diff --git a/packages/core/__e2e__/monographs.test.js b/packages/core/__e2e__/monographs.test.js
index 7ceabff5f..0e8397507 100644
--- a/packages/core/__e2e__/monographs.test.js
+++ b/packages/core/__e2e__/monographs.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { databaseTest, noteTest } from "../__tests__/utils/index.js";
+import { databaseTest, noteTest } from "../__tests__/utils/index.ts";
 import { login, logout } from "./utils.js";
 import { test, expect, afterAll } from "vitest";
 
diff --git a/packages/core/__e2e__/offers.test.js b/packages/core/__e2e__/offers.test.js
index 77835e717..6ab658081 100644
--- a/packages/core/__e2e__/offers.test.js
+++ b/packages/core/__e2e__/offers.test.js
@@ -17,8 +17,8 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import hosts from "../src/utils/constants.js";
-import { Offers } from "../src/api/offers.js";
+import hosts from "../src/utils/constants.ts";
+import { Offers } from "../src/api/offers.ts";
 import { test, expect } from "vitest";
 
 test("get offer code", async () => {
diff --git a/packages/core/__e2e__/pricing.test.js b/packages/core/__e2e__/pricing.test.js
index e53b8392c..6e335f516 100644
--- a/packages/core/__e2e__/pricing.test.js
+++ b/packages/core/__e2e__/pricing.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { Pricing } from "../src/api/pricing.js";
+import { Pricing } from "../src/api/pricing.ts";
 import { test, expect, describe } from "vitest";
 
 test.each(["monthly", "yearly", undefined])(`get %s price`, async (period) => {
diff --git a/packages/core/__e2e__/sync.test.js b/packages/core/__e2e__/sync.test.js
index a88a0098c..15a783025 100644
--- a/packages/core/__e2e__/sync.test.js
+++ b/packages/core/__e2e__/sync.test.js
@@ -17,11 +17,11 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import Database from "../src/api/index.js";
-import { NodeStorageInterface } from "../__mocks__/node-storage.mock.js";
-import { FS } from "../__mocks__/fs.mock.js";
+import Database from "../src/api/index.ts";
+import { NodeStorageInterface } from "../__mocks__/node-storage.mock.ts";
+import { FS } from "../__mocks__/fs.mock.ts";
 import Compressor from "../__mocks__/compressor.mock.js";
-import { CHECK_IDS, EV, EVENTS } from "../src/common.js";
+import { CHECK_IDS, EV, EVENTS } from "../src/common.ts";
 import { EventSource } from "event-source-polyfill";
 import { test, expect, vitest } from "vitest";
 import { login } from "./utils.js";
diff --git a/packages/core/__e2e__/token-manager.test.js b/packages/core/__e2e__/token-manager.test.js
index d3e4cda1c..77e1ef6f7 100644
--- a/packages/core/__e2e__/token-manager.test.js
+++ b/packages/core/__e2e__/token-manager.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { databaseTest } from "../__tests__/utils/index.js";
+import { databaseTest } from "../__tests__/utils/index.ts";
 import { login } from "./utils.js";
 import { test, expect } from "vitest";
 
diff --git a/packages/core/__e2e__/user-manager.test.js b/packages/core/__e2e__/user-manager.test.js
index 156658f56..8ff4d4eeb 100644
--- a/packages/core/__e2e__/user-manager.test.js
+++ b/packages/core/__e2e__/user-manager.test.js
@@ -18,7 +18,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 import { authenticator } from "otplib";
-import { databaseTest } from "../__tests__/utils/index.js";
+import { databaseTest } from "../__tests__/utils/index.ts";
 import { login, USER } from "./utils.js";
 import { test, expect } from "vitest";
 
diff --git a/packages/core/__tests__/backup.test.js b/packages/core/__tests__/backup.test.js
index 8df0c5d65..8a4d090db 100644
--- a/packages/core/__tests__/backup.test.js
+++ b/packages/core/__tests__/backup.test.js
@@ -17,7 +17,12 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { TEST_NOTE, databaseTest, loginFakeUser, notebookTest } from "./utils/index.js";
+import {
+  TEST_NOTE,
+  databaseTest,
+  loginFakeUser,
+  notebookTest
+} from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 test("export backup", () =>
diff --git a/packages/core/__tests__/db.test.js b/packages/core/__tests__/db.test.js
index f0206f74e..8c4df3aef 100644
--- a/packages/core/__tests__/db.test.js
+++ b/packages/core/__tests__/db.test.js
@@ -17,9 +17,9 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import Constants from "../src/utils/constants.js";
+import Constants from "../src/utils/constants.ts";
 import { test, expect } from "vitest";
-import { databaseTest } from "./utils/index.js";
+import { databaseTest } from "./utils/index.ts";
 
