diff --git a/src/background.ts b/src/background.ts
index e69de29..b441701 100644
--- a/src/background.ts
+++ b/src/background.ts
@@ -0,0 +1,49 @@
+import browser from 'webextension-polyfill';
+import WakaTimeCore from './core/WakaTimeCore';
+
+// Add a listener to resolve alarms
+browser.alarms.onAlarm.addListener(async (alarm) => {
+  // |alarm| can be undefined because onAlarm also gets called from
+  // window.setTimeout on old chrome versions.
+  // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+  if (alarm?.name == 'heartbeatAlarm') {
+    console.log('recording a heartbeat - alarm triggered');
+
+    await WakaTimeCore.recordHeartbeat();
+  }
+});
+
+/**
+ * Whenever a active tab is changed it records a heartbeat with that tab url.
+ */
+browser.tabs.onActivated.addListener(async () => {
+  console.log('recording a heartbeat - active tab changed');
+  await WakaTimeCore.recordHeartbeat();
+});
+
+/**
+ * Whenever a active window is changed it records a heartbeat with the active tab url.
+ */
+browser.windows.onFocusChanged.addListener(async (windowId) => {
+  if (windowId != browser.windows.WINDOW_ID_NONE) {
+    console.log('recording a heartbeat - active window changed');
+    await WakaTimeCore.recordHeartbeat();
+  } else {
+    console.log('lost focus');
+  }
+});
+
+/**
+ * Whenever any tab is updated it checks if the updated tab is the tab that is
+ * currently active and if it is, then it records a heartbeat.
+ */
+browser.tabs.onUpdated.addListener(async (tabId, changeInfo) => {
+  if (changeInfo.status === 'complete') {
+    // Get current tab URL.
+    const [tab] = await browser.tabs.query({ active: true, currentWindow: true });
+    // If tab updated is the same as active tab
+    if (tabId == tab.id) {
+      await WakaTimeCore.recordHeartbeat();
+    }
+  }
+});
diff --git a/src/components/MainList.test.tsx b/src/components/MainList.test.tsx
index 9ef54a5..514587f 100644
--- a/src/components/MainList.test.tsx
+++ b/src/components/MainList.test.tsx
@@ -2,6 +2,16 @@ import React from 'react';
 import { renderWithProviders } from '../utils/test-utils';
 import MainList from './MainList';
 
+jest.mock('webextension-polyfill', () => {
+  return {
+    runtime: {
+      getManifest: () => {
+        return { version: 'test-version' };
+      },
+    },
+  };
+});
+
 describe('MainList', () => {
   let loggingEnabled: boolean;
   let totalTimeLoggedToday: string;
diff --git a/src/config/config.test.ts b/src/config/config.test.ts
index 0c3d068..b44d77a 100644
--- a/src/config/config.test.ts
+++ b/src/config/config.test.ts
@@ -1,5 +1,15 @@
 import config from './config';
 
+jest.mock('webextension-polyfill', () => {
+  return {
+    runtime: {
+      getManifest: () => {
+        return { version: 'test-version' };
+      },
+    },
+  };
+});
+
 describe('wakatime config', () => {
   it('snapshot of config', () => {
     expect(config).toMatchInlineSnapshot(`
diff --git a/src/config/config.ts b/src/config/config.ts
index b6f15da..20a1106 100644
--- a/src/config/config.ts
+++ b/src/config/config.ts
@@ -1,3 +1,5 @@
+import browser from 'webextension-polyfill';
+
 /**
  * Logging
  */