mcp-tmpfs-server

MCP server (stdio, JSON-RPC 2.0) with no dependencies. Exposes 5 tools scoped to one sandbox directory:

• list_files — list files/dirs (path, recursive)

• read_file — read a text file (path)

• write_file — write or append a text file (path, content, append)

• delete_file — delete a file (path)

• unzip_file — extract a ZIP file (zipPath, extractTo)

All paths are relative to the sandbox root and are checked to prevent ../ traversal outside it.

Run

npx mcp-tmpfs-server

The package is published on npm, so you can run it from anywhere using the command above.

To run locally without npm: node index.js, or npx . from this folder.

Sandbox directory

Defaults to <os tmpdir>/mcp-tmpfs-server. Override with:

npx mcp-tmpfs-server --dir=/path/to/dir
# or
MCP_TMPFS_DIR=/path/to/dir npx mcp-tmpfs-server

Security options

By default, the server blocks symlink-based directory traversal for security. To allow following symlinks (use with caution):

MCP_TMPFS_ALLOW_SYMLINKS=true npx mcp-tmpfs-server
# or
MCP_TMPFS_ALLOW_SYMLINKS=1 npx mcp-tmpfs-server

Add to an MCP client (e.g. Claude Desktop config)

{
  "mcpServers": {
    "tmpfs": {
      "command": "npx",
      "args": ["mcp-tmpfs-server"]
    }
  }
}