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Harden
On-device security layer that inspects coding agent actions before they execute
Editorially reviewedChecked Sep 2026How we review
Free plan Self-hosted Teams
Toolglade’s take
Harden is targeting the right layer. Most agent safety tooling reviews what happened; Harden intervenes before the command runs, which is where the risk actually sits. Running the models on-device is a meaningful design choice for teams that cannot ship code context to a vendor, and the free tier being genuinely free rather than a trial is unusual in security tooling. The constraints are real: macOS and Linux only, with the full local model requiring Apple Silicon, and no Windows support at all. Benchmark claims are the vendor own, so treat them as a starting point rather than independent validation.
About Harden
Harden is an on-device security layer that intercepts coding agent tool calls before execution and allows, blocks, redacts, or logs them using local cybersecurity models.
Harden, from the Agentic Integrity Foundation, addresses the gap that opens once coding agents can run commands and touch files: the damage happens at execution time, and reviewing transcripts afterwards is too late. Harden sits in front of that moment, intercepting tool calls and evaluating them with cybersecurity models that run locally on the device. Each intercepted action is allowed, blocked, redacted, or logged, with a block-and-steer behaviour that lets the agent retry safely rather than simply failing. Because the models are local, prompts and code do not leave the machine, and the product requires no account to start. A local decision store keeps an audit view with no retention cap. The company publishes benchmark results against suites including SLEIGHT, AgentHazard, SABER, and LinuxArena. Harden supports macOS and Linux; Windows is not supported. The Enterprise tier adds compliance reporting, air-gapped operation, MDM-managed installation, and support SLAs.
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TL;DR
Harden is a free, on-device guardrail that inspects and blocks coding agent tool calls before they execute.
Company overview
Harden is built by the Agentic Integrity Foundation and launched publicly in September 2026, reaching the top of Product Hunt in its category.
The project focuses on pre-execution control for coding agents, arguing that transcript review after the fact is too late to prevent damage.
Product features
Harden installs a local CLI and daemon that intercept agent tool calls, evaluate them with on-device cybersecurity models, and allow, block, redact, or log each one, with a block-and-steer retry path.
It integrates natively with major coding agents and falls back to an MCP proxy for others. A local decision store provides an audit view. Enterprise adds compliance reporting, air-gap mode, MDM installation, and SLAs.
Target market
Engineering teams that give coding agents shell and file access, particularly in security-conscious or regulated environments on macOS and Linux.
Buyer personas
End users
Developers running coding agents locally.
Buyers
Security and platform engineering leads.
Key influencers
AI security researchers and agent tooling communities.
Ideal customer profile
A macOS or Linux engineering team running autonomous coding agents that needs pre-execution controls without sending code off-device.
Funding & performance
Funding is not stated on the vendor site; verify via public sources.
Pros & cons
Pros
- Intervenes before execution rather than after the fact
- Models run locally, so code stays on the device
- Free tier is free forever, not a trial
- No account required to start
- Works with many agents natively or via MCP proxy
- Local audit view with no retention cap
- Telemetry can be opted out
Cons
- macOS and Linux only, no Windows support
- Full local model requires Apple Silicon
- Benchmark results are vendor published
- Enterprise pricing is not public
- Adds a layer that can block legitimate actions
Pricing plans
Free
$0
- Pre-execution blocking on your machine
- Works with Claude Code, Codex, Cursor, Kiro and more
- Block and steer with safe retry
- Local decision store with no retention cap
- No account required
Enterprise
Custom
- Compliance reporting
- Air-gap and zero-telemetry mode
- Managed installation via MDM
- Support SLAs and custom terms
Key features
Team collaboration
Self-hosted
Integrations
Claude Code, OpenAI Codex, Cursor, Kiro, Antigravity CLI, Hermes, OpenClaw, MCP
Input types
code, text
Output types
text
Best For
blocking risky agent commands, on-device agent guardrails, agent audit trails
Compare key features
View all alternatives →Feature
Harden
Neuphonic
MacWhisper
Pricing
Freemium
Freemium
Paid
Free plan
Yes
Yes
Yes
Free trial
No
No
No
API
No
Yes
No
Self-hosted
Yes
Yes
Yes
Team support
Yes
Yes
No
Frequently asked questions
What does Harden actually block?+
It evaluates each tool call a coding agent is about to make and can allow, block, redact, or log it before execution.
Does my code leave my machine?+
No. The cybersecurity models run locally on the device, and telemetry can be opted out.
Which agents does it support?+
Claude Code, Codex, Cursor, Kiro, Antigravity CLI, Hermes, and OpenClaw natively, with an MCP proxy fallback for others.
Does Harden run on Windows?+
No. It supports macOS and Linux, with the full local model requiring Apple Silicon.
Is the free plan a trial?+
No. The Free plan is described as free forever and does not require an account.
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