Harmonic Security vs Knostic

Harmonic Security sells software that shows security teams how employees and AI agents use generative AI tools and stops sensitive data from going into them. It was founded in 2023 (its About page dates the founding to August 2023) by CEO Alastair Paterson, the former chief executive of Digital Shadows, and CTO Bryan Woolgar-O'Neil. It launched in October 2023, jointly headquartered in London and San Francisco, and its privacy policy names Harmonic Security Limited in London and Harmonic Security Inc. in San Francisco. It says it has raised $76 million in total: a $7 million seed round led by Ten Eleven Ventures (October 2023), a $17.5 million Series A led by Next47 (October 2024) and a $50 million Series B led by Crosspoint Capital Partners, announced on October 14, 2026, when it reported more than 100 customers and more than 90 staff in the US and UK. We found no acquisition. The platform is sold as three packages. Explore uses a browser extension to find the AI tools in use and gives prompt-level visibility, usage intelligence, sensitive data detection and risk scores for each app; Harmonic says it covers more than 1,000 AI applications, including AI features inside SaaS tools. Guide adds an endpoint agent for desktop AI apps, IDEs and command-line tools such as Claude Code and Codex, inline coaching (block, warn or log), granular policies and webhook alerts for SIEM and SOAR tools. Command adds MCP client and server discovery, permissions on what agents may read, write and execute, and data protection inside agentic workflows; prompt injection detection is listed as coming soon. Its locally installed MCP Gateway, launched in October 2025, intercepts MCP traffic on Windows, macOS and Linux. Instead of pattern matching, Harmonic classifies prompts with its own small language models, which it says decide in under 200 milliseconds. **AI compliance coverage** Harmonic treats compliance as a by-product of governance. Its compliance page says it flags high-risk uses such as automated hiring screens and credit scoring "so you can apply the specific guardrails the EU AI Act and local laws require", keeps an audit trail of AI interactions, and blocks health and personal data from unapproved AI tools for HIPAA and GDPR. Documentation mapping its controls to specific regulations is available on request, as is EU hosting. For Harmonic itself, its trust center lists SOC 2 Type 2 and ISO/IEC 27001:2022, with a SOC 2 report available on request, and its site footer shows SOC 2 Type 2 and ISO 27001 badges. ISO/IEC 42001 and the NIST AI RMF also appear in the trust center's list, but the site shows no badge or certification claim for either. **Who it's for** Security and IT teams that want to let staff use ChatGPT, Claude, Copilot, Cursor and similar tools while keeping company data out of them. Harmonic has industry pages for technology, legal, insurance and healthcare, and its site quotes customers at Apax and Advisor360.

Knostic is an AI security company founded in 2023 by Gadi Evron (CEO) and Sounil Yu (CTO). It is based in Herndon, Virginia. It started out selling need-to-know access controls for enterprise AI assistants such as Microsoft 365 Copilot and Glean, which keep answers from exposing data a user shouldn't see. Its website now calls it "the control plane for agentic AI on the endpoint", and it sells two products for AI coding assistants and agents. Kirin runs alongside Cursor, Claude Code, GitHub Copilot, Windsurf, Codex, JetBrains, Devin Desktop and Gemini CLI, and supports Claude Cowork through a plugin. It checks each tool call against policy before it runs and blocks it, downgrades it or sends it to a human. It also validates MCP connections, scans dependencies for hallucinated, vulnerable or malicious packages, and finds and redacts secrets before they reach the model. It audits agent instruction files such as CLAUDE.md and .cursorrules. Kirin installs as a lightweight user-space client that admins can roll out with MDM scripts, on macOS and Windows; Linux is in beta. Its Shadow AI Discovery reports unsanctioned AI use but doesn't block it. AgentMesh scans agent skills, MCP servers and VS Code extensions and labels each one dangerous, risky or clean. In June 2026 VirusTotal added AgentMesh analysis of VS Code extensions. Knostic also publishes an open-source scanner, OpenAnt. Knostic still has a page that pairs it with Microsoft Purview against Copilot oversharing, and its AWS Marketplace listing is still the Copilot Readiness product. Its homepage, product and pricing pages no longer describe that product. It raised a $3.3 million pre-seed round in April 2024 and an $11 million round led by Bright Pixel Capital in March 2025. In 2025 it also received a $5 million investment as an RSAC Innovation Sandbox finalist. In June 2025 Virginia Business put its total funding at $19 million and its headcount at about 30. In October 2025 Gartner named Knostic a Cool Vendor in AI Cybersecurity Governance, for its controls on AI oversharing. **AI compliance coverage** Knostic doesn't map its products to the EU AI Act, the NIST AI RMF or ISO 42001. Its trust center lists a SOC 2 Type 2 report and GDPR, its FAQ offers a compliance package with the SOC 2 report and pen test results, and its Enterprise plan includes compliance reporting. **Who it's for** Security teams at companies whose developers use AI coding agents, agent skills and MCP servers. It is not a governance, model inventory or model testing platform.