CalypsoAI was acquired by F5 in September 2025.
The technology has been integrated into the acquirer's product line. New buyers should evaluate the successor product directly.
See the current product from F5CalypsoAI
CalypsoAI Corp.
AI security company acquired by F5 in September 2025; its guardrails and red-teaming technology is now sold as F5 AI Guardrails and F5 AI Red Team
Last checked October 15, 2026Quick facts: CalypsoAI is an AI compliance vendor founded in 2018 and headquartered in Dublin, Ireland. The vendor publicly documents coverage for EU AI Act. Pricing is available on request. Profile last checked October 15, 2026; sources are cited at the bottom of this page.
About CalypsoAI
CalypsoAI was an AI security company founded in the US in 2018 by Neil Serebryany, its first CEO; it describes itself as founded in Silicon Valley, and its early press releases carry Washington datelines. It began with software for testing, validating and monitoring AI and machine learning models for national security, finance and other regulated customers, and moved to securing generative AI with CalypsoAI Moderator in 2023. Donnchadh Casey became CEO in August 2024. In October 2024 CalypsoAI named Dublin its global co-headquarters, alongside a US headquarters in New York; IDA Ireland says the CEO, the CTO and most of its R&D were based in Dublin. Paladin Capital Group led its $13 million Series A (July 2020) and a $23 million Series A-1 (June 2023), and F5 says it raised more than $40 million in venture funding. Investors also included Lockheed Martin Ventures and Hakluyt Capital. F5 announced on September 11, 2025 that it would acquire CalypsoAI for $180 million in purchase consideration, mostly cash. F5's 10-Q says the deal closed on September 26, 2025 and records $145.2 million in cash consideration. CalypsoAI is no longer sold separately: calypsoai.com now redirects to F5's AI Guardrails page. F5 introduced F5 AI Guardrails and F5 AI Red Team when it announced the close, and made both generally available in January 2026. Buyers should evaluate those products. **What it sold** By 2025 CalypsoAI sold an inference security platform with two main products. Inference Defend checked prompts and responses in real time to block prompt injection, jailbreaks and sensitive data leakage, using custom scanners that could be versioned, tested and enforced per project. Inference Red-Team ran automated and agent-driven multi-turn attacks, drawing on more than 10,000 new attack prompts a month, and produced a risk score. The platform logged AI interactions for audit, sent logs to Splunk, and ran as SaaS, on premises or hybrid. In August 2025 CalypsoAI said an on-premises version of Red-Team, for organizations with strict data residency or air-gapped requirements, would soon be available in early access. **Frameworks** In August 2025 CalypsoAI added an EU AI Act scanner package to Inference Defend, covering four Article 5 prohibited-practice categories: manipulation, social scoring, biometric data harvesting and surveillance. F5's deal announcement said its governance features help customers meet GDPR and EU AI Act requirements. We found no CalypsoAI mapping to the NIST AI RMF or ISO 42001.
Frameworks supported
Regulations, voluntary standards and compliance programs CalypsoAI documents support for on their own materials. Chip shading reflects the strength of the claim, not an independent audit.
Regulation · EU · Phased — in force; high-risk rules deferred
CalypsoAI features
Capabilities CalypsoAI markets publicly. Inclusion means the feature is documented on the vendor's site — not that it's best-in-class. Last checked October 15, 2026.
AI Guardrails
Runtime controls that constrain LLM input and output to enforce safety, compliance, and brand policies.
Prompt Injection Defense
Detection and mitigation of malicious prompts intended to bypass system instructions or exfiltrate data.
Data Leakage Prevention
Inspection of LLM outputs to block PII, secrets, and regulated data from leaving the boundary.
Policy Enforcement
Mechanism for applying organizational and regulatory policies to AI usage at runtime.
Runtime Enforcement
Inline policy enforcement on AI inputs and outputs at request time.
LLM Red Teaming
Automated adversarial testing of LLMs for jailbreaks, prompt injection, and unsafe outputs.
Agentic Red Teaming
Automated adversarial testing using AI agents to probe model and application weaknesses.
Risk Scoring
Quantitative risk assessment for AI use cases, vendors, or model deployments.
Audit Logging
Tamper-evident logging of governance events (approvals, model changes, policy decisions) required by EU AI Act Article 12 and similar regulations.
Industries served
Integrations
Documented by CalypsoAI in public product materials.
- Splunk
CalypsoAI pricing
CalypsoAI is no longer sold on its own; calypsoai.com redirects to F5's AI Guardrails page. F5 doesn't publish prices for F5 AI Guardrails or F5 AI Red Team. AWS Marketplace shows a $100,000.00 12-month figure for F5 AI Guardrails but says it is a placeholder for a private offer, and lists F5 AI Red Team at $100,000.00 for a 12-month contract.
Third-party reviews
Publicly cited ratings from independent review platforms. We don't collect reviews ourselves and we don't weight these in our rankings. Low review counts (≤2) are noted so you can decide how much signal to take from them.
G2
2 reviews · thin sample
We publish the cited numbers as-is and do not combine them into an aggregate rating, on this page or in search-result markup.
Vendor changelog
Durable events we've independently sourced — acquisitions, certification milestones, product launches. Each entry cites a primary or trusted secondary source.
- product launch
F5 introduced F5 AI Guardrails and F5 AI Red Team
F5 announced the products built on CalypsoAI's technology when it confirmed the acquisition was complete.
