Struct FilesystemProvider 

pub struct FilesystemProvider { /* private fields */ }

A resource provider that exposes filesystem directories.

Files under the configured root directory are exposed as MCP resources with URIs like file://{prefix}/{relative_path}.

Security

• Path traversal attempts (e.g., ../../../etc/passwd) are blocked
• Symlinks can be optionally followed or blocked
• Maximum file size limits prevent memory exhaustion
• Hidden files (starting with .) can be excluded

Example

use fastmcp_server::providers::FilesystemProvider;

let provider = FilesystemProvider::new("/app/data")
    .with_prefix("data")
    .with_patterns(&["*.json", "*.yaml"])
    .with_recursive(true);

Implementations

impl FilesystemProvider

pub fn new(root: impl AsRef<Path>) -> Self

Creates a new filesystem provider for the given root directory.

Arguments

• root - The root directory to expose

Example

let provider = FilesystemProvider::new("/data/docs");

pub fn with_prefix(self, prefix: impl Into<String>) -> Self

Sets the URI prefix for resources.

Files will have URIs like file://{prefix}/{path}.

Example

let provider = FilesystemProvider::new("/data")
    .with_prefix("mydata");
// Results in URIs like file://mydata/readme.md

pub fn with_patterns(self, patterns: &[&str]) -> Self

Sets glob patterns to include.

Only files matching at least one of these patterns will be exposed. Empty patterns means all files are included.

Example

let provider = FilesystemProvider::new("/data")
    .with_patterns(&["*.md", "*.txt", "**/*.json"]);

pub fn with_exclude(self, patterns: &[&str]) -> Self

Sets glob patterns to exclude.

Files matching any of these patterns will be excluded. By default, hidden files (starting with .) are excluded.

Example

let provider = FilesystemProvider::new("/data")
    .with_exclude(&["**/secret/**", "*.bak"]);

pub fn with_recursive(self, enabled: bool) -> Self

Enables or disables recursive directory traversal.

When enabled, files in subdirectories are also exposed.

Example

let provider = FilesystemProvider::new("/data")
    .with_recursive(true);

pub fn with_max_size(self, bytes: usize) -> Self

Sets the maximum file size in bytes.

Files larger than this limit will return an error when read. Default is 10 MB.

Example

let provider = FilesystemProvider::new("/data")
    .with_max_size(5 * 1024 * 1024); // 5 MB

pub fn with_follow_symlinks(self, enabled: bool) -> Self

Enables or disables following symlinks.

When disabled (default), symlinks are not followed. When enabled, symlinks are followed but must still point within the root directory.

Example

let provider = FilesystemProvider::new("/data")
    .with_follow_symlinks(true);

pub fn with_description(self, description: impl Into<String>) -> Self

Sets the description for the resource template.

Example

let provider = FilesystemProvider::new("/data")
    .with_description("Documentation files");

pub fn build(self) -> FilesystemResourceHandler

Builds a resource handler from this provider.

The returned handler can be registered with a server.

Example

let handler = FilesystemProvider::new("/data")
    .with_prefix("docs")
    .build();

let server = Server::new("demo", "1.0")
    .resource(handler);

Trait Implementations

impl Clone for FilesystemProvider

fn clone(&self) -> FilesystemProvider

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FilesystemProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.