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AMZScratchpad

InvalidClient (UnauthorizedException): Amazon Creators API error

HTTP 401UnauthorizedExceptionAuthentication (401)Documented by Amazon

What it means

The token was issued for a different Credential ID than this request expects.

Message returned by the API: The client identifier does not match the expected value.

Typical causes

  • Token fetched with one credential, request made for an application that expects another.
  • Mixed up credentials when several applications exist.

How to fix it

  1. Fetch the token with the same Credential ID you intend to use.
  2. Clear token caches when you switch credentials.

Not sure which part fails? Run Test credentials in the Scratchpad. It checks the token, the API access and the partner tag separately.

Example response

{
  "type": "UnauthorizedException",
  "message": "The client identifier does not match the expected value.",
  "reason": "InvalidClient"
}

Related errors

  • invalid_client: Amazon’s token endpoint rejected your Credential ID or Secret, so no access token was issued.
  • UnsupportedClient: The Credential ID behind the token is not registered for the Creators API.