F5 - acquisition
F5 closed its acquisition of CalypsoAI
F5's 10-Q records $145.2 million in cash consideration.
F5 Form 10-Q - acquisition
F5 announced it would acquire CalypsoAI for $180M
F5 said the $180 million purchase consideration would be financed primarily with cash.
F5 - funding
Raised a $23M Series A-1 led by Paladin Capital Group
Total funding reached $38.2M; the round came with the launch of CalypsoAI Moderator for generative AI.
Business Wire - funding
Raised a $13M Series A led by Paladin Capital Group
Lockheed Martin Ventures, 8VC, Frontline Ventures, Lightspeed Venture Partners, Manta Ray Ventures and Pallas Ventures also took part.
Business Wire
Pros and cons of CalypsoAI
Pros
- The technology continues under F5: F5 AI Guardrails and F5 AI Red Team came out of the acquisition and became generally available in January 2026.
- Paired testing and protection: Inference Red-Team ran multi-turn, agent-driven attacks and Inference Defend enforced custom scanners on every prompt and response.
- Flexible deployment for regulated buyers: SaaS, on premises or hybrid, with an on-premises red-teaming option for air-gapped environments announced for early access in August 2025.
- One of the few AI security tools with a specific EU AI Act feature: a scanner package for four Article 5 prohibited-practice categories.
Cons
- No longer sold as CalypsoAI: new buyers have to buy F5's products, and calypsoai.com redirects to F5.
- No usable public price: the AWS Marketplace figure for F5 AI Guardrails is a placeholder, and F5 AI Red Team is listed at $100,000.00 for 12 months.
- EU AI Act coverage was limited to four Article 5 categories, and we found no mapping to the NIST AI RMF or ISO 42001.
- We found no model-file or AI supply chain scanning in CalypsoAI's or F5's materials, which Cisco AI Defense and Prisma AIRS both document.
Alternatives to CalypsoAI
Frequently asked
What was CalypsoAI?+
CalypsoAI was an AI security company founded in the US in 2018 and co-headquartered in Dublin and New York from October 2024. Its Inference Defend product blocked prompt injection, jailbreaks and data leakage at runtime, and Inference Red-Team ran automated attacks against AI models and applications.
Who owns CalypsoAI now?+
F5. It announced the acquisition on September 11, 2025 for $180 million in purchase consideration, mostly cash, and closed it on September 26, 2025. F5 now sells the technology as F5 AI Guardrails and F5 AI Red Team.
Where was CalypsoAI headquartered?+
CalypsoAI was founded in the US and its early releases carry Washington datelines. In October 2024 it named Dublin its global co-headquarters, alongside a US headquarters in New York. Its CEO, CTO and most of its R&D were in Dublin.
How much did CalypsoAI raise?+
More than $40 million, according to F5. Paladin Capital Group led its $13 million Series A in July 2020 and a $23 million Series A-1 in June 2023; other investors included Lockheed Martin Ventures and Hakluyt Capital.
What are the alternatives to CalypsoAI?+
F5 AI Guardrails is its direct successor. Other AI guardrail and red-teaming platforms in this directory are Lakera, Prompt Security, Cisco AI Defense, Prisma AIRS and HiddenLayer.
Sources
- calypsoai.com: redirects (302) to F5's AI Guardrails page (checked October 15, 2026)
- CalypsoAI: August 2025 release (Inference Defend, Inference Red-Team, EU AI Act scanner package, Splunk, Red-Team On-Prem)
- CalypsoAI: Best Use of AI award (March 27, 2025; Dublin co-headquarters since October 2024)
- F5: F5 to acquire CalypsoAI (September 11, 2025; $180 million; founded 2018; funding over $40 million)
- F5 Form 10-Q, quarter ended December 31, 2025 (CalypsoAI acquisition closed September 26, 2025; $145.2 million in cash)
- F5 blog: F5 completes acquisition of CalypsoAI, introduces F5 AI Guardrails and F5 AI Red Team (September 29, 2025)
- Business Wire: F5 AI Guardrails and F5 AI Red Team generally available (January 2026)
- Frontier Enterprise: F5 wraps up US$180M acquisition of CalypsoAI (October 8, 2025)
- Business Wire: CalypsoAI announces $13 million Series A (July 2020; founder and CEO Neil Serebryany)
- Business Wire: CalypsoAI raises $23 million Series A-1 (June 2023; $38.2 million raised to date; CalypsoAI Moderator)
- Business Wire: CalypsoAI awards (November 2023; founded in Silicon Valley in 2018; Dublin headquarters opened)
- IDA Ireland: CalypsoAI opens global co-headquarters in Dublin (October 2, 2024; US headquarters moving to New York; Donnchadh Casey CEO)
- IDA Ireland: CalypsoAI success story (Dublin and New York co-headquarters; CEO, CTO and most R&D in Dublin)
- Paladin Capital Group: F5 to acquire portfolio company CalypsoAI (2025; Paladin led the $13M Series A in 2020 and a $23M round in 2023)
- F5 blog (CalypsoAI post): Agentic Fingerprints (August 1, 2025; Agentic Warfare runs multi-turn attacks)
- AWS Marketplace: F5 AI Guardrails (placeholder price; private offer)
- AWS Marketplace: F5 AI Red Team ($100,000.00 per 12-month contract)
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