Simon Willison: Client-Side Python Vulnerability Scanner Using OSV.dev Open CORS API
Simon Willison·low signal
Simon Willison built a client-side HTML tool (via Claude Code) that scans pyproject.toml or requirements.txt files against the OSV.dev open-source vulnerability database, which exposes a CORS-enabled JSON API allowing direct browser queries with zero backend. Users paste dependency files or enter a GitHub repo name and get severity classifications, affected version ranges, and disclosure links instantly. The tool demonstrates that useful security tooling can be zero-infrastructure — no server, no auth, no install.