OpenAI acquires AI security startup Promptfoo

OpenAI has announced the acquisition of Promptfoo , an AI security startup founded in 2024 and used by more than 25% of Fortune 500 companies. The terms of the acquisition have not been announced.

OpenAI to acquire Promptfoo | OpenAI

Promptfoo is joining OpenAI | Promptfoo

The open-source AI red-teaming tool used by Fortune 500 companies is now part of OpenAI
https://thenextweb.com/news/openai-acquires-promptfoo-ai-security-frontier

OpenAI acquires Promptfoo to secure its AI agents | TechCrunch
https://techcrunch.com/2026/03/09/openai-acquires-promptfoo-to-secure-its-ai-agents/

While the emergence of AI agents promises to improve productivity through independent development, it also creates the risk of attackers gaining access to sensitive data and manipulating automated systems.

Promptfoo is a security platform that helps identify and remediate vulnerabilities in AI systems. Once acquired, it will be integrated into OpenAI Frontier, an AI agent building and operations platform. Once integrated, OpenAI Frontier will be able to run automated red team exercises, assess agent workflows for security concerns, and monitor activity for risk and compliance needs.

Promptfoo has grown at a rate that even the founding team never anticipated, with 130,000 monthly active users and more than 25% of Fortune 500 companies using the service.

The company says that it will continue to build open source projects even after the acquisition.