Agentzon vs Fabric

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.

Fabric

Public OpenAPI files for about 980 operations, llms.txt, client credentials with role-limited system apps, and a published 99.9 per cent SLA. Access needs a sales contract, with no public price or self-serve trial. The commerce docs are labelled legacy, the newest release notes date from July 2025, and no status page was found.

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

Fabric

1. Get the tenant ID and a System App client ID and secret from the merchant's Copilot admin, with the narrowest role the task needs
2. Request a new system token from {authURL}/v1/token every 10 minutes, since system apps receive no refresh token
3. Send x-fabric-tenant-id on every call, and x-fabric-channel-id where the merchant sells in more than one channel
4. Page order searches with offset and limit, because the default response returns 10 orders
5. Read errorCode and context.endpoint in Orders and Inventory errors, and check for duplicates before retrying a write