MCP Servers Documentation

Overview

This directory contains comprehensive documentation for the four core Model Context Protocol (MCP) servers that enhance Claude Code's capabilities.

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Available Servers

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Server Comparison

By Use Case

Code Development

• Serena: Deep codebase understanding and navigation
• Sequential Thinking: Planning complex implementations
• Memory: Remember project patterns and preferences

Web Automation

• Playwright: Browser control and testing
• Memory: Store authentication and workflow preferences

Research & Analysis

• Serena: Analyze code structure and dependencies
• Sequential Thinking: Break down complex problems
• Playwright: Gather web data

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Server Synergies

Powerful Combinations

1. Serena + Sequential Thinking

Use case: Complex refactoring projects
- Sequential Thinking breaks down the approach
- Serena navigates and modifies code intelligently

2. Memory + All Servers

Use case: Enhanced context awareness
- Memory stores project conventions
- Other servers leverage this knowledge

3. Playwright + Memory

Use case: Automated testing workflows
- Playwright executes browser automation
- Memory remembers test patterns and credentials

4. All Four Together

Use case: Full-stack development
- Serena for backend code intelligence
- Playwright for frontend testing
- Sequential Thinking for planning
- Memory for project knowledge

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Getting Started

Prerequisites

Before installing MCP servers, ensure the following tools are installed:

Verify Prerequisites

Run the following commands to check installations:

node --version
npx --version
uv --version
uvx --version
claude --version

Note: All commands should return version numbers. If any command fails, install the missing prerequisite.

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MCP Registry & Ecosystem (2026)

Official MCP Registry

The MCP Registry is now live (launched September 2025), providing a centralized directory for discovering MCP servers.

Features:

• 🔍 Browse hundreds of official and community servers
• 📦 One-click installation instructions
• 📚 Comprehensive documentation for each server
• ✅ Quality-verified listings
• 🔐 Support for public and private sub-registries

Discovering New Servers:

1. Visit https://registry.modelcontextprotocol.io/
2. Search by category (code, database, browser, AI, etc.)
3. Copy installation command for Claude Code CLI
4. Install with claude mcp add

Popular Server Categories:

• Code Intelligence: Serena, GitHub, GitLab integrations
• Databases: PostgreSQL, SQLite, MongoDB servers
• Browser Automation: Playwright, Puppeteer
• AI & ML: Sequential Thinking, Memory, various AI tool integrations
• APIs & Services: REST clients, GraphQL, authentication servers

Latest MCP Protocol Features (2026)

New Capabilities:

• MCP Apps: Interactive UI components from servers
• OAuth Support: Built-in client credentials authentication
• Async Operations: Non-blocking server operations
• Server Discovery: .well-known URLs for automatic discovery
• Improved Performance: Stateless architecture for better scaling

Agentic AI Foundation

MCP is now maintained by the Agentic AI Foundation (Linux Foundation), ensuring:

• Open governance and community-driven development
• Vendor-neutral standardization
• Long-term sustainability

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Installation

MCP servers can be installed in two scopes:

• Global (-s user): Available across all projects (recommended for everyday use)
• Local (-s local): Project-specific installations (useful for testing)

Global Installation (Recommended)

Install servers globally to use them across all your projects:

# Serena - Semantic code intelligence
claude mcp add serena -s user -- uvx --from git+https://github.com/oraios/serena serena start-mcp-server

# Sequential Thinking - Step-by-step reasoning
claude mcp add sequential-thinking -s user -- npx -y @modelcontextprotocol/server-sequential-thinking

# Memory - Persistent context across sessions
claude mcp add memory -s user -- npx -y @modelcontextprotocol/server-memory

# Playwright - Browser automation
claude mcp add playwright -s user -- npx -y @playwright/mcp@latest

Local Installation (Project-Specific)

Install servers for a specific project only:

# Serena
claude mcp add serena -s local -- uvx --from git+https://github.com/oraios/serena serena start-mcp-server

# Sequential Thinking
claude mcp add sequential-thinking -s local -- npx -y @modelcontextprotocol/server-sequential-thinking

# Memory
claude mcp add memory -s local -- npx -y @modelcontextprotocol/server-memory

# Playwright
claude mcp add playwright -s local -- npx -y @playwright/mcp@latest

Verify Installation

After installing MCP servers, verify they are connected:

claude mcp list

Expected output:

Checking MCP server health...
sequential-thinking: ✓ Connected
serena: ✓ Connected
memory: ✓ Connected
playwright: ✓ Connected

Tip: If a server shows as disconnected, try removing and reinstalling it, or see the Troubleshooting section.

