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Claude Code Extensions — Skills, Hooks, Plugins and MCP
Claude Code is extensible in four distinct ways — and "extension" is a synonym for any of them depending on who you ask. This page is the disambiguation table plus the open catalog.
Claude Code is extensible in four distinct ways — and "extension" is a synonym for any of them depending on who you ask. This page is the disambiguation table plus the open catalog.
(1) Skills — SKILL.md files under ~/.claude/skills/. The most common shape: a named, invokable task that Claude picks up when relevant. ClaudSkills catalogs 67,000+. See /skills/.
(2) Hooks — shell commands wired into settings.json, fired at lifecycle events. Deterministic, not model-judged. See /learn/claude-code-hooks/.
(3) MCP servers — standalone processes Claude Code connects to over the Model Context Protocol, exposing tools and data sources. The driver layer. See /arcade/mcp-server/ for raw servers and /learn/claude-code-mcp-servers/ for skills that use them.
(4) Slash commands — Markdown files under ~/.claude/commands/ that the user invokes with /<name>. Lighter-weight than skills; no allowed-tools declaration, no auto-discovery in conversation.
The listing below is the top-quality slice of all four, ranked by the content-derived ClaudSkills quality score.
Top 40 indexed skills
- coverTools
Generate and run comprehensive test suites — unit tests, integration tests with real services (testcontainers/docker-compose), and Playwright E2E tests. Analyzes coverage gaps, spawns parallel test-generator agents…
- sales-attioSales
Attio platform help — AI-native CRM with custom objects, relationship database, deal pipelines, email sequences, automations, and built-in enrichment for 80,000+ startups. Covers custom data model design (objects,…
- sales-hypeauditorSales
HypeAuditor platform help — AI-powered influencer marketing with Influencer Discovery (223.6M+ profiles across Instagram, TikTok, YouTube, X, Twitch, Snapchat), Analytics Reports (35+ metrics, AQS scoring), Fraud…
- browser-toolsSecurity
OrchestKit security wrapper for browser automation. Adds URL blocklisting, rate limiting, robots.txt enforcement, and ethical scraping guardrails on top of the upstream agent-browser skill. Use when automating…
- sales-integrationSales
Connects sales tools with webhooks, Zapier/Make, native integrations, and custom API pipelines — CRM sync, event triggers, data mapping, and error handling. Use when CRM data isn't syncing from…
- sales-sendgridSales
SendGrid platform help — transactional email via Email API (REST + SMTP), Marketing Campaigns (drag-and-drop editor, automations, A/B testing, signup forms, segmentation), Email Validation API, Dynamic Templates…
- sales-transactional-emailSales
Transactional and triggered email delivery — order confirmations, password resets, welcome emails, receipts, shipping notifications, account alerts. Covers provider selection, template design, deliverability, API…
- testing-e2eEngineering
End-to-end testing patterns with Playwright — page objects, AI agent testing, visual regression, accessibility testing with axe-core, and CI integration. Use when writing E2E tests, setting up Playwright,…
- multimodal-llmGeneral
Vision, audio, video generation, and multimodal LLM integration patterns. Use when processing images, transcribing audio, generating speech, generating AI video (Kling v3, Sora 2, Veo 3.1 std/lite/fast, Runway…
- sales-grainSales
Grain AI meeting recorder platform help — REST API for transcripts, recordings, tags, action items, and video uploads (Business+), MCP Server for Claude/ChatGPT/Cursor with built-in SPICED/MEDDICC prompts, Zapier…
- sales-peerlistSales
Peerlist platform help — professional network for tech builders with weekly Launchpad, portfolio profiles, Scroll feed, and job board. Covers Launchpad submissions (free, weekly Monday launches, all projects…
- sales-trendheroSales
trendHERO platform help — Instagram influencer analytics (95M+ profiles, 20+ filters), Account Quality Score (AQS 1-100, fake follower detection), Audience Analysis, Daily Tracking, Ads Database (10M+ posts),…
- duplicate-rule-person-account-edge-casesGeneral
When and how to author Duplicate Rules and Matching Rules in B2C / Person Account orgs without breaking lead conversion, cross-object matching, or PII hygiene. Covers PA's dual-record (001/003) shape,…
- github-operationsGeneral
GitHub CLI operations for issues, PRs, milestones, and Projects v2. Covers gh commands, REST API patterns, and automation scripts. Use when managing GitHub issues, PRs, milestones, or Projects with gh.
