Node.js Ampli Wrapper

Note

This page covers Node.js JavaScript and TypeScript runtimes. All (Itly) runtimes are deprecated. If you are still using an (Itly) runtime, see the migration guide to ugrade to the newest runtime. Docs for the Itly version are available here.

Amplitude Data supports tracking analytics events from Node.js apps written in JavaScript (ES6 and above) and TypeScript (2.1 and above). The generated tracking library is packaged as a CJS module.

The tracking library exposes a function for every event in your team’s tracking plan. The function’s arguments correspond to the event’s properties and are strongly typed to allow for code completion and compile-time checks.

Enable type checking

Because JavaScript is not a type-safe language, static type checking isn't built in like TypeScript. Some common IDEs allow for real-time type checks in JavaScript based on JSDoc. For a better development experience Ampli generates JSDocs for all methods and classes.

To enable real-time type checking in VSCode for JavaScript:

1. Go to Preferences > Settings then search for checkJs.
2. Select JS/TS > Implicit Project Config: Check JS.

After it's activated, type errors appear directly in the IDE.

Jetbrains provides similar support:

1. Go to Preferences > Editor > Inspections > JavaScript and TypeScript > General.
2. In Signature mismatch and Type mismatch, set the Severity to Warning or Error based on your desired level of strictness.

Linting with Prettier

To prevent linting errors for eslint and tslint, the SDK-generated files have the following to diasable the linters:

/* tslint:disable */

/* eslint-disable */

There's no corresponding “in-code” functionality with Prettier. Instead, add the generated path/to/ampli to your .prettierignore file. You can get the path with ampli pull. See the Prettier documentation for more information.

Installation

These instructions are also available from the Implementation page of your Amplitude Data workspace.

Install the Ampli CLI

If you haven't installed the Ampli CLI, install it now.

Install dependencies

If you haven't already, install the core Amplitude SDK dependencies.

npm install @amplitude/node @amplitude/identify @amplitude/types

Pull the SDK into your project

At the project root, run pull command.

ampli pull

This prompts you to log in to your workspace and select a source.

JavaScriptTypeScript

➜ ampli pull sourcename
Ampli project is not initialized. No existing `ampli.json` configuration found.
? Create a new Ampli project here? Yes
Organization: Amplitude
Workspace: My Workspace
Source: sourcename
Runtime: Node.js - JavaScript
Branch: main
Pulling latest version (1.0.0)...
Tracking library generated successfully.
Path: ./src/itly

➜ ampli pull sourcename
Ampli project is not initialized. No existing `ampli.json` configuration found.
? Create a new Ampli project here? Yes
Organization: Amplitude
Workspace: My Workspace
Source: sourcename
Runtime: Node.js - TypeScript
Branch: main
Pulling latest version (1.0.0)...
Tracking library generated successfully.
Path: ./src/itly

API

Load

Initialize Ampli in your code.

JavaScriptTypeScript

const { ampli } = require('./ampli');
ampli.load({ environment: 'production' });

import { ampli } from './ampli';
ampli.load({ environment: 'production' });

The load() function accepts an options object to configure the SDK's behavior:

Option	Type	Required	Description
disabled	Boolean	optional	Specifies whether the Ampli Wrapper does any work. When true, all calls to the Ampli Wrapper will be no-ops. Useful in local or development environments. Defaults to false.
environment	String	optional	Specifies the environment the Ampli Wrapper is running in: production or development. Environment determines which Access Token is used to load the underlying analytics provider libraries. Defaults to development.
client.apiKey	String	optional	Specifies an API Key. This option overrides the default, which is the API Key configured in your tracking plan.
client.instance	AmplitudeClient	optional	Specifies an Amplitude instance. By default Ampli creates an instance for you.
client.options	Amplitude.Options	optional	Overrides the default configuration for the AmplitudeClient.

Identify

Call identify() to set user properties.

Just as Ampli creates types for events and their properties, it creates types for user properties.

The identify() function accepts an optional userId, optional user properties, and optional options.

For example, your tracking plan contains a user property called role. The property's type is a string.

TypeScriptJavaScript

ampli.identify('user-id', {
  role: 'Admin'
});

ampli.identify('user-id', {
  role: 'Admin'
});

The options argument allows you to pass Amplitude fields for this call, such as deviceId.

TypeScriptJavaScript

ampli.identify('user-id', {
  role: 'admin'
}, {
  deviceId: 'my-device-id'
});

ampli.identify('user-id', {
  role: 'admin'
}, {
  deviceId: 'my-device-id'
});

Group

Feature availability

This feature is available in Growth and Enterprise accounts with the Accounts add-on.

Call setGroup() to associate a user with their group (for example, their department or company). The setGroup() function accepts a required groupType, and groupName.

TypeScriptJavaScript

ampli.setGroup('user-id', 'Group name', 'Group Value');

ampli.setGroup('user-id', 'Group name', 'Group Value');

Amplitude supports assigning users to groups and performing queries, such as Count by Distinct, on those groups. If at least one member of the group has performed the specific event, then the count includes the group.

