diff --git a/.changeset/cli-turso-loud-error.md b/.changeset/cli-turso-loud-error.md
new file mode 100644
index 0000000000..7cc6d0bcdd
--- /dev/null
+++ b/.changeset/cli-turso-loud-error.md
@@ -0,0 +1,19 @@
+---
+'@objectstack/cli': patch
+---
+
+fix(cli): fail loudly when `turso`/libSQL is selected in the open-core CLI (#3276 follow-up)
+
+Same "declared ≠ enforced" class as the `memory` fix: the CLI advertised `turso`
+(`--database-driver turso`, `OS_DATABASE_DRIVER=turso`, `libsql://` URLs) but the
+driver dispatch had no `turso` branch, so it silently fell through to the SQLite
+default and ignored the requested engine.
+
+`turso`/libSQL ships in the cloud / enterprise distribution
+(`@objectstack/driver-turso`, composed by the cloud runtime's own kernel factory —
+open-core's standalone stack deliberately does not consume it). Rather than pull an
+EE driver into open-core, `createStorageDriver` now throws a typed
+`UnsupportedDriverError` for `turso`/`libsql`, and `serve.ts` surfaces it as a
+fatal, actionable boot error (naming the cloud/EE package and the open-core
+alternatives) instead of silently degrading to SQLite. `libsql://` / `*.turso.*`
+URLs stay classified as `turso` so they hit the same loud failure.
diff --git a/packages/cli/src/commands/serve.ts b/packages/cli/src/commands/serve.ts
index 73f90a8f5d..ce770599bb 100644
--- a/packages/cli/src/commands/serve.ts
+++ b/packages/cli/src/commands/serve.ts
@@ -8,7 +8,7 @@ import chalk from 'chalk';
 import { bundleRequire } from 'bundle-require';
 import { loadConfig, BUNDLE_REQUIRE_EXTERNALS } from '../utils/config.js';
 import { isHostConfig, shouldBootWithLibrary } from '../utils/plugin-detection.js';
-import { resolveDriverType, createStorageDriver } from '../utils/storage-driver.js';
+import { resolveDriverType, createStorageDriver, UnsupportedDriverError } from '../utils/storage-driver.js';
 import { readEnvWithDeprecation, resolveMultiOrgEnabled, resolveAllowDegradedTenancy, isMcpServerEnabled, resolveSearchPinyinEnabled, isModuleNotFoundError } from '@objectstack/types';
 import { PLATFORM_CAPABILITY_TOKENS, canonicalizePlatformCapability } from '@objectstack/spec/kernel';
 import { resolveObjectStackHome } from '@objectstack/runtime';
@@ -937,6 +937,14 @@ export default class Serve extends Command {
              }
            }
          } catch (e: any) {
+           // "declared ≠ enforced" guard (#3276-class): a driver that is
+           // RECOGNIZED but the open-core CLI cannot construct — currently
+           // `turso`/libSQL, a cloud/EE driver — must fail LOUDLY, never silently
+           // fall through to the SQLite default and ignore the selected engine.
+           // Re-throw so run()'s fatal handler restores output, prints the
+           // actionable message, and exits 1 (in dev AND prod). All OTHER driver
+           // construction errors keep the prior best-effort silent behavior.
