There is currently not really such a thing as a Nutils adapter. Coupling Nutils is so simple that directly calling the preCICE Python API from the application scripts is the way to go.
The best way to learn how to couple a Nutils application script is to look at some examples:
- Two heat conduction scripts coupled to one another
- A heat conduction script coupled to CFD for conjugate heat transfer
- An ALE incompressible Navier-Stokes solver coupled to solid mechanics for fluid-structure interaction
- A fracture mechanics solver volume-coupled to a dummy electro-chemistry corrosion model
- A 1D compressible fluid solver coupled to a 3D compressible fluid solver (uses deprecated version of Python bindings)