OpenAI announced on Monday that it has acquired Promptfoo, an AI security startup founded in 2024 to protect large language models from online adversaries. The frontier lab stated that once the deal closes, Promptfoo’s technology will be integrated into OpenAI Frontier, its enterprise platform for AI agents.
The rise of independent AI agents that perform digital tasks has generated excitement about potential productivity gains. However, it has also created new opportunities for bad actors to access sensitive data or manipulate automated systems. This acquisition highlights how leading AI labs are working to prove their technology can be used safely in critical business operations.
Promptfoo was founded by Ian Webster and Michael D’Angelo to develop tools that companies can use to test security vulnerabilities in large language models. Their products include an open-source interface and library. The company reports that its tools are already used by more than twenty-five percent of Fortune 500 companies.
Since its founding, Promptfoo has raised just twenty-three million dollars. According to Pitchbook, the company was valued at eighty-six million dollars after its most recent funding round in July 2025. OpenAI did not disclose the financial terms of the acquisition.
OpenAI stated that Promptfoo’s technology will enable its agent platform to perform automated red-teaming, evaluate agentic workflows for security concerns, and monitor activities for risks and compliance needs. The company also said it expects to continue developing and supporting Promptfoo’s open-source offerings.