Filesystem Server

A practical Delta-MCP server exposing filesystem tools. Good starting point for your own servers.

Tools

Tool	Description
`read_file`	Read a text file (large files auto-truncated)
`write_file`	Write or overwrite a text file
`list_dir`	List directory contents (auto-paginated)
`search_files`	Find files matching a substring pattern
`file_info`	Get size, mtime, and type for a path

Run

stdio (for Claude Desktop / AI agents)

# Allow access only to /home/me/projects
npx tsx examples/filesystem-server/index.ts /home/me/projects

HTTP

# Listen on port 3001, allow access to current directory
npx tsx examples/filesystem-server/index.ts --http 3001 .

Using with Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["tsx", "/path/to/examples/filesystem-server/index.ts", "/allowed/root"]
    }
  }
}

Security

All paths are resolved under the configured root. Any attempt to traverse outside it (e.g. ../../etc/passwd) returns an “Access denied” error.

Token efficiency in practice

A directory with 200 entries: standard MCP returns all 200. Delta-MCP returns the first 50 with pagination metadata — the model requests page 2 only if it needs to go deeper.

A 100 KB file: standard MCP returns the full content. Delta-MCP returns a preview + token count estimate — the model knows the file is large and can decide whether to request it in chunks or summarize.

View on GitHub →

See http-oauth-server to run a similar server over HTTP with OAuth 2.1 protection.