[Please HELP] Invalid input on Endpoint /feeds/2021-06-30/documents

[Kinggrass]

Hello everyone,

hopefully someone could help me or having a clue.

I am sending following request to the Endpoint:

Short for Search Engine:

{
  "contentType": "text/xml; charset=UTF-8"
}

and getting back:

Short for Search Engine:

{"errors":[{"code":"400","message":"Invalid input","details":"Invalid input"}]}

I don't get what should be wrong. I have checked all credentials and again against the documentation.

I should get back a feedDocumentId and an url.

I am trying to follow this guide:

https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/use-case-guides/feeds-api-use-case-guide/feeds-api-use-case-guide_2021-06-30.md#step-1-create-a-feed-document

Retrieving Orders is working, for those who will question if anything else works.

[Kinggrass]

Figured it out myself.

I am trying to use the "Sandbox". Per definition a place where you can try things out and they will work as expected and are then deleted after a period of time without a impact on Production.

But the Sandbox is only expecting predefined input which makes it useless as a "Sandbox" and is more a Test-Mode if the endpoints are reachable rather than to try things out.

Expected input in the sandbox mode can be found in the swagger files:
https://github.com/amzn/selling-partner-api-models

[ml-deb]

Did you find a real sandbox environnent or only the mock api ? I'm afraid I'll have to test in production