How to flatten parameters by using proc macro?

[wakuflair]

Hi, I have an API defined by proc macro like this:

#[method(name = "foo")]
async fn foo(&self, parameter: FooParameter) -> Result<(), ErrorObjectOwned>;

Using a struct FooParameter because there are many parameters and I think it's a best practice for grouping parameters.

But now the client has to have one more level to construct the parameter:

var payload = {
      jsonrpc: "2.0",
      method: "foo",
      params:  {
        parameter: {
          name: "bob",
          age: 40,
        },
      id: 1,
    }
  }

So is there a way to flatten the struct parameter when using proc macro to allow the client use like this:

var payload = {
  jsonrpc: "2.0",
  method: "foo",
  params: {
    name: "bob",
    age: 40,
  },
  id: 1,
};