On Monday, OpenAI revealed its acquisition of Promptfoo, a security startup established in 2024 that focuses on protecting large language models from online threats. In a blog post, the frontier lab stated that following the deal's completion, Promptfoo's technology will be incorporated into OpenAI Frontier, its enterprise platform designed for AI agents.

The rise of independent AI agents capable of executing digital tasks has sparked enthusiasm for potential productivity improvements. However, this advancement also presents new avenues for malicious actors to exploit sensitive data or interfere with automated systems. This acquisition highlights the urgent efforts by frontier labs to demonstrate that their technologies can be deployed securely within essential business operations.

Promptfoo was co-founded by Ian Webster and Michael D’Angelo to create tools that enable companies to test for security weaknesses in LLMs. Their offerings include an open-source interface and library. The startup reports that its products are currently utilized by over 25% of Fortune 500 companies.

Since its inception, Promptfoo has secured only $23 million in funding. According to Pitchbook, the company was most recently valued at $86 million following a funding round in July 2025. OpenAI has not disclosed the financial terms of the transaction.

In its announcement, OpenAI explained that Promptfoo's technology will empower its agent platform to conduct automated red-teaming exercises, assess agentic workflows for security issues, and monitor activities for potential risks and compliance requirements. The company also indicated plans to further develop and expand Promptfoo's open-source offerings.