Head to head · Checked against vendor sites, September 2026
Onyx Security vs Koi (Palo Alto Networks): AI agent security compared
The verdict
Onyx Security scores higher overall on our weights (7.4 vs 7.1 out of 10). Onyx Security scores higher on tool-call control, policy, identity and audit and breadth; Koi scores higher on visibility. They tie on footprint and maturity. Neither publishes list prices.
Koi (Palo Alto Networks Cortex Agentic Endpoint Security)
Owner: Palo Alto Networks (acquisition completed 14 April 2026)
Best for Palo Alto Cortex customers
How do Onyx Security and Koi compare on each criterion?
| Criterion | Weight | Onyx Security | Koi | Edge |
|---|---|---|---|---|
| Visibility | 22% | 7 | 9 | Koi |
Why these scoresOnyx Security: Discovers AI agents across SaaS, cloud, endpoint and code; endpoint inventory detail is lighter than endpoint-first tools. Koi: Visibility into models, MCPs, extensions and packages on the endpoint, with risk scoring. | ||||
| Tool-call control | 20% | 8 | 7 | Onyx Security |
Why these scoresOnyx Security: Inspects every prompt, tool call and model response inline. Koi: Blocks unsafe AI application interactions and prevents prompt injections; tool-call level mechanics not published. | ||||
| Policy | 15% | 8 | 7 | Onyx Security |
Why these scoresOnyx Security: Five enforcement actions: alert, block, mask, steer, or ask a human. Koi: Out-of-the-box policies and one-click removal of insecure packages, extensions and AI tools. | ||||
| Identity and audit | 12% | 7 | 5 | Onyx Security |
Why these scoresOnyx Security: Agent identity and access governance is a named solution. Koi: Agent vs human attribution not described on the pages we reviewed. | ||||
| Footprint | 13% | 6 | 6 | Tie |
Why these scoresOnyx Security: Works across endpoint agents, browser extensions, APIs and gateways; the endpoint component is a resident agent or extension. Koi: Agent-based; offered as a Cortex XDR module and as a standalone offering. | ||||
| Breadth | 8% | 9 | 7 | Onyx Security |
Why these scoresOnyx Security: Browser AI, coding assistants, desktop agents, cloud workloads and MCP servers, plus agentic red teaming. Koi: Palo Alto Networks is integrating Koi with Prisma AIRS for wider AI coverage. | ||||
| Maturity | 10% | 7 | 7 | Tie |
Why these scoresOnyx Security: $113M Series B announced 29 July 2026; SOC 2 Type II and ISO 27001 listed; pricing not published. Koi: Acquisition completed 14 April 2026 by Palo Alto Networks; pricing not published. | ||||
| Total | 100% | 7.4 | 7.1 | Onyx Security |
How do they deploy, and what do they cost?
| Attribute | Onyx Security | Koi |
|---|---|---|
| Owner | Not acquired | Palo Alto Networks (acquisition completed 14 April 2026) |
| How it reaches devices | Endpoint agent, browser extension, API, gateway | Cortex XDR module or standalone agent |
| Deployment detail | Onyx says it needs no SDK changes and works across endpoint agents, browser extensions, APIs and gateways. It integrates with Okta, Entra, Splunk and CrowdStrike. On devices this means a resident component, which is why it scores lower on footprint than tools that deploy through EDR or MDM. | Integrates with Cortex XDR as a module and is also available standalone as an agent-based deployment. If you run Cortex XDR, this is the lowest-friction path; if you run another EDR, expect a separate agent. |
| Pricing | Contact sales. Onyx Security does not publish pricing. | Contact sales. Pricing is not published. |
Source: onyx.security · Onyx AI security · Onyx Series B · Cortex Agentic Endpoint Security · Press release, 14 April 2026 · Reviewed Sep 2026
Which should you choose?
Choose Onyx Security if
- Your priority matches our designation for Onyx Security: best for inline control across many AI surfaces.
- You need an audit record that separates agent actions from human actions: Onyx Security scores 7 to 5.
- Your agents also run in SaaS platforms, cloud workloads or apps you build: Onyx Security scores 9 to 7.
Choose Koi if
- Your priority matches our designation for Koi: best for Palo Alto Cortex customers.
- You need a fleet-wide inventory of AI agents, MCP servers, extensions and credentials on devices: Koi scores 9 to 7.
Frequently asked questions
Which is better, Onyx Security or Koi (Palo Alto Networks)?
Onyx Security scores higher overall on our weights (7.4 vs 7.1 out of 10). Onyx Security scores higher on tool-call control, policy, identity and audit and breadth; Koi scores higher on visibility. They tie on footprint and maturity. Scores are editorial assessments from public vendor material, reviewed September 2026.
Do Onyx Security and Koi (Palo Alto Networks) publish prices?
No. Neither publishes list prices, so ask both for a quote.
Do Onyx Security or Koi (Palo Alto Networks) replace EDR?
No. The tools in this guide add control over AI agent actions and work alongside EDR. Onyx Security: Endpoint agent, browser extension, API, gateway. Koi: Cortex XDR module or standalone agent.
Related
Sources
- onyx.security · Reviewed Sep 2026
- Onyx AI security · Reviewed Sep 2026
- Onyx Series B · Reviewed Sep 2026
- Cortex Agentic Endpoint Security · Reviewed Sep 2026
- Press release, 14 April 2026 · Reviewed Sep 2026