OpenAI is acquiring Promptfoo, an AI security startup founded in 2024 that builds open-source tools for testing LLMs against adversarial prompts, prompt injection, and jailbreak attempts. Promptfoo had raised $23 million before the deal, with reported valuations ranging from $86 million to $119 million depending on the source.
The technology will be folded into OpenAI Frontier, the company’s enterprise AI agent platform. In practice, that means automated red-teaming, real-time prompt injection testing, jailbreak detection, data exposure prevention, and compliance reporting built directly into the platform rather than bolted on afterward.
Promptfoo’s tools were already in use at over 25% of Fortune 500 companies before the acquisition, which says something about how seriously enterprises are taking agent security right now. AI agents moving from pilots to production has a way of concentrating minds on what happens when something goes wrong.
OpenAI says Promptfoo will remain open source under its current license, and existing customers will continue to be supported. The plan is to develop both the open-source project and proprietary enterprise features in parallel.
The acquisition fits a broader pattern: as frontier labs push harder into enterprise sales, demonstrating that their agent infrastructure is safe enough for production use is increasingly a prerequisite, not an afterthought. Red-teaming and evaluation tooling are becoming table stakes, with organizations applying the same shift-left security thinking to AI that they’ve long applied to traditional software development.

Collections

OpenAI is acquiring Promptfoo, a 2024-founded AI security startup that builds open-source tools for testing LLMs against adversarial prompts, prompt injection, and jailbreak attempts. The startup had raised $23M and was already used by over 25% of Fortune 500 companies. Promptfoo's technology will be integrated into OpenAI Frontier, the company's enterprise AI agent platform, adding automated red-teaming, real-time prompt injection testing, jailbreak detection, data exposure prevention, and compliance reporting. OpenAI has committed to keeping Promptfoo open source while developing proprietary enterprise features in parallel. The acquisition reflects a broader industry shift where enterprise AI safety and red-teaming tooling are becoming prerequisites for production agent deployments.

OpenAI acquires Promptfoo to bolster agentic security testing