@@ -0,0 +1,14 @@
+---
+'@objectstack/plugin-auth': minor
+---
+
+feat(plugin-auth): `registerOrganizationRecordPage: false` leaves out the platform's `sys_organization` default record page, so a host that ships its own page is the only default
+
+Clause-②: yes (widening)
+
+A deployment holds at most one `isDefault: true` record page per object, and a second one is refused at registration with `DEFAULT_RECORD_PAGE_CONFLICT`. `AuthPlugin` always registered `sys_organization_detail` (the Members / Invitations / Teams tab strip) as the default record page of `sys_organization`, so a deployment composing `AuthPlugin` beside a host that ships its own default page for that object was refused at boot.
+
+- **New option.** `AuthPluginOptions.registerOrganizationRecordPage` defaults to `true`. Only an explicit `false` leaves out `sys_organization_detail`, so the host's page is the only default whichever plugin starts first. Plugin order and precedence rules play no part.
+- **Nothing else moves.** With `false`, `AuthPlugin` still registers the identity objects, the `sys_user_detail` record page, the System Overview dashboard, and the auth routes and services. It logs one `info` line at boot naming the option.
+- **The default is unchanged.** A deployment that does not set the option registers `sys_organization_detail` as before. A host page beside it, with no option set, is still refused with `DEFAULT_RECORD_PAGE_CONFLICT`.
+- **To adopt it:** construct `new AuthPlugin({ …, registerOrganizationRecordPage: false })` in the host that registers its own `isDefault: true` record page for `sys_organization`. With the option set and no default page of the host's own, the organization record view opens the synthesized default layout, without the Members / Invitations / Teams tabs.
@@ -106,6 +106,33 @@ The plugin accepts configuration via `AuthConfig` schema from `@objectstack/spec
 - `plugins` - Enable additional auth features (organization, backend 2FA, passkeys, magic link)
 - `session` - Session configuration (expiry, update frequency)
 
+### Shipping your own organization record page
+
+`AuthPlugin` registers the platform's default record page for `sys_organization`:
+`sys_organization_detail`, the Members / Invitations / Teams tab strip. A deployment holds at
+most one `isDefault: true` record page per object, and a second one is refused at registration
+with `DEFAULT_RECORD_PAGE_CONFLICT`. A host that ships its own default record page for
+`sys_organization` turns the platform page off, so the host's page is the only default:
+
+```typescript
+new AuthPlugin({
+  secret: process.env.AUTH_SECRET,
+  baseUrl: 'http://localhost:3000',
+  // The host registers its own `isDefault: true` record page for sys_organization.
+  registerOrganizationRecordPage: false,
+})
+```
+
+- `registerOrganizationRecordPage` (default `true`): only an explicit `false` leaves out
+  `sys_organization_detail`. Nothing else changes: the identity objects, the `sys_user_detail`
+  record page, the System Overview dashboard, and the auth routes and services are registered
+  as before.
+- Neither plugin order nor any precedence rule decides which page is the default. Without the
+  option, the platform page and the host's page conflict, and the boot is refused whichever
+  plugin starts first.
+- With the option set and no default page of the host's own, the organization record view
+  opens the synthesized default layout, without the Members / Invitations / Teams tabs.
+
 ## API Routes
 
 The plugin forwards all requests under `/api/v1/auth/*` directly to better-auth's universal handler, so **better-auth's own route table is the route table** — the plugin does not hand-register a `login` / `register` / `logout` / `session` route set.
 
@@ -253,6 +253,33 @@ export interface AuthPluginOptions extends Partial<AuthConfig> {
    * @default false
    */
   hostSignInHandoff?: boolean;
+
+  /**
+   * Whether this plugin registers the platform's default record page for
+   * `sys_organization`: `sys_organization_detail`, the Members / Invitations /
+   * Teams tab strip (`SysOrganizationDetailPage`, `@objectstack/platform-objects`).
+   *
+   * A deployment holds at most ONE `isDefault: true` record page per object; a
+   * second is refused at registration with `DEFAULT_RECORD_PAGE_CONFLICT`
+   * (maintainer ruling A on objectstack#23015, record 6134056653). A host that
+   * ships its OWN default record page for `sys_organization` passes `false`, so
+   * its page is the single default by composition. Neither registration order
+   * nor a precedence rule decides it: ruling A takes neither.
+   *
+   * `false` removes exactly one registration, `sys_organization_detail`.
+   * Everything else stays: the `sys_organization` object and every other
+   * identity object, the `sys_user_detail` record page, the System Overview
+   * dashboard, and the auth routes and services. The host's page then owns what
+   * the platform page gave. Set `false` with no default record page of the
+   * host's own, and `sys_organization`'s record view opens the synthesized
+   * default layout, without the Members / Invitations / Teams tabs.
+   *
+   * Only an explicit `false` removes the page; `true` and an absent key keep
+   * it. Read from this option alone (no env var, no setting), so the code that
+   * composes the host's own page is the one place the choice is stated.
+   * @default true
+   */
+  registerOrganizationRecordPage?: boolean;
 }
 
