ContextFort - AI Agent Security and Observability

TL;DR

TL;DR: ContextFort is a YC-backed endpoint security tool that gives teams OS-level visibility into what AI coding agents like Cursor and Claude Code are doing on engineer machines, using eBPF, ESF, and ETW telemetry.

Source and Accuracy Notes

• Project page: contextfort.ai
• Source repository: github.com/ContextFort-AI/ContextFort
• License: ContextFort Source-Available License v1.0 (verified from LICENSE file)
• HN launch thread: news.ycombinator.com/item?id=46614015
• Source last checked: 2026-06-17

What Is ContextFort?

ContextFort addresses a growing security gap: when engineers run AI coding agents like Cursor or Claude Code, those agents inherit full system permissions. There is no sandbox, no restrictions, and no visibility into what the agent touches.

From the ContextFort website:

Know exactly what coding agents are doing on your engineers’ machines.

The tool monitors at the kernel level, independently of the agent itself. It tracks every file the agent reads or writes, every outbound network connection, and every subprocess spawned. Because the monitoring happens at the OS level, the agent cannot tamper with or hide its own logs.

How It Works

ContextFort uses platform-native kernel telemetry:

| Platform | Technology | |---|---| | Linux | eBPF (Extended Berkeley Packet Filter) | | macOS | Endpoint Security Framework (ESF) | | Windows | ETW + Minifilter drivers |

What Gets Monitored

File access telemetry — Every file the agent reads or writes: .env files, credentials, SSH keys, source code. The website specifically calls out the risk of agents reading .env to “understand your project” and inadvertently sending secrets to AI provider APIs.

Network monitoring — Every outbound connection: what data is sent, where it goes, and which process initiated it.

Process tree tracking — Full visibility into every subprocess: shell commands, package installs, builds.

Independent audit trail — OS-level logs the agent cannot tamper with.

ContextFort vs Traditional EDR

ContextFort positions itself as complementary to, not a replacement for, traditional endpoint detection and response (EDR) tools like CrowdStrike:

| Traditional EDR | ContextFort | |---|---| | Detects malware and known threats | Logs all AI agent activity, malicious or not | | Asks “Is this process malicious?” | Asks “What did this agent access?” | | No concept of AI-generated actions | Built specifically for AI coding agents | | Relies on agent self-reported logs | Independent OS-level monitoring | | No audit trail for AI actions | Complete audit trail of every agent action |

Installation and Setup

ContextFort is available as a commercial product with a demo booking flow on their website. They also offer:

• Chrome extension — Available on the Chrome Web Store for browser agent control
• Claude Code plugin — Enterprise browser isolation for AI agents (via github.com/ContextFort-AI/plugin)
• GitHub org — github.com/ContextFort-AI with runtime controls and open-source components

To book a demo for the enterprise endpoint product:

Visit https://contextfort.ai and click "Book a demo"
or use their calendar link directly from the website

Security and Compliance

From the GitHub repository’s SECURITY.md:

• Local storage only — no data transmitted to external servers
• No third-party cloud environments
• No PII transmission
• Open source code available for review
• Protected branches requiring pull requests for code changes

The enterprise compliance roadmap (from the GitHub README) includes:

• SOC2 Type 2 compliance
• ISO 27001 certification
• GDPR compliance documentation
• Centralized dashboard for enterprise deployment

Practical Evaluation Checklist

Use this checklist when evaluating ContextFort for your team:

1. Identify which AI coding agents your team uses — Cursor, Claude Code, Copilot, Codex, etc.
2. Audit current visibility — Do you know what files these agents access? What network calls they make?
3. Check compliance requirements — SOC2, HIPAA, or internal policies may require audit trails for all code-adjacent tools.
4. Test the Chrome extension first — The browser-based version is free and gives a taste of the monitoring approach.
5. Book an enterprise demo — For OS-level endpoint monitoring, the enterprise product requires a demo and custom deployment.
6. Review the license — The source-available license allows personal and non-commercial use but restricts commercial competing products.

Security Notes

• ContextFort monitors from the kernel, so it operates independently of the AI agent being monitored. The agent cannot disable or alter the telemetry.
• All data stays local by default — no cloud transmission unless you configure enterprise features.
• The tool does not block or sandbox agent actions by default; it provides visibility first. Sandboxing is a separate capability.
• If you use AI coding agents in production environments, ContextFort fills the gap between “the agent has my full system permissions” and “I have no idea what it did.”

FAQ

Q: Is ContextFort open source? A: The source code is available on GitHub under a Source-Available License v1.0. It allows personal and non-commercial use but restricts building competing commercial products.

Q: Does ContextFort work with all AI coding agents? A: The website specifically mentions Cursor and Claude Code. Since monitoring happens at the OS level, it should work with any process running on the machine, but official support focuses on those two.

Q: Does it slow down my machine? A: eBPF and ESF are designed for low-overhead kernel monitoring. ContextFort uses the same primitives that production security tools use, so the performance impact should be minimal.

Q: Can it block agents from accessing sensitive files? A: The primary product focuses on telemetry and visibility. Sandboxing and blocking are listed as separate capabilities on their website.

Q: Is there a free tier? A: The Chrome extension is free on the Chrome Web Store. The enterprise endpoint monitoring product requires booking a demo for pricing.

Conclusion

As AI coding agents become standard tools in engineering workflows, the security gap they create — full system access with no audit trail — becomes a real risk. ContextFort addresses this with OS-level telemetry that gives teams visibility into exactly what agents like Cursor and Claude Code are doing, independently of the agents themselves.

For teams already using AI coding agents in production, especially in regulated environments, ContextFort is worth evaluating as part of your security stack.