We've looked into WeChat beffore, though I'll admit it was more than a year ago. It looks like they've improved their API documentation and made website authentication simpler to implement. It's something we'll have to look into again, but from what I see, it seems to use most of the standards we require, which would make it not overly difficult to add. You linked to their mobile apps integration guide. I'm adding a link below for our reference to their website integration guide:
open.wechat.com/cgi-bin/newreadtemplate?...in/login#login_login
On the website side, it seems like the user:
* Clicks login
* Is redirected to a page with a QR code
* Uses the WeChat app on their phone to scan the code
* The user grants any permissions required
* User is redirected back to your site
The QR code thing is new for us.. and no one on our side has used WeChat before. As long as we can get it to test with (in the US), it seems possible. If anything above seems out of the ordinary from ways you've used WeChat to login, please let us know.
I'm adding this to our to-do list. I can't guarantee when this would be implemented, but this is a start.
Thanks,
Alex