How to Extend Claude Code

Claude Code ships with powerful defaults, but its real strength comes from extensions. Skills, plugins, and MCP servers let you teach Claude new workflows, connect it to external systems, and tailor it to your exact stack — without touching any configuration files.

The Three Extension Types

Claude Code supports three distinct extension mechanisms. Each solves a different problem — understanding the distinction helps you pick the right tool for the job.

skill

Skills — Teach Claude a Task

Skills are Markdown instruction files that encode expert knowledge into a workflow Claude can follow consistently. A code review skill tells Claude exactly what to check; a commit message skill ensures every commit follows your team's convention.

542 skills available · lightweight · version-controllable

plugin

Plugins — Install a Complete Toolkit

Plugins bundle multiple skills, MCP server configs, and tool preferences into a single install. The fastest way to set up Claude for a new framework, language, or workflow — one command, everything configured.

2548 plugins available · batteries-included · team-shareable

mcp

MCP Servers — Connect to External Systems

MCP (Model Context Protocol) servers give Claude real-time access to external tools and data sources. Query your PostgreSQL database, search GitHub issues, or read from a remote API — all through natural language.

775 MCP servers available · real-time data · standardized protocol

Installing Extensions

Each extension type has its own install command. All three follow the same pattern — find the extension on Claude Bazaar, copy its install command, run it in your terminal.

Installing a Skill

claude skill add <skill-url>

Add --global to install across all projects, or omit to scope to the current project.

Installing a Plugin

claude plugin add <plugin-url>

Plugins auto-install all bundled skills and register MCP server configs in one step.

Installing an MCP Server

claude mcp add <server-name> <command>

MCP server configs are stored in .claude/settings.json and loaded automatically on startup.

Recommended Starting Point

Not sure where to start? These are the most popular extensions across the Claude Code community — a solid foundation for any development workflow.

Top MCP Servers

See top 20 MCP servers →

Choosing the Right Extension

If you want to… Use a…
Teach Claude your team's code review checklist skill
Set up Claude for a new React or Next.js project plugin
Let Claude query your PostgreSQL database mcp server
Standardize commit messages across the team skill
Give Claude full access to GitHub PRs and issues mcp server
Onboard a new developer with your full tool stack plugin

Managing Installed Extensions

Claude Code stores extension configuration in .claude/settings.json at the project or global level. You can inspect, edit, or remove extensions at any time.

claude skill list
claude mcp list

Extensions can also be committed alongside your project so every team member gets the same setup when they clone the repo.

Frequently Asked Questions

Can I use skills and MCP servers together?

Yes. Skills and MCP servers are complementary. A skill might tell Claude how to structure a database migration, while an MCP server gives it live access to your database to run that migration.

Are extensions safe to install?

Skills are plain Markdown files — they contain instructions, not executable code. MCP servers run as local processes and only have the permissions you grant them. Always review the source before installing any extension.

Can I write my own skill or plugin?

Yes. Skills are Markdown files that follow a simple format — you can write one in minutes. Plugins are directories containing a manifest plus any skills, MCP configs, and settings they bundle.

How many extensions can I install?

There's no hard limit. Skills are lightweight and load instantly. MCP servers each consume a small amount of memory as background processes — most setups run comfortably with five to ten servers active.

Explore More