Add to an audience in Mailchimp when a new order comes in to Shopify

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.

• 

  Only for a store that already has an admin-created custom app. In the client’s Shopify admin: Apps → Develop apps → the app: its Admin API scopes must include write_customers and read_orders; the token is under API credentials (shown once when it is made; if it is no longer shown, generate a new one).

• 

  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 Shopify, for “A new order comes in”
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)