diff --git a/amplitude-js/v2/amplitude-js-tests.ts b/amplitude-js/v2/amplitude-js-tests.ts
new file mode 100644
index 0000000000..3e69d7c867
--- /dev/null
+++ b/amplitude-js/v2/amplitude-js-tests.ts
@@ -0,0 +1,87 @@
+// Tests for Amplitude SDK TypeScript definitions
+
+/// <reference path="amplitude-js.d.ts" />
+
+module Amplitude.Tests {
+    function all() {
+        amplitude.init('YOUR_API_KEY_HERE', null, {
+            // optional configuration options
+            saveEvents: true,
+            includeUtm: true,
+            includeReferrer: true,
+            batchEvents: true,
+            eventUploadThreshold: 50
+        });
+        amplitude.init('YOUR_API_KEY_HERE', 'USER_ID_HERE', null, () => {});
+
+        amplitude.logEvent('EVENT_IDENTIFIER_HERE');
+        amplitude.setUserId('USER_ID_HERE');
+        amplitude.init('YOUR_API_KEY_HERE', 'USER_ID_HERE');
+        amplitude.setUserId(null); // not string 'null'
+        amplitude.setVersionName('VERSION_NAME_HERE');
+
+        amplitude.regenerateDeviceId();
+        amplitude.setDeviceId('CUSTOM_DEVICE_ID');
+
+        amplitude.logEvent('EVENT_IDENTIFIER_HERE', {
+            'color': 'blue',
+            'age': 20,
+            'key': 'value'
+        });
+        amplitude.logEvent("EVENT_IDENTIFIER_HERE", null, (httpCode, response) => { });
+
+        let identify = new amplitude.Identify().set('gender', 'female').set('age', 20);
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().setOnce('sign_up_date', '08/24/2015');
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().setOnce('sign_up_date', '09/14/2015');
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().unset('gender').unset('age');
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().add('karma', 1).add('friends', 1);
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().append('ab-tests', 'new-user-test').append('some_list', [1, 2, 3, 4, 'values']);
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify().prepend('ab-tests', 'new-user-test').prepend('some_list', [1, 2, 3, 4, 'values']);
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify()
+            .set('karma', 10)
+            .add('karma', 1)
+            .unset('karma');
+        amplitude.identify(identify);
+
+        identify = new amplitude.Identify()
+            .set('colors', ['rose', 'gold'])
+            .append('ab-tests', 'campaign_a')
+            .append('existing_list', [4, 5]);
+        amplitude.identify(identify);
+
+        amplitude.setUserProperties({
+            gender: 'female',
+            age: 20
+        });
+
+        amplitude.clearUserProperties();
+
+        amplitude.setOptOut(true);
+        amplitude.setOptOut(false);
+
+        amplitude.setGroup('orgId', '15');
+        amplitude.setGroup('sport', ['soccer', 'tennis']);
+
+        // TODO: Implement those.
+        /*
+        var revenue = new amplitude.Revenue().setProductId('com.company.productId').setPrice(3.99).setQuantity(3);
+        amplitude.logRevenueV2(revenue);
+
+        amplitude.logEventWithGroups('initialize_game', { 'key': 'value' }, { 'sport': 'soccer' });
+        */
+    }
+}
diff --git a/amplitude-js/v2/amplitude-js.d.ts b/amplitude-js/v2/amplitude-js.d.ts
new file mode 100644
index 0000000000..613f5ad5d8
--- /dev/null
+++ b/amplitude-js/v2/amplitude-js.d.ts
@@ -0,0 +1,61 @@
+// Type definitions for Amplitude SDK 2.12.1
+// Project: https://github.com/amplitude/Amplitude-Javascript
+// Definitions by: Arvydas Sidorenko <https://github.com/Asido>
+// Definitions: https://github.com/Asido/DefinitelyTyped
+
+declare module amplitude {
+    interface Config {
+        batchEvents?: boolean;
+        cookieExpiration?: number;
+        cookieName?: string;
+        deviceId?: string;
+        domain?: string;
+        eventUploadPeriodMillis?: number;
+        eventUploadThreshold?: number;
+        includeReferrer?: boolean;
+        includeUtm?: boolean;
+        language?: string;
+        optOut?: boolean;
+        platform?: string;
+        saveEvents?: boolean;
+        savedMaxCount?: number;
+        sessionTimeout?: number;
+        uploadBatchSize?: number;
+    }
+
+    export class Identify {
+        set(key: string, value: any): Identify;
+        setOnce(key: string, value: any): Identify;
+        add(key: string, value: number): Identify;
+        append(key: string, value: any): Identify;
+        prepend(key: string, value: any): Identify;
+
+        unset(key: string): Identify;
+    }
+
+    export function init(apiKey: string): void;
+    export function init(apiKey: string, userId: string): void;
+    export function init(apiKey: string, userId: string, options: Config): void;
+    export function init(apiKey: string, userId: string, options: Config, callback: () => void): void;
+
+    export function setVersionName(version: string): void;
+    export function setUserId(userId: string): void;
+
+    export function setDeviceId(id: string): void;
+    export function regenerateDeviceId(): void;
+
+    export function identify(identify: Identify): void;
+
+    export function setUserProperties(properties: Object): void;
+    export function clearUserProperties(): void;
+
+    export function setOptOut(optOut: boolean): void;
+
+    export function setGroup(groupType: string, groupName: string | string[]): void;
+
+    export function logEvent(event: string): void;
+    export function logEvent(event: string, data: Object): void;
+    export function logEvent(event: string, data: Object, callback: (httpCode: number, response: any) => void): void;
+
+    export var options: Config;
+}