How to use Mailchimp API in Wordpress


There may have been times where you had to update Mailchimp regarding changes in user particulars. Most of the time, a plugin like Autochimp works incredibly well.

Unfortunately, non of these plugins work exceptionally well if you need to introduce complex things like interest groups.

In this article, I’ll show you how to set up the Mailchimp API with Wordpress, and how you can use it to update a user interest group when he changes his profile. You’ll learn how to use the Mailchimp API for other purposes along the way.


You should already have a mailchimp account and at least one interest group set up before attempting this.

Setting up a Mailchimp API Wrapper

The first step to use Mailchimp is to set up an API Wrapper that allows you to quickly and easily use Mailchimp’s commands.

Since this tutorial is about Wordpress, we’re going to use the PHP Wrappers, particularly the version by Drew McLellan.

Head over to download the zip.

Remane the folder to mailchimp and place it into your theme. (Note: It might be better to place this into a plugin, but lets work with themes for now)

Then create a file called mailchimp.php within the mailchimp folder.

Within mailchimp.php, we can now get ready to use Mailchimp by setting up the following code.

// This is to tell Wordpress our file requires Drewm/MailChimp.php.
require_once( 'src/Drewm/MailChimp.php' );
// This is for namespacing since Drew used that.
use \Drewm;

To then link it to your mailchimp account, set up the following code

// Your Mailchimp API Key
$api = 'f3335c741cb441d9576fa6936eb45813-us3';
// Initializing the $MailChimp object
$MailChimp = new \Drewm\MailChimp($api);

We’re done with the setup. Now lets do something awesome.

Using the Mailchimp API

The way to use Drew’s API Wrapper as simple as using a method called “call”. Here’s an example to show what I mean.

Right now, you’re trying to find out about “Mr Potato” is in your list. After checking the mailchimp api reference page, you see a method called “member-info”. Here’s how you would use it.

$member_info = $MailChimp->call('lists/member-info', array(
  'id' => $id, // your mailchimp list id here
  'emails' => array(
    array('email' => "[email protected]") // Mr Potato's email here

// Essentially, what you're doing is this
$Mailchimp->call('Mailchimp api method here',
  // Mailchimp required things here. Refer to Mailchimp API to have a good understanding of what is required since everything is different.
  // Note that you don't have to use your api key anymore because Drew already took care of that.

Thats basically it!

This looks simple. But looking through Mailchimp API methods is probably not so, which is the reason for the next section :)

Important API Methods

You have to check for a few things when a member saves, just to make sure everything runs smoothly. Here’s a few methods I think are important.

  1. list/member-info - To find out whether member X is in your list.
  2. list/subscribe - If member is not in the list, you can subscribe him.
  3. list/update-member - If member is in the list, you can go ahead and update
  4. list/interest-groupings - Since we’re working with interest groups, we need to get the interest group id from here.

After understanding which methods you need, you can now nail this in code. In the next post, I’ll walk through the steps of using these methods in wordpress.

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