MailerLite

Introduction

Automatically sync your paying customers to MailerLite subscriber lists when payment events occur. Add customers to specific groups, trigger automation workflows, and keep your email marketing lists up-to-date with real payment data. MailerLite is a powerful email marketing platform for newsletters, campaigns, and automations. This integration helps you automatically manage subscribers based on payment activity - perfect for onboarding sequences, customer segmentation, and targeted marketing campaigns.

This integration requires your MailerLite API Key for authentication. You can generate one from your MailerLite Integrations page.

Getting Started

Open the Webhook Section

In your Dodo Payments dashboard, navigate to Webhooks + Add Endpoint and expand the integrations dropdown.

Select MailerLite

Choose the MailerLite integration card.

Enter API Key

Provide your MailerLite API Key in the configuration.

Configure Transformation

Edit the transformation code to format subscriber data for MailerLite’s API.

Test & Create

Test with sample payloads and click Create to activate the subscriber sync.

Done!

Payment events will now automatically sync customers to your MailerLite lists.

Transformation Code Examples

Add Customer on Successful Payment

add_customer.js

function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    webhook.url = "https://connect.mailerlite.com/api/subscribers";
    webhook.payload = {
      email: p.customer.email,
      fields: {
        name: p.customer.name,
        company: p.customer.business_name || "",
        last_name: ""
      },
      groups: ["your-group-id-here"],
      status: "active"
    };
  }
  return webhook;
}

Add Subscriber to Multiple Groups Based on Product

product_segmentation.js

function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    
    // Determine groups based on product or amount
    const groups = ["customers-group-id"];
    
    // Add to premium group if high-value purchase
    if (p.total_amount >= 10000) { // $100+
      groups.push("premium-customers-group-id");
    }
    
    webhook.url = "https://connect.mailerlite.com/api/subscribers";
    webhook.payload = {
      email: p.customer.email,
      fields: {
        name: p.customer.name,
        last_purchase_amount: (p.total_amount / 100).toFixed(2),
        last_purchase_date: new Date(webhook.payload.timestamp).toISOString().split('T')[0],
        payment_id: p.payment_id
      },
      groups: groups,
      status: "active"
    };
  }
  return webhook;
}

Add New Subscriber on Subscription Activation

subscription_subscriber.js

function handler(webhook) {
  if (webhook.eventType === "subscription.active") {
    const s = webhook.payload.data;
    webhook.url = "https://connect.mailerlite.com/api/subscribers";
    webhook.payload = {
      email: s.customer.email,
      fields: {
        name: s.customer.name,
        subscription_plan: s.product_id,
        subscription_amount: (s.recurring_pre_tax_amount / 100).toFixed(2),
        billing_frequency: s.payment_frequency_interval,
        subscription_start: new Date().toISOString().split('T')[0]
      },
      groups: ["subscribers-group-id", "active-subscriptions-group-id"],
      status: "active"
    };
  }
  return webhook;
}

Update Subscriber on Subscription Cancellation

subscription_cancelled.js

function handler(webhook) {
  if (webhook.eventType === "subscription.cancelled") {
    const s = webhook.payload.data;
    // Use PUT to update existing subscriber
    webhook.url = "https://connect.mailerlite.com/api/subscribers/" + encodeURIComponent(s.customer.email);
    webhook.method = "PUT";
    webhook.payload = {
      fields: {
        subscription_status: "cancelled",
        cancellation_date: new Date().toISOString().split('T')[0]
      },
      groups: ["churned-customers-group-id"]
    };
  }
  return webhook;
}

Add Customer with Custom Fields

custom_fields.js

function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    webhook.url = "https://connect.mailerlite.com/api/subscribers";
    webhook.payload = {
      email: p.customer.email,
      fields: {
        name: p.customer.name,
        company: p.customer.business_name || "",
        country: p.customer.country || "",
        city: p.customer.city || "",
        phone: p.customer.phone || "",
        // Custom fields (must be created in MailerLite first)
        total_spent: (p.total_amount / 100).toFixed(2),
        customer_since: new Date().toISOString().split('T')[0],
        payment_method: p.payment_method || "unknown",
        currency: p.currency || "USD"
      },
      groups: ["paying-customers-group-id"],
      status: "active",
      subscribed_at: new Date().toISOString().replace('T', ' ').split('.')[0]
    };
  }
  return webhook;
}

