Citadel AI
Citadel AI is a Tokyo-headquartered AI governance software company that provides evaluation, monitoring, and compliance tooling for LLMs, computer vision, and tabular AI systems, serving regulated enterprises in healthcare, financial services, and manufacturing across Japan and select international markets.
- Company typePrivate
- Founded2020
- HeadquartersTokyo, Japan
- Headcount11–50
- GTM typeB2B
- OfferingSoftware
What Citadel AI does
Citadel AI (legally Citadel AI Inc., US-registered, headquartered in Tokyo) is an AI governance and MLOps software company founded in 2020 that provides evaluation, monitoring, and compliance tooling for AI systems across the full lifecycle from research and development through commercial deployment. The company targets regulated and quality-sensitive buyers in healthcare, financial services, manufacturing, automotive, and government/audit, with named customers including Mayo Clinic Platform, Tokio Marine Holdings, MUFG, Ono Pharmaceutical, Suntory System Technology, DeepEyeVision, and Deloitte Japan. Its stated positioning centers on third-party unified AI evaluation, jailbreak security testing for generative AI, and ISO-based compliance testing for predictive AI.
The product stack is anchored by Citadel Lens, an AI governance platform supporting LLMs, computer vision, and tabular AI, supplemented by Citadel Radar (firewall monitoring of generative AI application usage launched in 2026), Lens Governance (management and compliance reporting module launched in 2026), LangCheck (an open-source multilingual LLM evaluation library on GitHub), LangCheck Studio (browser-based LLM-as-a-judge interface), Eval Insight (LLM-driven plain-language issue summarization), and the Lens Safety Dataset. Supporting credentials include ISO 27001, HIPAA, GDPR compliance, CHAI AI Assurance Resource Provider certification (October 2025), and participation in the NEDO AI Safety Enhancement R&D project and the Global AI Assurance Sandbox.
The business operates on quote-based annual enterprise subscriptions, sold via direct field sales with a demo-request intake and a channel reseller agreement with NSSOL (Nippon Steel Solutions) for the Japanese market. A strategic alliance with BSI bundles third-party certification services with the tooling. Citadel AI has 11-50 employees, no publicly disclosed revenue, and no publicly disclosed funding to date. Co-founders Hironori Kobayashi (CEO) and Kenny Song lead the company.
Citadel AI firmographics
Firmographics- Name
- Citadel AI
- Legal name
- Citadel AI Inc.
- Website
- https://citadel.co.jp
- Company type
- Private
- Founded year
- 2020
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Citadel AI is a Tokyo-headquartered AI governance software company that provides evaluation, monitoring, and compliance tooling for LLMs, computer vision, and tabular AI systems, serving regulated enterprises in healthcare, financial services, and manufacturing across Japan and select international markets.
- Ownership category
- akta.pro rank
Citadel AI industry classification
Industry- Product category
- AI Governance Platform
- NAICS
- Computer Systems Design Services (541512)
- SIC
- Services-Computer Programming Services (7371)
- akta.pro primary industry
- AI Observability, Monitoring & Evaluation Platforms (Drift, Quality, Safety) (HDAEANAF)
- akta.pro secondary industries
- Enterprise AI Governance, Risk & Compliance Platforms (Model Risk, Audit, Policies) (HDAEANAE), Responsible AI, Security & Privacy Platforms (Safety, Guardrails, PII) (HDAEANAG)
Keywords
Where Citadel AI is headquartered
LocationHeadquarters
- HQ city
- Tokyo
- HQ country
- Japan
- HQ region
- Asia
Offices1 record
Markets served
Citadel AI business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Personnel, Technology or R&D, Marketing or Sales, Operations, Infrastructure
Revenue model
- AI Governance Platform Subscriptions: Subscription-based AI governance and monitoring tools including Citadel Lens, Citadel Radar, and Lens Governance. Provides evaluation, monitoring, and compliance capabilities for organizations deploying AI systems.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | Annual | Enterprise subscription model with custom pricing based on organizational requirements |
Go-to-market motion2 records
Distribution channels2 records
Marketing channels7 records
Citadel AI product offering
Product offeringCore offering
Citadel AI provides enterprise software for AI evaluation, monitoring, and governance, enabling organizations to test, secure, and oversee machine learning and large language model (LLM) applications in production. Its platform helps enterprises detect performance regressions, security vulnerabilities, and compliance risks across the AI lifecycle, with particular support for regulated industries such as healthcare, finance, and manufacturing.
