GraphBLAS is wrapped by https://github.com/python-graphblas/python-graphblas/ and the algorithms are available at https://github.com/python-graphblas/graphblas-algorithms. NetworkX only dispatches the computation for a subset of algorithms to graphblas-algorithms right now.

If you want the graphblas API in python, https://github.com/python-graphblas/python-graphblas/ is the right place :)