Welcome new Stripe customers in MailForge and Slack

Build an agent workflow triggered by a Stripe webhook. Subscribe to customer.created and checkout.session.completed events so we catch the moment a new paying customer appears in Stripe.

When the webhook fires, the agent should:

1. Read the Stripe event payload and pull the customer's email, name, plan or product name, and amount paid (converted from Stripe's smallest currency unit into dollars). If the event is checkout.session.completed, expand line_items to get the plan. If it is customer.created, read the customer object directly.

2. Skip the event entirely if livemode is false in the Stripe payload. We never want test-mode charges to reach MailForge or Slack.

3. Dedupe on the customer email so a re-charge, plan change, or duplicate webhook does not spam Slack or re-add the person to the welcome list. Use a simple keyed idempotency check on customer email plus the customer.created or first paid checkout session.

4. Call MailForge Create or Update Contact to upsert the person by email. Carry over the plan name and any useful attributes (region, currency, amount) as custom fields on the contact, and tag with the plan tier so downstream segmentation works.

5. Call MailForge Add Contact to List to drop them into a dedicated "New Customers" onboarding list. The list should be configurable by the operator when they run the workflow; the welcome campaign is triggered by MailForge itself when a contact joins that list.

6. In parallel, use the Slack Bot Send a Message operation to post a short celebratory note to a #new-customers channel. Include the customer's name (or email if name is missing), the plan they bought, and the amount in dollars. Keep it one line, friendly, and use Slack mrkdwn formatting.

If any step fails, log the error and continue. A MailForge failure should never block the Slack celebration and vice versa.

Ask the operator at setup time for: the Slack channel to post to, the MailForge list id (or name) to add contacts to, and whether to include the dollar amount publicly in the Slack message.