Transactional API Quick Start

At a glance

This guide will give you everything you need to start using the Mailchimp Transactional API to send fast, personalized transactional emails, analyze sent email for trends, and handle and parse inbound email from your users. We’ll cover creating a Transactional Email account, generating your API key, installing the client library for your preferred language, and making your first call to the Transactional API. 

Note: While using the Mailchimp Transactional API, you may notice a glaring discrepancy: At times, what we’re referring to as the Transactional API will instead be called Mandrill. In fact, the two are the same, and wherever you see the legacy “Mandrill,” you can assume we’re referring to the Transactional API.

Create an account

If you don't have a Mailchimp Transactional Email account, you’ll need to create one in order to get started using the API. If you have a Mailchimp Standard plan or higher, you can enable Transactional Email from the Monthly plans or credits page of your account.

Generate your API key

You authenticate a request to the Transactional API using an API key. 

To generate one: 

  1. Navigate to the Settings page of your Transactional Email account and look for the API Keys section.

  2. If you already have an API key listed and you’d like to use it for your application, you can simply copy it. 

  3. Otherwise, click New API Key and give it a description.

Note: It’s important to remember that your Mailchimp Transactional API key provides full account access, so you should keep it secure, as you would a password.

Install the client library for your language

You can make calls to the Transactional API with whichever method you usually use to make HTTP requests, but Mailchimp offers client libraries that make interacting with the API even simpler. 

To install the client library for your preferred language:

Install the client library for your language

# No client installation necessary; just using curl

Make your first API call

To test that you have everything set up correctly, we'll make a simple request to the /users/ping endpoint. Hitting this endpoint acts as a health check on the Mailchimp Transactional API service, and will not affect your account in any way.

Make your first API call

curl -sS -X POST "" \
  --header 'Content-Type: application/json' \
  --data-raw '{ "key": "YOUR_API_KEY" }'

If the call was successful, the response you receive will be a string reading PONG!

Next steps

Now that you’re successfully making authenticated requests to the API with your API key and client library of choice, you’re ready to dive into the Transactional API. 

To get started with Transactional Email, we recommend starting with the “Send Your First Transactional Email” guide, which will walk you through, well, sending your first transactional email. You can also familiarize yourself with some of the common conventions you’ll run into across the Transactional API endpoints.

If you’re looking for more information about what you can do with the Transactional API, check out the full list of Transactional API guides, or browse the extensive API Reference documentation.