@@ -0,0 +1,19 @@
+---
+'@objectstack/service-settings': patch
+---
+
+fix(service-settings)!: a host that binds its own engine and states no organization source reads and writes as the organization ADR-0131 D9 derives through that engine, not as no organization
+
+Clause-②: no (narrowing)
+Metadata-protocol: none
+
+<!-- adr-0087: not-required (no-migration-prescription) Which organization a self-binding host's settings reads and writes take changes. No key of any metadata schema is removed, renamed or re-shaped, so `objectstack migrate meta` has nothing to rewrite and no tombstone is needed. No export, type, option, error code or route is added, removed or renamed: `SettingsServiceOptions` and the `bindEngine` extras are unchanged, and `SettingsServicePlugin` already states its source. The remedy for a host this narrows is one line at its bind site, stated below. The other categories are closed on facts: the package publishes (not unpublished); no ADR-0087 id covers this read (not registered or already-registered); and nothing exported is removed or narrowed (not runtime-interface-only, type-surface-only or runtime-export-retired). -->
+
+**BREAKING** read narrowing (ADR-0131 D8/D9, follow-up to the organization-less rung fix). It changes which organization a host's settings reads take, not what a metadata author can write, so it ships as `patch` with this banner.
+
+- FROM: a host that bound its own engine (`new SettingsService({ engine })` or `bindEngine(engine)`) and stated no `organization` source read and wrote, for a caller that names no organization, as a composition with no organization object: its rows with no organization answered, and its writes stored none.
+- TO: such a host's service asks D9 itself, through the engine it holds (`resolveGuestOrganization`, the call the plugin's source makes). Under `single` with one organization it reads and writes as that organization; at none or several it has no tenant or user rung. An engine that exposes no `registry` cannot say the organization object is absent, so D9 asks `sys_organization`. Over a store with no such object, a tenant-rung read or write by a caller naming none is then refused as organization-less (reads answer from the global rung or the default, tenant writes are refused with `SETTINGS_VALIDATION`), or raises `AuthzStoreUnavailableError` naming `sys_organization` where the engine does not know that object. No engine at all (the in-memory store), a stated source, an engine whose `registry.getObject` answers, and `SettingsServicePlugin` (`os serve`, `os dev`) are unchanged.
+
+**Who is affected.** Only a host that binds its own engine and states no source: a control-plane mock or an embedded runtime. On a composition with an organization object it now reads and writes the derived organization's rows, and its rows with no organization stop answering. On one without, it meets the refusal above. A deployment booted through `SettingsServicePlugin` is not affected.
+
+**The fix.** State the composition at the bind site: `service.bindEngine(engine, audit, { organization: async () => ({ kind: 'no-organization-object' }) })` (a host that hands its engine to the constructor binds it this way instead), or hand over an engine whose `registry.getObject` can answer.
@@ -0,0 +1,28 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * Test scaffolding: how a suite that binds its own engine states the
+ * composition's organization facts (#25249, ADR-0131 D9).
+ *
+ * A host that states no organization source has the service ask D9 itself,
+ * through the engine it holds — and an engine with no registry to ask is read
+ * the fail-closed way, as one that DOES register `sys_organization`. So a
+ * suite states it, one of two ways:
+ *
+ *  - {@link LEAN_ORGANIZATION_SOURCE}, at the bind site, for a double: this
+ *    composition registers no organization object.
+ *  - {@link withEngineRegistry}, for a suite that runs the real ObjectQL behind
+ *    the production adapter: the real registry answers, as it would through
+ *    the raw engine the plugin hands D9.
+ */
+
+import type { SettingsOrganizationSource } from '../settings-service.js';
+import type { SettingsEngine } from '../settings-service.types.js';
+
+/** A lean composition's answer: no organization object is registered. */
+export const LEAN_ORGANIZATION_SOURCE: SettingsOrganizationSource = async () => ({ kind: 'no-organization-object' });
+
+/** `wrapped`, carrying the real engine's registry, so D9's registry question reaches it. */
+export function withEngineRegistry<E extends SettingsEngine>(wrapped: E, engine: { registry: unknown }): E & { registry: unknown } {
+  return Object.assign(wrapped, { registry: engine.registry });
+}
@@ -78,7 +78,11 @@ export {
 // because a host that binds its own engine (control-plane mocks, embedded
 // runtimes) has to be able to get the SAME ledger row rather than re-deriving
 // its shape; the action value and target-object constants travel with it for the
-// same reason a pin must not spell them by hand.
+// same reason a pin must not spell them by hand. [#25249] Such a host with no
+// organization object declares it (`bindEngine`'s `organization` extra answering
+// `no-organization-object`); left out, a tenant-rung read or write by a caller naming
+// none is refused as organization-less, or raises `AuthzStoreUnavailableError`
+// naming `sys_organization`.
 export {
   buildConfigChangeAuditSink,
   CONFIG_CHANGE_ACTION,
 
