feat: add platform and install_type as MetaMetrics user traits (#39606)

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## **Description**

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Add platform (browser type) and install_type (installation source) as
user traits sent via identify() instead of as properties on every event.
This is the appropriate approach for static installation properties.

- Add initInstallType() to cache install type from browser.management
API
- Add Platform and InstallType to MetaMetricsUserTrait enum
- Update _buildUserTraitsObject to include these traits
- Update unit test expectations

[![Open in GitHub
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CHANGELOG entry: null

## **Related issues**

Fixes:

## **Manual testing steps**

1. Lauch Extension
2. Enable metametrics
3. Get your metametricsId
4. Go to MixPanel
5. Search user with your metametricsId
6. Confirm it has `platform` and `install_type` defined in its user
profile properties

## **Screenshots/Recordings**

<img width="1080" height="898" alt="Screenshot 2026-01-28 at 15 39 35"
src="https://github.com/user-attachments/assets/a0b09edf-3a4c-4eda-b0f7-bd14e7250f54"
/>

<img width="1083" height="902" alt="Screenshot 2026-01-28 at 15 40 08"
src="https://github.com/user-attachments/assets/fb1c79db-b64f-439c-afe2-8e938f8da007"
/>

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I’ve included tests if applicable
- [x] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Medium risk because it touches analytics trait generation and Sentry
error-tagging, plus adds an early background initialization side-effect
via `browser.management.getSelf()` (albeit fire-and-forget).
Functionality is additive but could impact telemetry correctness and
startup behavior across browsers.
> 
> **Overview**
> Adds `platform` and `install_type` as new MetaMetrics *user traits*
(via `identify()`), and wires
`MetaMetricsController._buildUserTraitsObject` to populate them using
`getPlatform()` and a new cached `getInstallType()`.
> 
> Introduces a dedicated `install-type` helper (with `initInstallType()`
+ cached value) and initializes it early in both `background.js` startup
and Sentry setup; Sentry reports now tag/include `installType` via the
cache rather than an inline async fetch. Updates shared constants/types
to formalize `Platform`/`InstallType` and adjusts MetaMetrics controller
tests accordingly.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
cbb9c64. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: gauthierpetetin

app/scripts/background.js

@@ -79,6 +79,7 @@ import getObjStructure from './lib/getObjStructure';
 import setupEnsIpfsResolver from './lib/ens-ipfs/setup';
 import {
   getPlatform,
+  initInstallType,
   isWebOrigin,
   shouldEmitDappViewedEvent,
 } from './lib/util';
@@ -711,6 +712,10 @@ function saveTimestamp() {
  * @returns {Promise} Setup complete.
  */
 async function initialize(backup) {
+  // Initialize install type early so it's cached for MetaMetrics user traits
+  // This is fire-and-forget - we don't await it to avoid blocking initialization
+  initInstallType();
+
   const offscreenPromise = isManifestV3 ? createOffscreen() : null;
 
   // Set up connectivity listener IMMEDIATELY for MV3 (before any awaits)

app/scripts/controllers/metametrics-controller.test.ts

@@ -1610,6 +1610,8 @@ describe('MetaMetricsController', function () {
           [MetaMetricsUserTrait.TokenSortPreference]: 'token-sort-key',
           [MetaMetricsUserTrait.PrivacyModeEnabled]: true,
           [MetaMetricsUserTrait.NetworkFilterPreference]: [],
+          [MetaMetricsUserTrait.Platform]: 'Chrome',
+          [MetaMetricsUserTrait.InstallType]: 'unknown',
         });
       });
     });

app/scripts/controllers/metametrics-controller.ts

@@ -63,6 +63,7 @@ import { METAMETRICS_FINALIZE_EVENT_FRAGMENT_ALARM } from '../../../shared/const
 import {
   checkAlarmExists,
   generateRandomId,
+  getInstallType,
   getPlatform,
   isValidDate,
 } from '../lib/util';
@@ -1459,6 +1460,8 @@ export default class MetaMetricsController extends BaseController<
       [MetaMetricsUserTrait.ProfileId]: Object.entries(
         metamaskState.srpSessionData || {},
       )?.[0]?.[1]?.profile?.profileId,
+      [MetaMetricsUserTrait.Platform]: getPlatform(),
+      [MetaMetricsUserTrait.InstallType]: getInstallType(),
     };
 
     if (!this.previousUserTraits && metamaskState.participateInMetaMetrics) {

app/scripts/lib/install-type.ts

@@ -0,0 +1,39 @@
+import browser from 'webextension-polyfill';
+import { INSTALL_TYPE, type InstallType } from '../../../shared/constants/app';
+
+/**
+ * Cached install type value.
+ *
+ * @see {@link INSTALL_TYPE} for possible values and their meanings.
+ */
+let cachedInstallType: InstallType = INSTALL_TYPE.UNKNOWN;
+
+/**
+ * Initializes the install type by fetching it from the browser API.
+ * This should be called early in the extension lifecycle.
+ * The result is cached and can be retrieved synchronously via getInstallType().
+ *
+ * @returns A promise that resolves to the install type
+ */
+export const initInstallType = async (): Promise<InstallType> => {
+  try {
+    const extensionInfo = await browser.management.getSelf();
+    if (extensionInfo.installType) {
+      cachedInstallType = extensionInfo.installType as InstallType;
+    }
+  } catch (error) {
+    // Silently fail - install type will remain 'unknown'
+    console.error('Error getting extension installType', error);
+  }
+  return cachedInstallType;
+};
+
+/**
+ * Returns the cached install type.
+ * Call initInstallType() first to populate the cache.
+ *
+ * @returns The install type
+ */
+export const getInstallType = (): InstallType => {
+  return cachedInstallType;
+};

app/scripts/lib/setupSentry.js

@@ -8,8 +8,7 @@ import { getManifestFlags } from '../../../shared/lib/manifestFlags';
 import { getSentryRelease } from '../../../shared/lib/sentry-release';
 import extractEthjsErrorMessage from './extractEthjsErrorMessage';
 import { filterEvents } from './sentry-filter-events';
-
-let installType = 'unknown';
+import { getInstallType, initInstallType } from './install-type';
 
 const internalLog = createModuleLogger(log, 'internal');
 
