Monday
Programmatically access and update data inside a monday.com account

Integrate with Notion.
Notion API is a free Documents & Productivity API that requires OAuth authentication, is served over HTTPS and has unconfirmed CORS support.
Discover what Notion connections are, when to use each type, and what you can build.
Details from developers.notion.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
The Notion API is provided by Notion Docs (developers.notion.com). Discover what Notion connections are, when to use each type, and what you can build.
Yes. The Notion API is listed in the Documents & Productivity 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 Notion API uses OAuth authentication, so you need to register for credentials before making requests.
CORS support for the Notion API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Notion API is served over HTTPS, so it's safe to use in production.