HOL Plugin Marketplace

• Public directory of AI agent plugins, MCP servers, and agent skills
• Searchable catalog with filters for categories, tags, and supported agent ecosystems
• HOL trust scores based on publisher identity, activity, verification, and security signals
• Security scanning information and findings for listed plugins
• Publisher verification indicators to help identify plugin maintainers
• Agent-specific installation commands and setup instructions
• Compatibility information for Claude Code, Codex, Cursor, OpenCode, and other agent environments
• Plugin launch listings and recently published extensions
• Developer submission workflow for publicly available plugin repositories
• Paid publisher verification, listing insights, and promotional placement options

What Is HOL Plugin Registry?

HOL Plugin Registry is a public directory designed to help developers and AI agent users discover plugins, Model Context Protocol (MCP) servers, and agent skills. It brings listings from different AI agent ecosystems into one searchable catalog, making it easier to explore available extensions, review publisher information, compare trust signals, and find installation instructions.

The registry is part of HOL (Hashgraph Online), an open infrastructure project focused on AI agent discovery, security, and interoperability. Its plugin directory provides information about third-party tools that extend the capabilities of AI agents.

AI Agent Plugin Discovery

HOL provides a searchable catalog of plugins designed for different AI agent environments. Users can explore extensions based on their intended purpose, supported agent, category, and available tags.

The directory includes tools for coding, research, documentation, workflow automation, testing, security, memory management, and other development activities. This allows users to find relevant extensions without searching through multiple independent repositories.

Support for Plugins, MCP Servers, and Skills

The registry organizes several types of AI agent extensions:

• Plugins: Packages that extend an AI agent with additional functionality.
• MCP servers: Connections that allow AI agents to interact with external tools, applications, and data sources through the Model Context Protocol.
• Skills: Instructions and optional scripts that teach AI agents how to perform particular tasks and workflows.
• Apps: Bundled interfaces or services that can operate alongside supported agent environments.

A listing can contain one or more of these components. The registry identifies the available components so users can better understand what an extension provides.

Trust Scores and Security Information

One of HOL’s main features is its trust-scoring system. Plugin listings can display a trust score based on signals such as publisher identity, activity, verification, and security information.

Security-related information helps users compare available extensions before deciding whether to install them. Listings may also include scanner-backed findings and other signals that provide additional context about the plugin and its source.

These scores are intended to support informed evaluation, not guarantee that a plugin is completely safe. Users should still review permissions, source repositories, installation instructions, and the latest available security information before using third-party extensions.

Publisher Verification

HOL provides owner verification indicators to help users identify plugin publishers. Verified ownership can offer additional confidence that a listing is associated with its stated maintainer.

Publisher information and verification status are displayed alongside other listing details. This helps users distinguish between identified maintainers and listings that have not completed the verification process.

Agent Compatibility and Installation Instructions

HOL Registry supports discovery across multiple AI agent environments, including Claude Code, Codex, Cursor, OpenCode, Antigravity CLI, and other supported runtimes.

Users can select their preferred agent environment and view installation commands adapted to the selected runtime. Individual plugin pages provide additional setup instructions and information about the extension’s declared compatibility.

Installation methods can differ depending on whether an extension is packaged as a plugin, skill, or MCP server. Users should follow the instructions provided for their particular agent environment.

Plugin Categories and Topic Discovery

The registry organizes plugins into categories and topic groups to make discovery more convenient. Users can explore extensions for common development and productivity tasks.

Topics include planning and workflow, memory and context, code review, documentation, security, multi-agent orchestration, testing, design, research, debugging, and DevOps.

Topic pages provide curated discovery pathways and ranked listings based on the registry’s available signals. These categories help users narrow their searches according to the work they want an AI agent to perform.

Plugin Submission and Developer Visibility

Developers can submit publicly available plugin repositories through HOL’s submission workflow. The registry provides a discovery channel for builders who want their extensions to become visible across supported AI agent ecosystems.

Listed projects can benefit from searchable catalog entries, compatibility information, publisher details, trust signals, and launch-feed visibility. Standard public repository listings are free.

Developers can also explore optional paid verification and promotional services to provide additional listing information and visibility.

Launch Feed and Featured Listings

HOL includes a plugin launch feed that helps users discover recently published extensions. Users can explore current launches, upcoming listings, and archived entries.

The directory also provides featured and sponsored placement options. Promotional placements are identified separately and do not automatically change the organic trust-based ranking of plugins.

Paid Publisher Services

Although browsing and standard plugin listings are free, HOL offers optional paid services for plugin owners.

HOL Blue provides a verification checkmark for an individual listing, a README badge, publisher insights, and additional listing-related features. Its published price starts at $4.99 per month per listing.

HOL Gold provides broader owner-level benefits, including insights across verified listings, CSV export, priority rescans, and a gold verification mark. Its published price is $29 per month per owner account.

Separate advertising options are also available for developers and organizations interested in featured directory placements.

Who Can Benefit From HOL Plugin Registry?

• AI developers searching for plugins and agent integrations
• Users extending coding agents with additional capabilities
• Developers looking for MCP servers and external tool connections
• Teams evaluating third-party AI agent extensions
• Plugin creators seeking discovery and publisher visibility
• Organizations comparing security and verification information
• Researchers exploring the AI agent plugin ecosystem

Frequently Asked Questions

What is HOL Plugin Registry used for?

HOL Plugin Registry helps users discover, evaluate, and compare plugins, MCP servers, and skills designed to extend AI agent capabilities.

Is HOL Plugin Registry free?

Yes. Browsing the directory and submitting standard public plugin listings are free. Optional paid services include publisher verification and promotional placements.

What types of extensions are listed?

The registry includes AI agent plugins, MCP servers, skills, and supported apps that provide additional tools, integrations, and workflows.

Which AI agents does HOL support?

The registry covers multiple agent environments, including Claude Code, Codex, Cursor, OpenCode, Antigravity CLI, and other supported runtimes. Compatibility varies by individual listing.

How does the HOL trust score work?

The trust score uses signals related to publisher identity, activity, verification, and security information to help users compare plugin listings. It is an evaluation aid rather than a guarantee of safety.

Can developers submit their own plugins?

Yes. Developers can submit publicly available plugin repositories through the HOL submission process for consideration in the registry.

Does HOL provide installation instructions?

Yes. Plugin listings can provide installation commands and setup instructions adapted to supported AI agent environments.

Does a verified publisher mean a plugin is completely safe?

No. Publisher verification identifies the associated maintainer, while trust and security signals provide additional evaluation information. Users should independently review permissions, source code, and installation requirements.

Does HOL offer paid promotional services?

Yes. HOL provides optional paid verification memberships and advertising placements for plugin owners who want additional listing features and visibility.

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