 test("db.host should change HOST", () =>
   databaseTest().then((db) => {
diff --git a/packages/core/__tests__/lookup.test.js b/packages/core/__tests__/lookup.test.js
index 9641e86c9..f5765d972 100644
--- a/packages/core/__tests__/lookup.test.js
+++ b/packages/core/__tests__/lookup.test.js
@@ -23,7 +23,7 @@ import {
   notebookTest,
   TEST_NOTEBOOK2,
   databaseTest
-} from "./utils/index.js";
+} from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 const content = {
diff --git a/packages/core/__tests__/note-history.test.js b/packages/core/__tests__/note-history.test.js
index 5ed5b6f6f..e7f742e03 100644
--- a/packages/core/__tests__/note-history.test.js
+++ b/packages/core/__tests__/note-history.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { delay, noteTest, TEST_NOTE } from "./utils/index.js";
+import { delay, noteTest, TEST_NOTE } from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 // async function sessionTest(db, noteId) {
diff --git a/packages/core/__tests__/notebooks.test.js b/packages/core/__tests__/notebooks.test.js
index 540cf1202..50c72b122 100644
--- a/packages/core/__tests__/notebooks.test.js
+++ b/packages/core/__tests__/notebooks.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { notebookTest, TEST_NOTEBOOK } from "./utils/index.js";
+import { notebookTest, TEST_NOTEBOOK } from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 test("add a notebook", () =>
diff --git a/packages/core/__tests__/reminders.test.js b/packages/core/__tests__/reminders.test.js
index 46f2dfd8f..a7387d2cb 100644
--- a/packages/core/__tests__/reminders.test.js
+++ b/packages/core/__tests__/reminders.test.js
@@ -23,10 +23,10 @@ import {
   formatReminderTime,
   getUpcomingReminderTime,
   isReminderActive
-} from "../src/collections/reminders.js";
+} from "../src/collections/reminders.ts";
 import MockDate from "mockdate";
 import { describe, afterAll, beforeEach, test, expect } from "vitest";
-import { databaseTest } from "./utils/index.js";
+import { databaseTest } from "./utils/index.ts";
 import dayjs from "dayjs";
 import assert from "assert";
 
diff --git a/packages/core/__tests__/settings.test.js b/packages/core/__tests__/settings.test.js
index 73eba0677..4293028b2 100644
--- a/packages/core/__tests__/settings.test.js
+++ b/packages/core/__tests__/settings.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { databaseTest } from "./utils/index.js";
+import { databaseTest } from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 test("save group options", () =>
diff --git a/packages/core/__tests__/shortcuts.test.js b/packages/core/__tests__/shortcuts.test.js
index 30f12d83d..efdc48627 100644
--- a/packages/core/__tests__/shortcuts.test.js
+++ b/packages/core/__tests__/shortcuts.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { databaseTest, notebookTest } from "./utils/index.js";
+import { databaseTest, notebookTest } from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 test("create a shortcut of an invalid item should throw", () =>
diff --git a/packages/core/__tests__/storage.test.js b/packages/core/__tests__/storage.test.js
index f5382b279..4b57d2d37 100644
--- a/packages/core/__tests__/storage.test.js
+++ b/packages/core/__tests__/storage.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { NodeStorageInterface } from "../__mocks__/node-storage.mock.js";
+import { NodeStorageInterface } from "../__mocks__/node-storage.mock.ts";
 import { test, expect } from "vitest";
 
 test("add a value", async () => {
diff --git a/packages/core/__tests__/utils/index.ts b/packages/core/__tests__/utils/index.ts
index ebf8a8492..fbad5b126 100644
--- a/packages/core/__tests__/utils/index.ts
+++ b/packages/core/__tests__/utils/index.ts
@@ -23,8 +23,7 @@ import { FS } from "../../__mocks__/fs.mock.js";
 import Compressor from "../../__mocks__/compressor.mock.js";
 import { EventSourcePolyfill as EventSource } from "event-source-polyfill";
 import { randomBytes } from "../../src/utils/random.js";
-import { Note, Notebook } from "../../src/types.js";
-import { NoteContent } from "../../src/collections/session-content.js";
+import { Note, Notebook, NoteContent } from "../../src/types.js";
 import { SqliteDialect } from "@streetwriters/kysely";
 import BetterSQLite3 from "better-sqlite3-multiple-ciphers";
 import path from "path";
diff --git a/packages/core/__tests__/vault.test.js b/packages/core/__tests__/vault.test.js
index cd016ac05..a39922df6 100644
--- a/packages/core/__tests__/vault.test.js
+++ b/packages/core/__tests__/vault.test.js
@@ -17,8 +17,8 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { VAULT_ERRORS } from "../src/api/vault.js";
-import { databaseTest, delay, noteTest, TEST_NOTE } from "./utils/index.js";
+import { VAULT_ERRORS } from "../src/api/vault.ts";
+import { databaseTest, delay, noteTest, TEST_NOTE } from "./utils/index.ts";
 import { test, expect } from "vitest";
 