Product overview
Citadel AI is an AI governance and safety platform providing evaluation, monitoring, and compliance tools for AI systems including LLMs, computer vision, and tabular AI. The core platform Citadel Lens evaluates and monitors AI systems throughout the AI lifecycle. Related products include Citadel Radar (firewall monitoring for generative AI applications), Lens Governance (governance reporting module), LangCheck (open-source LLM evaluation library with LangCheck Studio browser interface), and Eval Insight (concise AI issue visualization). The platform offers unified third-party evaluation perspective, automated report generation for both technical and governance audiences, and supports ISO compliance, jailbreak security testing, and continuous monitoring capabilities.
Differentiator
Problem solved
Functional benefit
Brands
- Citadel Lens: AI governance tool for evaluating and monitoring AI system risks to maximize AI performance. Applicable to LLMs, computer vision, and tabular AI systems. Includes safety testing, compliance testing based on ISO standards, and continuous automated monitoring.
- LangCheck
- Citadel Radar
- Lens Governance
Products and services
- Citadel Lens Enterprise AI evaluation and monitoring platform that enables organizations to test, validate, and continuously monitor machine learning and LLM applications for performance, accuracy, and reliability in production.
- Citadel Radar Real-time AI firewall and monitoring tool that detects prompt injections, jailbreaks, hallucinations, and other security or quality threats in production LLM and ML systems.
- Lens Governance Governance module that provides oversight, audit trails, and compliance management for AI systems, supporting regulatory and internal risk management requirements for enterprise AI deployments.
- LangCheck Open-source Python library for evaluating LLM outputs that supports multilingual evaluation, prompt injection and jailbreak testing, and integration with major LLM providers.
Quantifiable outcome
- Faster and richer AI model reliability evaluation compared to traditional methods
- +1 more outcomes
Companies that use Citadel AI
Customer profileNamed customers7 records
Segments5 records
Ideal customer profiles4 records
Citadel AI technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
AI capability9 records
Feature7 records
Citadel AI partnerships and signals
Strategic signalPartnerships
Seven partnerships are on record, tiered core.
- Coalition for Health AI (CHAI)coreCertified as AI Assurance Resource Provider, enabling participation in CHAI's AI assurance ecosystem and contributing to healthcare AI governance standards.
- Global AI Assurance SandboxcoreParticipation in Global AI Assurance Sandbox for AI governance testing and validation. Addresses AI governance as a management challenge.
- BSI (British Standards Institution)coreStrategic partnership combining BSI's regulatory expertise and Citadel AI's technical capabilities to implement responsible AI. BSI provides third-party certification services with Citadel AI's tools.
- NSSOL (日鉄ソリューションズ/Nippon Steel Solutions)coreSales partner agreement for AI governance tool distribution. NSSOL resells and distributes Citadel AI's products.
- NEDO (New Energy and Industrial Technology Development Organization)coreSelected for NEDO AI Safety Enhancement Research and Development project. Jointly building AI safety foundation with consistent guidelines and evaluation infrastructure.
- AIST (産業技術総合研究所)corePartner in AI safety foundation research project building consistent guidelines and evaluation infrastructure for safe human-AI coordination.
- CorpycorePartner in AI safety foundation research project supporting safe human-AI coordination.
Scale indicators2 records
Recent moves6 records
Expansion highlights6 records
Citadel AI competitors and assessment
Company assessmentDirect peers
- Credo AI: Credo AI is an AI governance and risk management platform that automates AI compliance, auditing, and policy enforcement for enterprises. Directly comparable to Citadel AI's Lens Governance and ISO-based compliance testing capabilities.
