I have a bunch of links to google maps in the form of https://maps.google.com/?cid=<identifier>.
How can you go from that CID to a Place ID that can be used with the Google Places API? Is there any API endpoint that you can use to convert these URLs into the new places?
Got lucky and found an undocumented api. If you have the CID, you can call the api like https://maps.googleapis.com/maps/api/place/details/json?cid=${CID}&key=YOUR_API_KEY.
I just changed place_id=${the_end_val_i_needed} to cid=${CID} and in the json response is the place_id.