+           if (e instanceof UnsupportedDriverError) throw e;
            // silent
          }
       }
diff --git a/packages/cli/src/utils/storage-driver.test.ts b/packages/cli/src/utils/storage-driver.test.ts
index 0d3e20c098..91f297d041 100644
--- a/packages/cli/src/utils/storage-driver.test.ts
+++ b/packages/cli/src/utils/storage-driver.test.ts
@@ -6,6 +6,7 @@ import {
   inferDriverTypeFromUrl,
   resolveDriverType,
   createStorageDriver,
+  UnsupportedDriverError,
 } from './storage-driver.js';
 
 describe('inferDriverTypeFromUrl', () => {
@@ -131,3 +132,42 @@ describe('createStorageDriver', () => {
     expect(await createStorageDriver('nonsense', { isDev: false })).toBeNull();
   });
 });
+
+describe('createStorageDriver: turso / libSQL is recognized but fails loud', () => {
+  // turso is a cloud/EE driver (@objectstack/driver-turso) the open-core CLI
+  // cannot construct. Selecting it must THROW a typed error — NOT fall through
+  // to the SQLite default. Remove the `turso` branch in storage-driver.ts and
+  // these go red: in dev it resolves to a SqlDriver, in prod it returns null —
+  // both silently ignoring the requested turso engine (the reported bug).
+  it('throws UnsupportedDriverError for `turso` in DEV and PROD', async () => {
+    await expect(createStorageDriver('turso', { isDev: true })).rejects.toBeInstanceOf(UnsupportedDriverError);
+    await expect(createStorageDriver('turso', { isDev: false })).rejects.toBeInstanceOf(UnsupportedDriverError);
+  });
+
+  it('throws for the `libsql` alias too', async () => {
+    await expect(createStorageDriver('libsql', { isDev: true })).rejects.toBeInstanceOf(UnsupportedDriverError);
+  });
+
+  // The message must be actionable: name the cloud/EE package and the open-core
+  // alternatives, so an operator knows exactly how to proceed.
+  it('carries an actionable message (cloud/EE package + open-core alternatives)', async () => {
+    await expect(createStorageDriver('turso', { isDev: false })).rejects.toThrow(/@objectstack\/driver-turso/);
+    await expect(createStorageDriver('turso', { isDev: false })).rejects.toThrow(/cloud|enterprise/i);
+    const err = await createStorageDriver('turso', { isDev: false }).catch((e) => e);
+    expect(err).toBeInstanceOf(UnsupportedDriverError);
+    expect((err as UnsupportedDriverError).driverType).toBe('turso');
+  });
+
+  // A `libsql://` / Turso URL routes to the same loud failure — it is NOT left
+  // unrecognized (which would silently fall through to SQLite).
+  it('routes libsql:// and *.turso.* URLs to the turso failure, never SQLite', async () => {
+    expect(resolveDriverType(undefined, 'libsql://my-db.turso.io')).toBe('turso');
+    expect(resolveDriverType(undefined, 'https://my-db.turso.io')).toBe('turso');
+    await expect(
+      createStorageDriver(resolveDriverType(undefined, 'libsql://my-db.turso.io'), {
+        databaseUrl: 'libsql://my-db.turso.io',
+        isDev: true,
+      }),
+    ).rejects.toBeInstanceOf(UnsupportedDriverError);
+  });
+});
diff --git a/packages/cli/src/utils/storage-driver.ts b/packages/cli/src/utils/storage-driver.ts
index 48bbc2d02e..25f3debb5d 100644
--- a/packages/cli/src/utils/storage-driver.ts
+++ b/packages/cli/src/utils/storage-driver.ts
@@ -32,6 +32,28 @@
 /** Engines the shared sqlite step-down (`resolveSqliteDriver`) can produce. */
 export type SqliteFamilyEngine = 'better-sqlite3' | 'sqlite-wasm' | 'memory';
 
+/**
+ * Thrown by {@link createStorageDriver} when a driver kind is *recognized* but the
+ * open-core CLI cannot construct it — currently `turso`/libSQL, which ships in the
+ * ObjectStack cloud / enterprise distribution (`@objectstack/driver-turso`, an
+ * extension of SqlDriver over `@libsql/client`), composed by the cloud runtime's
+ * own kernel factory, not by open-core's auto driver-registration.
+ *
+ * The whole point of surfacing this as a *typed* error is so `serve.ts` can fail
+ * LOUDLY (fatal) instead of letting the selection fall through to the SQLite
+ * default. That silent fall-through is the same "declared ≠ enforced" bug as
+ * #3276 (the CLI advertised `memory`/`turso` but had no dispatch branch, so both
+ * silently became SQLite-in-memory).