Server-Specific Documentation

• Serena - For code-heavy projects
• Sequential Thinking - For complex problem-solving
• Memory - For persistent project knowledge
• Playwright - For web automation needs

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Installation Scopes

Global (-s user)

• Available across all projects
• Recommended for everyday use
• Single installation, universal access

Local (-s local)

• Project-specific configuration
• Useful for testing
• Isolated from other projects

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Troubleshooting

Having issues with MCP server installation or connection? This section covers common problems and their solutions.

General Troubleshooting

1️⃣ Server Shows "Failed to connect"

Step 1: Verify Prerequisites

node --version
npx --version
uv --version
uvx --version

All commands should return version numbers. Install any missing prerequisites.

Step 2: Remove and Reinstall Server

claude mcp remove <server-name> -s user
claude mcp add <server-name> -s user -- <command>

Step 3: Check Configuration File

Check ~/.claude.json (macOS/Linux) or %USERPROFILE%\\.claude.json (Windows) for syntax errors.

Step 4: Restart Claude Code

claude

2️⃣ "Command not found" Errors

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Serena-Specific Issues

3️⃣ Serena Connection Failures

Verify uv Installation

uv --version
uvx --version

Test Serena Directly

uvx --from git+https://github.com/oraios/serena serena --help

Common Issues

Reinstall Serena

claude mcp remove serena -s user
claude mcp add serena -s user -- uvx --from git+https://github.com/oraios/serena serena start-mcp-server

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Playwright-Specific Issues

4️⃣ Playwright Connection Failures

Verify Node.js

node --version
npx --version

Test Playwright Directly

npx @playwright/mcp@latest --help

Install Missing Browser Binaries

npx playwright install chromium
npx playwright install firefox
npx playwright install webkit

Common Issues

Reinstall Playwright

claude mcp remove playwright -s user
claude mcp add playwright -s user -- npx -y @playwright/mcp@latest

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Sequential Thinking & Memory Issues

5️⃣ Sequential Thinking / Memory Failures

Both servers require Node.js and npx. If they fail to connect:

Verify Prerequisites

node --version
npx --version

Test Server Directly

# Sequential Thinking
npx -y @modelcontextprotocol/server-sequential-thinking --help

# Memory
npx -y @modelcontextprotocol/server-memory --help

Reinstall Server

# Sequential Thinking
claude mcp remove sequential-thinking -s user
claude mcp add sequential-thinking -s user -- npx -y @modelcontextprotocol/server-sequential-thinking

# Memory
claude mcp remove memory -s user
claude mcp add memory -s user -- npx -y @modelcontextprotocol/server-memory

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Complete Reinstall

6️⃣ Full Server Reinstallation

If a server repeatedly fails, perform a complete reinstall:

# Remove from both scopes
claude mcp remove <server-name> -s local
claude mcp remove <server-name> -s user

# Reinstall globally
claude mcp add <server-name> -s user -- <command>

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Verification

7️⃣ Verify All Servers

After troubleshooting, always verify server status:

claude mcp list

Expected output:

Checking MCP server health...
sequential-thinking: ✓ Connected
serena: ✓ Connected
memory: ✓ Connected
playwright: ✓ Connected

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Important Notes

• Restart Claude Code after configuration changes
• Prefer one scope per server: Combining global and local installations may cause conflicts
• Check logs in ~/.claude/logs/ for detailed error messages
• Update regularly: Use @latest for npm packages to get the newest versions

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Still Having Issues?

If problems persist:

1. Check the Claude Code GitHub Issues
2. Review server-specific documentation (links below)
3. Ensure all prerequisites are correctly installed
4. Try reinstalling Claude Code CLI itself

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Additional Resources

• Main README - Complete Claude Code guide