Nexter Fields REST API Returns 403 Forbidden

A request to a Content Fields admin route comes back 403 Forbidden. That is the API behaving correctly — those routes are administrator-only.

What It Does

The routes that create and edit field groups, post types and taxonomies all require the manage_options capability. Reading field values is a different surface and uses the ordinary WordPress REST API.

Before You Start

• You are calling a content-types/v1 route.
• You know which user the request authenticates as.

Diagnose the 403

1. Check the user. Every Content Fields admin route requires manage_options. An editor or author gets 403 by design.

2. Check the request is authenticated at all. An unauthenticated request gets 401, not 403 — so a 403 means you are logged in as someone without the capability.

3. Check you want that surface. To read field values, query the post through /wp/v2/ and read its meta. That does not need administrator rights.

4. Check the nonce or application password if you are calling from a browser or an external tool.

Limitations

• This is not configurable. The admin routes are gated on manage_options deliberately, because they change the site’s data model.
• A 400 response with a missing-parameter code is not an authorisation problem — WordPress validates required parameters before it runs the permission check, so the 400 comes first.

Troubleshooting

My editor account gets 403

Correct behaviour. Field group management is administrator-only. Use an administrator account, or read values through /wp/v2/ instead.

I get 401, not 403

The request is not authenticated. Add an application password or a valid nonce.

Related Docs

• Content Fields and the WordPress REST API
• Why is my custom field empty?
• Create a field group in WordPress