@@ -22,6 +22,7 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import { SettingsService } from './settings-service.js';
 import { UnknownKeyError } from './settings-service.types.js';
+import { LEAN_ORGANIZATION_SOURCE } from './__tests__/settings-organization.testkit.js';
 
 // WHERE-matcher gate: implement exactly the combinators the service emits and
 // THROW on the rest — a bare field-equality read of `$or` would silently match
@@ -91,7 +92,7 @@ async function makeService(rows = ROWS) {
   const engine = makeEngine(rows);
   const svc = new SettingsService();
   svc.registerManifest(MANIFEST);
-  svc.bindEngine(engine as any);
+  svc.bindEngine(engine as any, undefined, { organization: LEAN_ORGANIZATION_SOURCE });
   return { svc, engine };
 }
 
 
@@ -31,6 +31,7 @@ import { SysPlatformSetting, SysSecret, SysSetting } from '@objectstack/platform
 import type { SettingsManifest } from '@objectstack/spec/system';
 import { SettingsService } from './settings-service.js';
 import { SettingsServicePlugin, wrapEngineAsSettingsEngine } from './settings-service-plugin.js';
+import { withEngineRegistry } from './__tests__/settings-organization.testkit.js';
 import { LocalCryptoProvider } from './local-crypto-provider.js';
 import { SettingsLockedError } from './settings-service.types.js';
 
@@ -151,7 +152,7 @@ async function boot() {
   const cryptoProvider = new LocalCryptoProvider();
   const svc = new SettingsService({
     env: {},
-    engine: wrapEngineAsSettingsEngine(engine as any),
+    engine: withEngineRegistry(wrapEngineAsSettingsEngine(engine as any), engine),
     cryptoProvider,
     secretStore: (new SettingsServicePlugin() as any).buildSecretStore(engine),
   });
 
@@ -18,15 +18,21 @@
  * The callers this stands for read with an empty context: plugin-auth's email
  * brand name and boot-time locale, the anonymous runtime-config door's
  * branding read, and a signed-in caller with no active organization.
+ *
+ * [#25249] The last section pins a host that binds its OWN engine and states
+ * no organization source: the service asks D9 itself, through the engine it
+ * holds, and an engine with no registry to ask is read as one that registers
+ * the organization object.
  */
 
 import { describe, it, expect } from 'vitest';
-import { ObjectKernel } from '@objectstack/core';
-import { ObjectQL } from '@objectstack/objectql';
+import { isAuthzStoreUnavailableError, ObjectKernel } from '@objectstack/core';
+import { assertEngineUpdateDispatch, ObjectQL } from '@objectstack/objectql';
 import { SysOrganization, SysUser } from '@objectstack/platform-objects/identity';
 import { SysPlatformSetting, SysSetting } from '@objectstack/platform-objects/system';
-import { SettingsServicePlugin } from './settings-service-plugin.js';
-import type { SettingsService } from './settings-service.js';
+import { SettingsServicePlugin, wrapEngineAsSettingsEngine } from './settings-service-plugin.js';
+import { SettingsService } from './settings-service.js';
+import { LEAN_ORGANIZATION_SOURCE } from './__tests__/settings-organization.testkit.js';
 
 const SYS = { context: { isSystem: true } } as const;
 const NS = 'org_reach_fixture';
@@ -39,6 +45,7 @@ const MANIFEST = {
   specifiers: [
     { key: 'brand', type: 'text', label: 'Brand', scope: 'tenant', default: 'none' },
     { key: 'legacy', type: 'text', label: 'Legacy', scope: 'tenant', default: 'none' },
+    { key: 'theme', type: 'text', label: 'Theme', scope: 'user', default: 'none' },
   ],
 } as any;
 
