WPGraphQL: Custom Post Types query using SLUG as unique identifier returns no data

Question

I've created a Custom Post Type in WordPress named "projects" and now I'm trying to query a single project using the slug as an identifier. In other words, I want the idType to be the SLUG, not ID. I tried the following query but it does not work.

However, this query works (it's a common query that is using the ID) :

The query above is not what i'm looking for, but at least i know that my CPT is registered correctly and that my data can be fetched somehow.

Why I think this is a problem? Because I used the same type of query for querying WordPress posts (not custom posts types, just posts) and it works fine. I'm being returned the correct data.

Any help is appreciated ;) I don't know if i'm missing something with my query, or if custom post types don't work the same way that posts do.

WPGraphQL version: 1.3.10 Other WordPress plugins installed: Advanced Custom Fields, Custom Post Type UI

Answer 1

Set the idType to URI . Here's an example, querying a page (it's the same for other post types as well):

NOTE: the GraphiQL IDE has some nice auto-completions and drop-downs to show the available options:

My understanding is the idType:SLUG option is not available when your custom post type is hierarchical since the slug would not be a unique identifier at that point.