Add to an audience in Mailchimp when a customer pays (checkout or payment link) in Stripe

What each client fills in

Mailchimp: Audience ID

For example Audience → Settings → Audience name and defaults

The accounts it needs

Each is the client’s own, stored encrypted and never copied between clients. Until one is added the client’s checklist shows it, and nothing runs.

• 

  In the client’s Stripe dashboard: Developers → API keys → Create restricted key. Give it only what the steps need: Customers write, Payment Links write, Prices read, Invoices write, and Webhook Endpoints write for the triggers. Leave “IP access” empty: Thrum has no fixed addresses, so a key locked to IPs fails every call.

• 

  In the client’s Mailchimp: Profile → Extras → API keys → Create A Key. The server prefix is the part after the dash (us21).

After you install it

It lands switched off. The client’s checklist holds exactly this:

1. Connect the client’s Stripe, for “A customer pays (checkout or payment link)”
2. Connect the client’s Mailchimp, for “Add to an audience”
3. Fill in Mailchimp: Audience ID (For example Audience → Settings → Audience name and defaults)