@@ -227,3 +234,127 @@ describe('a composition with no organization object (the lean embedding, ADR-013
     expect(b.rows()).toEqual([['brand', null, 'Lean again']]);
   });
 });
+
+/**
+ * [#25249] A host that binds its own engine — a control-plane mock, an embedded
+ * runtime — through the production adapter, which carries no registry. No
+ * kernel, no plugin, no posture source (`single`). `organizations` is as in
+ * {@link boot}; `source` is the organization source the host states, if any.
+ */
+async function bootSelfBound(organizations: string[] | null, source?: typeof LEAN_ORGANIZATION_SOURCE) {
+  const engine = new ObjectQL();
+  engine.registry.logLevel = 'silent';
+  const memory = makeMemoryDriver();
+  engine.registerDriver(memory.driver, true);
+  await engine.init();
+  const objects: any[] = [SysUser, SysSetting, SysPlatformSetting];
+  if (organizations !== null) objects.push(SysOrganization);
+  for (const o of objects) engine.registry.registerObject(o, '@objectstack/platform-objects');
+  for (const id of organizations ?? []) {
+    await engine.insert('sys_organization', { id, name: id, slug: id }, SYS);
+  }
+  // The user a user-rung write names, as the store already holds it.
+  memory.rowsOf('sys_user').set('usr_1', { id: 'usr_1', name: 'Ada', email: 'ada@example.test' });
+  const service = new SettingsService({ env: {} });
+  service.registerManifest(MANIFEST);
+  service.bindEngine(wrapEngineAsSettingsEngine(engine as any), undefined, source ? { organization: source } : undefined);
+  const seed = (row: Record<string, unknown>) => {
+    const id = `seed_${memory.rowsOf('sys_setting').size + 1}`;
+    memory.rowsOf('sys_setting').set(id, {
+      id, namespace: NS, scope: 'tenant', user_id: null, value_enc: null, encrypted: false,
+      locked: false, locked_reason: null, ...row,
+    });
+  };
+  const rows = () => [...memory.rowsOf('sys_setting').values()]
+    .map((r) => [r.key, r.organization_id ?? null, r.value])
+    .sort((a, b) => String(a[0]).localeCompare(String(b[0])));
+  return { service, seed, rows };
+}
+
+/**
+ * The same host over a double: an `IDataEngine`-shaped object with no registry,
+ * whose `sys_organization` holds no rows, and one tenant row written with no
+ * organization.
+ */
+function selfBoundDouble(source?: typeof LEAN_ORGANIZATION_SOURCE) {
+  const stored: Array<Record<string, unknown>> = [
+    { id: 'seed_1', namespace: NS, key: 'brand', scope: 'tenant', user_id: null, organization_id: null, value: 'Lean', encrypted: false, locked: false },
+  ];
+  const engine = {
+    async find(object: string, query: any) {
+      if (object !== 'sys_setting') return [];
+      const where = query?.where ?? {};
+      const branches: Array<Record<string, unknown>> = Array.isArray(where.$or) ? where.$or : [where];
+      const { $or: _or, ...rest } = where;
+      const hits = stored.filter((r) => branches.some((b) => Object.entries({ ...rest, ...b }).every(([k, v]) => (r[k] ?? null) === (v ?? null))));
+      return typeof query?.limit === 'number' ? hits.slice(0, query.limit) : hits;
+    },
+    async insert(_object: string, data: Record<string, unknown>) { stored.push({ ...data }); return { ...data }; },
+    async update(_object: string, data: Record<string, unknown>, options?: any) { assertEngineUpdateDispatch(data, options); return 1; },
+  };
+  const service = new SettingsService({ env: {} });
+  service.registerManifest(MANIFEST);
+  service.bindEngine(engine as any, undefined, source ? { organization: source } : undefined);
+  return { service };
+}
+
+describe('[#25249] a host that binds its own engine and states no organization source', () => {
+  it('(a) one organization: the tenant and user rungs read and write as that organization, through an adapter with no registry', async () => {
+    const b = await bootSelfBound([ORG]);
+    await b.seed({ key: 'brand', value: 'Acme', organization_id: ORG });
+    await b.seed({ key: 'legacy', value: 'Unowned', organization_id: null });
+    await b.seed({ key: 'theme', value: 'Unowned dark', scope: 'user', user_id: 'usr_1', organization_id: null });
+
+    expect((await b.service.get(NS, 'brand', {})).value).toBe('Acme');
+    expect((await b.service.get(NS, 'legacy', {})).source).toBe('default');
