Best shadow AI discovery tools in 2026: Nudge Security, Harmonic Security, Netskope and Lutril

Four with public documentation of how they find AI use: Nudge Security (email metadata, OAuth grants and a browser extension, nothing on endpoints), Harmonic Security (browser extension, endpoint agent and a local MCP gateway), Netskope (secure web gateway, the Netskope Client on endpoints and Cloud Confidence Index ratings) and Lutril (OAuth grants, sign-up emails, a Chrome extension and code scanning, tied to access governance). LayerX, now sold as Akamai Workforce Protector, is another browser-based option. Choose first on which signals match where your AI use happens, then on what the tool lets you do once it has found something.

By combining signals, because each one misses something. OAuth grants show AI apps authorized with a Google or Microsoft account, with their scopes. Sign-up emails show tools adopted with an email and a password. A browser extension shows AI used in the browser, including with personal accounts. A secure web gateway shows traffic from steered networks and devices. An endpoint agent shows desktop apps, CLI tools and local models. Code scanning shows agents built in your repositories. None of the four tools on this page documents all six.

Only with something on the laptop. A model run through Ollama or LM Studio does its inference locally: no OAuth grant, often no sign-up email, and once the model is downloaded, no traffic to an AI provider for a gateway to inspect. Netskope's Client scans Windows and macOS endpoints against a signature list that includes Ollama, LM Studio, Jan AI and GPT4All, and Harmonic's endpoint coverage lists Ollama and locally hosted models. Lutril has no endpoint agent and does not detect local inference; it sees the traces around it, such as a visit to Hugging Face, a vendor sign-up email or agent code committed to GitHub or GitLab. Your MDM software inventory or EDR is the other place to look, since both list installed applications and running processes.

Three families. SaaS security platforms such as Nudge Security discover from email and OAuth with nothing to install and remediate through nudges. AI data security and secure access platforms such as Harmonic Security and Netskope sit in the browser, on the endpoint or in the network path, see prompts and enforce DLP in real time. Access governance platforms such as Lutril discover from OAuth, email, the browser and code, then govern what they find: a decision per tool, an owner per agent, policy on each agent tool call through an MCP proxy, and OAuth revocation at offboarding. The families are not exclusive: an inline control for prompts and a governance layer for owners and access can run side by side.

Prevention works when the approved path is easier than the shadow one, and enforcement needs a control point. For prompts, inline tools act before data leaves: Harmonic warns or blocks in the browser and on the desktop, Netskope blocks or coaches through real-time policies, Nudge Security steers users toward sanctioned tools, and Lutril's extension warns on sensitive data in ChatGPT, Claude and Gemini and redacts on the user's click. For agents, enforcement means an owner, scoped access and a policy decision on each tool call, which Lutril applies through its agent registry and MCP proxy. Blocking alone tends to move usage to devices and accounts you do not manage.

Discovery answers which AI tools and agents are in use and by whom. Governance answers what happens next: who owns each one, what it may reach, who approved it, when access ends and what evidence an auditor gets. The tools on this page differ in how far they go past the inventory: Nudge Security routes changes to owners and revokes grants at offboarding, Harmonic Security and Netskope enforce inline on prompts and traffic, and Lutril registers agents with owners, governs their tool calls through its MCP proxy and revokes OAuth access when someone leaves.