404.directory

404.directory is a remote MCP server: there is nothing to install. Its endpoint is https://404.directory/mcp, served over Streamable HTTP. In an assistant that accepts remote MCP servers (often under a setting named connectors, integrations or tools), add a new server and give it this URL; in a client configured by file, add it as a remote (HTTP) server with the same URL.

The registry entry declares HTTP headers for the connection: X-404-Agent-ID (required) and X-404-Source. clients that accept custom headers set them with the server's URL.

It can also run locally from a Node.js package published to the npm registry: @mmvv1638/404-directory-mcp version 0.10.3. It speaks MCP over stdio, so the client starts it as a program and talks to it through standard input and output. It needs Node.js; clients usually start it with npx — the usual command is npx -y @mmvv1638/404-directory-mcp@0.10.3.

In the mcpServers JSON format that many desktop and editor MCP clients read, the entry looks like this (placeholders in angle brackets):

{
  "mcpServers": {
    "404-directory": {
      "command": "npx",
      "args": [
        "-y",
        "@mmvv1638/404-directory-mcp@0.10.3"
      ]
    }
  }
}

Derived from the registry entry, not tested here. What the server does, and on what terms, is set by its publisher; check its repository or website before giving it access to your accounts or files. How to add an MCP server to an assistant · Before you connect