Hi - I answer from the OpenSmartRoute documentation: routing, the API, plans and quotas, self-hosting. Ask away, or open a support ticket if you need a person.
Grounded in the docs - follow a source before acting on it.
unpaywall - Tool - OpenSmartRoute
Toolv1.0.1
unpaywall
Open-access availability for 120M+ scholarly articles via the Unpaywall API