Marketing Automation · Integration
lemlist
Add lemlist to your product for your customers, and give your AI agents governed access to it.
lemlist exposes a REST API at api.lemlist.com/api that authenticates with HTTP Basic auth, where the username is an empty string and the API key goes in the password field, which trips up implementers expecting a bearer token. The core objects are campaigns, the leads inside them, the sequence steps that make up a campaign, and activity events such as emailsSent, emailsOpened, emailsClicked and emailsBounced. Adding a lead is scoped to a single campaign rather than to a global contact list, so the same email address can exist independently in several campaigns with different custom variables. Activity retrieval is paginated with offset and limit and is capped per request, so backfilling a busy sender means walking pages by type and date rather than pulling one large export. Team-level rate limits apply across the whole key, so a shared key used for both sync and writes will throttle itself. fastn holds each customer's lemlist key separately and keeps the connection working as keys are rotated or campaigns are rebuilt.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Let a customer connect their own lemlist account so their outreach campaigns appear in your product
Push newly qualified leads from your app into a named lemlist campaign with the custom variables the templates expect
Mirror email open, click, reply and bounce activity back onto your own contact timeline
Pause or resume a lead in a sequence when their status changes in your product
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
Let an agent add a lead to a specific campaign only after a human approves the target campaign
Have an agent summarise reply and bounce rates per campaign, with every read audited per tenant
Let an agent unsubscribe or stop a lead across campaigns when a customer asks to be removed
Example prompt
Which of my lemlist campaigns had the highest reply rate last month?
Set up lemlist in 4 steps
- 01Enable the lemlist connector from your fastn dashboard.
- 02Have each customer authorise their own lemlist account, so calls run under their credentials rather than a shared key.
- 03Decide which campaigns, segments and subscribers your product needs, map those fields, then enable the actions and triggers you want.
- 04Call it from your product and expose it to your agents through the same governed connection.
Why teams use the lemlist integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a lemlist integration without building it. Your customers connect their own lemlist 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 lemlist update is not your on-call problem.
- One integration serves your product and your agents. The same governed lemlist 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
Marketo
Google AdsOften used alongside
Tools the same teams tend to run next to lemlist, across other categories.
Salesforce
HubSpot
Pipedrive
Zoho CRMlemlist integration FAQ
How do I add a lemlist integration to my product?
Enable the lemlist connector in your fastn dashboard, then let each customer authenticate their own lemlist account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no lemlist client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own lemlist account?
Yes. Every connection is scoped to the individual customer, so each authorises their own lemlist 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 lemlist integration?
Yes. The same connection is exposed to your agents through the fastn MCP gateway, with permissions scoped per tenant and every call audited. Let an agent add a lead to a specific campaign only after a human approves the target campaign
Who maintains the lemlist integration?
fastn does. When lemlist 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 lemlist 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 lemlist?
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 lemlist integration?
A common starting point: let a customer connect their own lemlist account so their outreach campaigns appear in your product. 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 lemlist integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding lemlist does not change your per-connector cost. You can start free with 3 connected accounts.
Add lemlist to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.