Ruskel produces a syntactically correct, single-page skeleton of a crate's public API. If the crate is not found in the local workspace, it is fetched from crates.io.

Ruskel is great for:

• Quick access to Rust documentation from the command line.
• Exporting the full public API of a crate as a single file to pass to LLMs and other tools.
• Quick access to std library documentation, including std, core, and alloc prefixes - e.g. ruskel std::vec::Vec.

For example, here is the skeleton of the very tiny termsize crate. Note that the entire public API is included, but all implementation is omitted.

pub mod termsize {
    //! Termsize is a tiny crate that provides a simple
    //! interface for retrieving the current
    //! [terminal interface](https://www.manpagez.com/man/4/tty/) size
    //!
    //! ```rust
    //! extern crate termsize;
    //!
    //! termsize::get().map(|size| println!("rows {} cols {}", size.rows, size.cols));
    //! ```

    /// Container for number of rows and columns
    #[derive(Debug)]
    pub struct Size {
        pub rows: u16,
        pub cols: u16,
    }
    /// Gets the current terminal size
    pub fn get() -> Option<self::super::Size> {}
}

Ruskel can run as a Model Context Protocol (MCP) server, allowing it to be used as a tool by AI assistants and other MCP clients.

To start Ruskel in MCP server mode:

ruskel --mcp

This starts the MCP server on stdout, ready to accept requests. The server exposes a single tool called ruskel_skeleton that generates skeletonized outlines of Rust crates.

To use Ruskel with Claude Desktop or other MCP clients, add this configuration:

{
  "mcpServers": {
    "ruskel": {
      "command": "ruskel",
      "args": ["--mcp"]
    }
  }
}

Or if running from source:

{
  "mcpServers": {
    "ruskel": {
      "command": "cargo",
      "args": ["run", "--", "--mcp"],
      "cwd": "/path/to/ruskel"
    }
  }
}

The ruskel_skeleton tool accepts the following parameters:

• target (required): The crate/module to generate a skeleton for
• auto_impls: Include auto-implemented traits (default: false)
• private: Include private items (default: false)
• no_default_features: Disable default features (default: false)
• all_features: Enable all features (default: false)
• features: Array of features to enable (default: [])
• quiet: Enable quiet mode (default: false)
• offline: Enable offline mode (default: false)

Want to contribute? Have ideas or feature requests? Come tell us about it on Discord.

• Generate a skeletonized view of any Rust crate
• Support for both local crates and remote crates from crates.io
• Syntax highlighting for terminal output
• Optionally include private items and auto-implemented traits
• Support for custom feature flags and version specification
• Full support for Rust standard library documentation (std, core, alloc)

Ruskel requires the Rust nightly toolchain for its operation:

• Nightly toolchain: Required for unstable rustdoc features used to generate JSON documentation
• rust-docs-json component (optional): Required only for standard library documentation access

Install the nightly toolchain:

rustup toolchain install nightly

For standard library support, also install:

rustup component add --toolchain nightly rust-docs-json

To install Ruskel, run:

cargo install ruskel

Note: While ruskel requires the nightly toolchain to run, you can install it using any toolchain.

Basic usage:

ruskel [TARGET]

See the help output for all options:

ruskel --help

Ruskel has a flexible target specification that tries to do the right thing in a wide set of circumstances.

# Current project
ruskel
# If we're in a workspace and we have a crate mypacakage
ruskel mypackage
# A dependency of the current project, else we fetch from crates.io 
ruskel serde
# A sub-path within a crate
ruskel serde::de::Deserialize 
# Path to a crate
ruskel /my/path
# A module within that crate
ruskel /my/path::foo
# A crate from crates.io with a specific version
ruskel serde@1.0.0

Ruskel has full support for Rust's standard library documentation. You can access documentation for std, core, and alloc crates using the same familiar import paths you use in your code. The core crate contains the core functionality that works without heap allocation, alloc provides heap allocation support, and std re-exports from both while adding OS-specific functionality. Ruskel automatically handles these re-exports, so std::vec::Vec works even though Vec actually lives in alloc.

Ruskel supports accessing documentation for Rust standard library crates (std, core, alloc, proc_macro, test) using the official rust-docs-json component.

Before using ruskel with standard library crates, install the rust-docs-json component:

rustup component add --toolchain nightly rust-docs-json

Once installed, you can use ruskel with standard library crates:

# Access via std re-exports (recommended - matches your import statements)
ruskel std::vec::Vec        # Vec type from std
ruskel std::rc::Rc          # Rc type from std  
ruskel std::mem::size_of    # size_of function from std
# Direct access to core and alloc
ruskel core::mem            # Memory utilities from core
ruskel alloc::vec           # Vec module from alloc
# Get entire crate documentation
ruskel std                  # All of std
ruskel core                 # Core library (no_std compatible)
ruskel alloc                # Allocation library

Note: Ruskel automatically handles std re-exports, displaying them as std:: even when the actual implementation lives in core or alloc. This matches how you import these items in your code. Bare module names like rc or vec will show an error suggesting the correct std:: path.

libruskel is a library that can be integrated into other Rust projects to provide Ruskel functionality.

Here's a basic example of using libruskel in your Rust code:

use libruskel::Ruskel;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let rs = Ruskel::new("/path/to/target")?;
    let rendered = rs.render(false, false)?;
    println!("{}", rendered);
    Ok(())
}