For example, you want to group your users based on what organization they're in by using an 'orgId'. Joe is in 'orgId' '10', and Sue is in 'orgId' '15'. Sue and Joe both perform a certain event. You can query their organizations in the Event Segmentation Chart.

When setting groups, define a groupType and groupName. In the previous example, 'orgId' is the groupType and '10' and '15' are the values for groupName. Another example of a groupType could be 'sport' with groupName values like 'tennis' and 'baseball'.

Setting a group also sets the groupType:groupName as a user property, and overwrites any existing groupName value set for that user's groupType, and the corresponding user property value. groupType is a string, and groupName can be either a string or an array of strings to indicate that a user is in multiple groups.

Example

For example, if Joe is in 'orgId' '10' and '20', then the groupName is '[10, 20]').

Your code might look like this:

TypeScriptJavaScript

ampli.setGroup('user-id', 'orgId', ['10', '20']);

ampli.setGroup('user-id', 'orgId', ['10', '20']);

Track

To track an event, call the event's corresponding function. Every event in your tracking plan gets its own function in the Ampli Wrapper. The call is structured like this:

TypeScriptJavaScript

ampli.eventName(
    userId: string | undefined,
    properties: EventProperties,
    options: EventOptions,
    extra: MiddlewareExtra
)

ampli.eventName(
    userId: string | undefined,
    properties: EventNameProperties,
    options: EventOptions,
    extra: MiddlewareExtra
)

userId in multi-tenant, server environments a userId must be provided for each tracking call to associate it to a

properties passes in event properties specific to this event in the tracking plan.

The options argument allows you to pass Amplitude fields, like price, quanity and revenue.

The extra argument lets you pass data to middleware.

For example, your tracking plan contains an event called Song Played. The SDK generates the songPlayed function for the event, using camelcase to make it valid JavaScript. The event is defined with two required properties: songId and songFavorited. The property type for songId is string, and songFavorited is a boolean.

The event has two Amplitude fields defined: price, and quantity. Learn more about Amplitude fields here. The event has one MiddlewareExtra defined: myMiddleware. Learn more about middleware.

TypeScriptJavaScript

ampli.songPlayed('ampli-user-id', {
  songId: 'songId', // string,
  songFavorited: true, // boolean
}, {
  price: 1.23,
  quantity: 2
}, {
  myMiddleware: { myMiddlewareProp: "value to send to middleware" }
});

ampli.songPlayed('ampli-user-id', {
  songId: 'songId', // string,
  songFavorited: true, // boolean
}, {
  price: 1.23,
  quantity: 2
}, {
  myMiddleware: { myMiddlewareProp: "value to send to middleware" }
});

Ampli also generates a class for each event.

TypeScriptJavaScript

const myEventObject = new SongPlayed({
  songId: 'songId', // string,
  songFavorited: true, // boolean
});

const myEventObject = new SongPlayed({
  songId: 'songId', // string,
  songFavorited: true, // boolean
});

Track Event objects using Ampli track:

TypeScriptJavaScript

ampli.track('ampli-user-id', new SongPlayed({
  songId: 'songId', // string,
  songFavorited: true, // boolean
}));

ampli.track('ampli-user-id', new SongPlayed({
  songId: 'songId', // string,
  songFavorited: true, // boolean
}));

Verify implementation status

Verify events are implemented in your code with the status command:

ampli status

To update the implementation status in your tracking plan use the --update flag or -u:

ampli status -u

The output displays status and indicates what events are missing.

➜ ampli status
✘ Verifying event tracking implementation in source code
 ✔ Song Played (1 location)
 ✘ Song Stopped Called when a user stops playing a song.
Events Tracked: 2 missed, 3 total

Learn more about ampli status.

Migrating from an Itly runtime

Migrate from an Itly Node.js runtime to Ampli by following these steps.

1. Update Source runtime. In the web app open the Connections > Source modal. From the dropdown, update the source to a non-(Itly) runtime.
2. Go to the Implementation page, then select the new Source for detailed setup and usage instructions.

3. Remove legacy Itly dependencies from your project. This includes anything that contains @itly:

   yarn remove @itly/sdk @itly/plugin-schema-validator @itly/plugin-amplitude-node ... 4. Add Amplitude dependencies:

   yarn add @amplitude/node

4. Pull the latest Ampli Wrapper:

   ampli pull

5. Check your Ampli Wrapper path.

   ampli pull prints the download location of the SDK. If the path contains itly, you can update the Path by hand in the ampli.json file, or pull again using the --path parameter: ampli pull -p ./path/to/ampli.

6. Find and replace:

   • import { itly } from '../itly' => import { ampli } from '../ampli'
   • itly.group(userId, groupId) => ampli.setGroup(userId, groupType, groupName)
   • itly.load() => ampli.load()
   • All itly. with ampli.
7. See updated Event tracking details on your Implementation page in the web app.

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Last update: 2022-07-19