How to set sessionVariable using agenix

Help
1

When I run

$ echo $SOME

The output is
/nix/store/xxxxx-coreutils-9.1/bin/cat /run/agenix/something
Instead of the value I set in agenix, When I run cat myself in the terminal I get the expected value.

$ cat /run/agenix/something

home.sessionVariables.SOME = ''${pkgs.coreutils}/bin/cat ${config.age.secrets."something".path}'';


    age.secrets."something" = {
      file = ../../../secrets/something.age;
      owner = "myname";
      group = "users";
    };
2

Found it.

home.sessionVariables.SOME = ''$(${pkgs.coreutils}/bin/cat ${config.age.secrets."something".path}')';