+ */
+export class UnsupportedDriverError extends Error {
+  readonly driverType: string;
+  constructor(driverType: string, message: string) {
+    super(message);
+    this.name = 'UnsupportedDriverError';
+    this.driverType = driverType;
+  }
+}
+
 /**
  * Infer a canonical driver kind from an `OS_DATABASE_URL` scheme.
  * Returns `''` when the URL is absent or its scheme is unrecognized (the caller
@@ -43,6 +65,11 @@ export function inferDriverTypeFromUrl(url: string | undefined): string {
   if (/^mongodb(\+srv)?:\/\//i.test(u)) return 'mongodb';
   if (/^postgres(ql)?:\/\//i.test(u)) return 'postgres';
   if (/^mysql2?:\/\//i.test(u)) return 'mysql';
+  // libSQL / Turso URLs are DELIBERATELY still classified as `turso` (not left
+  // unrecognized). Open-core can't construct that driver, but classifying it
+  // lets createStorageDriver fail LOUDLY with a clear cloud/EE message — if we
+  // returned '' here instead, a `libsql://` URL would fall through to the SQLite
+  // default and silently ignore the remote connection (the very bug we're fixing).
   if (/^libsql:\/\//i.test(u)) return 'turso';
   if (/^https?:\/\//i.test(u) && /\.turso\./i.test(u)) return 'turso';
   if (/^wasm-sqlite:\/\//i.test(u) || /\.wasm\.db$/i.test(u)) return 'sqlite-wasm';
@@ -101,6 +128,10 @@ export interface StorageDriverResolution {
  * nothing matches and we are NOT in dev (production with an unknown/absent
  * driver registers no driver, matching the prior inline behavior).
  *
+ * Throws {@link UnsupportedDriverError} for `turso`/libSQL — a cloud/EE driver the
+ * open-core CLI cannot construct. serve.ts surfaces that as a fatal, actionable
+ * boot error so the selection never silently degrades to SQLite.
+ *
  * @see {@link resolveDriverType}
  */
 export async function createStorageDriver(
@@ -207,6 +238,27 @@ export async function createStorageDriver(
     };
   }
 
+  // turso / libSQL: recognized but NOT constructible by the open-core CLI. The
+  // driver (`@objectstack/driver-turso`) ships in the cloud / enterprise
+  // distribution and is composed by the cloud runtime's own kernel factory —
+  // runtime/standalone-stack.ts explicitly stopped consuming its auth token, and
+  // its config schema lives in the cloud package so it never pollutes open-core
+  // `@objectstack/spec`. Fail LOUDLY here rather than let the selection fall
+  // through to the SQLite default (the reported "declared ≠ enforced" bug):
+  // serve.ts turns this typed error into a fatal, actionable boot message.
+  if (driverType === 'turso' || driverType === 'libsql') {
+    throw new UnsupportedDriverError(
+      'turso',
+      'The `turso`/libSQL driver ships with the ObjectStack cloud / enterprise '
+        + 'distribution (@objectstack/driver-turso), not the open-core CLI. To use '
+        + "it, register it explicitly in your stack config (a datasource with driver: "
+        + "'turso' and config { url, authToken }, with @objectstack/driver-turso "
+        + 'installed), or run under the cloud distribution. Otherwise select an '
+        + 'open-core driver via OS_DATABASE_DRIVER / OS_DATABASE_URL: '
+        + 'sqlite | postgres | mysql | mongodb | memory.',
+    );
+  }
+
   // #3276: explicit in-memory (mingo) driver. Honored in dev AND production — an
   // operator asking for `memory` gets the mingo InMemoryDriver (ephemeral, not
   // real SQL), never the SQLite `:memory:` default. This is the branch whose