What does the routing service need from you?

Give it positions for the start and end and choose a travel mode such as walking or driving. A written address needs a lookup first. To show the route line inside your app, add a map display and decide where the background tiles come from.

What changes if you run the route engine yourself?

For hosted directions, use the current api.heigit.org host. A HeiGIT Account comes with a free Standard key. Check the remaining Directions quota for your key in the HeiGIT dashboard. Other operations have their own limits.

You can run the open-source route engine yourself. Budget for server resources and map data updates. Check what separate service you need for address lookup or map tiles.

Keep a private key on your app’s server. Only expose a key in the browser if the service explicitly intends that key for public use.

Can you treat the returned route as your own map data?

Keep the start, destination and entrance notes you collected. The hosted service has its own attribution and reuse terms. Check those and the map-data license before storing or redistributing a result. Running the engine yourself still leaves you responsible for the data you use.

How would you check whether a walking route answers the right question?

Draw a fictional park with an entrance on each side. Use no real address, key or request.

Mark the entrance
Choose where a visitor should actually arrive, such as a footpath gate.
Set the travel mode
Write walking beside the route and mark where a road-only route would make a wrong turn.
Plan an alternate answer
Keep written entrance directions available if no useful route is returned.