Plugin Apache-2.0
code-simplifier
by Anthropic
Agent that simplifies code for clarity and maintainability while preserving behaviour.
- Does
- 3 things
- Install
- 4 steps
- Works with
- Claude Code
Skills · plugins · MCP · rules114 official
MCP servers, skills, plugins and rules for AI coding agents
Extensions are the things you plug into an AI coding agent: MCP servers that give it tools and data, skills and plugins that package workflows, and rules files that set how it should behave in a repository. This index covers 116 of them, each documented from its official repository or docs, with install steps, the permissions it asks for, and known limits.
Pick your host above to see what works with it: Claude Code has the widest set (84), followed by Cursor (32), Windsurf and OpenAI Codex (14 each) and Gemini CLI (9). MCP servers marked "any MCP client" run in all of them.
Claude Code84 extensions
OpenAI Codex14 extensions
Cursor32 extensions
Windsurf14 extensions
Gemini CLI9 extensions
GitHub Copilot1 extensions
Any MCP client46 extensions
Skill · 19Reusable instructions and scripts the agent loads for a taskAlgorithmic Art, brand-guidelines, Canvas Design…
Plugin · 42Bundles of skills, commands, hooks and agentsAgent SDK Development Plugin, C# LSP, clangd LSP…
MCP server · 49Connect the agent to tools, data and servicesApify MCP Server, Atlassian Rovo MCP Server, AWS API MCP Server…
Rules & instructions · 6Project instructions the agent reads every sessionAGENTS.md, CLAUDE.md, Cursor Rules…
116 extensions
MCP server Apache-2.0
Codex MCP configuration
by OpenAI
How OpenAI Codex connects to MCP servers via codex mcp add or [mcp_servers] tables in config.toml, for CLI and IDE.
- Does
- 5 things
- Install
- 5 steps
- Works with
- OpenAI Codex
Plugin Apache-2.0
commit-commands
by Anthropic
Slash commands for git commit, push and PR creation in one step.
- Does
- 4 things
- Install
- 4 steps
- Works with
- Claude Code
MCP server MIT
Context7 MCP
by Upstash
Upstash's MCP server that injects up-to-date, version-specific library docs and code examples into your prompt.
- Does
- 5 things
- Install
- 5 steps
- Works with
- 3 hosts
Cursor MCP
by Cursor (Anysphere)
Connect Cursor to external tools and data via MCP servers configured in mcp.json or installed from the Cursor Marketplace.
- Does
- 4 things
- Install
- 4 steps
- Works with
- Cursor
Cursor Plugins and Marketplace
by Cursor (Anysphere)
Cursor Plugins bundle skills, MCP servers, rules, agents, commands and hooks; official ones are listed in the Cursor Marketplace.
- Does
- 5 things
- Install
- 4 steps
- Works with
- Cursor
Cursor Rules
by Cursor (Anysphere)
Persistent prompt-level instructions for Cursor Agent: project .mdc rules, user rules, team rules and AGENTS.md.
- Does
- 4 things
- Install
- 4 steps
- Works with
- Cursor
Plugin Apache-2.0
CWC Makers
by Anthropic
One-command onboarding for the Code-with-Claude Makers M5Stack Cardputer kit: clone, flash, install apps.
- Does
- 6 things
- Install
- 4 steps
- Works with
- Claude Code
Skill Apache-2.0
Discernment Nudge
by Anthropic
Appends 2-3 short follow-up questions to substantive answers so users check facts, reasoning and missing context.
- Does
- 5 things
- Install
- 4 steps
- Works with
- Claude Code
doc-coauthoring
by Anthropic
Structured workflow for co-authoring docs, proposals, specs and decision docs with context gathering, refinement and reader testing.
- Does
- 4 things
- Install
- 4 steps
- Works with
- Claude Code
MCP server MIT
Docker MCP Toolkit and MCP Gateway
by Docker
Docker's MCP Toolkit and gateway: run catalog MCP servers in isolated containers and expose them to any client through one endpoint.
- Does
- 6 things
- Install
- 5 steps
- Works with
- 3 hosts
document-skills
by Anthropic
Collection of document skills: Excel, Word, PowerPoint and PDF.
