SubscribeToMailchimp by danielstieber

A lightweight module to subscribe, update, unsubscribe and delete users from lists in Mailchimp


Lightweight module for ProcessWire that let you subscribe a user to a mailchimp list.

I have only tested it with PHP7.x and Processwire 3.x.

The basic idea

// Easily subscribe a user with SubscribeToMailchimp
$mc = $modules->get("SubscribeToMailchimp");

How To Install

  1. Download the zip file at Github or clone directly the repo into your site/modules
  2. If you downloaded the zip file, extract it in your sites/modules directory.
  3. You might have to change the folders name to 'SubscribeToMailchimp'.
  4. Goto the modules admin page, click on refresh and install it.


  1. Log into your Mailchimp account and go to Profile > Extras > API Keys.
  2. If you don't have an API Key, create a new one.
  3. Copy your API Key and paste it in the module settings (Processwire > Modules > Site > SubscribeToMailchimp).
  4. Back in Mailchimp, go to the Audience, where you want your new subscribers.
  5. Go to Settings > audience name and defaults. Copy the Audience ID and paste it into the module settings.
  6. Test your settings with the provided checkbox.

module settings


// load module into template
$mc = $modules->get("SubscribeToMailchimp");

 // subscribe / update a user in your default audience

// add merge_fields to fill out user data, based on your audience MERGE_FIELD options
// You need to setup the fields at "Settings > List fields and *|MERGE|* tags" first!
$mc->subscribe('', ['FNAME' => 'John', 'LNAME' => 'Doe']);

// Subscribe a user to a custom audience (other than default)
$mc->subscribe('', ['FNAME' => 'John', 'LNAME' => 'Doe'], 'adcdef12345');

// Work with additional parameters (not merge_field values!)
$mc->subscribe('', NULL, NULL, [
	'language' => 'en', // find language audience here:
	'vip' => true, // boolean vip status
	'location' => [ // geo location based on lat/log coordinates 
		'latitude' => '48.8722344',
		'longitude', => '2.7736192'
	'interests' => [ // subscribe user to interest categories / groups based on group id
		'32fec3561e' => true,
		'63mel4395m' => false

Additional methods

// Unsubscribe a user

// Unsubscribe a user from a custom audience
$mc->unsubscribe('', 'abcdef1356');

// Archives a user. Archived users can be found in your audience at "manage contacts -> view archived contacts"

// Get the subscription status of a user.

// Static function to test your settings.
// If no audience id is provided, it will test your default audience and returns a formated html result
$mc->testSettings('audience id');

Important Notes

  • This module does not do any data validation. Use a sever-sided validation like Valitron
  • Make sure that you have set up your fields in your Mailchimp audience. You can do it at Settings > Audience fields and *|MERGE|* tags


Example usage after a form is submitted on your page:

// ... validation of form data

$mc = $modules->get("SubscribeToMailchimp");
$email = $input->post->email;
$subscriber = [
  'FNAME' => $input->post->firstname,
  'LNAME' => $input->post->lastname,
$mc->subscribe($email, $subscriber);


In case of trouble check your ProcessWire warning logs.


I can't see the subscriber in the audience

If you have enabled double opt-in (it is enabled by default) you will not see the subscriber, until he confirmed the subscription in the email sent by Mailchimp

I get an error in my ProccessWire warning logs
  • Check if you have the right audience ID and API Key.
  • Check if you pass fields, that exist in your audience.
  • Check if you pass a valid email address.

Go to Mailchimps Error Glossary for more Information


Until now, you can update from every version without changing your code

0.0.6 (May 19, 2020)

  • #10: Fixed an error regarding raw data option with CURL – thanks to @ml-eds for the fix!
  • #9: Fixed a bug where users couldn't be subscribed when not found via getStatus – thanks @ml-eds for the fix!
  • Updated description for delete() method, removed some typos

0.0.5 (July 11, 2019)

  • #8: Fixed a bug, that prevents re-subscribing, if double-opt in was disabled – thanks to @jliebermann for pointing this out
  • #7: Removed the 'warning', that was logged appeared when trying to add a new subscriber – thanks to @horst-n for mentioning
  • Updated wording from 'list' to 'audience' (Introducing Audience)

0.0.4 (May 27, 2018)

  • #6: Fixed a bug, where you couldn't use the 'ADDRESS' merge field and removed more unused lines - Big thanks to @ml-eds for the quick fix!
  • #4: Deleted unused line

0.0.3 (May 17, 2018)

  • #3: Updated subscribe method. You can now add additional parameters like language or interests. Find more about this in the Mailchimp API Documentation
  • #2: Added getStatus method $mc->getStatus($email, $list = "")
  • #2: Added ability to resubscribe a user, if he has unsubscribed. The user will have to confirm his subscription again via double-opt-in (if not disabled)
  • #1: Added testSetting method and a beautiful way to test your settings right in the module settings pages - Big thanks to @horst-n
  • Centralized the validation warning via a constant
  • Updated the getApiBase to be more flexible with different API calls

0.0.2 (April 24, 2018)

  • Added 'Unsubscribe' method $mc->unsubscribe($email, $list = "")
  • Added 'Delete' method $mc->delete($email, $list = "")
  • Removed type declarations to be compatible with PHP 5.1* (thanks to wbmnfktr)
  • Changed the way, the base url for the api gets called

*I have only tested it with PHP 7.x so far, so use on owners risk :)


Any suggestions? Join the Discussion in the ProcessWire Forums or contribute directly on Github.

Install and use modules at your own risk. Always have a site and database backup before installing new modules.

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