Webhooks allow your local application data to stay in sync with data in MailChimp. In essence, enabling webhooks makes your application a two-way communication. The API sends data handled at the site to MailChimp, while webhooks allow MailChimp to send data handled there back to the local site.
The most important place for this to be operable is with subscribe/unsubscribe data. If a user unsubscribes via MailChimp rather than updating their local site profile, webhooks are necessary for MailChimp to notify the site of the user data change so that the site data can reflect that the user is unsubscribed.
Webhooks can be used for updating the user’s status (subscribe/unsubscribe), changing their email address, as well as any profile data that is mapped as a merge field or an interest field.
Enable Webhooks
To enable receiving webhooks, you need to create a webhook key in the WP-Members > MailChimp tab. This doesn’t have to be a random string, it can be anything really, but the more random, the better. The value you enter in this setting will be used to create the endpoint for receiving webhooks from MailChimp.
Once you add the key to the settings and save, you will be provided a callback URL to set up at MailChimp. This is the URL MailChimp will send webhook notifications to.
Now you are ready to add the webhook URL to Mailchimp. This step is required! If you do not add the created webhook URL to Mailchimp, Mailchimp does not know you have a site to sync.
Log into Mailchimp. Go to your audience, then click the additional settings (the “…” button) and select “Audience Settings” from the dropdown menu:
In the Audience Settings screen, click the link that says “Manage webhooks”:
From the webhooks screen, click the button to “Add webhook:
In the create webhook dialog, paste the webhook URL from your WP-Members Mailchimp settings screen in the “Callback URL” field. Select the types of updates you want synced from Mailchimp.
Once you click “create webhook”, you should see the webhooks screen refresh with your newly added webhook:
