HOL Guard

HOL Guard is a local-first runtime security layer for AI agents, built by HOL (Hashgraph Online). On supported integrations it checks risky actions such as shell commands, tool calls, package installs and configuration changes before they run, then allows, asks or blocks them and keeps a local record. Its core Guard Local runtime is open source under Apache-2.0 and runs on the developer machine without a cloud account.

What It Is

Guard sits between a coding agent and the machine it runs on. Routine work such as running tests goes through, new or ambiguous actions such as a first package install pause for approval, and clearly dangerous actions such as reading cloud credentials or sending a .env file to a remote host are blocked. Each decision is saved as a local receipt. Guard is described by HOL as not a cloud MCP gateway, not a network firewall, and not a complete prompt-injection preventer. It reduces impact at supported action boundaries.

Coverage and Protection Model

HOL says Guard protects supported workflows against secret and credential exposure, destructive commands, prompt-injection-driven actions, malicious or changed packages, risky MCP configuration, and unsafe plugins, skills, hooks and agent settings. Supported agents listed include Codex, Claude Code, Cursor, OpenCode, Antigravity CLI, Hermes, OpenClaw, GitHub Copilot CLI, Antigravity, Kimi, Grok, Pi / Oh My Pi and Zcode. Enforcement depth varies by agent and event type, so a public coverage matrix states what is blocked, reviewed, observed or not covered.

Setup Path

Installation is a one-line shell command for macOS or Linux that pipes the install script from hol.org into bash, with an option to configure a specific agent such as Cursor and verify the install. After installing, users run hol-guard init. A free risk check is also offered before installing.

Guard Local and Guard Cloud

Guard Local enforces policy on the developer machine and keeps working offline. Guard Cloud is an optional, separate service that adds synchronized evidence, shared policy, fleet visibility and team dashboards; HOL states cloud connectivity is for visibility and coordination, not enforcement.

For Plugin Maintainers

HOL also publishes plugin-scanner and a GitHub Action that validate plugins, skills and MCP configuration in CI, checking manifests, MCP transport hardening and skill-level issues such as prompt injection markers and dangerous shell commands. HOL's site lists v3.58.0 as the latest Guard release, dated October 27, 2026.