- Does
- 3 things
- Install
- 4 steps
- Works with
- Claude Code
MCP server Apache-2.0
Elasticsearch MCP Server (deprecated)
by Elastic
Elastic's MCP server for querying Elasticsearch indices in natural language; deprecated in favor of Elastic Agent Builder MCP.
- Does
- 4 things
- Install
- 5 steps
- Works with
- Any MCP client
MCP server MIT
Everything MCP Server
by Model Context Protocol
Reference test MCP server that exercises prompts, resources, tools and sampling, for people building MCP clients.
- Does
- 3 things
- Install
- 4 steps
- Works with
- Any MCP client
MCP server MIT
Exa MCP Server
by Exa Labs
Hosted Exa MCP server giving AI agents web search, page fetching and multi-step research.
- Does
- 5 things
- Install
- 5 steps
- Works with
- 6 hosts
Plugin Apache-2.0
Example Plugin
by Anthropic
Reference plugin showing skills, legacy commands and MCP server config for Claude Code plugin authors.
- Does
- 4 things
- Install
- 3 steps
- Works with
- Claude Code
example-skills
by Anthropic
Collection of example skills: skill-creator, MCP builder, design, algorithmic art, comms, web testing, artifacts, Slack GIFs, themes.
- Does
- 3 things
- Install
- 4 steps
- Works with
- Claude Code
Plugin Apache-2.0
explanatory-output-style
by Anthropic
SessionStart hook adding educational insights on implementation choices (replaces deprecated output style).
- Does
- 3 things
- Install
- 4 steps
- Works with
- Claude Code
Plugin Apache-2.0
feature-dev
by Anthropic
7-phase guided feature development workflow with exploration, architecture and review agents.
- Does
- 4 things
- Install
- 4 steps
- Works with
- Claude Code
MCP server MIT
Fetch MCP Server
by Model Context Protocol
Reference MCP server that fetches a URL and returns its content as markdown, in chunks, for LLM use.
- Does
- 5 things
- Install
- 4 steps
- Works with
- Any MCP client
Figma MCP Server
by Figma
Figma's MCP server (remote or desktop) to get design context, generate code from frames and write to the canvas.
- Does
- 6 things
- Install
- 4 steps
- Works with
- 5 hosts
MCP server MIT
Filesystem MCP Server
by Model Context Protocol
Reference MCP server for reading, writing, searching and moving files inside directories you explicitly allow.
- Does
- 6 things
- Install
- 4 steps
- Works with
- Any MCP client
MCP server MIT
Firecrawl MCP Server
by Firecrawl
Firecrawl's MCP server to search, scrape, crawl and interact with the live web, hosted or self-run.
- Does
- 5 things
- Install
- 4 steps
- Works with
- Any MCP client
What is in the index
49 MCP servers, 42 plugins, 19 skills and 6 rules files. Each entry records the author (official vendor or community), the hosts it supports, the transport and authentication it needs, and whether it is maintained or deprecated.
MCP servers, skills, plugins and rules: the difference
An MCP server exposes tools and data over the Model Context Protocol and works in any host that speaks it. A skill or plugin is host-specific and bundles prompts, commands and sometimes an MCP server. A rules file (CLAUDE.md, AGENTS.md, .cursor/rules) is plain text the agent reads before working. The explainer on what an MCP server is goes deeper.
How entries are checked
We read the README, the install instructions and the permission list in the official repository and record them as stated. Deprecated or archived repositories are labelled. Community entries are marked as such and are not endorsed.
FAQ
Which hosts are covered?
Claude Code, Cursor, Windsurf, OpenAI Codex, Gemini CLI and GitHub Copilot, plus MCP servers that work in any MCP client.
Are these official?
Each entry says who published it. 114 of 116 come from the vendor or the official project; community entries are labelled.
Do I need an API key?
It depends on the extension. The entry lists the authentication it requires, such as an API key, OAuth or none.
How do I install an MCP server?
Each entry shows the install step for its hosts. The MCP servers hub has a comparison table by transport, auth and host.