Onboard new Stripe paid customers into beehiiv with a Slack welcome draft

Build me an agent workflow that onboards new paid Stripe customers into beehiiv and drafts a personalized founder welcome for our customer success team to review in Slack.

Trigger: a Stripe webhook. Use customer.subscription.created for recurring plans, or checkout.session.completed if I mainly sell one-time paid access. Let me pick which one at setup. From the event, pull the customer's email, name if available, and the Stripe price or product ID they bought.

Step 1. Check if this email already exists in beehiiv using Get Subscription by Email. If they are already an active subscriber, skip the add and post a short 'already a subscriber, no action taken' note in the Slack channel below, then stop.

Step 2. Map the Stripe price or product to a beehiiv premium tier. I will maintain the mapping as a simple lookup (Stripe price ID or product name to beehiiv tier ID or name). If no mapping matches, do not silently default to a free or catch-all tier. Instead, post a clearly labeled mapping-failure alert in Slack that includes the customer email, the Stripe price or product, and a nudge to update the mapping, then stop.

Step 3. Call beehiiv Create Subscription to add the customer to the publication on the matched premium tier. Set utm_source to 'stripe' and include a custom field with the human-readable plan name so we can segment on it later. Include their name if we captured one.

Step 4. Call beehiiv Add Subscription to Automation to enroll them in our existing 'Paid Welcome' journey. That automation already has an active Add by API trigger, so just reference it by ID or name.

Step 5. Draft a short personalized welcome note, roughly three to five sentences, written in a warm founder voice. It should thank them by first name if we have it, name the specific plan they picked, and suggest one concrete thing they can do in their first 24 hours that is relevant to that plan. Keep it human, no marketing fluff, no emoji spam.

Step 6. Post the draft into our customer success Slack channel (I will provide the channel at setup) using slackbot Send a Message. Format it so a human on the CS team can copy, tweak, and DM it themselves. Include the customer's email and the plan they bought above the draft so it is obvious who this is for.

Guardrails: never send the welcome directly to the customer, only draft it into Slack. Never silently default the tier if the mapping fails. Do not re-enroll people who are already subscribed. Log clearly at each step so I can trace what happened for any given Stripe event.