HEAD-TO-HEAD · FACTS ONLY
Harmonic vs Sun: AI endpoint control facts side by side
Short answer
Harmonic describes 2 of the four product control types on the pages we read and Sun describes 0; they differ on browser extension and AI or MCP gateway. On decisions, Harmonic describes some control over tool calls and Sun decides on a tool call before it runs. We do not score either; the right choice depends on the AI tools people use, your devices, your current stack and whether you block or guide.
By The Device Desk · Endpoint AI Finder · Published 2026-10-11
Desk research from public vendor pages read on 27 September and 11 October 2026. Profiles follow our published method; we did not run the products.
Vendor pages read September and October 2026 · updated 2026-10-13
Where do their controls sit?
- Filled or hatched marker: Harmonic
- Dashed teal ring: Sun, described
- DEV Filled marker: described on the product pages we read
- DEV Hatched marker: partly described (another component, a narrower scope, or method not detailed)
- DEV Dashed marker: not in our sources (it may exist; we did not find it)
What are the facts, side by side?
| Fact | Harmonic | Sun |
|---|---|---|
| Owner | None | None |
| Positioning | A data protection product for everyday AI use, sold as Explore, Guide and Command, covering browser extensions, desktop apps and CLI tools, MCP gateways and an API. | AI agent security that says it sits in the path of every AI agent across workstations, cloud and SaaS, with three capabilities: discovery, posture management that learns each agent's purpose, and runtime checks of every tool call, connection and resource draw against that purpose before it executes. |
| How it reaches devices | Rolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not described; the site says you can get started in 5 minutes. Source: Sun Security homepage · Read 13 Oct 2026 |
| On-device control | Partly describedDeployment options include desktop apps and AI agents, rolled out through device management; the on-device component is not described in detail. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026 | Partly describedCovers agents on workstations; the on-device method is not described. Source: Sun Security homepage · Read 13 Oct 2026 |
| Browser extensionDiffers | DescribedBrowser extensions are a listed surface, with block, warn or log actions. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not in our sourcesNot described on the pages we read. |
| Network or SSE proxy | Not in our sourcesNot described on the pages we read. | Not in our sourcesNot described on the pages we read. |
| AI or MCP gatewayDiffers | DescribedMCP gateways are a listed surface, and Harmonic Command governs at the MCP layer and at the tool surface. Source: Harmonic Security: Command · Read 27 Sep 2026 | Not in our sourcesNot described on the pages we read. |
| Names the coding agents it coversDiffers | MatchesThe Guide tier adds desktop AI apps and developer tools, naming Claude Code, GitHub Copilot, ChatGPT Desktop and Microsoft 365 Copilot. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026 | PartlyNames Cursor and Claude Cowork; Claude Code, Codex and GitHub Copilot are not named. Source: Sun Security homepage · Read 13 Oct 2026 |
| Decides on a tool call before it runsDiffers | PartlyThe Command tier adds MCP client and server discovery, agent permissions for read, write and execute, and MCP server tool controls. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026 | MatchesEvery tool call, connection and resource draw is checked against the agent's purpose before it executes. Source: Sun Security homepage · Read 13 Oct 2026 |
| Controls what goes into browser AIDiffers | MatchesBlock, warn or log on AI use in the browser. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not in our sources |
| Rolls out through EDR or device management you runDiffers | MatchesRolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not in our sources |
| Can warn or ask instead of only blockingDiffers | MatchesWarn is one of three actions, with block and log. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not in our sources |
| Can block an agent, tool or actionDiffers | MatchesBlock is one of three actions. Source: Harmonic Security homepage · Read 27 Sep 2026 | PartlyIts demo shows a stopped action. Source: Sun Security homepage · Read 13 Oct 2026 |
| Has a watch-only or simulation modeDiffers | MatchesLog is one of three actions, for watching before enforcing. Source: Harmonic Security homepage · Read 27 Sep 2026 | Not in our sources |
| Records who or what took each actionDiffers | Not in our sources | PartlyIts demo shows an action log. Source: Sun Security homepage · Read 13 Oct 2026 |
| Also covers SaaS, cloud or homegrown AIDiffers | PartlyAn API is listed alongside device surfaces; SaaS or cloud agents are not described. Source: Harmonic Security homepage · Read 27 Sep 2026 | MatchesNames Copilot Studio and AWS Bedrock agents. Source: Sun Security homepage · Read 13 Oct 2026 |
| Has a public price or tiers (vendor site or marketplace)Differs | PartlyNames three tiers (Explore, Guide, Command) on its pricing page, without prices. Source: Harmonic Security: pricing · Read 27 Sep 2026 | Not in our sources |
| Built into | None | None |
| Works with | None in our sources | None in our sources |
| Price | Three named tiers (Explore, Guide, Command) with no prices; a full prompt audit log is an add-on on Guide and Command. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026 | Not published (demo request). Source: Sun Security homepage · Read 13 Oct 2026 |
Where do they differ?
- Browser extension: Harmonic describes it; Sun is not in our sources.
- AI or MCP gateway: Harmonic describes it; Sun is not in our sources.
- Names the coding agents it covers: Harmonic matches; Sun partly matches.
- Decides on a tool call before it runs: Harmonic partly matches; Sun matches.
- Controls what goes into browser AI: Harmonic matches; Sun is not in our sources.
- Rolls out through EDR or device management you run: Harmonic matches; Sun is not in our sources.
- Can warn or ask instead of only blocking: Harmonic matches; Sun is not in our sources.
- Can block an agent, tool or action: Harmonic matches; Sun partly matches.
- Has a watch-only or simulation mode: Harmonic matches; Sun is not in our sources.
- Records who or what took each action: Harmonic is not in our sources; Sun partly matches.
- Also covers SaaS, cloud or homegrown AI: Harmonic partly matches; Sun matches.
- Has a public price or tiers (vendor site or marketplace): Harmonic partly matches; Sun is not in our sources.
Choose Harmonic if
- Your main risk is employees pasting sensitive data into AI tools and you would rather coach than block
- You manage devices with Intune, JAMF, Kandji or Group Policy
Choose Sun if
- You want each agent action checked against that agent's purpose
Which limits should you check?
Harmonic
- Tier names only, no prices, and the full prompt audit log is an add-on.
- An activity record that separates a person from an agent is not described, and prompt injection protection is listed as coming soon.
Sun
- Sun's site is a single marketing page, so most details are not described.
- How it reaches devices is not described, and no price is published.