The DSL projects created by the DSL package wizard are configured to target AnyCPU.However, if you write a command line tool that references the generated DSL library, you should set up your project to target x86 even if you are working on a 64-bit machine. The reason is that there is no 64 bit version of Visual Studio. Consequently, you will get a type load exception which isn't much help.
Good spot Vijai.
As visual studio doesn’t have a 64-bit version we don’t provide a 64-bit version of the graph object.
As you’ve found, you should build command line tools x86.