AI features and surprise bills in AI-built apps

43% of the apps call an AI model (Anthropic and OpenAI most often). Every such endpoint costs money per call, so an open one is a bill anyone can run up.

441

apps call an AI model themselves

43%

of them had a high or critical problem

6%

had an AI or email feature anyone could use on the owner's bill

Most common problems in apps with AI features

Share of apps that call an AI model.

Most common problems in apps with AI features
ProblemShare of apps
Packages with a known security flaw38%
Raw HTML from users put on the page9%
User input built into SQL (Python)9%
No limit on how often an endpoint can be called7%
API route with no login check6%
User input reaches a shell command (Python)6%
AI endpoint anyone can call5%

What protects an AI feature

Most apps had some of these; few had all four. The spending limit is the cheapest and catches everything the others miss.

  • A signed-in user behind every call
  • A limit per user and per IP address
  • A cap on input length and on output tokens
  • A spending limit in the provider's console

Data: Redproof's automated checks on public GitHub repositories, November 2026. No repository is named. Method and limits