Data about buses routes, parking and traffic.
Transport for Lisbon, Portugal API is a free Transportation API that requires apiKey authentication, is served over HTTPS and has unconfirmed CORS support.

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Data about positions of Metro vehicles in real time and travel their routes
Yes. The Transport for Lisbon, Portugal API is listed in the Transportation category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Transport for Lisbon, Portugal API uses apiKey authentication, so you need to register for credentials before making requests.
CORS support for the Transport for Lisbon, Portugal API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Transport for Lisbon, Portugal API is served over HTTPS, so it's safe to use in production.