You can already do this easily by implementing the SerializerContextBuilderInterface: https://api-platform.com/docs/core/serialization/#changing-the-serialization-context-dynamically

Also, please note that using request attributes will not work when using GraphQL (because a single HTTP request can contain many GraphQL request).

Can you tell us a bit more about your use case?

I didn't like your "way". Now I'm trying to make interceptors.
api-platform/core#3624

Then I can make a group just like that (by Intercepting the request)

$user = $this->security->getUser();
if ($user and ($this->security->isGranted('ROLE_ADMIN'))) {
    // $key '_api_normalization_context' or  '_api_serializer_context'
    $context = $request->attributes->get($key);
    if (!$context) {
        $context = [];
    }
    $context['groups'][] = 'admin';
    $context['groups'] = array_unique($context['groups']);
    $request->attributes->set($key, $context);
}

You can do it as easily by doing as in the example I provided isn't it? That being said I'm not against supporting such attribute (especially because it will be a very tiny patch to support it).

I don't understand well how it works. I did an ugly hack on my fork.
https://github.com/tebaly/core/blob/95d4b1cc9b57bd1debcea7387c2af6efdee6cf28/src/Serializer/SerializerContextBuilder.php#L60

If you do it right. And it will work as well. I will grateful to you.

I'm not sure. Combining REST and GraphQL will end well. I think they are too different to combine. One will limit the other. Undoubtedly.

• api-rest (rest-platform)
• api-graphql (graphql-platform)

It is possible to leave common components as a dependency for both (api-core or something else).