 /**
@@ -647,6 +674,10 @@ export class AuthPlugin implements Plugin {
     ctx.registerService('tenancy', tenancy);
     this.tenancy = tenancy;
 
+    // Only an explicit `false` leaves the organization page out — see
+    // `AuthPluginOptions.registerOrganizationRecordPage`.
+    const registerOrganizationRecordPage = this.options.registerOrganizationRecordPage !== false;
+
     ctx.getService<{ register(m: any): void }>('manifest').register({
       // The header, `objects` and `objectExtensions`, from the ONE builder
       // `IdentityObjectsPlugin` registers on its own in a reduced kernel, so the
@@ -671,7 +702,13 @@ export class AuthPlugin implements Plugin {
       // sys_organization gets a Members / Invitations / Teams tab strip
       // (see SysOrganizationDetailPage for the rationale and the
       // intentionally-omitted OAuth / SSO tabs).
-      pages: [SysOrganizationDetailPage, SysUserDetailPage],
+      //
+      // `registerOrganizationRecordPage: false` leaves the organization page
+      // out, for a host that ships its own `sys_organization` default record
+      // page: one default per object per deployment, kept by composition
+      // (ruling A on objectstack#23015). `SysUserDetailPage` is registered
+      // either way.
+      pages: [...(registerOrganizationRecordPage ? [SysOrganizationDetailPage] : []), SysUserDetailPage],
       // List views for each Setup-nav object are defined on the schema
       // itself via the canonical `listViews` map (e.g.
       // sys_user.listViews.{all_users,unverified,two_factor}). Registering
@@ -713,6 +750,15 @@ export class AuthPlugin implements Plugin {
           }
         : {}),
     });
+    if (!registerOrganizationRecordPage) {
+      // A deliberate composition, said once at boot so a missing tab strip is
+      // never left to be diagnosed from its absence.
+      ctx.logger.info(
+        '[auth] sys_organization_detail is not registered (registerOrganizationRecordPage: false): the host ' +
+          'composes its own default record page for sys_organization. Without one, the organization record ' +
+          'view opens the synthesized default layout, with no Members / Invitations / Teams tabs.',
+      );
+    }
 
