API capability pack for bounded Mailchimp Marketing API 3.0 operations. The default egress base is https://us1.api.mailchimp.com/3.0; enroll a Mailchimp connection named mailchimp with HTTP Basic auth using the API key as the password, and set the connection base_url to the account data-center host such as https://us21.api.mailchimp.com/3.0 when it is not us1. Reads account health, audiences, members, tags, notes, segments, merge fields, campaigns, campaign content, send checklists, campaign feedback, reports, templates, automations, and ecommerce store/customer/order/product metadata. Bundles a scheduled audience health digest, an AI-assisted campaign performance brief, and an approval-gated campaign draft workflow. Writes are approval-gated and limited to one audience, member, tag update, event, note, segment, merge field, campaign draft/content/feedback, template, ecommerce store, ecommerce customer, or ecommerce product at a time. Subscriber detail/tag/note routes use Mailchimp's documented subscriber_hash value, the MD5 hash of the lowercase email address. The pack intentionally excludes arbitrary API passthrough, batch operations, campaign send/schedule/cancel/pause/resume, SMS sends, automation start/pause/archive, destructive deletes including permanent subscriber deletion, webhook mutation, OAuth token exchange, file uploads, and admin/billing operations.