
Toronto (CA) City Open Data.
City, Toronto Open Data API is a free Government API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Details from open.toronto.ca.

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Colorado State Government Open Data
The City, Toronto Open Data API is provided by City of Toronto Open Data Portal (open.toronto.ca).
Yes. The City, Toronto Open Data API is listed in the Government 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.
No. The City, Toronto Open Data API requires no authentication, so you can start making requests without signing up.
Yes. The City, Toronto Open Data API supports CORS, so front-end JavaScript can call it directly.
Yes. The City, Toronto Open Data API is served over HTTPS, so it's safe to use in production.