Right now if your "API credit remaining" is $0 (or lower than the cost of a single API request) and you make a search request of the API, I believe API clients receive an HTTP 400 (Bad Request) response.
It might be slightly more informative if clients would receive an HTTP 402 (Payment Required) response instead.
PS - The "This suggestion concerns" field options are "Desktop", "Mobile" and "Both Desktop and Mobile". This suggestion actually concerns neither Desktop, nor Mobile, so 🤷
This would give products who integrate Kagi API search like Open WebUI the ability to show a more actionable error message to their users.
Today in Open WebUI if you run out of Kagi balance, you see a generic "400 Bad Request" error in the UI with a block of JSON, which is cool for computers, but not as cool for humans.
After changing to 402, Open WebUI could handle that case explicitly and tell the user exactly what's going wrong, even translated into their respective display language.
