Module folder 

The root folders and the seven operations on them.

Folder holds each root opened as a cap_std::fs::Dir. Every file operation goes through one of those handles with a root-relative path, so the operating system (via cap-std) refuses anything that would resolve outside that root: absolute paths, .., and symlinks pointing out, including symlinks from one root into another. Listing and search walk with the ignore crate (ripgrep’s walker, .gitignore and hidden-file aware, symlinks not followed); each path the walker yields is made relative to its root and re-opened through the Dir, never by its absolute path, so an entry swapped for an escaping symlink mid-walk is skipped rather than read.

With one root, tool paths are plain root-relative paths. With several, a tool path starts with the root’s name (docs/guide.md), and . is a virtual folder holding the roots.

The operations are synchronous; the MCP layer runs them on the blocking pool.

Structs

Config

What the operator configured at start-up.

Folder

The root folders, opened once, and the operator’s limits.

RootSpec

One root folder as the operator named it: DIR or NAME=DIR.

Enums

ReadOutput

Result of read.

WriteMode

How write treats an existing file.

Constants

DEFAULT_MAX_CHARS

Default for Config::max_chars: emperor-mcp’s default output cap.

DEFAULT_MAX_FILE_BYTES

Default for Config::max_file_bytes: 1 MiB.

DEFAULT_MAX_RESULTS

Default for Config::max_results.

MAX_IMAGE_BYTES

Largest image read returns as image content: 5 MiB.