Fair point — and one I thought about carefully before open-sourcing. A few reasons why I think open patterns are actually the right call: 1. The patterns are

Fair point — and one I thought about carefully before open-sourcing. A few reasons why I think open patterns are actually the right call: 1. The patterns are already public. Most prompt injection techniques are documented on GitHub, in research papers, and on sites like jailbreakchat. Attackers don't need my regex list — they already have the playbook. 2. Security through obscurity doesn't work for defense. History (from antivirus to WAFs to OWASP) shows that open detection rules get more eyes, more contributions, and faster updates than closed ones. Snort, ModSecurity, YARA — all open, all industry standard. 3. The real threat isn't regex bypass. If an attacker is sophisticated enough to craft novel prompts that evade pattern matching, they'll also evade most LLM-based detectors. The answer for that 20% is layered defense (output filtering, sandboxing, least-privilege), not secret patterns. 4. Open source = trust. Enterprise customers want to audit what's running in their pipeline. "Trust us, it's secret" is a harder sell than "here are the exact 42 patterns, verify them yourself." That said — the paid Shield API does include additional detection layers beyond the open-source patterns, specifically for this reason.