- Langfuse: Langfuse is an open-source LLM observability and evaluation platform for tracing, scoring, and debugging generative AI applications. Comparable to Citadel AI's LangCheck open-source library and LLM evaluation tooling.
- WhyLabs: WhyLabs offers an AI observability and monitoring platform (whylogs) covering data and model quality, drift, and performance for production AI. Comparable to Citadel Lens's drift/quality/safety evaluation across the AI lifecycle.
- Arize AI: Arize AI is an AI observability and evaluation platform purpose-built for LLMs and ML models in production. Directly comparable to Citadel Lens's LLM/CV/tabular evaluation and monitoring capabilities serving enterprise AI/ML engineering teams.
- Fiddler AI: Fiddler AI provides an AI observability and model monitoring platform with explainability and governance features for production ML models. Comparable to Citadel AI's combination of model evaluation, monitoring, and governance reporting.
- Arthur AI: Arthur AI is an AI observability and performance monitoring platform for enterprise LLMs and ML models. Comparable to Citadel Lens's continuous monitoring across generative and predictive AI deployments.
- Evidently AI: Evidently AI provides an open-source and cloud ML observability and evaluation toolkit for testing and monitoring ML/LLM systems. Comparable to Citadel AI's LangCheck and Lens for LLMs evaluation capabilities.
Emerging players
- Lakera: Lakera provides AI security and guardrails for LLM applications, including jailbreak and prompt-injection defense. Comparable to Citadel AI's Citadel Radar firewall and jailbreak security testing capabilities for generative AI.
- Monitaur: Monitaur is an AI governance, risk, and compliance platform focused on model audit, monitoring, and policy enforcement for regulated enterprises. Comparable to Citadel AI's Lens Governance governance reporting and compliance testing modules.
Broad incumbents
- Datadog: Datadog is a large enterprise infrastructure and APM platform that has expanded into LLM observability (Datadog LLM Observability) and watch/watchdog-style monitoring. Comparable as a broad incumbent moving into the AI evaluation/monitoring category where Citadel AI operates.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks6 records
Key highlights3 records
Customer concentration
Citadel AI social profiles
Digital presenceCitadel AI compliance and trust
Trust signalCompliance3 records
Citadel AI financial estimates
Financial estimateRevenue estimate
Valuation estimate
Citadel AI leadership team
Management profileNumber of profiles
Profiles2 records
Citadel AI funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Citadel AI M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Citadel AI
What does Citadel AI do?
Citadel AI provides enterprise software for AI evaluation, monitoring, and governance, enabling organizations to test, secure, and oversee machine learning and large language model (LLM) applications in production. Its platform helps enterprises detect performance regressions, security vulnerabilities, and compliance risks across the AI lifecycle, with particular support for regulated industries such as healthcare, finance, and manufacturing.
Is Citadel AI a public or private company?
Citadel AI is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was Citadel AI founded?
Citadel AI was founded in 2020. It employs 11 to 50 people.
Where is Citadel AI based?
Citadel AI is headquartered in Tokyo, Japan, in the Asia region.
How does Citadel AI make money?
One revenue line is on record: AI Governance Platform Subscriptions.
Who are Citadel AI's main competitors?
Direct peers on record are Credo AI, Langfuse, WhyLabs, Arize AI, Fiddler AI, Arthur AI and Evidently AI. Emerging players are Lakera and Monitaur. Datadog is listed as a broad incumbent.
Does Citadel AI have an API?
No public API is recorded for Citadel AI.
What industry is Citadel AI in?
Citadel AI's product category is AI Governance Platform. Its primary akta.pro industry code is HDAEANAF, AI Observability, Monitoring & Evaluation Platforms (Drift, Quality, Safety), with a secondary code of HDAEANAE, Enterprise AI Governance, Risk & Compliance Platforms (Model Risk, Audit, Policies). Its NAICS code is 541512 and its SIC code is 7371.