When someone gives you their email in a DM, Ellipsend can save them in Klaviyo and subscribe them to a list a second later. It takes two requests. New to API requests? Start with Send Contact Info to Your Other Tools With API Requests.

In Klaviyo, open Settings → API keys and click Create Private API Key. Name it Ellipsend, choose Custom key, and give it write access to Profiles, Lists and Subscriptions. Copy the key. It starts with pk_ and Klaviyo only shows it once.

In Klaviyo, open Audience → Lists & segments, open the list, then Settings. The List ID is under Details. Use a list, not a segment. Klaviyo segments fill themselves from rules, so you can't add someone to one directly.

In Ellipsend, go to Settings → Integrations → HTTP requests and click Add request. Name it Save profile in Klaviyo, pick Create · POST, and paste https://a.klaviyo.com/api/profile-import.

Open Connection and click Add connection:

Klaviyo also needs a version header on every request. Open Advanced options → Headers, click Add a header, and add revision with the value 2026-10-15.

Save profile in Klaviyo creates or updates the profile with their first name. Click Edit as JSON and paste:

The parts in double curly braces, like {{ contact.email }}, are variables. When the request runs, Ellipsend swaps each one for that contact's real details, so paste them exactly as they are. To add a different detail, click inside the box where it should go, click Insert variable just above the box, and pick it from the list. More on variables.

Subscribe to Klaviyo list adds the email to your list. Use Create · POST with https://a.klaviyo.com/api/profile-subscription-bulk-create-jobs, the same Klaviyo connection and revision header, and this JSON with your list ID in place of the placeholder:

Send a test request on each. The profile request answers 200 or 201. The list request answers 202, which means Klaviyo accepted it and finishes it a moment later. If your list uses double opt-in (Klaviyo's default), the contact gets a confirmation email and shows up on the list once they confirm.

One request sends to one list. Most people put every DM lead in the same list, so one request is all they need. If some automations should land contacts in a different list, save one request per list. Open Subscribe to Klaviyo list, click More, then Duplicate request. Rename the copy after the list, like Subscribe to Klaviyo list · Meal Plan, swap in that list's ID, and save.

Then pick the matching request in each automation. Save profile in Klaviyo stays the same for all of them. Your connection is shared, so you only enter your key once.

In your automation's DM steps, add Ask for Email, then Run API Request with Save profile in Klaviyo, then a second Run API Request with Subscribe to Klaviyo list, then your freebie message.