MCP Servers Reference

Skill by ara.so — MCP Skills collection.

Overview

The Model Context Protocol (MCP) is a standardized interface that lets AI agents (Claude Code, Cursor, Codex, Gemini CLI, Windsurf) connect to external tools and services. This reference catalogs 50 essential, vetted MCP servers across 9 categories: core development, databases, infrastructure, productivity, fintech, web3, trading, creator tools, and reasoning/memory.

Critical context: Over 20,000 MCP servers exist in public registries, but most are abandoned, insecure, or poorly maintained. This curated list focuses on official or well-maintained community servers with verified install commands.

The Three Non-Negotiable Rules

Don't install more than 5-7 servers — Tool bloat degrades agent performance and reasoning quality. Pick 3-5 that match your actual workflow.
Treat every server like untrusted code — Pin versions, scope tokens to read-only until tested, prefer vendor-official over forks.
Never enable writes against production from an agent loop — Point at read replicas, snapshots, or dev environments for anything that can mutate data.

Installation Patterns

Claude Code (Desktop)

# Local server (npx/uvx)
claude mcp add github npx -y @modelcontextprotocol/server-github

# Hosted server (HTTP transport)
claude mcp add supabase --transport http https://mcp.supabase.com

Codex

# Add via CLI
codex mcp add github -- npx -y @modelcontextprotocol/server-github

# Or edit ~/.codex/config.toml
[mcp.servers.github]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-github"]
env = { GITHUB_TOKEN = "github_pat_xxx" }

Gemini CLI

// Edit ~/.gemini/settings.json
{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_TOKEN": "github_pat_xxx"
      }
    }
  }
}

Server Categories & Recommendations

Core Development (Start Here)

GitHub (Official, Hosted)

claude mcp add github npx -y @modelcontextprotocol/server-github
# Env: GITHUB_TOKEN (create at github.com/settings/tokens)
# Use cases: Create issues, review PRs, search repos, manage branches
# Gotcha: Needs repo/write scopes for PRs; start with read-only

Context7 (Official, Hosted/Local)

# Hosted (recommended)
claude mcp add context7 --transport http https://api.context7.com/mcp
# Local
claude mcp add context7 npx -y @context7/mcp-server
# Use cases: Deep codebase indexing, semantic search across repos
# Gotcha: Heavy memory use on large monorepos

Playwright (Official, Local)

claude mcp add playwright npx -y @modelcontextprotocol/server-playwright
# Use cases: Browser automation, web scraping, E2E testing
# Gotcha: No write protection — can mutate sites you're logged into

Filesystem (Official, Local)

claude mcp add filesystem npx -y @modelcontextprotocol/server-filesystem
# Env: ALLOWED_DIRECTORIES=/path/to/project
# Use cases: Read/write files, navigate directories
# Gotcha: Scope to project dirs only; dangerous system-wide

Brave Search (Official, Local)

claude mcp add brave npx -y @modelcontextprotocol/server-brave-search
# Env: BRAVE_API_KEY (get at brave.com/search/api)
# Use cases: Web research, real-time data lookup

Database & Backend

PostgreSQL (Official-Archived, Local)

claude mcp add postgres npx -y @modelcontextprotocol/server-postgres
# Env: DATABASE_URL=postgresql://user:pass@host:5432/db
# Gotcha: Full write access; ONLY point at dev/staging

Supabase (Official, Hosted)

claude mcp add supabase --transport http https://mcp.supabase.com
# Requires: Supabase project URL + anon/service key
# Use cases: Database queries, storage, auth operations
# Gotcha: Service role key has admin access; use anon key + RLS

Neon (Official, Hosted)

claude mcp add neon --transport http https://mcp.neon.tech
# Env: NEON_API_KEY (from neon.tech console)
# Use cases: Serverless Postgres, branch databases

SQLite (Community, Local)

claude mcp add sqlite npx -y @benborla29/mcp-server-sqlite
# Env: SQLITE_DB_PATH=/path/to/db.sqlite
# Use cases: Local dev databases, lightweight analytics

Redis (Official, Local)

claude mcp add redis npx -y @modelcontextprotocol/server-redis
# Env: REDIS_URL=redis://localhost:6379
# Use cases: Cache inspection, session debugging

Infrastructure & Ops

Cloudflare (Official, Hosted)

claude mcp add cloudflare --transport http https://mcp.cloudflare.com
# Env: CLOUDFLARE_API_TOKEN (read-only recommended)
# Use cases: DNS management, worker deployment, analytics
# Gotcha: Can deploy code and change DNS; read-only until tested

