Segments
The basics
A segment is a named subset of the contacts in an audience. Mailchimp distinguishes three kinds of segment:
Static segments are also tags. When you tag a contact, Mailchimp creates or reuses a static segment behind the scenes. A static segment and a tag are the same underlying object, just reached through different features. See Contacts for tagging.
Segment conditions
A saved segment’s conditions are grouped under a match type, any or all,
which determines whether a contact needs to satisfy just one condition or
every condition to belong to the segment. Each condition targets a specific
kind of data—a merge field, a campaign interaction, a purchase, a location—and
each kind of data has its own condition shape, documented in
Alternative schemas.
The Marketing API supports regular segments only: a single match type applied across up to 10 conditions. The Mailchimp app also offers the advanced segment builder, which nests and/or logic across groups of conditions with no limit on count. Advanced segments aren’t available through the API yet.
Working with segments through the API
The Segments endpoints let you create, update, and delete segments, and read back which contacts currently belong to one with List members in segment. For a saved segment, that membership list reflects the conditions evaluated against your contacts right now, not a snapshot from when the segment was created.