Knostic vs Prompt Security

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.

Prompt Security is an AI security product that controls how employees use AI tools and protects the AI applications and agents companies build. Itamar Golan (CEO) and Lior Drihem (CTO), who had worked at Check Point and Orca Security, founded it in August 2023; it is based in Tel Aviv. It raised $23 million: a $5 million seed round led by Hetz Ventures (January 2024) and an $18 million Series A led by Jump Capital (November 2024), with Ridge Ventures, Okta and F5 joining. SentinelOne, the Mountain View, California security company, agreed to buy Prompt Security on August 5, 2025 and completed the deal on September 5, 2025. Its Form 8-K puts the consideration at approximately $180 million in cash and SentinelOne Class A stock. Prompt Security is still sold under its own name, as part of SentinelOne's Singularity Platform. The product page is on sentinelone.com; prompt.security now hosts research and free tools such as the open-source Prompt Fuzzer, and the old press release we checked there redirects to SentinelOne. **What it does** SentinelOne's Prompt Security page lists three areas. AI Usage Control inventories the AI tools and code assistants employees and developers use, including unsanctioned shadow AI, and redacts sensitive data and enforces policies across more than 15,000 AI services in real time. It also covers GitHub Copilot, Cursor and Claude Code, keeping secrets and intellectual property out of them. AI Application Security tests homegrown AI apps for prompt injection, jailbreaks and data poisoning before deployment, runs a real-time AI firewall, and turns red-team findings into guardrails. Agentic AI Security finds shadow MCP servers and unsanctioned agents, enforces least-privilege access for agents and keeps a searchable audit log. SentinelOne says Prompt's MCP gateway scores the risk of more than 13,000 known MCP servers and can allow, block, filter or redact their actions. Prompt deploys through a lightweight agent and browser extensions, and covers major LLM providers, including OpenAI, Anthropic and Google, and self-hosted models. **Product changes since the acquisition** At its OneCon conference in November 2025 SentinelOne launched Prompt Security for Employees, for AI Code Assistants and for AI Applications, plus Prompt Security for Agentic AI in beta. At RSAC in March 2026 it announced Prompt AI Agent Security, a discovery and governance control plane for agents and MCP servers (agent posture management was in preview), and Prompt AI Red Teaming for testing homegrown AI apps. **Frameworks** Neither SentinelOne's Prompt Security pages nor prompt.security name the EU AI Act, ISO 42001 or the NIST AI RMF; they refer only to meeting compliance requirements in general terms. This profile lists no frameworks. **Who it's for** Companies that want to let employees use generative AI and coding assistants while controlling data exposure, especially existing SentinelOne customers. Named customers include 10x Banking and Carnival Corporation.