v0.5.0 — E-commerce carts, promo rules and codes

This release adds write operations to the e-commerce surface area:
cart lifecycle management for abandoned-cart workflows, and full CRUD for
promo rules and promo codes for campaign-driven discount automation. The
server now exposes 112 tools (up from 97) and continues to ship with
read-only and dry-run safety modes.

Fully backwards-compatible — no existing tool signatures changed.

Highlights

Abandoned-cart workflows

Five new tools let you push cart state into Mailchimp from any external
storefront, then trigger Mailchimp-driven recovery emails.

# Push an in-progress cart from your storefront
create_store_cart(
    store_id="store_a",
    cart_id="cart_42",
    customer_id="cust_1",
    currency_code="EUR",
    order_total=49.99,
    checkout_url="https://shop.example/cart/cart_42",
    lines_json='''[
      {"id": "line_1", "product_id": "p_1", "quantity": 2, "price": 24.99}
    ]''',
)

# Delete it once the customer completes the purchase
delete_store_cart(store_id="store_a", cart_id="cart_42")

Full set: list_store_carts, get_store_cart, create_store_cart,
update_store_cart, delete_store_cart.

Discount automation: promo rules

Five new tools to define the discount mechanic. Rules cover fixed amounts,
percentages, or free shipping, targeting per-item, total, or shipping cost.

# Create a "20% off entire order" rule, scheduled for a campaign window
create_promo_rule(
    store_id="store_a",
    promo_rule_id="rule_summer",
    description="Summer Sale 20% off",
    amount=20,
    type="percentage",
    target="total",
    starts_at="2026-06-01T00:00:00Z",
    ends_at="2026-06-30T23:59:59Z",
)

# Pause without losing attached codes
update_promo_rule(store_id="store_a", promo_rule_id="rule_summer", enabled=False)

Full set: list_promo_rules, get_promo_rule, create_promo_rule,
update_promo_rule, delete_promo_rule.

Discount automation: promo codes

Five new tools to manage the codes customers redeem at checkout. Each code
attaches to a rule, with usage_count exposed for tracking.

# Attach a code to the rule
create_promo_code(
    store_id="store_a",
    promo_rule_id="rule_summer",
    promo_code_id="code_vip",
    code="VIP25",
    redemption_url="https://shop.example/checkout",
)

# Disable when the campaign ends, preserving usage history
update_promo_code(
    store_id="store_a",
    promo_rule_id="rule_summer",
    promo_code_id="code_vip",
    enabled=False,
)

Full set: list_promo_codes, get_promo_code, create_promo_code,
update_promo_code, delete_promo_code.

What's in this release

Added

• E-commerce cart CRUD (5 tools): list_store_carts, get_store_cart,
  create_store_cart, update_store_cart, delete_store_cart
• Promo rule CRUD (5 tools): list_promo_rules, get_promo_rule,
  create_promo_rule, update_promo_rule, delete_promo_rule
• Promo code CRUD (5 tools): list_promo_codes, get_promo_code,
  create_promo_code, update_promo_code, delete_promo_code
• 16 new smoke tests covering JSON parsing for cart line items, partial PATCH
  paths on every update tool, and the create/list/update/delete cycle for
  each entity

Changed

• Tool count bumped to 112 (was 97) across README.md, glama.json,
  and the pyproject.toml description
• Version bumped to 0.5.0

Scope note on #19

The original issue asked for "full CRUD for stores, orders, products,
variants, carts, promo rules/codes, customers". This release implements the
high-value subset (carts + promo rules + promo codes). Writes for stores,
customers, orders, products, and variants are intentionally deferred —
in 99% of Mailchimp setups that data is synced one-way from external
storefronts (Shopify, Woo) and write-back is rarely useful. Closes #19;
happy to reopen a follow-up issue if anyone has a specific use case for the
deferred writes.

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

All new write tools respect the existing safety modes:

• MAILCHIMP_READ_ONLY=true — blocks all writes (cart creation/updates/deletes,
  promo rule and code mutations)
• 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/v0.4.0...v0.5.0