Plugin

Severity1 Marketplace

Severity level classification and prompt improvement for marketplace plugins. Assigns severity ratings (S1-Critical through S4-Low) and enhances plugin prompts for clarity, safety, and effectiveness.

Type: Plugin
Repository: jeremylongshore/tons-of-skills-marketplace
GitHub stars: 2.8k
License: MIT
Repo last updated: Sep 27, 2026
Source file: plugins/security/severity1-marketplace/.claude-plugin/plugin.json
Version: 1.7.0
Author: severity1

What Severity1 Marketplace is

Severity1 Marketplace is a plugin published in the jeremylongshore/tons-of-skills-marketplace repository on GitHub, which has about 2.8k stars. The repository describes itself as: “Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com.”

A plugin is a package that bundles skills, slash commands, subagents, hooks, and MCP connectors so they install together. Plugins are plain files with a manifest at .claude-plugin/plugin.json, and they work in both Claude Code and Claude Cowork.

Installing Severity1 Marketplace adds everything it ships in one step. Connectors inside a plugin still need to be connected separately, and hooks and subagents only run in Cowork and Claude Code, not in regular chat.

How to install Severity1 Marketplace

Claude Code

Add the repository as a plugin marketplace: claude plugin marketplace add jeremylongshore/tons-of-skills-marketplace
Install the plugin: claude plugin install severity1-marketplace@<marketplace-name>, using the marketplace name from the repository's .claude-plugin/marketplace.json.
Restart the session if the new skills or commands don't appear straight away.

Claude Cowork

Open Customize → Plugins and choose Add marketplace.
Enter jeremylongshore/tons-of-skills-marketplace (the owner/repo shorthand works for GitHub).
Find Severity1 Marketplace in the list, click Install, then connect any connectors it needs from its Connectors tab.

New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.

Inside the source file

An excerpt from plugins/security/severity1-marketplace/.claude-plugin/plugin.json, shared under the repository's MIT license. Read the full file on GitHub.

Severity level classification and prompt improvement for Claude Code marketplace plugins.

Features

Severity Classification: Assigns severity ratings (S1-Critical, S2-High, S3-Medium, S4-Low) to security findings, bugs, and issues
Prompt Improver: Analyzes and enhances plugin prompts for clarity, safety, effectiveness, and best-practice adherence
Triage Agent: Automated severity triage for incoming issues and vulnerability reports

Severity Levels

Commands

/severity-classify — Classify an issue or finding by severity level
/prompt-improve — Analyze and improve a plugin prompt or skill definition

Skills

prompt-improver — Auto-activates when users ask to improve, review, or enhance prompts, skill definitions, or command instructions

Agents

severity-triage — Automated severity triage agent for issues and vulnerabilities

Installation

claude plugin marketplace add severity1/severity1-marketplace

Usage

/severity-classify "Users can bypass authentication by..."
/prompt-improve

Contributors

severity1

License

MIT

Before you install

Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
Try it in a test project or a copy of your files before pointing it at real work.
Pin the version you tested, and review changes before updating.
Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.

FAQ

What is Severity1 Marketplace?

Severity1 Marketplace is a plugin for Claude Code and Claude Cowork from the jeremylongshore/tons-of-skills-marketplace repository on GitHub. Severity level classification and prompt improvement for marketplace plugins. Assigns severity ratings (S1-Critical through S4-Low) and enhances plugin prompts for clarity, safety, and effectiveness.

How do I install Severity1 Marketplace in Claude Code?

Add the repository as a plugin marketplace: claude plugin marketplace add jeremylongshore/tons-of-skills-marketplace Install the plugin: claude plugin install severity1-marketplace@<marketplace-name>, using the marketplace name from the repository's .claude-plugin/marketplace.json. Restart the session if the new skills or commands don't appear straight away.

Can I use Severity1 Marketplace in Claude Cowork?

Open Customize → Plugins and choose Add marketplace. Enter jeremylongshore/tons-of-skills-marketplace (the owner/repo shorthand works for GitHub). Find Severity1 Marketplace in the list, click Install, then connect any connectors it needs from its Connectors tab.

Is Severity1 Marketplace safe to install?

It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.

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Listing data comes from the public GitHub repository and was last checked in September 2026. Excerpts are © their authors and shared under MIT. This directory is independent and not affiliated with Anthropic or the resource's authors.