Can I annotate model classes so they are automatically included in a source-generated JsonSerializerContext?

[tsctsc6]

Hi, I am using .NET (AOT) with the System.Text.Json source generator.
Right now, to enable static reflection (source-generated serialization), I have to manually list every DTO/model type inside a custom JsonSerializerContext, for example:

[JsonSerializable(typeof(UserDto))]
[JsonSerializable(typeof(ProductDto))]
[JsonSerializable(typeof(OrderDto))]
public partial class MyJsonSerializerContext : JsonSerializerContext;

This becomes hard to maintain as the number of models grows, because I have to write all DTO/model at the same place while all DTO/model distributed in various files.

Is there a way to annotate each model class directly so that the generator automatically adds it to my MyJsonSerializerContext? For example something like:

[JsonIncludeInContext(typeof(MyJsonSerializerContext))]
public class UserDto
{
}

And then the source generator would automatically include it in the specified context.

The ways I thought of

Method 1

Declare partial class MyJsonSerializerContext at in various files:

[JsonSerializable(typeof(OrderDto))]
public partial class MyJsonSerializerContext : JsonSerializerContext;

[JsonSerializable(typeof(ProductDto))]
public partial class MyJsonSerializerContext : JsonSerializerContext;

However, it does not work, I got some compiler errors:

• "MyJsonSerializerContext" is not include "Default".
• "MyJsonSerializerContext" is not impl "GetTypeInfo".
• "AppJsonSerializerContext" is not impl "JsonSerializerContext.GeneratedSerializerOptions.get".
• The required parameter "options" for "JsonSerializerContext.JsonSerializerContext(JsonSerializerOptions?)" was not provided.

Method 2

One class corresponds to one JsonSerializerContext.

However, I still have to regester all JsonSerializerContexts, the situation has not changed substantially.

What I am looking for

• A built-in attribute that works like JsonIncludeInContext mentioned above
  OR
• A code pattern that declare the DTO/model's JsonSerializerContext in the distributed file with the same JsonSerializerContext
  OR
• Confirmation that this is currently impossible by design

Environment

• .NET 10

Thanks!