# Best AI Security
> Editorial buyer's guide to AI security tools that let companies use AI agents, coding assistants, MCP servers and browser AI safely on employee endpoints. Nine vendors scored 0-10 on seven weighted criteria. Based on public vendor pages and documentation. Checked against vendor sites, September 2026.

## Rankings
- [Best AI security tools for AI agents at the endpoint](https://bestaisecurity.com/)
- [All tools](https://bestaisecurity.com/tools)
- [How we score](https://bestaisecurity.com/how-we-score)
- [Score calculator](https://bestaisecurity.com/calculator): re-weight the seven criteria and re-rank the nine tools
- [Compare tools side by side](https://bestaisecurity.com/compare)
- [FAQ](https://bestaisecurity.com/faq)

## Tool reviews
- [Bay](https://bestaisecurity.com/tools/bay)
- [Noma Security](https://bestaisecurity.com/tools/noma-security)
- [Zenity](https://bestaisecurity.com/tools/zenity)
- [Onyx Security](https://bestaisecurity.com/tools/onyx)
- [Harmonic Security](https://bestaisecurity.com/tools/harmonic-security)
- [Koi (Palo Alto Networks Cortex Agentic Endpoint Security)](https://bestaisecurity.com/tools/palo-alto-koi)
- [Prompt Security (SentinelOne)](https://bestaisecurity.com/tools/prompt-security)
- [Lasso Security](https://bestaisecurity.com/tools/lasso-security)
- [Bloom Security](https://bestaisecurity.com/tools/bloom-security)

## Comparisons
- [Bay vs Noma Security](https://bestaisecurity.com/versus/bay-noma)
- [Bay vs Koi](https://bestaisecurity.com/versus/bay-koi)
- [Harmonic Security vs Prompt Security](https://bestaisecurity.com/versus/harmonic-prompt-security)
- All 36 head-to-head pages are linked from https://bestaisecurity.com/compare#all-comparisons (pattern: /versus/<vendor>-vs-<vendor>).

## Alternatives
- [Bay alternatives](https://bestaisecurity.com/bay-alternatives)
- [Noma Security alternatives](https://bestaisecurity.com/noma-security-alternatives)
- [Zenity alternatives](https://bestaisecurity.com/zenity-alternatives)
- [Onyx Security alternatives](https://bestaisecurity.com/onyx-security-alternatives)
- [Harmonic Security alternatives](https://bestaisecurity.com/harmonic-security-alternatives)
- [Koi (Palo Alto Networks) alternatives](https://bestaisecurity.com/koi-alternatives)
- [Prompt Security (SentinelOne) alternatives](https://bestaisecurity.com/prompt-security-alternatives)
- [Lasso Security alternatives](https://bestaisecurity.com/lasso-security-alternatives)
- [Bloom Security alternatives](https://bestaisecurity.com/bloom-security-alternatives)

## Guides
- [What is AI agent security](https://bestaisecurity.com/guide/ai-agent-security)
- [MCP security](https://bestaisecurity.com/guide/mcp-security)
- [Shadow AI](https://bestaisecurity.com/guide/shadow-ai)
- [AI agent security and EDR](https://bestaisecurity.com/guide/ai-agent-security-and-edr)
- [Buyer's checklist](https://bestaisecurity.com/guide/buyers-checklist)

## Notes
- [AI agent security news recap: April to September 2026](https://bestaisecurity.com/notes/ai-agent-security-news-recap-april-september-2026)
- [What AI agent security tools cost, and why no vendor publishes a price](https://bestaisecurity.com/notes/ai-agent-security-pricing-explained)
- [How to run a proof of concept for an AI agent security tool](https://bestaisecurity.com/notes/how-to-run-an-ai-agent-security-proof-of-concept)
- [Seven myths about AI agent security, and what the facts say](https://bestaisecurity.com/notes/ai-agent-security-myths-and-facts)
- [Excessive Agency in the OWASP 2026 Top 10: what it means for AI agents](https://bestaisecurity.com/notes/owasp-2026-top-10-excessive-agency)
- [How to inventory AI agents and MCP servers on employee devices](https://bestaisecurity.com/notes/how-to-inventory-ai-agents-and-mcp-servers)
- [What the MCP 2026-07-28 specification changes for security teams](https://bestaisecurity.com/notes/mcp-2026-07-28-specification-security-changes)
- [Allow, ask or deny: how to write a policy for AI agent actions](https://bestaisecurity.com/notes/allow-ask-deny-ai-agent-action-policy)

## University
- [AI security university](https://bestaisecurity.com/university)
- [AI agent security glossary](https://bestaisecurity.com/university/glossary)
- [Lesson: how an MCP tool call works](https://bestaisecurity.com/university/how-an-mcp-tool-call-works)
- [Lesson: where AI agent controls sit](https://bestaisecurity.com/university/where-ai-agent-controls-sit)
- [Lesson: how to read vendor claims](https://bestaisecurity.com/university/reading-vendor-claims)
- [Lesson: Indirect prompt injection and why agent controls sit at the action layer](https://bestaisecurity.com/university/indirect-prompt-injection-action-layer)
- [Lesson: How to read an endpoint AI control score](https://bestaisecurity.com/university/reading-the-score)
- [Lesson: Managed settings and hooks: controlling coding agents from the inside](https://bestaisecurity.com/university/managed-settings-and-hooks)
- [Lesson: How to build an AI agent activity record your SOC can use](https://bestaisecurity.com/university/agent-activity-record)

## News
- [AI agent security news](https://bestaisecurity.com/news): monthly summaries of public announcements from the vendors on this site and from standards projects, with links to the original source.