I Spy AI detects AI images via classical CV and MCP

I Spy AI is an AI-generated image detector created by shawhunterm, who has been building it full-time since February 5 after being laid off. The tool is intentionally built without any ML model or GPU dependency — detection runs on a FastAPI backend using pure OpenCV, targeting the visual artifacts that diffusion models characteristically leave behind. The author explicitly tested Gemini for this purpose and found it could not accurately identify images it had just generated, which reinforced the decision to rely on classical computer vision instead.

The Next.js frontend handles authentication, billing through Dodo Payments, and proxies images as raw binary to minimize latency, with async polling on the client side.

The service is accessible in two ways: through a web dashboard where users can upload images directly, or programmatically via any MCP client (Claude Desktop, Cursor, and others) using the `analyze_image` tool. The Next.js frontend handles authentication, billing through Dodo Payments, and proxies images as raw binary to minimize latency, with async polling on the client side. The project was inspired by the r/isthisai community, where the author observed users spending significant effort debating image authenticity, while existing detection tools were either locked behind enterprise sales processes or relied on opaque black-box classifiers. A stated design goal was to make the tool accessible to both regular users and LLM agents without data mining.

Key facts

1. 01Built by shawhunterm, who has been working on it full-time since February 5 after being laid off.
2. 02Detection uses pure OpenCV and classical computer vision — no ML model and no GPU required.
3. 03Exposes an `analyze_image` tool via an MCP server, compatible with Claude Desktop, Cursor, and other MCP clients.
4. 04Backend is FastAPI; frontend is Next.js with async polling and billing via Dodo Payments.
5. 05Images are proxied as raw binary to keep latency low.
6. 06The author tested Gemini and found it could not reliably identify images it had itself generated, motivating the ML-free approach.
7. 07Inspired by r/isthisai, where users debate image authenticity, and by the lack of accessible, non-enterprise detection tools.

Topics