Question: Drawing a Tour like swisstopo app

[rbotteon]

Hello all,

i would like the implement the tour drawing feature with the snap on route exactly like in swisstopo app.
i tried with the services Open Route Service and OSRM API , it works but the precision is a lot lower than the one in swisstopo app.

It's possible to do it with lib-open-swiss-maps-sdk or with GeoAdmin API’ ?
Otherwise, any suggestions?

Thank you in advance and sorry in case I overlooked the documentation.
rb