input" />
+      </fieldset>
+      <fieldset class="showcase-panel">
+        <legend>Inventory</legend>
+        <label class="fixture-label" for="settings-images">Maximum images per item</label>
+        <input id="settings-images" v-model.number="settings.inventory.maxImagesPerItem" class="fixture-input" type="number" min="1" max="100" />
+      </fieldset>
+      <fieldset class="showcase-panel">
+        <legend>Pricing</legend>
+        <label class="fixture-label" for="settings-strategy">Default valuation strategy</label>
+        <select id="settings-strategy" v-model="settings.pricing.defaultStrategy" class="fixture-input">
+          <option value="median">Median</option>
+          <option value="average">Average</option>
+          <option value="weighted_average">Weighted average</option>
+        </select>
+      </fieldset>
+      <fieldset class="showcase-panel">
+        <legend>Security</legend>
+        <label class="fixture-label" for="settings-idle">Session idle minutes</label>
+        <input id="settings-idle" v-model.number="settings.security.sessionIdleMinutes" class="fixture-input" type="number" min="5" max="43200" />
+      </fieldset>
+      <button class="button button--primary" type="submit" :disabled="isSaving">Save settings</button>
+    </form>
+  </section>
+</template>
diff --git a/apps/web/src/pages/AdminShell.vue b/apps/web/src/pages/AdminShell.vue
index 4d22b44..e6ea3e3 100644
--- a/apps/web/src/pages/AdminShell.vue
+++ b/apps/web/src/pages/AdminShell.vue
@@ -19,6 +19,7 @@ async function logout() {
       <h1>Inventory</h1>
       <nav aria-label="Admin navigation">
         <a href="/admin">Overview</a>
+        <RouterLink :to="{ name: 'admin-settings' }">Settings</RouterLink>
       </nav>
       <div class="admin-sidebar__footer">
         <span>{{ principal?.email }}</span>
diff --git a/apps/web/src/router/index.js b/apps/web/src/router/index.js
index efb4dce..adced1c 100644
--- a/apps/web/src/router/index.js
+++ b/apps/web/src/router/index.js
@@ -8,6 +8,7 @@ import AdminShell from '@/pages/AdminShell.vue';
 import LoginPage from '@/pages/LoginPage.vue';
 import { useAuth } from '@/composables/useAuth.js';
 import AdminImagePage from '@/pages/AdminImagePage.vue';
+import AdminSettingsPage from '@/pages/AdminSettingsPage.vue';
 
 const router = createRouter({
   history: createWebHistory(),
@@ -22,6 +23,7 @@ const router = createRouter({
       children: [
         { path: '', name: 'admin-home', component: AdminHomePage },
         { path: 'inventory/:id/images', name: 'admin-image-manager', component: AdminImagePage },
+        { path: 'settings', name: 'admin-settings', component: AdminSettingsPage },
       ],
     },
   ],
diff --git a/apps/web/src/services/admin-settings-service.js b/apps/web/src/services/admin-settings-service.js
new file mode 100644
index 0000000..83fe684
--- /dev/null
+++ b/apps/web/src/services/admin-settings-service.js
@@ -0,0 +1,24 @@
+const apiBaseUrl = import.meta.env?.VITE_API_BASE_URL ?? '/api/v1';
+
+async function request(path, options = {}) {
+  const response = await fetch(`${apiBaseUrl}${path}`, {
+    credentials: 'include',
+    ...options,
+    headers: { 'content-type': 'application/json', ...options.headers },
+  });
+  const payload = await response.json().catch(() => null);
+  if (!response.ok) throw new Error(payload?.error?.message ?? 'Settings request failed.');
+  return payload?.data;
+}
+
+export function getAdminSettings() {
+  return request('/admin/settings');
+}
+
+export function updateAdminSettings(settings, csrfToken) {
+  return request('/admin/settings', {
+    method: 'PATCH',
+    headers: { 'x-csrf-token': csrfToken },
+    body: JSON.stringify(settings),
+  });
+}
diff --git a/apps/web/tests/catalog-service.test.js b/apps/web/tests/catalog-service.test.js
index 0aa9334..d1b6847 100644
--- a/apps/web/tests/catalog-service.test.js
+++ b/apps/web/tests/catalog-service.test.js
@@ -116,4 +116,24 @@ test('updates selected admin inventory tags through the bulk API', async () => {
   } finally {
     globalThis.fetch = originalFetch;
   }
+});
+
+test('updates admin settings through the CSRF-protected API', async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async (url, options) => {
+    assert.equal(url, '/api/v1/admin/settings');
+    assert.equal(options.method, 'PATCH');
+    assert.equal(options.headers['x-csrf-token'], 'csrf-token');
+    assert.deepEqual(JSON.parse(options.body), { pricing: { defaultStrategy: 'median' } });
+    return { ok: true, async json() { return { data: { pricing: { defaultStrategy: 'median' } } }; } };
+  };
+
+  try {
+    const { updateAdminSettings } = await import('../src/services/admin-settings-service.js');
+    assert.deepEqual(await updateAdminSettings({ pricing: { defaultStrategy: 'median' } }, 'csrf-token'), {
+      pricing: { defaultStrategy: 'median' },
+    });
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
 });
\ No newline at end of file
diff --git a/database/migrations/0023_seller_settings.sql b/database/migrations/0023_seller_settings.sql
new file mode 100644
index 0000000..a4296c5
--- /dev/null
+++ b/database/migrations/0023_seller_settings.sql
@@ -0,0 +1,6 @@
+CREATE TABLE "seller_settings" (
+  "seller_id" uuid PRIMARY KEY REFERENCES "sellers"("id") ON DELETE CASCADE,
+  "settings" jsonb DEFAULT '{}'::jsonb NOT NULL,
+  "created_at" timestamptz DEFAULT now() NOT NULL,
+  "updated_at" timestamptz DEFAULT now() NOT NULL
+);
diff --git a/database/migrations/meta/_journal.json b/database/migrations/meta/_journal.json
index 798000d..bbf2b8e 100644
--- a/database/migrations/meta/_journal.json
+++ b/database/migrations/meta/_journal.json
@@ -162,6 +162,13 @@
       "when": 1790496000000,
       "tag": "0022_product_tags",
       "breakpoints": true
+    },
+    {
+      "idx": 23,
+      "version": "7",
+      "when": 1790582400000,
+      "tag": "0023_seller_settings",
+      "breakpoints": true
     }
   ]
 }
diff --git a/docs/API.md b/docs/API.md
index 8e7137a..9db5b78 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -102,6 +102,8 @@ GET    /api/v1/admin/dashboard
 GET    /api/v1/admin/exports/inventory.json
 GET    /api/v1/admin/exports/inventory.csv
 GET    /api/v1/admin/exports/inventory.xls
+GET    /api/v1/admin/settings
+PATCH  /api/v1/admin/settings
 
