How do I connect an email marketing platform?

Standard pattern

1. Get an API key from your email platform (Mailchimp, ConvertKit, Klaviyo, ActiveCampaign, etc.).
2. Ask Lovable to store it as a secret.
3. Ask Lovable to build a server function that adds/updates a subscriber via that platform's API.
4. Call it from your signup form or relevant trigger.

"When someone submits the newsletter signup form, add their email to my Mailchimp audience using my API key stored as a secret, and tag them 'website-signup'."

Transactional vs marketing email

Be clear with Lovable about which you mean:

• Transactional (order confirmations, password resets): typically sent via Resend, which has a native Lovable connector — see /questions/how-do-i-connect-openai style setup but for Resend specifically.
• Marketing (newsletters, campaigns): typically sent via Mailchimp/Klaviyo/ConvertKit, which is what this integration usually means.

Double opt-in and compliance

Many platforms require or strongly encourage double opt-in (confirmation email before the subscriber is fully added) — check your platform's requirements and your local anti-spam laws before launch.

What usually goes wrong

• API key exposed client-side instead of routed through a server function.
• Silent failures — if the API call fails, the form still looks like it succeeded to the user unless you explicitly handle and surface the error.
• List/audience ID mismatches (some platforms need both an API key and a specific list ID) causing subscribers to go nowhere.
• No de-duplication, so re-submitting the form repeatedly can trigger errors or duplicate tags depending on the platform.

If you're running email marketing at meaningful volume with segmentation and automation, PromptSites.com can wire up a more robust integration than a single form-to-API call.