MailerLite

This tutorial shows how to connect a WordPress form in Mosaic to MailerLite, so every submission becomes a subscriber automatically.

Say you have a sign-up form for a conference. Someone drops in their name, email, company, and the day they’ll show up, then saves their seat. With this set up, that submission becomes a subscriber in MailerLite instantly, not just an email address, but the whole picture: their company, the day they chose, and any other fields you map. Wiring it up takes about a minute.

Connect MailerLite API key

Get your MailerLite API key

In your MailerLite dashboard, go to Integrations, then next to API, click Use. Create a new API token, give it a name, confirm you’ve read the terms of use, and generate the token. Copy it when it’s ready.

Add the key to Mosaic

In Mosaic, open Settings and scroll to the bottom. Paste in your MailerLite API key and save. You’re ready to start building.

Set up the form action

Add the MailerLite action

On the form you want to connect, add a new action and select MailerLite.

Insert the email variable

For the email field, open the dynamic data panel and insert the email variable.

Map the fields

Map the name field

Add a new record, select Name, then pick the matching variable from your form’s dynamic data.

Map the last name field

Add another record, select Last name, then pick the matching variable.

Map any custom fields

Repeat the same steps for any other fields you want to send, such as company. Select the field, then pick the variable that holds its value. You’re matching each MailerLite field to the corresponding field in your Mosaic form.

Assign a group (optional)

If you want these submissions to land in a specific MailerLite group, select it here.

Set the opt-in status

Change the opt-in status from double opt-in to active, so subscribers are added the moment they submit the form.

Preview and confirm it works

Submit a test entry

Fill out the form with a first name, last name, email, company, and any other fields, then submit it.

Check the submission

Look for the entry in your Mosaic form submissions to confirm it captured everything you configured. Then check your MailerLite subscribers to confirm the same person was added there too.

Result

Your form now adds a MailerLite subscriber the moment someone submits it, complete with their mapped fields, group assignment, and opt-in status, no separate integration plugin needed.

Still have more questions? Let us help!

Last updated: September 10, 2026

Still have more questions? Let us help!

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