HarnessCommunity★ 50k

MCP Reference Servers

Updated Jul 7, 2026

The reference MCP server implementations maintained by the MCP steering group. Includes Filesystem, Git, Memory (knowledge graph), Sequential Thinking, Fetch, Time, and Everything servers — each an educational reference implementation showing how to build an MCP server, not a production-ready solution. Install any server in seconds via npx or uvx.

View on GitHub

What it does

npx -y @modelcontextprotocol/server-memory
Start the Memory MCP server, which persists entities and relations as a knowledge graph in a local JSONL file.
uvx mcp-server-git
Start the Git MCP server (Python), exposing git log, diff, and repo-manipulation queries as agent-callable tools.
npx -y @modelcontextprotocol/server-filesystem /path/to/dir
Start the Filesystem MCP server, giving the agent read/write access scoped to the specified directory.
npx -y @modelcontextprotocol/server-fetch
Start the Fetch MCP server, which retrieves and converts web content into LLM-friendly text.
npx -y @modelcontextprotocol/server-sequentialthinking
Start the Sequential Thinking MCP server, which exposes a structured multi-step reasoning tool.

Files (1)

OVERVIEW.mdprimary · markdown · 1.9 KB

## What it does

The MCP Reference Servers repository hosts the small set of reference implementations maintained by the MCP steering group. Each server is designed as an educational example for developers building their own MCP servers — the README explicitly notes they are not production-ready solutions.

Active reference servers:
- **Memory** — knowledge graph-based persistent memory using a local JSONL store
- **Filesystem** — secure file read/write with configurable access controls on a scoped directory
- **Git** — read, search, and manipulate git repositories via MCP tools
- **Sequential Thinking** — dynamic problem-solving through chained thought sequences
- **Fetch** — retrieve and convert web content for LLM consumption
- **Time** — time and timezone conversion tools
- **Everything** — reference/test server demonstrating prompts, resources, and tools in one package

Many formerly included servers (GitHub, Slack, PostgreSQL, Puppeteer, Google Drive, etc.) have been archived to a separate repo as of 2025.

## Install

TypeScript-based servers run directly with npx; Python-based servers use uvx or pip.

npx -y @modelcontextprotocol/server-memory

uvx mcp-server-git

## Wire into Claude Code

Add to claude_desktop_config.json or .claude/settings.json under mcpServers:

memory: command npx, args [-y, @modelcontextprotocol/server-memory]

git: command uvx, args [mcp-server-git, --repository, path/to/repo]

filesystem: command npx, args [-y, @modelcontextprotocol/server-filesystem, /path/to/allowed/files]

## When to use

Use these servers as working references when building your own MCP server — study how they handle tool registration, error handling, and stdio transport. For production use, look for maintained forks or purpose-built alternatives. The Memory server is genuinely useful for cross-session context; the Filesystem and Git servers are solid for local development.