Thanks for this. I was maybe using one of these keys until this morning. When I logged in at dashboard.algolia.com and went to Settings -> API Keys, I found that none of the keys (Search, Analytics, Usage, Monitoring) matched the key I was using on a frontend. I made a decent attempt looking for that old key anywhere in their admin panels and could not find it. poof!
So perhaps at some point, they were only giving admin keys (because I don't remember there being a choice; and I would think given the choice I'd make the right one) and when called out (or sometime prior) realized the problem and made a new Settings -> API Keys page. Currently on the page the first one listed is the Search Key, with the subtext "This is the public API key which can be safely used in your frontend code. This key is usable for search queries and it's also able to list the indices you've got access to."
So perhaps at some point, they were only giving admin keys (because I don't remember there being a choice; and I would think given the choice I'd make the right one) and when called out (or sometime prior) realized the problem and made a new Settings -> API Keys page. Currently on the page the first one listed is the Search Key, with the subtext "This is the public API key which can be safely used in your frontend code. This key is usable for search queries and it's also able to list the indices you've got access to."