Marketing Automation · Integration
MailerLite
Add MailerLite to your product for your customers, and give your AI agents governed access to it.
MailerLite keeps its model deliberately small, which is most of its appeal: subscribers, the groups they belong to, custom fields defined per account, campaigns, automations and forms. A subscriber write is an upsert against the email address, so the same call creates a person or updates one and your product never has to check first, which removes the usual race between a signup and an import running at the same time. Groups do the work segments do elsewhere, and adding somebody to a group is how an automation gets started from outside, so most integrations turn out to be group writes rather than campaign calls. Statuses matter more than they look: unconfirmed, unsubscribed and bounced are not interchangeable, and rolling them into one number gives a customer a list size they cannot act on. Each customer brings their own API token, so sends come off their plan and their reputation.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Let each customer connect their own MailerLite account so subscribers, groups and sends stay under the plan they pay for.
Upsert a subscriber by email so a signup and a bulk import cannot create two records for the same person.
Add someone to a group to start an automation, rather than calling a campaign endpoint your product then has to keep in step.
Report subscriber status honestly, keeping unconfirmed, unsubscribed and bounced apart when your product shows list health.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent reports how a campaign performed from its own opens, clicks and unsubscribes.
An agent adds a subscriber to a group within scoped permissions, and the group it wrote to is recorded.
An agent explains why somebody stopped receiving mail by reading their status and bounce history.
Example prompt
How many subscribers in this group are still unconfirmed, and when did each of them sign up?
Set up MailerLite in 4 steps
- 01Enable the MailerLite connector in your fastn dashboard.
- 02Have each customer create their own API token, so sends come off their plan rather than a key you hold.
- 03Map that account's groups and custom fields, then decide which group writes start which automations and subscribe to the webhooks you need.
- 04Call it from your product and expose the same connection to your agents through the MCP gateway.
Why teams use the MailerLite integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a MailerLite integration without building it. Your customers connect their own MailerLite account inside your product and work their campaigns, segments and subscribers there, with no per-customer code on your side.
- Handle the part that actually costs time: engagement data arrives as a high-volume event stream, so ordering and deduplication matter. fastn owns the auth, token refresh, rate limits, pagination and breaking-change fixes, so a MailerLite update is not your on-call problem.
- One integration serves your product and your agents. The same governed MailerLite connection powers in-product features and gives AI agents scoped, audited access, so you trigger and measure campaigns from inside your product without wiring it twice.
Used by these teams
Compare with
Mailchimp
Kit
AWeberOften used alongside
Tools the same teams tend to run next to MailerLite, across other categories.
Salesforce
HubSpot
Pipedrive
Zoho CRMMailerLite integration FAQ
How do I add a MailerLite integration to my product?
Enable the MailerLite connector in your fastn dashboard, then let each customer authenticate their own MailerLite account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no MailerLite client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own MailerLite account?
Yes. Every connection is scoped to the individual customer, so each authorises their own MailerLite account and only ever sees their own campaigns, segments and subscribers. That per-tenant isolation is the point of an embedded integration: you support the long tail of customer setups without maintaining an integration per customer.
Can AI agents use this MailerLite integration?
Yes. The same connection is exposed to your agents through the fastn MCP gateway, with permissions scoped per tenant and every call audited. An agent reports how a campaign performed from its own opens, clicks and unsubscribes.
Who maintains the MailerLite integration?
fastn does. When MailerLite changes an endpoint, deprecates a field or alters its auth, the fix lands in the connector rather than in your backlog, and your customers' connections keep working.
Can I trigger a MailerLite campaign from an event in my product?
Yes. Product events can start a campaign, add a contact to a segment, or enrol someone in a journey, so lifecycle messaging follows what a user actually did rather than a nightly export.
Can I read engagement results back from MailerLite?
Yes. Results come back scoped per tenant, so your product can act on them without one customer's data mixing with another's. What you get depends on the channel: opens, clicks, bounces and unsubscribes where there are sends, and impressions, spend and conversions where there are campaigns.
What can I build with the MailerLite integration?
A common starting point: let each customer connect their own MailerLite account so subscribers, groups and sends stay under the plan they pay for. Teams also use it for the other use cases listed above, and expose it to agents for governed reads and writes.
How much does the MailerLite integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding MailerLite does not change your per-connector cost. You can start free with 3 connected accounts.
Add MailerLite to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.