Harmonic Security vs WitnessAI

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.

WitnessAI is an AI security and governance platform for enterprise AI use by employees and by AI agents. It was founded in 2023 and incubated by Ballistic Ventures. CEO Rick Caccia, previously SVP of marketing at Palo Alto Networks, is the only co-founder the company names. It is based in Mountain View, California, and has raised about $85.5 million in two announced rounds: $27.5 million co-led by GV and Ballistic Ventures (May 2024) and $58 million in strategic funding led by Sound Ventures (January 2026), with Fin Capital, Qualcomm Ventures, Samsung Ventures and Forgepoint Capital Partners taking part. The platform has three modules. Observe finds the AI apps, agents and MCP servers in use, drawing on a catalog of thousands of AI applications, and classifies conversations by intent. Control sets policies by department, role, intent or workforce type, routes prompts to approved or cheaper models, limits agents to approved MCP servers and tools, redacts sensitive data in real time and keeps audit trails. Protect (Witness Protect, which WitnessAI calls "the enterprise AI firewall") screens prompts and responses for prompt injection, jailbreaks and harmful output and tokenizes PII, credentials and secrets. Witness Attack runs automated red teaming against models before deployment. WitnessAI says it sees AI activity across the network without browser extensions or endpoint clients, including native apps such as Windows 11 Copilot and Office 365, and it integrates with F5 BIG-IP SSL Orchestrator for encrypted AI traffic. Each customer gets a single-tenant instance with customer-controlled encryption. In January 2026 it launched WitnessAI Agentic Security, which covers coding agents such as Claude Code, Cursor and Codex and records the user, agent, tool and rule for every blocked tool call. In July 2026 it added AI FinOps features: spend estimates for unsanctioned AI apps and agents, metering of sanctioned token use, an ROI dashboard and cost-based model routing. **AI compliance coverage** The compliance page offers logging of every AI app and interaction, policy enforcement and masking of regulated data, but names no AI framework. WitnessAI's AWS Marketplace listing says its audit trails support compliance reporting for the EU AI Act, ISO/IEC 42001, the NIST AI RMF and PCI DSS 4.0.1. We found no control mappings for any of them. WitnessAI announced a SOC 2 Type II attestation in October 2025; it has no public trust center. **Who it's for** Large enterprises that want to see and govern how employees and agents use public and internal AI tools, and to add runtime protection to their own AI apps. WitnessAI says its customers include financial services firms, utilities, airlines, automakers, retailers and telecoms. InComm Payments is the only customer it names on its site.