# Claude Code Tools & Extensions
Useful tools, plugins, and extensions for Claude Code.
## MCP Servers
MCP (Model Context Protocol) servers are external processes that provide tools to Claude Code via a standardized protocol. They run alongside your session and extend Claude's capabilities.
### Context7
Up-to-date documentation and code examples for any library, available directly in your Claude Code session.
- **Website:**
- **Setup:**
```bash
claude mcp add --scope user --transport http context7 https://mcp.context7.com/mcp --header "CONTEXT7_API_KEY: "
```
- **Note:** API key can be created for free after signing in at [context7.com](https://context7.com/)
## Skills (Slash Commands)
Skills are a different extension mechanism from MCPs. They are prompt-based extensions invoked via `/skill-name` commands directly within Claude Code — no external server required.
### AST Index
Fast code search skill for Claude Code — find classes, symbols, usages, implementations, and more across large codebases using AST parsing.
- **Repository:**
- **Usage:** Invoke with `/ast-index` or related commands like "find class", "search for symbol", etc.
## Toolkits
### Everything Claude Code (ECC)
A comprehensive collection of skills, rules, agents, and hooks for Claude Code.
- **Repository:**
- **Setup guide:** [ecc-setup-guide.md](ecc-setup-guide.md)