Harden
AILocal security layer for AI coding agents that inspects every tool call before it runs and can block, rewrite, or pause the action.
Harden
Local security layer for AI coding agents that inspects every tool call before it runs and can block, rewrite, or pause the action.
About Harden
Harden builds the Agentic Integrity Foundation (AIF), an on-device firewall that sits between a coding agent and the actions it wants to take. Rather than detecting suspicious behaviour after the fact, AIF evaluates each command, file edit, tool call, and outbound request against the task the developer actually asked for, using the request and session context to judge intent. A purpose-trained 8-billion-parameter model makes the call locally, which its makers report beats frontier models on agent-security benchmarks while staying small enough to run alongside the agent without slowing it down. Decisions are recorded as Allow, Block, Ask, Redact, or Log-only and reviewed through a local dashboard, and when an action is stopped the agent keeps working on everything else instead of halting. Because the model runs on the developer's own machine, repository contents and tool output never leave it, and AIF is free for individual developers across agents including Claude Code, Cursor, Codex, and others.
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Key Features
Use Cases
Frequently asked questions about Harden
What is Harden?
Local security layer for AI coding agents that inspects every tool call before it runs and can block, rewrite, or pause the action.
How does Harden work?
Harden works by combining Pre-Execution Tool Call Checking: Every command, file edit, tool call, and outbound request is evaluated before it is allowed to run, not audited afterwards., Intent-Aware Decisions: The check compares the proposed action against the task the developer actually requested plus session context, rather than matching a static rule list., On-Device Model: A post-trained 8B-parameter model runs locally and is reported to beat frontier models on agent-security benchmarks while remaining fast enough to sit inline., Graduated Responses: Actions can be allowed, blocked, redacted, paused for a human answer, or simply logged, and a blocked action does not stop the agent's other work., Secret and Exfiltration Protection: Catches credential leaks, data exfiltration attempts, and destructive infrastructure operations before they execute. to help users with Guarding Autonomous Coding Sessions: Let a coding agent run with fewer manual approvals while a local check still catches destructive commands., Preventing Secret Leakage: Stop an agent from pasting API keys or credentials into an outbound request or a committed file., Blocking Prompt-Injection Damage: Catch actions an agent was steered into by malicious content in a repository, issue, or web page it read., Protecting Production Infrastructure: Intercept destructive infrastructure operations before they reach cloud resources or databases., Agent Behaviour Auditing: Review a logged trail of what an agent tried to do and which actions were blocked or redacted..
What are the main features of Harden?
Key features include Pre-Execution Tool Call Checking: Every command, file edit, tool call, and outbound request is evaluated before it is allowed to run, not audited afterwards., Intent-Aware Decisions: The check compares the proposed action against the task the developer actually requested plus session context, rather than matching a static rule list., On-Device Model: A post-trained 8B-parameter model runs locally and is reported to beat frontier models on agent-security benchmarks while remaining fast enough to sit inline., Graduated Responses: Actions can be allowed, blocked, redacted, paused for a human answer, or simply logged, and a blocked action does not stop the agent's other work., Secret and Exfiltration Protection: Catches credential leaks, data exfiltration attempts, and destructive infrastructure operations before they execute..
Who is Harden for?
Harden is useful for anyone interested in Guarding Autonomous Coding Sessions: Let a coding agent run with fewer manual approvals while a local check still catches destructive commands., Preventing Secret Leakage: Stop an agent from pasting API keys or credentials into an outbound request or a committed file., Blocking Prompt-Injection Damage: Catch actions an agent was steered into by malicious content in a repository, issue, or web page it read., Protecting Production Infrastructure: Intercept destructive infrastructure operations before they reach cloud resources or databases., Agent Behaviour Auditing: Review a logged trail of what an agent tried to do and which actions were blocked or redacted..
How much does Harden cost?
Harden is free to use.
How do I get started with Harden?
Visit https://harden.run/ to sign up and explore Harden.
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