Trigger Automation via Event

trigger_automation.js

function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    
    // First, ensure subscriber exists
    webhook.url = "https://connect.mailerlite.com/api/subscribers";
    webhook.payload = {
      email: p.customer.email,
      fields: {
        name: p.customer.name,
        // Add a trigger field that your automation watches
        last_payment_trigger: new Date().toISOString(),
        last_payment_amount: (p.total_amount / 100).toFixed(2)
      },
      status: "active"
    };
    
    // Tip: Create an automation in MailerLite that triggers
    // when 'last_payment_trigger' field is updated
  }
  return webhook;
}

Tips

Create custom fields in MailerLite before using them in your transformations
Use groups to segment customers by product, plan tier, or purchase behavior
Set up automation workflows in MailerLite that trigger on field updates
Use the upsert behavior (POST to /subscribers) to avoid duplicate subscriber errors
Store payment metadata in custom fields for better customer insights
Test with a small group before enabling for all payments

Custom Fields Setup

Before using custom fields, you need to create them in MailerLite:

Go to your MailerLite dashboard
Navigate to Subscribers Fields
Click Create field and add fields like:
- total_spent (Number)
- customer_since (Date)
- subscription_plan (Text)
- payment_method (Text)
- last_payment_amount (Number)

Troubleshooting

Subscribers not being added

Verify API Key is correct and active
Check that the email address is valid (RFC 2821 compliant)
Ensure group IDs are correct and exist in your account
Note: Unsubscribed, bounced, or junk subscribers cannot be reactivated via API

Custom fields not updating

Verify custom fields exist in MailerLite before using them
Check that field names match exactly (case-sensitive)
Ensure field values match the expected type (text, number, date)

Rate limit errors

MailerLite API has a rate limit of 120 requests per minute
Use batch endpoints if processing many subscribers
Implement backoff strategies for high-volume scenarios

Group assignment not working

Verify group IDs are numeric strings
Check that groups exist in your MailerLite account
Note: Using PUT with groups will remove subscriber from unlisted groups

API Reference

MailerLite Subscribers API accepts the following key parameters:

Parameter	Type	Required	Description
`email`	string	Yes	Valid email address (RFC 2821)
`fields`	object	No	Object with field name/value pairs
`fields.name`	string	No	Subscriber’s first name
`fields.last_name`	string	No	Subscriber’s last name
`fields.company`	string	No	Company name
`fields.country`	string	No	Country
`fields.city`	string	No	City
`fields.phone`	string	No	Phone number
`groups`	array	No	Array of group IDs to add subscriber to
`status`	string	No	One of: active, unsubscribed, unconfirmed, bounced, junk
`subscribed_at`	string	No	Date in format `yyyy-MM-dd HH:mm:ss`
`ip_address`	string	No	Subscriber’s IP address

For complete API documentation, visit MailerLite Developers.

External Integrations

Messaging

Workflow Automation

CRM

Email

Analytics

Introduction

Getting Started

Transformation Code Examples

Add Customer on Successful Payment

Add Subscriber to Multiple Groups Based on Product

Add New Subscriber on Subscription Activation

Update Subscriber on Subscription Cancellation

Add Customer with Custom Fields

Trigger Automation via Event

Tips

Custom Fields Setup

Troubleshooting

API Reference

​Introduction

​Getting Started

​Transformation Code Examples

​Add Customer on Successful Payment

​Add Subscriber to Multiple Groups Based on Product

​Add New Subscriber on Subscription Activation

​Update Subscriber on Subscription Cancellation

​Add Customer with Custom Fields

​Trigger Automation via Event

​Tips

​Custom Fields Setup

​Troubleshooting

​API Reference

Introduction

Getting Started

Transformation Code Examples

Add Customer on Successful Payment

Add Subscriber to Multiple Groups Based on Product

Add New Subscriber on Subscription Activation

Update Subscriber on Subscription Cancellation

Add Customer with Custom Fields

Trigger Automation via Event

Tips

Custom Fields Setup

Troubleshooting

API Reference