diff --git a/packages/plugins/driver-sql/src/sql-driver-autonumber-persistence.test.ts b/packages/plugins/driver-sql/src/sql-driver-autonumber-persistence.test.ts
new file mode 100644
index 000000000..580b94f3c
--- /dev/null
+++ b/packages/plugins/driver-sql/src/sql-driver-autonumber-persistence.test.ts
@@ -0,0 +1,91 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect, afterEach } from 'vitest';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { SqlDriver } from '../src/index.js';
+
+/**
+ * Autonumber persistence across a "restart" (#1603).
+ *
+ * The whole point of consolidating autonumber generation onto the driver's
+ * `_objectstack_sequences` table (instead of the engine's in-memory counter)
+ * is that the sequence SURVIVES a process restart and never re-mints a number
+ * that was already issued. We prove that here with a FILE-backed sqlite DB and
+ * two independent driver instances pointed at the same file: the second driver
+ * (a fresh process, cold caches) must continue the sequence, not reset to 1.
+ */
+describe('SqlDriver auto_number — persistence across driver restart', () => {
+  let dir: string | null = null;
+
+  afterEach(() => {
+    if (dir) {
+      rmSync(dir, { recursive: true, force: true });
+      dir = null;
+    }
+  });
+
+  const OBJECT = {
+    name: 'contract',
+    fields: {
+      organization_id: { type: 'string' },
+      contract_number: { type: 'autonumber', format: 'CTR-{0000}' },
+      name: { type: 'string' },
+    },
+  };
+
+  function newDriver(filename: string): SqlDriver {
+    return new SqlDriver({
+      client: 'better-sqlite3',
+      connection: { filename },
+      useNullAsDefault: true,
+    });
+  }
+
+  it('continues the sequence from persisted state after the driver is torn down and recreated', async () => {
+    dir = mkdtempSync(join(tmpdir(), 'objectstack-autonumber-'));
+    const file = join(dir, 'data.sqlite');
+
+    // ── "Process 1" ───────────────────────────────────────────────
+    const d1 = newDriver(file);
+    await d1.initObjects([OBJECT]);
+    const a = await d1.create('contract', { organization_id: 'org_a', name: 'A1' });
+    const b = await d1.create('contract', { organization_id: 'org_a', name: 'A2' });
+    expect(a.contract_number).toBe('CTR-0001');
+    expect(b.contract_number).toBe('CTR-0002');
+    await d1.disconnect(); // simulate shutdown — in-memory counters are gone
+
+    // ── "Process 2" — fresh driver, same file, cold caches ────────
+    const d2 = newDriver(file);
+    await d2.initObjects([OBJECT]);
+    const c = await d2.create('contract', { organization_id: 'org_a', name: 'A3' });
+    const e = await d2.create('contract', { organization_id: 'org_a', name: 'A4' });
+
+    // The sequence MUST continue — a non-persistent counter would reset to
+    // CTR-0001 (a duplicate) here.
+    expect(c.contract_number).toBe('CTR-0003');
+    expect(e.contract_number).toBe('CTR-0004');
+    await d2.disconnect();
+  });
+
+  it('keeps per-tenant sequences independent across a restart', async () => {
+    dir = mkdtempSync(join(tmpdir(), 'objectstack-autonumber-'));
+    const file = join(dir, 'data.sqlite');
+
+    const d1 = newDriver(file);
+    await d1.initObjects([OBJECT]);
+    await d1.create('contract', { organization_id: 'org_a', name: 'A1' }); // CTR-0001 (a)
+    await d1.create('contract', { organization_id: 'org_a', name: 'A2' }); // CTR-0002 (a)
+    await d1.create('contract', { organization_id: 'org_b', name: 'B1' }); // CTR-0001 (b)
+    await d1.disconnect();
+
+    const d2 = newDriver(file);
+    await d2.initObjects([OBJECT]);
+    const a3 = await d2.create('contract', { organization_id: 'org_a', name: 'A3' });
+    const b2 = await d2.create('contract', { organization_id: 'org_b', name: 'B2' });
+    expect(a3.contract_number).toBe('CTR-0003'); // org_a continues from 2
+    expect(b2.contract_number).toBe('CTR-0002'); // org_b continues from 1
+    await d2.disconnect();
+  });
+});