Coding agents now run commands, install packages and read whatever they are pointed at. HOL Guard reviews every action before it runs, the Plugin Registry scores plugins before you install one, and CIGAR gives agents cited context within a budget. All of it open source and free to run.
AI agents will write and run more of the world's software every year. The security underneath them should be open and owned by no single company. Sponsorship keeps it that way.
Works with Codex, Claude Code, Copilot CLI and 10 more coding agents.
02 · Before an agent installs
Check a plugin before you install it.
The HOL Plugin Registry lists plugins, MCP servers and skills for agent tools. Each shows who built it, whether the owner is verified, and a trust score.
CIGAR, the Context Intelligence Graph Agentic Runtime, turns documents and code into cited context that fits an agent's token budget. It runs locally through Python and TypeScript SDKs, with no model, account or API key.
Relevant by selection
Deterministic ranking packs only what the question needs, from your own sources.
Bounded by design
Your app sets the sources, scope and token budget. Relevance never overrides permission.
Traceable to the source
Every context carries citations and a snapshot you can verify before an answer ships.
Latest, v0.14.1: independent agents share one local evidence graph while the host keeps authority, now with security fixes. Release notes
The HOL Registry Broker searches and resolves AI agents across registries and protocols. Every result carries an HCS-14 universal agent ID and its trust signals.
Guard and the registries run on the Hiero Consensus Standards, written in the open with partners. Anyone can read, implement or propose changes to them.
Built in the open, with the companies that depend on it.
HOL is part of Hiero at the Linux Foundation Decentralized Trust. Everything here is developed in public with Partner Program members, in working groups on registries, payments, privacy and security, and inter-agent communication.
Nothing on this page sits behind a paywall. The work is paid for by the teams that run it, the companies that want to reach them, and sponsors. Every way to take part is listed here.
Sponsorship is how the open security work stays open.
Annual sponsorships pay for the engineering behind Guard, the registries, CIGAR and the standards, and let you scope the security problem you most want solved in public.
HOL, short for Hashgraph Online, is open infrastructure for AI agents. It builds HOL Guard for agent security, the HOL Plugin Registry for finding plugins, MCP servers, and skills, CIGAR for cited, budgeted agent context, the Registry Broker for agent discovery, and the open HCS standards behind them.
What is HOL Guard?
HOL Guard is a local-first security layer for AI agents. On supported integrations it checks risky actions such as commands, tool calls, package installs, and configuration changes before they run, lets you allow, ask, or block them, and keeps a record of what happened. Install it with the one-line command on this page, then run hol-guard init.
Which AI tools does HOL Guard work with?
HOL Guard connects to Codex, Claude Code, Copilot CLI, Antigravity CLI, Cursor, OpenCode, Hermes, OpenClaw, Antigravity, Kimi, Grok, Pi, Z Code, or a custom agent. How much Guard can intercept depends on what each tool exposes, so check the Guard documentation at hol.org/guard/docs for the coverage of your tool.
What is the HOL Plugin Registry?
The HOL Plugin Registry is a public directory of plugins, MCP servers, and skills for AI agent tools. Each listing shows its developer, category, verification and trust signals, and scan results, so you can compare options before you install one.
What is CIGAR?
CIGAR, the Context Intelligence Graph Agentic Runtime, is open-source infrastructure for agent context. It turns documents and code into relevant, cited context that fits a token budget, keeps the allowed sources and authority with your application, and returns a verifiable snapshot with every compiled context. The Rust core runs locally through Python and TypeScript SDKs. See hol.org/cigar.
How do developers build on the HOL Registry Broker?
The Registry Broker is the HOL API for discovering and resolving AI agents across registries. Start with the documentation at hol.org/docs and the developer hub at hol.org/developers, then call the API described by the OpenAPI document at hol.org/openapi.json and the registry docs at hol.org/registry/docs.
What are the HCS standards?
The HCS standards are open specifications for agent identity, messaging, registries, and trust that HOL and its partners publish. Examples include HCS-10 for agent communication, HCS-14 for Universal Agent IDs, and HCS-26 for agent skills registries. The full list is at hol.org/standards.
How can my company support HOL's open-source work?
Sponsorship starts at $5,000 a year and includes a linked company logo on an agreed HOL sponsor or partner page for 12 months, a jointly reviewed announcement on the HOL blog, and quarterly written updates on the work it supports; see hol.org/sponsor. Advertising starts at $50 a month for a plugin directory placement and $50 a month for an extension directory placement; see hol.org/advertise. Organizations building on the standards can apply to join the HOL Partner Program and co-author them alongside the founding cohort.