 GET    /api/v1/admin/saved-views
 POST   /api/v1/admin/saved-views
diff --git a/docs/DATA-MODEL.md b/docs/DATA-MODEL.md
index 596d51e..2dc1fdd 100644
--- a/docs/DATA-MODEL.md
+++ b/docs/DATA-MODEL.md
@@ -109,6 +109,13 @@ As described above.
 - active
 - sort
 
+## Seller Settings
+
+`seller_settings` stores one JSON settings document per Seller. Supported
+categories are general contact details, inventory image limits, pricing
+strategy, and session idle duration. Settings are private to the Seller and
+are validated through the admin API allowlist.
+
 `conditions`:
 - id
 - condition_profile_id
diff --git a/docs/IMPLEMENTATION-STATUS.md b/docs/IMPLEMENTATION-STATUS.md
index 4330973..dd3bd90 100644
--- a/docs/IMPLEMENTATION-STATUS.md
+++ b/docs/IMPLEMENTATION-STATUS.md
@@ -126,7 +126,7 @@ Verified locally: `npm test` passes 116 tests with no failures; worker tests, we
 Complete production configuration and operational maturity around the implemented vertical slices.
 
 1. Configure and validate an approved external pricing provider and provider-specific mapping data.
-2. Add richer exports/settings, broader accessibility/manual coverage, and any remaining integration edge cases.
+2. Add asynchronous large exports, broader accessibility/manual coverage, and any remaining integration edge cases.
 
 Acceptance criteria: production provider credentials are secret-managed, migrations and backups are exercised in the target environment, and CI runs integration, authenticated E2E, web, build, Storybook build, and Storybook interaction/accessibility gates.
 
@@ -136,7 +136,7 @@ Work through one bounded vertical slice at a time. The linked documentation rema
 
 Completed vertical slices include authentication, listings and image prerequisites, acquisitions, sales and audited corrections, dashboard metrics/alerts, pricing observations and quality handling, provider mappings, durable pricing refresh jobs, public search/detail/image states, admin workflows, CI integration/E2E gates, production Docker packaging, rollback/health checks, PostgreSQL backup verification, restore drill scripts, image-storage restore support, and deployment smoke checks.
 
-Remaining roadmap areas are bulk status/tag/pricing actions, richer exports/settings, approved external provider credentials/adapters, broader accessibility/manual coverage, and deployment-specific NAS/TLS validation.
+Remaining roadmap areas are bulk status actions, asynchronous large exports, approved external provider credentials/adapters, broader accessibility/manual coverage, and deployment-specific NAS/TLS validation.
 
 ## Known Gaps
 
@@ -152,6 +152,7 @@ Remaining roadmap areas are bulk status/tag/pricing actions, richer exports/sett
 - Admin inventory JSON export is implemented at `GET /api/v1/admin/exports/inventory.json` and serializes seller-scoped admin DTOs as a downloadable attachment.
 - Admin inventory CSV export is implemented at `GET /api/v1/admin/exports/inventory.csv` with escaped spreadsheet-safe fields and seller-scoped admin DTOs.
 - Admin inventory Excel-compatible export is implemented at `GET /api/v1/admin/exports/inventory.xls` using the XML workbook format and seller-scoped admin DTOs.
+- Seller-scoped admin settings are implemented through `GET/PATCH /api/v1/admin/settings` with strict category allowlists and server-side partial-update merging.
 - PostgreSQL restore verification and image snapshot restore scripts are implemented and covered by shell tests as part of the deployment drill workflow.
 - `npm audit --omit=dev` currently reports zero production vulnerabilities. Re-run the audit after dependency changes and review development-dependency findings separately before production releases.
 
diff --git a/packages/validation/settings.js b/packages/validation/settings.js
new file mode 100644
index 0000000..940d6a4
--- /dev/null
+++ b/packages/validation/settings.js
@@ -0,0 +1,17 @@
+import { z } from 'zod';
+
+export const sellerSettingsSchema = z.object({
+  general: z.object({
+    publicContactEmail: z.string().trim().email().optional(),
+    publicContactPhone: z.string().trim().max(50).optional(),
+  }).strict().optional(),
+  inventory: z.object({
+    maxImagesPerItem: z.int().min(1).max(100).optional(),
+  }).strict().optional(),
+  pricing: z.object({
+    defaultStrategy: z.enum(['average', 'median', 'weighted_average']).optional(),
+  }).strict().optional(),
+  security: z.object({
+    sessionIdleMinutes: z.int().min(5).max(43200).optional(),
+  }).strict().optional(),
+}).strict();