TLDR: F5 Networks, a Seattle-based application delivery and security company, has announced its intention to acquire Dublin-based AI security firm CalypsoAI for $180 million in cash. The acquisition, expected to close by September 30, 2025, aims to enhance F5’s capabilities in protecting enterprise AI systems from emerging cybersecurity threats like prompt injection and jailbreak attacks.
Seattle-based application delivery and security giant F5 Networks is set to acquire Dublin-headquartered technology firm CalypsoAI in an all-cash deal valued at $180 million. The strategic acquisition, announced on Thursday, September 11, 2025, is anticipated to conclude by September 30, 2025, marking a significant move by F5 to strengthen its enterprise AI security offerings.
This acquisition comes at a critical juncture as companies rapidly integrate generative AI systems into their operations, facing an escalating landscape of cybersecurity threats that traditional security tools are ill-equipped to handle. CalypsoAI, founded in 2018 with operations spanning Dublin and New York, specializes in providing a ‘model-agnostic’ security platform. This platform is designed to protect AI inference layers from sophisticated attacks such as prompt injection and jailbreak attempts, regardless of the AI models or cloud providers enterprises utilize.
François Locoh-Donou, President and CEO of F5, emphasized the urgency of this strategic move, stating, “AI is redefining enterprise architecture—and the attack surface companies must defend. Traditional firewalls and point solutions can’t keep up. The addition of CalypsoAI will give enterprises the confidence to innovate faster and better protect critical data as they rely on F5 to deliver and secure apps, APIs, and AI models across their environment.”
CalypsoAI’s platform offers real-time threat defense, large-scale cybersecurity exercises (red teaming), and robust data security capabilities. It conducts automated red-team testing against thousands of attack scenarios monthly, generating risk assessments and implementing real-time guardrails to prevent data leakage and policy violations. Donnchadh Casey, CEO of CalypsoAI, highlighted the customer need: “Enterprises want to move fast with AI while reducing the risk of data leaks, unsafe outputs, or compliance failures.” He added, “Our customers rely on us to pressure test AI systems at scale, set inference layer guardrails that adapt as models change, and to gain visibility and auditability across their AI estate.”
The integration of CalypsoAI’s technology into F5’s Application Delivery and Security Platform (ADSP) is expected to create a comprehensive AI security solution.
CalypsoAI has successfully raised over $40 million in venture funding from prominent investors, including Paladin Capital Group, Lockheed Martin Ventures, and Hakluyt Capital. The company was also recognized as a top-two finalist in the 2025 RSAC Innovation Sandbox contest and named one of Fast Company’s Most Innovative Companies in AI for 2025.
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F5 anticipates the transaction to be immaterial to its revenue and operating results. The company has been active in strategic acquisitions this year, having previously acquired San Francisco-based Fletch in June and observability firm MantisNet in August. Foros Advisors LLC served as the financial advisor to F5, with Sullivan & Cromwell LLP providing legal counsel. Cooley LLP advised CalypsoAI on legal matters.
