How to Install the Humanizer Skill as a Claude Plugin: Complete Setup Guide

You can install the Humanizer skill as a Claude plugin using Claude's built-in marketplace commands, the Skills CLI, or manual file placement, with the core logic residing in the SKILL.md file referenced by .claude-plugin/plugin.json.

The blader/humanizer repository provides a ready-to-use Claude plugin that transforms AI-generated text into natural, human-friendly prose. Unlike traditional software packages, Humanizer is delivered as a plain-text skill using the SKILL.md format, supplemented by JSON manifest files that enable seamless integration with Claude's plugin system.

Prerequisites

Claude version 2.1.142 or higher is required to support the plugin architecture used by Humanizer. Verify your Claude installation meets this minimum version before proceeding with any installation method.

Installation Methods

Claude supports three distinct approaches to install the Humanizer skill, ranging from automated marketplace integration to manual file management.

Method 1: Using Claude's Built-in Plugin Commands

The fastest way to install Humanizer leverages Claude's native marketplace integration. Execute these commands in your Claude interface:

/plugin marketplace add blader/humanizer
/plugin install humanizer@humanizer

The first command registers the Humanizer entry in your local marketplace cache by reading .claude-plugin/marketplace.json. The second command pulls the latest version from the repository and activates the plugin. After completion, invoke the skill using /humanizer:humanizer.

Method 2: Using the Skills CLI

For developers managing multiple agents or requiring project-scoped installations, the Skills CLI provides granular control:

# Install globally for all Claude agents

npx skills add blader/humanizer --global

Target specific agents or restrict installation to the current project:

# Project-local installation only

npx skills add blader/humanizer

# Target specific agents

npx skills add blader/humanizer --agent 'my-agent'

# Target all agents explicitly

npx skills add blader/humanizer --agent '*'

After CLI installation, reload your agents' skill sets to activate Humanizer's 35 rewrite patterns.

Method 3: Manual Installation

If you bypass the marketplace and CLI, copy the core skill file directly into Claude's skill directory:

mkdir -p ~/.claude/skills/humanizer/
cp SKILL.md ~/.claude/skills/humanizer/

While the JSON manifests in .claude-plugin/ are optional for manual installs, retaining them ensures future compatibility with marketplace updates.

Understanding the Plugin Architecture

The Humanizer repository separates functional logic from plugin metadata across three critical files:

• SKILL.md – Contains the 35 rewrite patterns and prompt engineering logic that defines Humanizer's behavior
• .claude-plugin/plugin.json – The plugin manifest that tells Claude where to locate SKILL.md and how to execute the skill
• .claude-plugin/marketplace.json – Discovery metadata enabling the plugin to appear in Claude's marketplace UI

This architecture follows Claude's skill-as-code philosophy, where the prompt itself (SKILL.md) serves as the executable artifact.

Verifying Your Installation

The repository includes .claude-plugin/validate-package.py (referenced as scripts/validate-package.py) to ensure consistency between SKILL.md, the README documentation, and plugin manifest files. Run this script after manual modifications to validate that plugin metadata remains synchronized with the skill content.

Using the Humanizer Plugin

Once installed, activate Humanizer by typing:

/humanizer:humanizer

Follow this command with the AI-generated text you wish to humanize. The plugin processes input through its pattern matching system defined in SKILL.md, outputting revised text that eliminates robotic phrasing and mechanical transitions.

Summary

• Humanizer installs as a Claude plugin via marketplace commands, Skills CLI, or manual SKILL.md placement
• The .claude-plugin/plugin.json manifest bridges Claude's plugin system with the SKILL.md prompt file
• Claude 2.1.142+ is required for full plugin functionality
• Use /plugin marketplace add blader/humanizer followed by /plugin install humanizer@humanizer for quickest setup
• The npx skills add command supports global, project-local, and agent-specific installations
• Validation scripts ensure plugin metadata consistency across updates

Frequently Asked Questions

What files are required to install Humanizer as a Claude plugin?

Only SKILL.md is technically required for functionality, as it contains the core prompt logic. However, to register as a proper Claude plugin with marketplace support, you need .claude-plugin/plugin.json (which points to SKILL.md) and optionally .claude-plugin/marketplace.json for discovery.

Can I install Humanizer without using the Claude marketplace?

Yes. You can install Humanizer manually by copying SKILL.md to your Claude agent's skill folder (typically ~/.claude/skills/humanizer/) or by using the npx skills add CLI command. The marketplace integration is optional but recommended for automatic updates.

How do I update the Humanizer plugin after installation?

If you installed via the marketplace commands, run /plugin update humanizer@humanizer or reinstall using the marketplace add command. For CLI installations, execute npx skills update blader/humanizer or re-run the add command with the same scope flags (--global or --agent).

What Claude versions support the Humanizer plugin?

Humanizer requires Claude version 2.1.142 or later. Earlier versions lack support for the plugin manifest schema used in .claude-plugin/plugin.json and the /plugin command namespace.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}