Node.js SDK to integrate MailChannels API into your JavaScript or TypeScript server-side applications.

This library provides a simple way to interact with the MailChannels API. It is written in TypeScript and can be used in both JavaScript and TypeScript projects and in different runtimes.

• ✨ Release Notes
• 📖 Documentation

• 🚀 Features
• 📏 Requirements
• 📦 Installation
• 📚 Usage
• 📐 Naming Conventions
• ⚖️ License
• 💻 Development
• 🧪 Local simulator

This SDK fully supports all features and operations available in the MailChannels API. It is actively maintained to ensure compatibility and to quickly add support for new API features as they are released.

Some of the things you can do with the SDK:

• Send transactional emails
• Check DKIM, SPF & Domain Lockdown
• Configure DKIM keys
• Webhook notifications
• Manage sub-accounts
• Retrieve metrics
• Inspect webhook delivery batches
• Handle suppressions
• Configure inbound domains
• Manage account and recipient lists

• Create a MailChannels account
• Create an API key

Add mailchannels-sdk dependency to your project

# npm
npm i mailchannels-sdk

# yarn
yarn add mailchannels-sdk

# pnpm
pnpm add mailchannels-sdk

To authenticate, you'll need an API key. You can create and manage API keys in Dashboard > Account Settings > API Keys.

Pass your API key while initializing a new MailChannels client.

import { MailChannels } from 'mailchannels-sdk'

const mailchannels = new MailChannels('your-api-key')

Send an email:

const { data, error } = await mailchannels.emails.send({
  from: 'Name <from@example.com>',
  to: 'to@example.com',
  subject: 'Test email',
  html: '<p>Hello World</p>'
})

Most properties in the MailChannels API use snake_case. To follow JavaScript conventions, the SDK adopts camelCase for all properties. This means:

• Most options and responses match the API docs, but field names are camelCase rather than snake_case.
• Some fields are grouped into nested objects or renamed for simplicity and better developer experience.
• While most fields match the API docs (just with camelCase), a few may be simplified or reorganized to feel more natural for JavaScript developers.

MIT License

# Install dependencies
pnpm install

# Build the package
pnpm build

# Run Oxlint
pnpm lint

# Run Vitest
pnpm test
pnpm test:watch

# Run typecheck
pnpm test:types

# Refresh API parity fixtures
pnpm parity:fixtures

# Run the local Email API simulator
pnpm simulate:email-api

# Release new version
pnpm release

This repo includes a small local MailChannels Email API simulator at scripts/email-api-simulator.mjs. It keeps state in memory and emulates the SDK-supported Email API endpoints so you can test your application without calling the real MailChannels service.

# default: http://127.0.0.1:8787
pnpm simulate:email-api

You can override the bind address with environment variables:

MAILCHANNELS_SIMULATOR_HOST=127.0.0.1 MAILCHANNELS_SIMULATOR_PORT=8787 pnpm simulate:email-api

Use the optional baseUrl constructor option when creating the client:

import { MailChannels } from 'mailchannels-sdk'

const mailchannels = new MailChannels('local-test-key', {
  baseUrl: 'http://127.0.0.1:8787'
})

const { data, error } = await mailchannels.emails.send({
  from: 'sender@example.com',
  to: 'recipient@example.com',
  subject: 'Hello from the simulator',
  html: '<p>Local test</p>'
})

• Email sends and async sends
• Domain checks
• DKIM key create, list, rotate, and update
• Webhook enrollment, listing, validation, signing key lookup, and batch inspection
• Sub-account lifecycle, API keys, SMTP passwords, limits, and usage
• Engagement, performance, recipient behaviour, sender, volume, and usage metrics
• Suppression create, list, and delete

• State is in-memory only and is reset when the process stops
• Any non-empty X-API-Key is accepted, with separate in-memory state per API key
• Webhook responses are simulated locally, but the simulator does not yet emit real webhook callbacks to your application

The next planned expansion is outbound webhook delivery so client applications can test webhook ingestion flows against the simulator as well.