# Follow Up With Waitlist Signups and Abandoned Carts on Email, LinkedIn and X | PumpGTM

Canonical URL: https://pumpgtm.com/plays/inbound-signups

# Your waitlist signed up. Now say hi like a person.

Waitlist signups, new accounts and abandoned checkouts usually get one automated email. Send each one to a PumpGTM play with one API call, and they get a welcome from you on email, LinkedIn and X.

[Create a signups play](https://app.pumpgtm.com/plays/new?story=webhook-signups)

Works with your own backend, HubSpot forms, or any tool that can send a webhook.

## Example: Alex joins your waitlist

“Thanks for joining. What’s the first thing you want to use it for?”

Connection request from your profile, then a short note once Alex accepts.

A follow or DM from your X account.

Alex replies on LinkedIn. The other follow-ups stop.

## The people who already raised their hand

Someone joins the waitlist, creates an account and never comes back, or leaves at checkout. They told you they were interested. A founder’s message on LinkedIn gets read when the tenth welcome email does not.

## 1. Create the play

In Plays, choose “Webhook signups” (or “HubSpot form signups”). Name it for the source, like “Waitlist” or “Abandoned checkout”, and link a sequence with your email, LinkedIn and X steps.

## 2. Send one API call

When someone signs up or abandons checkout, your backend posts their name and email, plus a LinkedIn URL or X handle if you have one. The play’s setup page shows the exact URL.

## 3. Review, then go automatic

New people land in the play for you to approve. Once the messages look right, turn on auto-add and every new signup enters the sequence by itself.

## The whole integration

Use your workspace API key from your server, never the browser. dryRun: true checks the request without saving anything, so you can test before a single message goes out. Reuse the same eventId on retries and nobody gets contacted twice.

Email works from the email alone. LinkedIn and X steps need the profile URL or handle in the request. Full field list in the [API docs](/docs/api).

POST https://app.pumpgtm.com/api/v1/plays/PLAY_ID/webhook
Authorization: Bearer YOUR_WORKSPACE_API_KEY
Content-Type: application/json

{
"eventId": "waitlist:signup_123",
"expectedRevision": 1,
"name": "Alex Smith",
"email": "alex@example.com",
"linkedinUrl": "https://www.linkedin.com/in/alexsmith",
"xUsername": "alexsmith",
"dryRun": true
}

## Welcome your next signup yourself

Set it up once. Every new signup gets a message from you on the channels they actually read.

[Create a signups play](https://app.pumpgtm.com/plays/new?story=webhook-signups)