LWA on Amazon.co.jp always shows login

Fire Devices & Appstore Q&A
1

We’re integrating LWA for a web app serving users in Japan.

Even when the customer is already signed in at amazon.co.jp, invoking LWA always sends them to the Amazon login page instead of reusing the existing session / showing the consent screen.

Endpoints used

  • Auth: https://www.amazon.co.jp/ap/oa

  • Token URL: https://api.amazon.co.jp/auth/o2/token

Steps to reproduce

Result: Amazon shows the login prompt (email/password) again instead of reusing the co.jp session.

Expected: If a valid Amazon.co.jp session exists, LWA should reuse it and either (a) show the consent screen or (b) silently succeed, then redirect with an auth code.

Questions

  1. Is session reuse from amazon.co.jp to apac.account.amazon.com expected to work, or is a fresh login normal due to cookie/domain separation?

  2. Are there additional settings needed for co.jp to avoid the login prompt?

3

Hi @Ishara ,

Thanks for posting. We have messaged the appropriate team for further investigation and will let you know once we receive an update.

4

Hi,

This behavior is expected.

Amazon.co.jp and Amazon.com have separate user pools, so signing in to Amazon.co.jp does not automatically sign you in to Amazon.com.

Since https://www.amazon.com/ap/oa is on the .com domain, it will use the existing session if the user is already signed in to Amazon.com and therefore skip the sign-in page.

Similarly, www.amazon.co.jp/ap/oa or lwa.amazon.co.jp will use the session from Amazon.co.jp.

Login With Amazon(LWA) operates on regional authorization domains rather than per-marketplace domains:

  • NA marketplaces (amazon.com) → na.account.amazon.com
  • EU marketplaces (amazon.co.uk, amazon.de, etc.) → eu.account.amazon.com
  • FE marketplaces (amazon.co.jp, amazon.com.au, etc.) → apac.account.amazon.com

For example, a user signed in on www.amazon.co.uk would still be prompted to sign in when hitting the LWA flow on eu.account.amazon.com. Similarly, a user signed in on www.amazon.co.jp will be prompted on apac.account.amazon.com. Since these are different domains, retail session cookies do not carry over to the LWA authorization flow.

5

Hi @Emma,
As I mentioned in original post I’m using https://www.amazon.co.jp/ap/oa as the auth URL NOT the Amazon.com.

Why it’s still not skipping the login page?
Can LWA skip logging again if user already logged in to amazon .co.jp?

Thanks,
Ishara