Promptfoo

Promptfoo, from Promptfoo, Inc. (300,000+ open-source users, used by 156 Fortune 500 companies), is an AI security testing platform that automates red teaming to find vulnerabilities — prompt injections, jailbreaks, data leaks, insecure tool use — in AI applications before they ship. Who it's for: teams building AI agents or RAG systems who need to test for real security vulnerabilities systematically, integrated into CI/CD, rather than relying on informal manual testing. Strengths: a genuinely large open-source user base (300k+) alongside real enterprise customers across finance, healthcare, and telecommunications is concrete evidence this isn't just an early-stage tool. Real-time guardrails against adversarial attacks and CI/CD-integrated code scanning mean security testing happens continuously, not just at one review checkpoint. Weaknesses and limitations: the open-source version requires real setup and configuration (running via CLI) rather than a one-click hosted service; the paid enterprise tier adds continuous monitoring and dedicated support for teams needing that. Real-world scenario: a team shipping an AI agent wants to systematically test for prompt injection and jailbreak vulnerabilities before launch, integrated into their existing CI/CD pipeline rather than as a one-off manual check.