diff --git a/changelog.d/fixes/10372-debug-mode-default-false.md b/changelog.d/fixes/10372-debug-mode-default-false.md
new file mode 100644
index 0000000000..c1a59b4fb3
--- /dev/null
+++ b/changelog.d/fixes/10372-debug-mode-default-false.md
@@ -0,0 +1 @@
+- **fix(db):** `getSettings()` defaults `debugMode` to `false` — fresh installs no longer run in debug mode (persisted `debugMode: true` is preserved) ([#10372](https://github.com/diegosouzapw/OmniRoute/pull/10372) — thanks @lamchun1110)
diff --git a/src/lib/db/settings.ts b/src/lib/db/settings.ts
index c04c1fb75b..c8bf28ae45 100644
--- a/src/lib/db/settings.ts
+++ b/src/lib/db/settings.ts
@@ -212,7 +212,9 @@ export async function getSettings() {
     idempotencyWindowMs: 5000,
     wsAuth: false,
     maxBodySizeMb: requestBodyLimitMbFromEnv(process.env.MAX_BODY_SIZE_BYTES),
-    debugMode: true,
+    // #10312: opt-in only — a fresh install (or one missing the persisted key)
+    // must not run in debug mode; installs that persisted `true` keep it.
+    debugMode: false,
     // Opt-in diagnostic: when true, the chat handler emits a `log.debug("TOOLS", …)`
     // line per request summarizing tool count + MCP/hosted/client source breakdown.
     logToolSources: false,
diff --git a/tests/unit/db-settings-debug-mode-default-10312.test.ts b/tests/unit/db-settings-debug-mode-default-10312.test.ts
new file mode 100644
index 0000000000..327b4ce74d
--- /dev/null
+++ b/tests/unit/db-settings-debug-mode-default-10312.test.ts
@@ -0,0 +1,50 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-settings-debug-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const settings = await import("../../src/lib/db/settings.ts");
+
+async function resetStorage() {
+  const globalDb = (globalThis as { __omnirouteDb?: { open: boolean; close(): void } })
+    .__omnirouteDb;
+  try {
+    if (globalDb?.open) {
+      globalDb.close();
+    }
+  } catch {}
+  delete (globalThis as { __omnirouteDb?: unknown }).__omnirouteDb;
+  core.resetDbInstance();
+  if (fs.existsSync(TEST_DATA_DIR)) {
+    fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  }
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+  core.getDbInstance();
+}
+
+await resetStorage();
+
+test("#10312: empty store defaults debugMode to false (fresh install is not in debug)", async () => {
+  await resetStorage();
+  const result = await settings.getSettings();
+  assert.equal(result.debugMode, false);
+});
+
+test("#10312: persisted debugMode=true is preserved after the default flip", async () => {
+  await resetStorage();
+  await settings.updateSettings({ debugMode: true });
+  const result = await settings.getSettings();
+  assert.equal(result.debugMode, true);
+});
+
+test("#10312: persisted debugMode=false stays false after the default flip", async () => {
+  await resetStorage();
+  await settings.updateSettings({ debugMode: false });
+  const result = await settings.getSettings();
+  assert.equal(result.debugMode, false);
+});