HEAD TO HEAD
Harmonic Security matched with Onyx Security: agentic endpoint security compared
SHORT ANSWER
On our published weights Onyx Security scores higher overall, 6.85 to 5.90 out of 10. Harmonic scores higher on capability rules, rollout path and named agent coverage; Onyx scores higher on stop before it runs, verdict range, actor trail and cloud and workspace reach; they tie on public proof. Which fits depends on which of those criteria matters most to you.
By The Agent Desk · Agentic Endpoint Compare · Published 2026-10-11
Desk research from public vendor pages, press releases and standards pages read on 27 September and 11 October 2026. Editorial assessment; we did not run the products.
How do they compare at a glance?
Harmonic Security
Coaching people through AI data risk
Rank 6 of 8 among broader AI security platforms
Onyx Security
Inline control with the widest set of verdicts
Rank 2 of 8 among broader AI security platforms
Which scores higher on each criterion?
| Criterion | Weight | Harmonic Security | Onyx Security | Higher |
|---|---|---|---|---|
| Stop before it runs | 25% | 7 / 10 Governs at the MCP layer and at the tool surface and can block in real time. Source: Harmonic Security: Harmonic Command · Read 27 Sep 2026 | 8 / 10 Inspects every prompt, tool call and model response inline before acting on it. Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Onyx |
| Verdict range | 15% | 3 / 10 Documents 2 of six verdict types: Block or deny and Alert or warn. "Block in real time, warn the employee with context, or log silently." Source: Harmonic Security homepage · Read 27 Sep 2026 | 7 / 10 Documents 4 of six verdict types: Block or deny, Ask a person, Alert or warn and Mask or modify. "Five actions: alert, block, mask, steer, or ask." Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Onyx |
| Capability rules | 15% | 7 / 10 Harmonic Command sets which systems agents can read, write to and act on. Source: Harmonic Security: Harmonic Command · Read 27 Sep 2026 | 6 / 10 Agent posture covers misconfigurations, excessive permissions and credential handling; rules by capability type (shell, packages, cloud CLIs) are not itemized. Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Harmonic |
| Actor trail | 10% | 6 / 10 Unified governance for people and agents; per-action attribution is not detailed. Source: Harmonic Security: Harmonic Command · Read 27 Sep 2026 | 7 / 10 Agent identity and access governance is a named solution; per-action attribution detail is lighter than the leader. Source: Onyx Security homepage · Read 27 Sep 2026 | Onyx |
| Rollout path | 10% | 8 / 10 Rolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026 | 6 / 10 Endpoint agents, browser extensions, APIs and gateways; the device component is resident software. Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Harmonic |
| Cloud and workspace reach | 10% | 4 / 10 Browser, desktop, CLI, MCP gateway and API surfaces; agents running in cloud workspaces or cloud apps are not described. Source: Harmonic Security homepage · Read 27 Sep 2026 | 9 / 10 Covers cloud workloads alongside browser AI, coding assistants, desktop agents and MCP servers, across SaaS, cloud, endpoint and code. Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Onyx |
| Named agent coverage | 5% | 3 / 10 Names 2 of the six agents we track: Claude Code and GitHub Copilot. Source: Harmonic Security pricing (re-read 11 October 2026) · Read 11 Oct 2026 | 0 / 10 Names 0 of the six agents we track: none. Source: Onyx Security: AI security platform · Read 27 Sep 2026 | Harmonic |
| Public proof | 10% | 7 / 10 Tier names are published (Explore, Guide, Command) but no prices. Source: Harmonic Security pricing · Read 27 Sep 2026 | 7 / 10 Series B of $113M announced 29 July 2026; SOC 2 Type II and ISO 27001 listed; pricing not published. Source: Onyx Security blog: $113M Series B (29 July 2026) · Read 27 Sep 2026 | Tie |
Which verdicts does each document?
| Verdict type | Harmonic Security | Onyx Security |
|---|---|---|
| Block or deny | Documented | Documented |
| Ask a person | Not described | Documented |
| Alert or warn | Documented | Documented |
| Mask or modify | Not described | Documented |
| Simulate first | Not described | Not described |
| Remove or scale back | Not described | Not described |
- Harmonic Security: "Block in real time, warn the employee with context, or log silently."
Source: Harmonic Security homepage · Read 27 Sep 2026
- Onyx Security: "Five actions: alert, block, mask, steer, or ask."
Source: Onyx Security: AI security platform · Read 27 Sep 2026
How does each reach devices?
Harmonic Security
Intune, JAMF, Kandji or Group Policy.
Source: Harmonic Security homepage · Read 27 Sep 2026
Onyx Security
Endpoint agents, browser extensions, APIs and gateways; Onyx says no SDK changes are needed.
Source: Onyx Security: AI security platform · Read 27 Sep 2026
Which agents does each name?
| Agent | Harmonic Security | Onyx Security |
|---|---|---|
| Claude Code | Named | Not named |
| Cursor | Not named | Not named |
| GitHub Copilot | Named | Not named |
| OpenAI Codex | Not named | Not named |
| Windsurf | Not named | Not named |
| Claude Desktop | Not named | Not named |
| Named | 2 of 6 | 0 of 6 |
Which should you choose?
Choose Harmonic Security if you need rollout path and stop before it runs. Harmonic Security is best for: Coaching people through AI data risk.
Choose Onyx Security if you need cloud and workspace reach and stop before it runs. Onyx Security is best for: Inline control with the widest set of verdicts.
Frequently asked questions
Which is better for agentic endpoint security, Harmonic Security or Onyx Security?
On our published weights Onyx Security scores higher overall, 6.85 to 5.90 out of 10. See the criterion table above for where each scores higher.
Which stops an agent action before it runs more fully, Harmonic Security or Onyx Security?
Onyx Security scores higher on stopping an action before it runs (8 to 7). Harmonic Security: Governs at the MCP layer and at the tool surface and can block in real time. Onyx Security: Inspects every prompt, tool call and model response inline before acting on it.
Do Harmonic Security and Onyx Security publish prices?
Harmonic Security: not published. Three tiers are named (Explore, Guide, Command); prices are not published. Onyx Security: not published. Onyx Security publishes no pricing.