     // [ADR-0108 / #3723] There is no organization-role derivation any more.
     //
 
@@ -0,0 +1,218 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * `AuthPluginOptions.registerOrganizationRecordPage`: a host that ships its own
+ * default record page for `sys_organization` composes without plugin-auth's.
+ *
+ * ## The rule this option serves
+ *
+ * One `isDefault: true` record page per object per deployment, a second refused
+ * at registration with `DEFAULT_RECORD_PAGE_CONFLICT` (maintainer ruling A on
+ * objectstack#23015, record 6134056653). Ruling A keeps one page "by
+ * overlay-by-name or by composition"; this option is the composition route. It
+ * is not a precedence ladder and not a registration-order rule: with it set,
+ * plugin-auth registers no organization page at all, so the host's page is the
+ * single default whichever plugin initialises first.
+ *
+ * ## The three pins, each with its control
+ *
+ *  1. With the option (`false`), the host's page is the single default record
+ *     page of `sys_organization` and the boot succeeds, in either plugin order.
+ *     Control: the same composition without the option is refused (pin 3).
+ *  2. Without it, plugin-auth's `sys_organization_detail` registers as today.
+ *     Control: with the option and no host page, `sys_organization` has no
+ *     default record page, so the assertion can tell the two apart.
+ *     `sys_user_detail` registers in both.
+ *  3. With both pages and no option, `DEFAULT_RECORD_PAGE_CONFLICT` still
+ *     refuses the boot, naming both pages, in either plugin order. Control: an
+ *     explicit `true` is today's behaviour and is refused the same way.
+ *
+ * ## The composition
+ *
+ * The cheapest real one: a real `ObjectKernel`, a real ObjectQL engine on
+ * in-memory SQLite, the real `AuthPlugin`, and a host plugin in the place of a
+ * product package (the cloud control plane's tenant service is the first such
+ * host) registering its own organization page through the `manifest` service,
+ * as `AppPlugin.init()` does. The refusal is the registry's own, reached
+ * through that door.
+ *
+ * ## Resolution
+ *
+ * `AuthPlugin` is imported from SOURCE (relative). `ObjectKernel`,
+ * `ObjectQLPlugin` and `SqlDriver` are the fixed instruments, read from
+ * `dist/` as this package's other kernel tests read them, and so is
+ * `@objectstack/spec/ui`'s `defaultRecordPageObject`, the one reading of "the
+ * default record page of object X" the registry's refusal asks too.
+ */
+
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import { ObjectKernel, type Plugin, type PluginContext } from '@objectstack/core';
+import { ObjectQLPlugin, type ObjectQL } from '@objectstack/objectql';
+import { SqlDriver } from '@objectstack/driver-sql';
+import { defaultRecordPageObject } from '@objectstack/spec/ui';
+import { AuthPlugin, type AuthPluginOptions } from './auth-plugin.js';
+import { AUTH_PLUGIN_ID } from './manifest.js';
+
+const HOST_PACKAGE_ID = 'com.example.host-tenant';
+const HOST_PAGE = 'host_organization_detail';
+const AUTH_PAGE = 'sys_organization_detail';
+
+/** Env the auth plugin's boot branches on; cleared per case so the default `single` posture holds. */
+const ENV_KEYS = ['OS_TENANCY_POSTURE', 'OS_MULTI_ORG_ENABLED', 'OS_PLATFORM_OWNER_EMAIL'] as const;
+
+type Holder = { kind: 'package'; packageId: string; page: string } | { kind: 'environment'; page: string };
+type Refusal = Error & { code?: string; status?: number; object?: string; incoming?: Holder; existing?: Holder };
+
+/** Publishes an in-memory SQLite driver the way a datasource plugin does. */
+function sqliteDriverPlugin(): Plugin {
+  return {
+    name: 'test.driver.sqlite',
+    type: 'standard',
+    version: '1.0.0',
+    async init(ctx: PluginContext) {
+      ctx.registerService(
+        'driver.default',
+        new SqlDriver({ client: 'better-sqlite3', connection: { filename: ':memory:' }, useNullAsDefault: true }),
+      );
+    },
+  };
+}
+
+/**
+ * A host shipping its own default record page for `sys_organization`,
+ * registered through the `manifest` service in `init()` as `AppPlugin.init()`
+ * does. No edge to `AuthPlugin`, so the order the case uses it in is the order
+ * the two initialise in.
+ */
+function hostPlugin(): Plugin {
+  return {
+    name: HOST_PACKAGE_ID,
+    type: 'app',
+    version: '1.0.0',
+    dependencies: ['com.objectstack.engine.objectql'],
+    async init(ctx: PluginContext) {
+      ctx.getService<{ register(m: unknown): unknown }>('manifest').register({
+        id: HOST_PACKAGE_ID,
+        name: 'host-tenant',
+        version: '1.0.0',
+        type: 'app',
+        pages: [
+          {
+            name: HOST_PAGE,
+            label: 'Workspace',
+            type: 'record',
+            object: 'sys_organization',
+            isDefault: true,
+            regions: [],
+          },
+        ],
+      });
+    },
+  };
+}
+
+const authPlugin = (options: Pick<AuthPluginOptions, 'registerOrganizationRecordPage'> = {}) =>
+  new AuthPlugin({ secret: 'test-secret-at-least-32-chars-long', baseUrl: 'http://localhost:3000', ...options });
