OpenAI Acquires Promptfoo to Strengthen Security for AI Agents

OpenAI is acquiring cybersecurity startup Promptfoo as part of a broader push to strengthen safeguards around the rapidly expanding ecosystem of AI agents. Financial terms of the deal were not disclosed, but Promptfoo’s team will join OpenAI and its technology will be integrated into the company’s Frontier platform, which is designed to power autonomous AI agents operating across real-world systems.

Promptfoo specializes in tools that allow developers to test, validate, and secure complex AI systems before they are deployed.

As AI agents increasingly interact with enterprise software, data systems, and automated workflows, ensuring that those systems behave safely and reliably has become one of the industry’s most pressing challenges. Promptfoo CEO Ian Webster said joining OpenAI will allow the company to accelerate work on “stronger security, safety, and governance capabilities” for teams building AI-powered applications.

OpenAI said it will continue supporting Promptfoo’s open-source testing framework, which enables developers to evaluate prompts, compare large language models, and measure the performance of systems like ChatGPT, Anthropic’s Claude, and Google’s Gemini. Those tools have become widely used within the developer community as organizations experiment with integrating AI into production systems.

The acquisition reflects a broader strategy by OpenAI to expand both its capabilities and talent base as competition intensifies across the AI sector. In recent months the company has been steadily acquiring startups and hiring prominent AI engineers, including bringing on Peter Steinberger, creator of the OpenClaw framework used to build autonomous AI agents.

OpenAI also acquired health-tech startup Torch earlier this year and purchased the AI interface startup Software Applications in late 2025.

Promptfoo raised an $18.4 million Series A round last July led by Insight Partners, with participation from Andreessen Horowitz. The startup has a small team of roughly 11 employees and was valued at about $85 million as of its last funding round.

The deal highlights a growing realization across the AI industry: as models become more powerful and agents begin to act autonomously, security, testing, and governance infrastructure will be just as important as the models themselves.

By bringing Promptfoo’s technology inside its platform, OpenAI is positioning itself not only as a builder of AI systems, but also as a provider of the safety frameworks required to deploy them at scale.