Why it happens
A large asset served on every page, a function called in a loop or hammered by a crawler, an image optimiser with no limits, or a bot on one endpoint.
How to tell
- The host's usage panel: one metric out of line with the others.
- Access logs: one path, or one client, dominating.
- A recent publish that added an asset or an endpoint.
The fix
- Find the top path by requests and by bytes in the host's analytics.
- Cache what can be cached, rate-limit the endpoint, block the obvious bots.
- Set a spend limit or an alert at the host.
The prompt for your builder
Paste this into Lovable, Bolt, Cursor, Claude Code or whatever built the app. Replace anything in capitals. It never asks you to paste a secret into a chat; keys go into your host’s environment, by you.
Prompt for your builder
Review my app for the usual hosting cost traps: uncached API routes, images not going through the optimiser with size limits, large files served from the app rather than a CDN, and public endpoints without rate limiting. Fix the top three and add a rate limit to every public endpoint.
How Keelnest catches it
Cost Guard reads host usage where the host exposes it and holds it against the budget you set for each app.
Know the moment this happens.
Keelnest watches your production app every five minutes and tells you in plain English what broke — with the fix. Free for your first app.