+    expect((await b.service.get(NS, 'theme', { userId: 'usr_1' })).source).toBe('default');
+    await b.service.set(NS, 'brand', 'Acme two', {});
+    await b.service.set(NS, 'theme', 'Light', { userId: 'usr_1' });
+    await b.service.set(NS, 'theme', 'Light two', { userId: 'usr_1' });
+
+    expect((await b.service.get(NS, 'brand', { tenantId: ORG })).value).toBe('Acme two');
+    expect((await b.service.get(NS, 'theme', { userId: 'usr_1' })).value).toBe('Light two');
+    expect((await b.service.get(NS, 'theme', { userId: 'usr_1', tenantId: ORG })).value).toBe('Light two');
+    expect(b.rows()).toEqual([
+      ['brand', ORG, 'Acme two'], ['legacy', null, 'Unowned'], ['theme', null, 'Unowned dark'], ['theme', ORG, 'Light two'],
+    ]);
+  });
+
+  it('(b) no organization object, real engine: the probe is refused as a failed read, loudly', async () => {
+    // Measured, not converted: the adapter cannot say the object is absent, so
+    // D9 asks `sys_organization`, and the engine refuses an unregistered name
+    // as "object not found" — which is not a missing table.
+    const b = await bootSelfBound(null);
+    const refusal = await b.service.get(NS, 'brand', {}).then(() => null, (e) => e);
+    expect(isAuthzStoreUnavailableError(refusal)).toBe(true);
+    expect(refusal.object).toBe('sys_organization');
+  });
+
+  it('(b) no organization object, a double with no registry: zero organizations, so no tenant row and no tenant write', async () => {
+    const d = selfBoundDouble();
+    expect((await d.service.get(NS, 'brand', {})).source).toBe('default');
+    const refusal = await d.service.set(NS, 'brand', 'Nobody', {}).then(() => null, (e) => e);
+    expect(refusal?.code).toBe('SETTINGS_VALIDATION');
+  });
+});
+
+describe('[#25249] the readings a stated source and an absent engine keep', () => {
+  it('(c) a host that states the lean composition reads and writes the rows with no organization', async () => {
+    const d = selfBoundDouble(LEAN_ORGANIZATION_SOURCE);
+    expect((await d.service.get(NS, 'brand', {})).value).toBe('Lean');
+
+    const b = await bootSelfBound(null, LEAN_ORGANIZATION_SOURCE);
+    await b.service.set(NS, 'brand', 'Lean', {});
+    await b.service.set(NS, 'brand', 'Lean again', {});
+    expect((await b.service.get(NS, 'brand', {})).value).toBe('Lean again');
+    expect(b.rows()).toEqual([['brand', null, 'Lean again']]);
+  });
+
+  it('(d) no engine: the in-memory store keeps its rows with no organization', async () => {
+    const service = new SettingsService({ env: {} });
+    service.registerManifest(MANIFEST);
+    await service.set(NS, 'brand', 'Memory', {});
+    expect((await service.get(NS, 'brand', {})).value).toBe('Memory');
+    expect(((service as any).memory as Array<Record<string, unknown>>).map((r) => r.organization_id ?? null)).toEqual([null]);
+  });
+});
@@ -81,6 +81,7 @@ import { SysPlatformSetting, SysSecret, SysSetting } from '@objectstack/platform
 import type { SettingsManifest } from '@objectstack/spec/system';
 import { SettingsService } from './settings-service.js';
 import { wrapEngineAsSettingsEngine } from './settings-service-plugin.js';
+import { withEngineRegistry } from './__tests__/settings-organization.testkit.js';
 import { LocalCryptoProvider } from './local-crypto-provider.js';
 import { dropEchoedSecretMasks, SETTINGS_SECRET_MASK } from './settings-secret-redaction.js';
 import type { SettingsEngine, SettingsSecretStore } from './settings-service.types.js';
@@ -306,11 +307,14 @@ async function boot(opts: {
   const logged: string[] = [];
   const svc = new SettingsService({
     env: {},
-    engine: opts.failVerificationRead
-      ? wrapEngineFailingPostUpdateReads(engine)
-      : opts.forwardContext === false
-        ? wrapEngineDroppingContext(engine)
-        : wrapEngineAsSettingsEngine(engine as any),
+    engine: withEngineRegistry(
+      opts.failVerificationRead
+        ? wrapEngineFailingPostUpdateReads(engine)
+        : opts.forwardContext === false
+          ? wrapEngineDroppingContext(engine)
+          : wrapEngineAsSettingsEngine(engine as any),
+      engine,
+    ),
     cryptoProvider: new LocalCryptoProvider(),
     secretStore: { ...baseStore, ...(opts.secretStoreOverrides ?? {}) },
     logger: { error: (m) => { logged.push(m); } },