- llm-integrationEngineering
LLM integration patterns for function calling, streaming responses, local inference with Ollama, and fine-tuning customization. Use when implementing tool use, SSE streaming, local model deployment, LoRA/QLoRA…
- sales-customerioSales
Customer.io platform help — customer engagement and marketing automation for behavior-based multi-channel messaging (email, SMS, push, in-app, WhatsApp). Use when automations aren't triggering on the right…
- storybook-mcp-integrationContent
Storybook MCP server integration for component-aware AI development. Covers 6 tools across 3 toolsets (dev, docs, testing): component discovery via list-all-documentation/get-documentation, story previews via…
- storybook-testingEngineering
Storybook 10 testing patterns with Vitest integration, ESM-only distribution, CSF3 typesafe factories, play() interaction tests, Chromatic TurboSnap visual regression, module automocking, accessibility addon testing,…
- audit-contractSecurity
Adversarial smart contract security audit. Auto-selects 5-7 specialist agents based on contract features (from a roster of 12). Attacks from every relevant angle: SWC registry, signatures, reentrancy, state machine,…
- process-flow-as-is-to-beSales
Documenting As-Is and To-Be business processes for a Salesforce project as swim-lane diagrams with one lane per actor (user, system, integration, customer), explicit decision points, parallel paths,…
- sales-adrollSales
AdRoll platform help — retargeting, display ads, social ads, CTV, native ads, DOOH, email retargeting, audience segmentation, cross-channel campaigns, Shopify/BigCommerce/WooCommerce integration, RollWorks ABM,…
- sales-airmailSales
Airmail platform help — Apple-exclusive email client with customizable swipe actions, multi-step Custom Actions, Smart Inbox, Send Later, snooze, AppleScript automation, Siri Shortcuts, Objective-C plugin framework,…
- sales-brevoSales
Brevo platform help — email/SMS/WhatsApp campaigns, marketing automation (journeys), transactional messaging, Sales CRM (deals, pipelines), Conversations (live chat, chatbot), Loyalty programs, push notifications,…
- sales-celigoSales
Celigo platform help — mid-market iPaaS, 1000+ connectors, AI-powered error management, endpoint+flow pricing, NetSuite depth, API Management, B2B/EDI, Embedded iPaaS, Celigo Ora AI agent. Use when integration errors…
- sales-fastmailSales
Fastmail platform help — independent privacy-respecting email with full JMAP API, custom domains, Masked Email aliases, calendar/contacts/files, OAuth 2.0, IMAP/SMTP/CardDAV/CalDAV/WebDAV, CORS-enabled, community MCP…
- sales-frontSales
Front platform help — AI-powered customer operations platform with shared inbox, omnichannel support (email, SMS, chat, social, WhatsApp), Autopilot AI resolution, Copilot agent assistant, Smart QA/CSAT, ticketing,…
- sales-influencer-heroSales
Influencer Hero platform help — all-in-one influencer marketing with discovery (200M+ profiles), automated outreach (AI-personalized email + DMs), CRM, affiliate tracking, product gifting, UGC capture, reporting,…
- sales-safetymailsSales
SafetyMails platform help — bulk email verification (up to 2M emails, 19-step algorithm), real-time API validation (JavaScript embed for forms), Email Finder (B2B corporate lookup), list cleaning,…
- sales-semrushSales
Semrush platform help — the leading SEO and online visibility management platform (27B keywords, 43T backlinks, 808M domain profiles, 142 geo databases). Covers keyword research, site audits, rank tracking, backlink…
- sales-snaplogicSales
SnapLogic platform help — enterprise iPaaS, 1000+ Snap connectors, AgentCreator AI agents, SnapGPT pipeline copilot, API Management 3.0, ETL/ELT/reverse ETL, visual pipeline designer. Use when pipeline debugging is…
- sales-socialhoseSales
Socialhose platform help — social listening and media monitoring with real-time and high-frequency monitoring modes, crisis detection, competitor analysis, webhook integrations (Pro+), no annual contracts. Use when…
- sales-syftenSales
Syften platform help — AI-filtered keyword monitoring across Reddit, Hacker News, X, Bluesky, Mastodon, GitHub, YouTube, Stack Exchange, Dev.to, Lobste.rs, Indie Hackers, Slack communities, newsletters, podcasts.…
- sales-tagshopSales
Tagshop.ai platform help — AI UGC video ad generator and shoppable social commerce galleries. Covers AI avatars (1000+ presenters), AI Twin (clone your voice/face), URL-to-Video, text-to-video, product video…
- sales-traySales
Tray.ai platform help — enterprise iPaaS with 700+ connectors, Intelligent iPaaS, Enterprise Core governance, Merlin Agent Builder for AI agents, Tray Embedded for SaaS vendors, GraphQL API, Connector Development…
- sales-workatoSales
Workato platform help — enterprise iPaaS, 1200+ connectors, recipe-based automation, API Management, MCP Gateway, Agent Studio (Genies AI agents), Data Tables, Event Streams, B2B/EDI, Embedded iPaaS, IDP. Use when…
- sales-yeswareSales
Yesware platform help — email tracking, campaigns, templates, Prospector, Meeting Scheduler, Salesforce integration, reporting. Use when Yesware tracking isn't showing opens, campaigns aren't sending to…
- tweetclawGeneral
OpenClaw plugin for X/Twitter automation. Post tweets, reply, like, retweet, follow, DM, search, extract data, run giveaways, monitor accounts via Xquik. 111 endpoints, 2 tools (explore + tweetclaw), 2 commands…
- builderProduct
Hands-on implementation partner for creating tools, scripts, dashboards, and prototypes. Use when the user wants to build something tangible — apps, scripts, automations, or internal tools. Triggers include…
- clickup-incident-runbookGeneral
Execute ClickUp API incident response: triage, diagnosis, mitigation, and postmortem for API failures and integration outages. Trigger: "clickup incident", "clickup outage", "clickup…
- clickup-prod-checklistGeneral
Production readiness checklist for ClickUp API v2 integrations covering auth, rate limits, error handling, monitoring, and rollback. Trigger: "clickup production", "clickup go-live", "clickup…
Frequently asked questions
Which extension type should I use for X?
Are Claude Code extensions sandboxed?
Can I disable extensions per-project?
./.claude/settings.json can override or disable globally-installed hooks. For skills, you can keep them in your global ~/.claude/skills/ directory; Claude will only invoke them when the model judges the task relevant, so unused skills don't fire.