
Services
The official MCP server list is seven reference servers. Package versions checked October 19, 2026. The old Postgres server is archived. Pin the version before you add one to a host.

The official MCP server list is seven reference servers in the modelcontextprotocol/servers repo. I read that README and the published package versions on October 19, 2026. The long catalog of community servers is the MCP Registry, which is a different page.
By Tayyab Javed, AI agent developer
Pin a package from the table below. Pass only the directory, repo, or URL that server is allowed to touch. The filesystem server is the one I launched. The other six I checked as published versions, and I did not start them. Postgres is not on this list anymore.
The repo says these are educational reference servers, not production appliances. Versions below are what npm and PyPI returned. The cluster index is the MCP servers hub.
| Server | Package | Version | What it is for |
|---|---|---|---|
| Filesystem | @modelcontextprotocol/server-filesystem | 1.0.0 | Read and write files inside directories you pass |
| Memory | @modelcontextprotocol/server-memory | 1.0.0 | A knowledge-graph memory |
| Everything | @modelcontextprotocol/server-everything | 1.0.0 | A test server that exercises the protocol |
| Sequential Thinking | @modelcontextprotocol/server-sequential-thinking | 1.0.0 | A scratchpad of thought steps |
| Git | mcp-server-git | 2026.10.10 | Read, search, and change a Git repo |
| Fetch | mcp-server-fetch | 2026.10.10 | Fetch a URL and turn it into text |
| Time | mcp-server-time | 2026.10.10 | Clock and timezone conversion |
The old Postgres reference server was archived. npm still has @modelcontextprotocol/server-postgres at 0.6.2. I did not run that tarball. For a database an agent can query, build the small read-only server in the Postgres MCP server post instead of installing 0.6.2.
A host config names a command. This is the filesystem entry. The argument after the package is the only directory the process may use. I installed @modelcontextprotocol/server-filesystem@1.0.0 and launched its dist/index.js with one temp directory. list_allowed_directories returned that directory, and a path outside it was rejected. Scope details are in the file system MCP server post.
{
"mcpServers": {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem@1.0.0", "/absolute/path/to/one/folder"]
}
}
}
Pin the version. npx -y without a version will take a later release the day it ships. On Windows the official README wraps npx as cmd /c. Building your own server, rather than launching one of these, starts at how to build an MCP server.
Filesystem can write inside the directories you pass. I called write_file inside the temp directory and the file was created. The same call outside the directory returned an access error and created nothing. Git's own description says it can manipulate a repository, so treat it as a write server. Fetch pulls the network. Memory stores a graph. Time is a clock. Everything is a protocol demo. Do not point the write-capable ones at a home directory or a production repo. Putting any of them on a URL other people can reach is how to deploy an MCP server, and that page is about your own process, not these reference bins.
I start from the official README, not the registry catalog. These seven are reference servers. I do not point them at a home directory or a production repo. The first check is a pinned version in the host config, because an unpinned npx -y takes whatever publishes next. Next I look at the argument that limits the process: one directory, one repo, or one URL. I do not install the archived Postgres package. A database job gets the small read-only server, not 0.6.2. Filesystem and Git can write, and Fetch reaches the network. I add a write-capable server only after I have called the path it must reject.
No. The list on this page is the seven reference servers maintained in the official servers repo, with the versions published on October 19, 2026. The registry is the broader catalog of servers other people have published.
No. The reference implementation was archived, and the npm package stopped at 0.6.2. Use a role that can only SELECT, and a tool that rejects anything except one read statement.
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