HEAD-TO-HEAD · FACTS ONLY
Koi vs Prompt Security: AI endpoint control facts side by side
Short answer
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: Koi
- Dashed teal ring: Prompt Security, 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 | Koi | Prompt Security |
|---|---|---|
| Owner | Palo Alto Networks (acquisition completed 14 April 2026) | SentinelOne (acquisition announced 5 August 2025; SentinelOne's blog of 3 September 2025 is titled SentinelOne Acquires Prompt Security) |
| Positioning | 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. | Prompt Security, now part of SentinelOne, inventories AI tools and code assistants, including unsanctioned shadow AI, through two local sensors, a browser extension and a dedicated AI endpoint agent, and is built into the SentinelOne Singularity Platform. |
| How it reaches devices | 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 | Two local sensors: a browser extension and a dedicated AI endpoint agent, managed from the SentinelOne Singularity Platform. Prompt Security argues that MDM or EDR integrations, which mostly run scripts periodically, are not enough. Source: Prompt Security blog: browser and endpoint sensors · Read 11 Oct 2026 |
| On-device control | 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 | DescribedA dedicated AI endpoint agent detects new AI agents, skills and connectors and applies runtime policies; it names GitHub Copilot, Cursor and Claude Code among the code assistants it inventories. Source: Prompt Security blog: browser and endpoint sensors · Read 11 Oct 2026 |
| Browser extensionDiffers | Not in our sourcesNot described on the pages we read. | DescribedA browser extension inspects prompts, redacts sensitive data and discovers shadow AI. Source: Prompt Security blog: browser and endpoint sensors · Read 11 Oct 2026 |
| 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 gateway | Not in our sourcesNot described on the pages we read. | Not in our sourcesNot described on the pages we read. |
| Names the coding agents it covers | 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 | MatchesNames GitHub Copilot, Cursor and Claude Code. Source: SentinelOne: Prompt Security · Read 27 Sep 2026 |
| Decides on a tool call before it runsDiffers | 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 | Not in our sources |
| Controls what goes into browser AIDiffers | Not in our sources | MatchesThe browser extension inspects prompts and redacts sensitive data. Source: Prompt Security blog: browser and endpoint sensors · Read 11 Oct 2026 |
| Rolls out through EDR or device management you run | PartlyA Cortex XDR module, or its own standalone agent. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 2026 | PartlyIts own agent and extension, managed in the SentinelOne console; it does not ride on other EDR or MDM tools. Source: Prompt Security blog: browser and endpoint sensors · Read 11 Oct 2026 |
| Can warn or ask instead of only blocking | Not in our sources | Not in our sources |
| Can block an agent, tool or actionDiffers | 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 | Not in our sources |
| Has a watch-only or simulation mode | Not in our sources | 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 AIDiffers | 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 | MatchesCovers homegrown AI apps from testing to runtime. Source: SentinelOne: Prompt Security · Read 27 Sep 2026 |
| Has a public price or tiers (vendor site or marketplace) | Not in our sources | Not in our sources |
| Built into | Offered as a Cortex XDR module. Source: Palo Alto Networks press release: acquisition of Koi completed · Read 27 Sep 2026 | Built into the SentinelOne Singularity Platform. Source: SentinelOne: Prompt Security · Read 27 Sep 2026 |
| Works with | None in our sources | None in our sources |
| Price | Not published. Source: Palo Alto Networks: Cortex Agentic Endpoint Security · Read 27 Sep 2026 | Not published. Source: SentinelOne: Prompt Security · Read 27 Sep 2026 |
Where do they differ?
- Browser extension: Koi is not in our sources; Prompt Security describes it.
- Decides on a tool call before it runs: Koi partly matches; Prompt Security is not in our sources.
- Controls what goes into browser AI: Koi is not in our sources; Prompt Security matches.
- Can block an agent, tool or action: Koi matches; Prompt Security is not in our sources.
- Also covers SaaS, cloud or homegrown AI: Koi partly matches; Prompt Security matches.
Choose Koi if
- You already run Palo Alto Networks Cortex XDR
- You want to find and remove risky extensions and packages across the fleet
Choose Prompt Security if
- You already run SentinelOne Singularity
- You need an inventory of AI tools and coding assistants first
Which limits should you check?
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.
Prompt Security
- Two new local sensors to roll out, a browser extension and an endpoint agent, unless you already run SentinelOne.
- Tool-call decisions, blocking, warning and activity records for agent actions are not described on the pages we read, and no pricing is published.