There’s an existing non-WP site, and I need their users to be able to log in on my new Wordpress site with the same credentials they already have.

I have been provided with an endpoint (www.example-api.com/token) and login creds (email and password) which gives out a token (and other details) as the response.

I have been reading on OAuth and most of what I get are resources from problems that are other way around (as in login on a non-WP site using their creds on the WP site). I don’t have access to the other site and I see it needs setting up there so, shall I cross this out?

I’ve stumbled upon overriding the wp_authenticate via a custom plugin, which I’ve already set up but I’m stumped as to what and HOW to even do this.

Any guide or boost for this?

  • There is absolutely no feasible way I currently see without a door from the non-WP site to this effect. Otherwise: where do you have to confirm the credentials submitted by users from the non-WP site on your site are truly correct and corresponds to a given user? Hope you understand! Commented May 31, 2017 at 11:17
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    I think I didn't made myself clear enough – I had access to an endpoint and also some test data for the email address and password of the accounts I need. I did it though, I'll post it. Thank you for your help! :)
    – Suika
    Commented Jun 5, 2017 at 9:58

1 Answer 1


Update: Made a blog post to explain this better :)

I was able to do this by WP's authenticate filter inside a new plugin; most of which is guided by this tutorial by Ben Lobaugh. Major points on the plugin:

  • Make an API call function using cURL (you can get guide codes from Postman upon testing if you don't know already).
  • Add filter checking if the response from the call says the user is existent and has access (based on user role in my case).
  • Still using the filter, check if the user already has an account on the WP site – if not, create one for them using wp_insert_user. For clarification, I used the email and password verified by the API because WP requires a registered user on its database.
  • If the user already exists on the WP database, make sure their credentials are the same using wp_update_user. These are for cases like when they changed their details on the main non-WP website.
  • Optionally, add a settings page for the plugin. In my case, I created a field for the Request URL by following this tutorial by Bharat Pareek.
  • so you have implemented a sort of SSO which is really the only way to go about it. But the "if user do not exists create an account" sound very wrong. Any brute force attack with some scale might bring your wordpress down Commented Jun 6, 2017 at 2:49
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    Can you explain it further? I was under the impression that I had to create them a local Wordpress user since the guide I followed (first link) specifically said "WordPress requires that a real user (WordPress user) be present in the WordPress database in order to perform operations on that user." I create a new user only if the response says so, and registering them also using their email and password from the API.
    – Suika
    Commented Jun 6, 2017 at 3:00
  • maybe it is just something in your description, or my misunderstanding, but it sounds like you create a user per each "check" request. Commented Jun 6, 2017 at 4:43
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    I see. Yes, it's probably the wording. I'll edit it to make it clearer. Thank you!
    – Suika
    Commented Jun 6, 2017 at 6:06
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    The blog link is returning a 404
    – M.Babcock
    Commented Jan 24, 2019 at 22:59

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