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

Server	Purpose	Key Features	Documentation
Serena	Semantic code intelligence	• Wide language support via LSP • Symbol-level navigation • Project indexing • Context-aware editing	serena.md
Sequential Thinking	Advanced reasoning	• Problem decomposition • Multi-step planning • Structured analysis • Decision support	sequential-thinking.md
Memory	Persistent context	• Cross-session memory • Project preferences • Historical context • Knowledge retention	memory.md
Playwright	Browser automation	• Web scraping • Automated testing • Screenshot capture • Device emulation	playwright.md

Tip: Keep only 3–6 MCP servers active at a time — every connected server adds tools to Claude's context.

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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:

Tool	Required By	Installation
Node.js & npx	Sequential Thinking, Memory, Playwright	nodejs.org
uv & uvx	Serena	Install uv
Claude Code CLI	All servers	Claude Code Docs

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

Official MCP Registry

The MCP Registry is the official directory for discovering MCP servers. It is currently in preview.

How it works:

• Servers are published under reverse-DNS namespaces (e.g., io.github.username/server-name)
• Namespace ownership is verified via GitHub, DNS, or HTTP
• The registry serves as the source of truth for downstream aggregators and marketplaces

Discovering New Servers:

1. Visit https://registry.modelcontextprotocol.io/
2. Search for the server you need
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

Ecosystem scale (as of December 2025): 97M+ monthly SDK downloads and roughly 10,000 active servers (source).

Current MCP protocol features

The current ratified spec revision is 2025-11-25, which added:

• OIDC discovery for authorization
• Icons for servers and their tools
• URL elicitation for gathering user input
• Sampling tool calls
• OAuth Client ID Metadata Documents
• Experimental tasks

MCP Apps — interactive HTML UIs rendered in sandboxed iframes — became the first official MCP extension on January 26, 2026 (announcement).

Coming up: a release candidate for the next spec revision — the largest since MCP launched — finalizes on July 28, 2026. It introduces a stateless core and official extensions (release candidate).

Agentic AI Foundation

Since December 9, 2025, MCP has been governed by the Agentic AI Foundation (AAIF), a directed fund under the Linux Foundation. Its founding projects are MCP, Block's goose, and OpenAI's AGENTS.md, with platinum members including AWS, Google, Microsoft, and Cloudflare. This ensures:

• 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

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