 test("create vault", () =>
diff --git a/packages/core/src/api/__tests__/debug.test.js b/packages/core/src/api/__tests__/debug.test.js
index 91b663e66..17612bcf5 100644
--- a/packages/core/src/api/__tests__/debug.test.js
+++ b/packages/core/src/api/__tests__/debug.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { Debug } from "../debug.js";
+import { Debug } from "../debug.ts";
 import createFetchMock from "vitest-fetch-mock";
 import { vi, test, expect } from "vitest";
 const fetchMocker = createFetchMock(vi);
diff --git a/packages/core/src/api/sync/__tests__/collector.test.js b/packages/core/src/api/sync/__tests__/collector.test.js
index d79d027ad..cadfc4726 100644
--- a/packages/core/src/api/sync/__tests__/collector.test.js
+++ b/packages/core/src/api/sync/__tests__/collector.test.js
@@ -21,8 +21,8 @@ import {
   databaseTest,
   TEST_NOTE,
   loginFakeUser
-} from "../../../../__tests__/utils/index.js";
-import Collector from "../collector.js";
+} from "../../../../__tests__/utils/index.ts";
+import Collector from "../collector.ts";
 import { test, expect } from "vitest";
 
 test("newly created note should get included in collector", () =>
diff --git a/packages/core/src/api/sync/__tests__/merger.test.js b/packages/core/src/api/sync/__tests__/merger.test.js
index 15534c8b0..4578fa839 100644
--- a/packages/core/src/api/sync/__tests__/merger.test.js
+++ b/packages/core/src/api/sync/__tests__/merger.test.js
@@ -21,9 +21,9 @@ import {
   TEST_NOTE,
   databaseTest,
   loginFakeUser
-} from "../../../../__tests__/utils/index.js";
+} from "../../../../__tests__/utils/index.ts";
 import { expect, describe, vi } from "vitest";
-import Merger from "../merger.js";
+import Merger from "../merger.ts";
 
 describe.concurrent("merge item synchronously", (test) => {
   test("accept remote item if no local item is found", () =>
diff --git a/packages/core/src/content-types/__tests__/tiptap.test.js b/packages/core/src/content-types/__tests__/tiptap.test.js
index dd366238a..d718e9001 100644
--- a/packages/core/src/content-types/__tests__/tiptap.test.js
+++ b/packages/core/src/content-types/__tests__/tiptap.test.js
@@ -20,8 +20,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 import {
   IMG_CONTENT,
   IMG_CONTENT_WITHOUT_HASH
-} from "../../../__tests__/utils/index.js";
-import { Tiptap } from "../tiptap.js";
+} from "../../../__tests__/utils/index.ts";
+import { Tiptap } from "../tiptap.ts";
 import { test, expect } from "vitest";
 
 test("img src is empty after extract attachments", async () => {
diff --git a/packages/core/src/utils/__tests__/html-diff.test.js b/packages/core/src/utils/__tests__/html-diff.test.js
index 9b6803e1e..9e3c39c52 100644
--- a/packages/core/src/utils/__tests__/html-diff.test.js
+++ b/packages/core/src/utils/__tests__/html-diff.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { isHTMLEqual } from "../html-diff.js";
+import { isHTMLEqual } from "../html-diff.ts";
 import { test, expect, describe } from "vitest";
 
 const equalPairs = [
diff --git a/packages/core/src/utils/__tests__/set.test.js b/packages/core/src/utils/__tests__/set.test.js
index 67b764c57..7c6a1e32f 100644
--- a/packages/core/src/utils/__tests__/set.test.js
+++ b/packages/core/src/utils/__tests__/set.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { set } from "../set.js";
+import { set } from "../set.ts";
 import { test, expect } from "vitest";
 
 test("union", () => {
diff --git a/packages/core/src/utils/__tests__/title-format.test.js b/packages/core/src/utils/__tests__/title-format.test.js
index df227961b..75de04e4e 100644
--- a/packages/core/src/utils/__tests__/title-format.test.js
+++ b/packages/core/src/utils/__tests__/title-format.test.js
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import { formatTitle } from "../title-format.js";
+import { formatTitle } from "../title-format.ts";
 import MockDate from "mockdate";
 import { test, expect, describe, beforeAll, afterAll } from "vitest";