v0.3.0 — A/B campaigns, audience lifecycle, advanced reports

This release closes three highly-requested gaps in the Mailchimp Marketing API
coverage: A/B testing, full audience CRUD, and post-send report analytics. The
server now exposes 87 tools (up from 82) and continues to ship with
read-only and dry-run safety modes.

Fully backwards-compatible — existing tool signatures are unchanged.

Highlights

A/B (variate) campaigns

create_campaign now accepts a campaign_type argument (defaults to
"regular") and a variate_settings_json payload describing the test.
Mailchimp will send each variant to a sample of recipients, then auto-pick a
winner based on your criteria and send it to the remaining audience.

Example:

create_campaign(
    list_id="abc123",
    subject_line="Spring Sale 20% off",
    campaign_type="variate",
    variate_settings_json='''{
      "winner_criteria": "opens",
      "test_size": 20,
      "wait_time": 1440,
      "subject_lines": [
        "Spring Sale 20% off",
        "Last chance: 20% off Spring"
      ]
    }'''
)

Subject lines, from-names, reply-to addresses, send times, and HTML contents
can all be A/B-tested via the same payload (2 to 8 variants each).

Audience lifecycle (create + delete)

Two new tools fill the most-asked-for gap in audience management:

• create_audience — full list creation with contact info, campaign defaults,
  and CAN-SPAM permission reminder
• delete_audience — permanent removal with the standard read-only / dry-run
  guards in front of it

Advanced report tools

Three new read-only report endpoints, useful for client-facing audits and
deeper post-send analysis:

• get_campaign_advice — surfaces Mailchimp's automated feedback on a sent
  campaign (open-rate diagnosis, content suggestions, etc.)
• get_campaign_locations — geographic breakdown of opens by country and
  region, great for region-targeted follow-ups
• get_eepurl_activity — social sharing stats (Twitter / Facebook / referrers)
  from Mailchimp's short-URL share link

What's in this release

Added

• create_audience, delete_audience (closes #9)
• get_campaign_advice, get_campaign_locations, get_eepurl_activity
  (closes #13)
• create_campaign extended with campaign_type and variate_settings_json
  for A/B testing support (closes #7)
• 10 new tests covering the additions, including the variate failure paths
  (missing settings, malformed JSON)

Changed

• Tool count bumped to 87 across README.md, glama.json, and the
  pyproject.toml description
• Version bumped to 0.3.0

Internal

• PyPI publishing now runs through GitHub Actions via PyPI Trusted Publishers
  (OIDC) — no static tokens required

Install

Recommended (no install):

uvx mailchimp-mcp

Via pip:

pip install --upgrade mailchimp-mcp

Configure your MCP client to launch uvx mailchimp-mcp with
MAILCHIMP_API_KEY in the environment. See the
README for the
full configuration block.

Safety modes

Both new write tools (create_audience, delete_audience) respect the
existing safety modes:

• MAILCHIMP_READ_ONLY=true — blocks all writes
• MAILCHIMP_DRY_RUN=true — returns a preview of the action without calling
  the API

Feedback

Bug reports, feature requests, and PRs are welcome — see
CONTRIBUTING.md.

Full Changelog: https://github.com/damientilman/mailchimp-mcp-server/compare/v0.2.0...v0.3.0