FOSRestBundle provides various tools to rapidly develop RESTful APIs in Symfony applications. EasyAdmin doesn't integrate with FOSRestBundle features in any way, but there are some options that you may need to configure to avoid errors in backend URLs.
This listener provided by FOSRestBundle determines the best format for the request based on the HTTP Accept header included in the request and some format priority configuration.
If you have enabled this format listener, disable it for the backend routes:
# app/config/config.yml
fos_rest:
format_listener:
enabled: true
rules:
# ... previous rules declarations
- { path: '^/admin', stop: true } # <-- add this line
When using FOSRestBundle 2.0, you may also need to configure the "zones" as explained in this chapter of the FOSRestBundle documentation.