Is Harmonic or Koi better for AI endpoint control?

Neither is scored on this site. Harmonic describes 2 of four product control types and Koi 1 on the pages we read, and they differ on 8 recorded facts. Which fits depends on the AI tools people use, your devices, where the work happens and whether you block or guide; the finder checks those.

Which of the two decides on a tool call before it runs?

Harmonic: Partly. Koi: Partly. Warn or ask: Harmonic Matches, Koi Not in our sources.

Do Harmonic or Koi publish prices?

Harmonic: Three named tiers (Explore, Guide, Command) with no prices; a full prompt audit log is an add-on on Guide and Command. Koi: Not published.

HEAD-TO-HEAD · FACTS ONLY

Harmonic vs Koi: AI endpoint control facts side by side

Short answer

Harmonic describes 2 of the four product control types on the pages we read and Koi describes 1; they differ on on-device control, browser extension and AI or MCP gateway. On decisions, Harmonic describes some control over tool calls and Koi describes some control over tool calls. 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: Koi, 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)

The map shows where each product's own pages describe a control, or where your answers point. It is not a measure of how well a product works.

What are the facts, side by side?

Harmonic Security and Koi (Palo Alto Networks), from each product's own pages. Differs is computed from recorded statuses, not wording.
Fact	Harmonic	Koi
Owner	None	Palo Alto Networks (acquisition completed 14 April 2026)
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.	Koi, now sold by Palo Alto Networks as Cortex Agentic Endpoint Security, gives visibility into models, MCPs and extensions on endpoints, removes insecure packages, extensions and AI tools in one click, and stops malicious actions.
How it reaches devices	Rolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026	Available as a Cortex XDR module or as a standalone agent. koi.ai now redirects to the Palo Alto Networks page. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 2026
On-device controlDiffers	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	DescribedAgent-based visibility into models, MCPs and extensions, one-click removal of insecure packages, extensions and AI tools, and blocking of unsafe AI application interactions. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 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 covers	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	MatchesA Palo Alto Networks blog of 18 August 2026 names Claude Code, Cursor, Codex and Antigravity. Source: Palo Alto Networks blog: A Quarter of Innovation with Koi Agentic Endpoint Security · Read 11 Oct 2026
Decides on a tool call before it runs	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	PartlyBlocks unsafe AI application interactions and prevents prompt injections; decisions on individual tool calls are not described. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 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	PartlyA Cortex XDR module, or its own standalone agent. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 2026
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 action	MatchesBlock is one of three actions. Source: Harmonic Security homepage · Read 27 Sep 2026	MatchesStops malicious actions and removes insecure packages, extensions and AI tools in one click. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 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 action	Not in our sources	Not in our sources
Also covers SaaS, cloud or homegrown AI	PartlyAn API is listed alongside device surfaces; SaaS or cloud agents are not described. Source: Harmonic Security homepage · Read 27 Sep 2026	PartlyPalo Alto Networks plans integration with Prisma AIRS, its wider AI security platform. Source: Palo Alto Networks press release: acquisition of Koi completed · Read 27 Sep 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	Offered as a Cortex XDR module. Source: Palo Alto Networks press release: acquisition of Koi completed · Read 27 Sep 2026
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. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 2026

Where do they differ?

On-device control: Harmonic partly describes it; Koi describes it.
Browser extension: Harmonic describes it; Koi is not in our sources.
AI or MCP gateway: Harmonic describes it; Koi is not in our sources.
Controls what goes into browser AI: Harmonic matches; Koi is not in our sources.
Rolls out through EDR or device management you run: Harmonic matches; Koi partly matches.
Can warn or ask instead of only blocking: Harmonic matches; Koi is not in our sources.
Has a watch-only or simulation mode: Harmonic matches; Koi is not in our sources.
Has a public price or tiers (vendor site or marketplace): Harmonic partly matches; Koi 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 Koi if

You already run Palo Alto Networks Cortex XDR
You want to find and remove risky extensions and packages across the fleet

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.

Koi

Agent-based: it adds an agent unless you run it as a Cortex XDR module.
Warn or ask actions and a record that separates a person from an agent are not described on the pages we read, and no pricing is published.

Line up Harmonic and Koi with others Run the finder