Vercel (Official, Hosted)

claude mcp add vercel --transport http https://mcp.vercel.com
# Env: VERCEL_TOKEN (from vercel.com/account/tokens)
# Use cases: Deploy previews, check build logs, manage env vars
# Gotcha: Can trigger production deployments

AWS (Official, Local)

claude mcp add aws npx -y @modelcontextprotocol/server-aws
# Env: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION
# Use cases: S3 operations, Lambda management, CloudWatch logs
# Gotcha: Use IAM policies to restrict; never admin credentials

Sentry (Official, Hosted)

claude mcp add sentry --transport http https://mcp.sentry.io
# Env: SENTRY_AUTH_TOKEN (read-only scope)
# Use cases: Error investigation, release tracking

Kubernetes (Community, Local)

claude mcp add k8s npx -y @kubernetes/mcp-server
# Env: KUBECONFIG=/path/to/config (or uses default)
# Use cases: Pod inspection, log streaming, deployment status
# Gotcha: Can delete resources; use read-only RBAC

Productivity & Team Tools

Slack (Community, Local)

claude mcp add slack npx -y @modelcontextprotocol/server-slack
# Env: SLACK_BOT_TOKEN, SLACK_APP_TOKEN
# Use cases: Send messages, search history, manage channels
# Gotcha: Can post to any channel bot is in; test in sandbox first

Linear (Official, Hosted)

claude mcp add linear --transport http https://mcp.linear.app
# Auth: OAuth flow on first connect
# Use cases: Create/update issues, query project status

Notion (Official, Hosted)

claude mcp add notion --transport http https://mcp.notion.so
# Auth: OAuth flow (grants page-level access)
# Use cases: Create pages, update databases, search workspace

Jira/Confluence (Official, Hosted)

claude mcp add atlassian --transport http https://mcp.atlassian.com
# Auth: OAuth (select Jira sites on connect)
# Use cases: Ticket management, wiki search

Google Drive (Official-Archived, Local)

claude mcp add gdrive npx -y @modelcontextprotocol/server-gdrive
# Env: GOOGLE_CREDENTIALS_JSON (service account JSON)
# Use cases: File search, doc reading, folder navigation

Fintech & Payments

Stripe (Official, Hosted/Local)

# Hosted (recommended)
claude mcp add stripe --transport http https://mcp.stripe.com
# Local
claude mcp add stripe npx -y @modelcontextprotocol/server-stripe
# Env: STRIPE_SECRET_KEY (use test key: sk_test_...)
# Gotcha: ONLY use test keys; can create real charges in live mode

PayPal (Official, Hosted)

claude mcp add paypal --transport http https://mcp.paypal.com
# Env: PAYPAL_CLIENT_ID, PAYPAL_SECRET (sandbox credentials)
# Gotcha: Verify you're in sandbox mode; can process real payments

Plaid (Official, Hosted)

claude mcp add plaid --transport http https://mcp.plaid.com
# Env: PLAID_CLIENT_ID, PLAID_SECRET (sandbox/dev environment)
# Gotcha: Has access to real banking data; use dev environment only

Web3 & Blockchain

Base MCP (Official, Hosted)

claude mcp add base --transport http https://mcp.base.org
# Env: BASE_RPC_URL (use testnet: sepolia-base)
# Gotcha: Can sign transactions; ONLY connect testnet wallets

Solana Agent Kit (Community, Local)

claude mcp add solana npx -y solana-agent-kit-mcp
# Env: SOLANA_RPC_URL, SOLANA_PRIVATE_KEY (devnet only)
# Use cases: Read wallet state, fetch NFTs, query programs
# Gotcha: Can broadcast transactions; use burner wallets

Thirdweb (Official, Local)

claude mcp add thirdweb npx -y @thirdweb-dev/mcp-server
# Env: THIRDWEB_SECRET_KEY (from thirdweb.com/dashboard)
# Use cases: Contract deployment, IPFS upload, wallet management
# Gotcha: Has write access to contracts; use testnets

The Graph (Community, Local)

claude mcp add graph npx -y @graphprotocol/mcp-server
# Env: GRAPH_API_KEY (read-only, from thegraph.com)
# Use cases: Query subgraphs, blockchain data indexing

Etherscan (Community, Local)

claude mcp add etherscan npx -y etherscan-mcp-server
# Env: ETHERSCAN_API_KEY (free tier at etherscan.io)
# Use cases: Contract verification, transaction lookup, gas prices

