Amazon Creators API vs opencommerce

Amazon Creators API

Read-only product search and lookup across 22 Amazon stores, with field selection, typed error reasons and documented rate limits. It cannot place or follow orders, so a person buys through the affiliate link. Access needs an accepted Associates account with 10 qualifying sales in 30 days, and the Agent Terms require agents to identify themselves.

opencommerce

One strictly typed buy tool covers search, cart, checkout and order updates, and every payment not covered by an auto-approval rule waits for the shopper's passkey. The tool's description runs to about 14.5 KB, the purchase API under it is undocumented, the monitoring page reports test passes rather than uptime, and the CLI says sign-ups are by invitation.

Amazon Creators API

1. Send x-marketplace as a header and marketplace and partnerTag in the body on every call
2. Cache the access token for its 3,600 seconds and share it across processes
3. Request only the resources the task needs, and use offersV2 for prices, because the older price resource is gone
4. Set the user agent to Agent/<name> as the Associates Agent Terms require
5. Hand purchases to the person through the returned detailPageURL without editing its parameters

opencommerce

1. Call buy with the shopper's words in ask, and set confirm true only after the shopper says yes to the cart you showed
2. After a timeout, unreachable or invalid_answer error, read the conversation before sending the turn again, since the order may have gone through
3. Show the cart's max_charge beside its total, because the approval holds up to that amount
4. Use sandbox credentials for tests. init writes production credentials by default, and they place real orders
5. Check a store with GET /buy/merchants before sending a shopper there, and suggest another store when it is held_back or supported is false