@@ -50,18 +49,10 @@ export default function setupSentry() {
 
   log('Initializing');
 
-  // Normally this would be awaited, but getSelf should be available by the time the report is finalized.
-  // If it's not, we still get the extensionId, but the installType will default to "unknown"
-  browser.management
-    .getSelf()
-    .then((extensionInfo) => {
-      if (extensionInfo.installType) {
-        installType = extensionInfo.installType;
-      }
-    })
-    .catch((error) => {
-      log('Error getting extension installType', error);
-    });
+  // Initialize install type early - fire and forget.
+  // By the time errors are reported, the cache should be populated.
+  initInstallType();
+
   integrateLogging();
   setSentryClient();
 
@@ -414,6 +405,8 @@ export function rewriteReport(report) {
       report.tags = {};
     }
 
+    const installType = getInstallType();
+
     Object.assign(report.extra, {
       appState,
       installType,

app/scripts/lib/util.ts

@@ -22,6 +22,7 @@ import {
   PLATFORM_EDGE,
   PLATFORM_FIREFOX,
   PLATFORM_OPERA,
+  type Platform,
 } from '../../../shared/constants/app';
 import { CHAIN_IDS, TEST_CHAINS } from '../../../shared/constants/network';
 import { stripHexPrefix } from '../../../shared/modules/hexstring-utils';
@@ -32,6 +33,9 @@ import {
   getIsQuicknodeEndpointUrl,
   KNOWN_CUSTOM_ENDPOINT_URLS,
 } from '../../../shared/lib/network-utils';
+// Re-export install type utilities from dedicated module to avoid circular dependencies
+// and keep the sentry bundle lightweight
+export { getInstallType, initInstallType } from './install-type';
 
 /**
  * @see {@link getEnvironmentType}
@@ -71,7 +75,7 @@ const getEnvironmentType = (url = window.location.href) =>
  *
  * @returns the platform ENUM
  */
-const getPlatform = () => {
+const getPlatform = (): Platform => {
   const { navigator } = window;
   const { userAgent } = navigator;
 

shared/constants/app.ts

@@ -26,6 +26,39 @@ export const PLATFORM_EDGE = 'Edge';
 export const PLATFORM_FIREFOX = 'Firefox';
 export const PLATFORM_OPERA = 'Opera';
 
+/**
+ * Object containing all platform constants for type-safe usage.
+ */
+export const PLATFORM = {
+  BRAVE: PLATFORM_BRAVE,
+  CHROME: PLATFORM_CHROME,
+  EDGE: PLATFORM_EDGE,
+  FIREFOX: PLATFORM_FIREFOX,
+  OPERA: PLATFORM_OPERA,
+} as const;
+
+export type Platform = (typeof PLATFORM)[keyof typeof PLATFORM];
+
+/**
+ * The type of installation of the extension.
+ * - 'normal' means installed from official store (Chrome Web Store, Firefox Add-ons, etc.)
+ * - 'development' means loaded unpacked in developer mode
+ * - 'sideload' means installed by other software
+ * - 'admin' means installed by admin policy (enterprise)
+ * - 'other' means other installation type
+ * - 'unknown' means the value hasn't been fetched yet or fetch failed
+ */
+export const INSTALL_TYPE = {
+  ADMIN: 'admin',
+  DEVELOPMENT: 'development',
+  NORMAL: 'normal',
+  SIDELOAD: 'sideload',
+  OTHER: 'other',
+  UNKNOWN: 'unknown',
+} as const;
+
+export type InstallType = (typeof INSTALL_TYPE)[keyof typeof INSTALL_TYPE];
+
 export const MESSAGE_TYPE = {
   ADD_ETHEREUM_CHAIN: 'wallet_addEthereumChain',
   ETH_ACCOUNTS: RestrictedMethods.eth_accounts,

shared/constants/metametrics.ts

@@ -1,5 +1,5 @@
 import { Json } from '@metamask/utils';
-import type { EnvironmentType } from './app';
+import type { EnvironmentType, InstallType, Platform } from './app';
 import { LedgerTransportTypes } from './hardware-wallets';
 
 type JsonWithUndefined =
@@ -565,6 +565,16 @@ export type MetaMetricsUserTraits = {
   // TODO: Fix in https://github.com/MetaMask/metamask-extension/issues/31860
   // eslint-disable-next-line @typescript-eslint/naming-convention
   rewards_referral_code_used?: string;
+  /**
+   * The platform (browser) where the extension is running.
+   */
+  platform?: Platform;
+  /**
+   * The installation type of the extension.
+   */
+  // TODO: Fix in https://github.com/MetaMask/metamask-extension/issues/31860
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  install_type?: InstallType;
 };
 
 export enum MetaMetricsUserTrait {
@@ -681,6 +691,14 @@ export enum MetaMetricsUserTrait {
   HasRewardsOptedIn = 'has_rewards_opted_in',
   RewardsReferred = 'rewards_referred',
   RewardsReferralCodeUsed = 'rewards_referral_code_used',
+  /**
+   * The platform (browser) where the extension is running.
+   */
+  Platform = 'platform',
+  /**
+   * The installation type of the extension.
+   */
+  InstallType = 'install_type',
 }
 
 /**