Trading & Markets

Alpaca (Official, Local)

claude mcp add alpaca npx -y @alpacahq/mcp-server
# Env: APCA_API_KEY_ID, APCA_API_SECRET_KEY, APCA_PAPER=true
# Gotcha: ALWAYS set APCA_PAPER=true; can place real trades

CCXT (Community, Local)

claude mcp add ccxt npx -y ccxt-mcp-server
# Env: CCXT_EXCHANGE=binance, CCXT_API_KEY, CCXT_SECRET (testnet)
# Use cases: Multi-exchange trading, market data
# Gotcha: Can execute trades on live accounts; use testnet

Polygon.io (Official, Local)

claude mcp add polygon npx -y @polygon.io/mcp-server
# Env: POLYGON_API_KEY (from polygon.io)
# Use cases: Real-time stock/crypto prices, historical data

CoinGecko (Official, Hosted)

claude mcp add coingecko --transport http https://mcp.coingecko.com
# Env: COINGECKO_API_KEY (optional, for pro tier)
# Use cases: Crypto prices, market cap, trending coins

Creator Tools & Media

Higgsfield (Official, Hosted)

claude mcp add higgsfield --transport http https://mcp.higgsfield.ai
# Auth: OAuth flow
# Use cases: AI video generation, style transfer

DaVinci Resolve (Community, Local)

claude mcp add resolve npx -y davinci-resolve-mcp
# Requires: DaVinci Resolve installed with scripting API enabled
# Use cases: Timeline editing, color grading automation, render jobs

Figma (Official, Hosted/Local)

# Hosted
claude mcp add figma --transport http https://mcp.figma.com
# Auth: OAuth (grants file access)
# Use cases: Read designs, export assets, update prototypes

ElevenLabs (Official, Local)

claude mcp add elevenlabs npx -y @elevenlabs/mcp-server
# Env: ELEVEN_API_KEY (from elevenlabs.io)
# Use cases: Text-to-speech, voice cloning, audio generation

YouTube (Community, Local)

claude mcp add youtube npx -y youtube-mcp-server
# Env: YOUTUBE_API_KEY (from console.cloud.google.com)
# Use cases: Search videos, fetch transcripts, channel analytics

Reasoning & Memory

Sequential Thinking (Official, Local)

claude mcp add sequential-thinking npx -y @modelcontextprotocol/server-sequential-thinking
# Use cases: Multi-step reasoning, complex problem decomposition
# No env vars needed; pure reasoning augmentation

Memory (Official, Local)

claude mcp add memory npx -y @modelcontextprotocol/server-memory
# Use cases: Persistent context across sessions, user preferences
# Stores: ~/.mcp/memory.json (local file storage)

Configuration Best Practices

Environment Variables

# Create .env file (never commit)
GITHUB_TOKEN=github_pat_xxxxx
DATABASE_URL=postgresql://user:pass@localhost:5432/devdb
STRIPE_SECRET_KEY=sk_test_xxxxx
AWS_ACCESS_KEY_ID=AKIA...
AWS_SECRET_ACCESS_KEY=...
SLACK_BOT_TOKEN=xoxb-...

# Load in agent config
# Claude: Automatically reads from .env in project root
# Codex: Specify in ~/.codex/config.toml env section
# Gemini: Specify in ~/.gemini/settings.json env object

Token Scoping (GitHub Example)

# Read-only (safe exploration)
# Scopes: repo:status, public_repo, read:user

# Write access (for PRs, commits)
# Scopes: repo, workflow

# Start narrow, expand only when needed

Multi-Environment Pattern

# ~/.codex/config.toml
[mcp.servers.postgres-dev]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-postgres"]
env = { DATABASE_URL = "postgresql://localhost:5432/dev" }

[mcp.servers.postgres-staging]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-postgres"]
env = { DATABASE_URL = "postgresql://staging.example.com:5432/app" }

# Never add postgres-prod

Workflow Examples

Full-Stack Developer Setup

# Core 5 servers
claude mcp add github npx -y @modelcontextprotocol/server-github
claude mcp add postgres npx -y @modelcontextprotocol/server-postgres
claude mcp add playwright npx -y @modelcontextprotocol/server-playwright
claude mcp add sentry --transport http https://mcp.sentry.io
claude mcp add vercel --transport http https://mcp.vercel.com

# Usage: "Check Sentry for errors in the last deploy, then write a Playwright test to reproduce"

Content Creator Setup

# Media pipeline
claude mcp add higgsfield --transport http https://mcp.higgsfield.ai
claude mcp add elevenlabs npx -y @elevenlabs/mcp-server
claude mcp add youtube npx -y youtube-mcp-server
claude mcp add figma --transport http https://mcp.figma.com

