Update a subscriber in Mailchimp when someone books a meeting in Calendly

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.

• Calendly

  In the client’s Calendly: Integrations & apps → API and webhooks → Personal access tokens → Generate new token, with the scopes scheduling_links:write (booking links) and, for the triggers, users:read, webhooks:read and webhooks:write. A token made before Calendly introduced scopes keeps full access.

• 

  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 Calendly, for “Someone books a meeting”
2. Connect the client’s Mailchimp, for “Update a subscriber”
3. Fill in Mailchimp: Audience ID (For example Audience → Settings → Audience name and defaults)
4. Confirm with the client: The client’s Calendly is on a paid plan (Standard, Teams or Enterprise): Calendly sends webhook events only on those.