Agentzon vs Medusa API + MCP

Agentzon

Public OpenAPI 3.1 description and llms.txt, with a whole-basket checkout that needs no account or key. The buyer pays on a private page, so a person completes each purchase. No status page, security.txt or registered seller address was found on agentzon.co, and 34 of 500 listed items cannot be bought.

Medusa API + MCP

MIT core you can self-host, with Medusa Cloud running the same APIs and no GMV fee. The official MCP server is docs-only and limited to Cloud accounts.

Agentzon

1. Search with GET /api/products. Use only items with checkoutAvailable true and a non-null unitAmount, because a null price means unavailable, never free
2. Send every item and quantity in one POST /api/checkout, with a new Idempotency-Key for each purchase attempt and the same key only to retry that basket
3. Show the buyer the product image from /api/products/{id}/image and get their approval before opening the checkout URL
4. Tell the buyer that catalogue prices exclude sales tax, that shipping is U.S. only and that change-of-mind returns exclude hygiene and food items
5. Keep the checkout URL and the orderToken private. A paid status confirms payment, not shipment

Medusa API + MCP

1. Send x-publishable-api-key on every /store call. It decides which sales channels and products the agent sees
2. Ask for only the fields you need with fields. Store routes reject relations nested more than three deep since 2.20.0
3. Read the store's regions before creating a cart, since prices and shipping options depend on region
4. Place the order with POST /store/carts/{id}/complete after shipping and payment sessions are set
5. Read the release notes before upgrading a minor version. Breaking changes land there