Skill Porter - Cross-Platform Skill Converter

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name: skill-porter description: Converts Claude Code skills to Gemini CLI extensions and vice versa. Use when the user wants to make a skill cross-platform compatible, port a skill between platforms, or create a universal extension that works on both Claude Code and Gemini CLI. allowed-tools:

• Read
• Write
• Edit
• Glob
• Grep
• Bash

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Skill Porter - Cross-Platform Skill Converter

This skill automates the conversion between Claude Code skills and Gemini CLI extensions, enabling true cross-platform AI tool development.

Core Capabilities

Bidirectional Conversion

Convert skills and extensions between platforms while preserving functionality:

**Example requests:**

• "Convert this Claude skill to work with Gemini CLI"
• "Make my Gemini extension compatible with Claude Code"
• "Create a universal version of this skill that works on both platforms"
• "Port the database-helper skill to Gemini"

Smart Platform Detection

Automatically analyzes directory structure to determine source platform:

**Detection criteria:**

• Claude: Presence of SKILL.md with YAML frontmatter or .claude-plugin/marketplace.json
• Gemini: Presence of gemini-extension.json or GEMINI.md context file
• Universal: Has both platform configurations

**Example requests:**

• "What platform is this skill built for?"
• "Analyze this extension and tell me what needs to be converted"
• "Is this a Claude skill or Gemini extension?"

Metadata Transformation

Intelligently converts between platform-specific formats:

**Conversions handled:**

• YAML frontmatter ↔ JSON manifest
• allowed-tools (whitelist) ↔ excludeTools (blacklist)
• Environment variables ↔ settings schema
• MCP server configuration paths
• Platform-specific documentation formats

**Example requests:**

• "Convert the metadata from this Claude skill to Gemini format"
• "Transform the allowed-tools list to Gemini's exclude pattern"
• "Generate a settings schema from these environment variables"

MCP Server Preservation

Maintains Model Context Protocol server configurations across platforms:

**Example requests:**

• "Ensure the MCP server config works on both platforms"
• "Update the MCP server paths for Gemini's ${extensionPath} variable"
• "Validate that the MCP configuration is compatible"

Validation & Quality Checks

Ensures converted output meets platform requirements:

**Validation checks:**

• Required files present (SKILL.md, gemini-extension.json, etc.)
• Valid YAML/JSON syntax
• Correct frontmatter structure
• MCP server paths resolve correctly
• Tool restrictions are valid
• Settings schema is complete

**Example requests:**

• "Validate this converted skill"
• "Check if this Gemini extension meets all requirements"
• "Is this conversion ready to install?"

Conversion Process

When you request a conversion, I will:

1. Analyze the source directory structure
2. Detect which platform it's built for
3. Extract metadata, MCP configuration, and documen