OpenAI Acquires AI Security Startup Promptfoo to Enhance Frontier Platform Safety

OpenAI announced on March 9, 2026, its acquisition of Promptfoo, an AI security platform specializing in evaluating and red-teaming large language model applications. The deal, with terms undisclosed, brings Promptfoo's team to OpenAI, where their technology will be integrated into the company's Frontier platform for building and operating AI agents, also known as AI coworkers. This move aims to embed automated security testing directly into enterprise AI development workflows, addressing vulnerabilities as AI agents connect to real data and systems.

Promptfoo, founded in 2024 and led by CEO Ian Webster and co-founder Michael D’Angelo, provides an open-source CLI and library used by over 25% of Fortune 500 companies for testing AI prompts and agents. The platform enables developers to validate prompts across models like ChatGPT, Claude, and Gemini, identifying risks such as prompt injections, jailbreaks, data leaks, tool misuse, and out-of-policy behaviors. Having raised $22.68 million, including an $18.4 million Series A in July 2025, Promptfoo's tools support continuous integration pipelines and compliance with frameworks like OWASP Top 10 for LLMs and NIST AI Risk Management.

The acquisition accelerates OpenAI's efforts to make security and safety testing native to Frontier, allowing enterprises to detect, investigate, and remediate agent risks before deployment. Features will include automated red-teaming, adversarial input generation, vulnerability reporting, and traceability for governance and accountability. OpenAI plans to continue developing Promptfoo's open-source project, integrating it to support multi-provider testing across OpenAI, Anthropic, Google, Meta, and open-source models via declarative configurations.

Srinivas Narayanan, OpenAI's CTO of B2B Applications, stated, “Promptfoo brings deep engineering expertise in evaluating, securing, and testing AI systems at enterprise scale. Their work helps businesses deploy secure and reliable AI applications, and we’re excited to bring these capabilities directly into Frontier.” Promptfoo CEO Ian Webster added, “We started Promptfoo because developers needed a practical way to secure AI systems. Joining OpenAI lets us accelerate this work, bringing stronger security, safety, and governance capabilities to the teams building real-world AI systems.”

This development underscores growing industry focus on agentic AI safety amid competitive pressures, following OpenAI's prior acquisitions like Torch and Software Applications. By embedding specialized testing for stochastic AI behaviors—beyond traditional security tools—the integration positions Frontier to enable safer enterprise deployments, quantifying risks and ensuring compliance in production environments.