# Usage: "Generate a 30-second promo video, add voiceover, export thumbnail from Figma, upload to YouTube"

Crypto Trader Setup (Read-Only First)

# Start with market data only
claude mcp add coingecko --transport http https://mcp.coingecko.com
claude mcp add graph npx -y @graphprotocol/mcp-server
claude mcp add etherscan npx -y etherscan-mcp-server

# After 2 weeks of testing, add execution (paper trading only)
claude mcp add alpaca npx -y @alpacahq/mcp-server
# APCA_PAPER=true in .env

# Usage: "Show me BTC price action, correlate with on-chain volume from The Graph, suggest entry points"

Troubleshooting

"Too many tools" / Slow responses

Cause: Agent is overwhelmed by 10+ servers with dozens of tools each. Fix: Remove unused servers. Keep 5 or fewer active.

# List active servers
claude mcp list

# Remove unused
claude mcp remove server-name

"Authentication failed" / 401 errors

Cause: Token expired, wrong scope, or env var not loaded. Fix:

Verify token in browser/curl: curl -H "Authorization: Bearer $TOKEN" https://api.example.com/user
Check token scopes match server requirements
Restart agent to reload env vars

Server crashes on startup

Cause: Missing dependency, wrong Node version, or port conflict. Fix:

# Check Node version (most servers need Node 18+)
node --version

# Manually test server
npx -y @modelcontextprotocol/server-github
# Read error output

# Check logs
# Claude: ~/Library/Logs/Claude/mcp.log
# Codex: ~/.codex/logs/mcp.log

"Permission denied" file/database errors

Cause: Server trying to access restricted paths or production databases. Fix:

# Filesystem: Set ALLOWED_DIRECTORIES
ALLOWED_DIRECTORIES=/Users/me/projects:/tmp

# Postgres: Verify DATABASE_URL points to dev
echo $DATABASE_URL
# Should NOT be production host

# AWS: Check IAM policy
aws sts get-caller-identity
# Verify it's a restricted role

Agent ignores newly added server

Cause: Config cache not refreshed. Fix:

# Claude: Restart app
# Codex: codex mcp reload
# Gemini: gemini mcp reload

# Verify server appears
claude mcp list

Security Checklist

Before enabling any server:

Common Patterns

Read-first, Write-later

# Week 1: Install with read-only token
claude mcp add github npx -y @modelcontextprotocol/server-github
# GITHUB_TOKEN has repo:status, read:user only

# Week 3: After observing behavior, upgrade to write
# Update GITHUB_TOKEN with repo, workflow scopes
# Restart agent

Seasonal Rotation

# Install for project duration
claude mcp add stripe npx -y @modelcontextprotocol/server-stripe

# Remove after project ships
claude mcp remove stripe

# Keeps tool count lean

Prompt-level Server Activation

# In your prompt to Claude:
"Using only the GitHub and Sentry servers, investigate why the payment flow is failing in production."

# Agent will ignore other connected servers, reducing noise

Quick Reference: Top 5 by Use Case

Use Case	Servers
Web dev	github, postgres, playwright, sentry, vercel
Mobile dev	github, supabase, sentry, firebase, linear
Data science	postgres, redis, jupyter, pandas, plotly
DevOps	aws, kubernetes, sentry, cloudflare, docker
Content	higgsfield, elevenlabs, figma, youtube, canva
Trading	coingecko, polygon.io, alpaca (paper), ccxt (testnet), dune
Web3 dev	thirdweb (testnet), the graph, etherscan, dune, base (testnet)
Startup ops	github, linear, notion, slack, stripe (test)

Resources

MCP Specification: https://spec.modelcontextprotocol.io
Official Server Registry: https://github.com/modelcontextprotocol/servers
Security Audit (March 2026): Reference mentions 2/3 of popular servers had issues; always verify official sources
Community Discord: Most servers link to support channels in their READMEs

Version Notes

This reference reflects the MCP ecosystem as of June 2026. The protocol and server landscape evolve rapidly:

Check server GitHub repos for latest install commands
Watch for deprecation notices (several official servers archived between 2024-2026)
Subscribe to agent release notes (Claude Code, Codex, Gemini) for breaking changes
Revisit your server config quarterly

The cardinal rule: Three to five well-chosen, thoroughly tested servers beat twenty that sounded useful when you installed them. Pick for your workflow, not for coverage.

mcp-servers-reference