+
+let kernel: ObjectKernel | undefined;
+const savedEnv: Partial<Record<(typeof ENV_KEYS)[number], string | undefined>> = {};
+
+beforeEach(() => {
+  for (const key of ENV_KEYS) {
+    savedEnv[key] = process.env[key];
+    delete process.env[key];
+  }
+});
+
+afterEach(async () => {
+  try {
+    await kernel?.shutdown();
+  } catch {
+    /* a refused boot leaves the kernel stopped */
+  }
+  kernel = undefined;
+  for (const key of ENV_KEYS) {
+    if (savedEnv[key] === undefined) delete process.env[key];
+    else process.env[key] = savedEnv[key];
+  }
+});
+
+/** Boot the composition with `plugins` used in the given order; resolves to the engine or the refusal. */
+async function boot(plugins: Plugin[]): Promise<{ ql?: ObjectQL; refusal?: Refusal }> {
+  await kernel?.shutdown().catch(() => undefined);
+  kernel = new ObjectKernel({ logger: { level: 'silent' }, gracefulShutdown: false });
+  await kernel.use(sqliteDriverPlugin());
+  await kernel.use(new ObjectQLPlugin());
+  for (const p of plugins) await kernel.use(p);
+  try {
+    await kernel.bootstrap();
+  } catch (e) {
+    return { refusal: e as Refusal };
+  }
+  return { ql: kernel.getService<ObjectQL>('objectql') };
+}
+
+/** Every default record page of `object` in the booted registry: its name and the package that registered it. */
+function defaultsOf(ql: ObjectQL, object: string): Array<{ name: string; packageId: string }> {
+  return ql.registry
+    .listItems<{ name: string; _packageId: string }>('page')
+    .filter((p) => defaultRecordPageObject(p) === object)
+    .map((p) => ({ name: p.name, packageId: p._packageId }));
+}
+
+const pkgPage = (packageId: string, page: string): Holder => ({ kind: 'package', packageId, page });
+
+/** The ADR-0112 envelope of the refusal and the two pages it names. */
+function expectConflict(refusal: Refusal | undefined, incoming: Holder, existing: Holder) {
+  expect(refusal, 'the boot was refused').toBeDefined();
+  expect({ code: refusal!.code, status: refusal!.status }).toEqual({ code: 'DEFAULT_RECORD_PAGE_CONFLICT', status: 422 });
+  expect(refusal!.object).toBe('sys_organization');
+  expect(refusal!.incoming).toEqual(incoming);
+  expect(refusal!.existing).toEqual(existing);
+}
+
+describe('registerOrganizationRecordPage: a host with its own sys_organization default record page', () => {
+  it('pin 1: with the option, the host\'s page is the single default and the boot succeeds, in either order', async () => {
+    for (const order of ['auth first', 'host first'] as const) {
+      const auth = authPlugin({ registerOrganizationRecordPage: false });
+      const { ql, refusal } = await boot(order === 'auth first' ? [auth, hostPlugin()] : [hostPlugin(), auth]);
+
+      expect(refusal, `${order}: the boot succeeds`).toBeUndefined();
+      expect(defaultsOf(ql!, 'sys_organization'), order).toEqual([{ name: HOST_PAGE, packageId: HOST_PACKAGE_ID }]);
+      expect(ql!.registry.listItems<{ name: string }>('page', AUTH_PLUGIN_ID).map((p) => p.name), order).not.toContain(
+        AUTH_PAGE,
+      );
+      // `SysUserDetailPage` is unchanged by the option.
+      expect(defaultsOf(ql!, 'sys_user'), order).toEqual([{ name: 'sys_user_detail', packageId: AUTH_PLUGIN_ID }]);
+    }
+  });
+
+  it('pin 2: without the option, plugin-auth\'s sys_organization_detail registers as today', async () => {
+    const today = await boot([authPlugin()]);
+    expect(today.refusal).toBeUndefined();
+    expect(defaultsOf(today.ql!, 'sys_organization')).toEqual([{ name: AUTH_PAGE, packageId: AUTH_PLUGIN_ID }]);
+    expect(defaultsOf(today.ql!, 'sys_user')).toEqual([{ name: 'sys_user_detail', packageId: AUTH_PLUGIN_ID }]);
+
+    // Control: the option, with no page of the host's own, leaves the object
+    // with no default record page — the reading above is not vacuous.
+    const omitted = await boot([authPlugin({ registerOrganizationRecordPage: false })]);
+    expect(omitted.refusal).toBeUndefined();
+    expect(defaultsOf(omitted.ql!, 'sys_organization')).toEqual([]);
+    expect(defaultsOf(omitted.ql!, 'sys_user')).toEqual([{ name: 'sys_user_detail', packageId: AUTH_PLUGIN_ID }]);
+  });
+
+  it('pin 3: with both pages and no option, DEFAULT_RECORD_PAGE_CONFLICT still refuses the boot, in either order', async () => {
+    const authFirst = await boot([authPlugin(), hostPlugin()]);
+    expect(authFirst.ql).toBeUndefined();
+    expectConflict(authFirst.refusal, pkgPage(HOST_PACKAGE_ID, HOST_PAGE), pkgPage(AUTH_PLUGIN_ID, AUTH_PAGE));
+
+    const hostFirst = await boot([hostPlugin(), authPlugin()]);
+    expect(hostFirst.ql).toBeUndefined();
+    expectConflict(hostFirst.refusal, pkgPage(AUTH_PLUGIN_ID, AUTH_PAGE), pkgPage(HOST_PACKAGE_ID, HOST_PAGE));
+
+    // Control: an explicit `true` is today's behaviour, refused the same way.
+    const explicit = await boot([authPlugin({ registerOrganizationRecordPage: true }), hostPlugin()]);
+    expect(explicit.ql).toBeUndefined();
+    expectConflict(explicit.refusal, pkgPage(HOST_PACKAGE_ID, HOST_PAGE), pkgPage(AUTH_PLUGIN_ID, AUTH_PAGE));
+  });
+});