Catch MCP Tool-Poisoning and Prompt-Injection Regressions on Every PR (GitHub Actions + pre-commit)

A working walkthrough of wiring sentinel-scan-cli into GitHub Actions and pre-commit as a CI gate that actually fails the build, including a gap I found in the CLI itself and the fix for it. All command output below is from real local runs, not fabricated.

We maintain sentinel-scan-cli, a free, zero-dependency scanner: a 15-attack prompt-injection suite against your own LLM endpoint, and a static MCP manifest scanner for tool poisoning and excessive agency, both mapped to the OWASP LLM Top 10 (2025). This post wires both into CI.

Run both scans locally first

pip install sentinel-scan-cli

sentinel-scan --demo --output pi-results.json