# ruskel
[](https://crates.io/crates/libruskel)
[](https://docs.rs/libruskel)
[](https://opensource.org/licenses/MIT)
Ruskel produces a syntactically correct skeleton of a crate's public API: docs
included, implementation stripped. Crates not found locally are fetched from
[crates.io](https://crates.io).
Ruskel is great for:
- Quick access to Rust documentation from the command line.
- Exporting a crate's public API as a single file for LLMs and other tools.
- Standard library documentation (`std`, `core`, `alloc`), e.g. `ruskel std::vec::Vec`.
For example, here is the skeleton of the very tiny `termsize` crate:
```rust
// Ruskel skeleton - syntactically valid Rust with implementation omitted.
// settings: target=termsize, visibility=public, auto_impls=false, blanket_impls=false
pub mod termsize {
//! Termsize is a tiny crate that provides a simple
//! interface for retrieving the current
//! [terminal interface](http://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 {
/// number of rows
pub rows: u16,
/// number of columns
pub cols: u16,
}
/// Gets the current terminal size
pub fn get() -> Option<self::super::Size> {}
}
```
---
## Features
- Filter output to specific items with `--search`
- Tabular item listings with `--list`
- Syntax highlighting for terminal output
- Include private items and auto-implemented traits
- Custom feature flags and version specification
---
## Installation
Ruskel requires the Rust nightly toolchain to run. Install the nightly
toolchain and the `rust-docs-json` component:
```sh
rustup toolchain install nightly
rustup component add --toolchain nightly rust-docs-json
```
Install Ruskel:
```sh
cargo install ruskel
```
Ruskel requires nightly to run but can be installed with any toolchain.
---
## Usage
Basic usage:
```sh
ruskel [TARGET]
```
See the help output for all options:
```sh
ruskel --help
```
```sh
# Current project
ruskel
# A crate in the workspace
ruskel mypackage
# A dependency of the current project, or fetched 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
# Specific version from crates.io
ruskel serde@1.0.0
# Search for "status" across names, signatures and doc comments
ruskel reqwest --search status
# Search for "status" in only names and signatures
ruskel reqwest --search status --search-spec name,signature
# Search for "status" in docs only
ruskel reqwest --search status --search-spec doc
# Access via std re-exports (recommended)
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
# Entire crate
ruskel std # All of std
ruskel core # Core library (no_std compatible)
ruskel alloc # Allocation library
```
---
## Search
Use `--search` to focus on specific items instead of rendering an entire crate.
The query runs across multiple domains and returns a skeleton containing only
the matches and their ancestors.
```sh
# Show methods and fields matching "status" within the reqwest crate
ruskel reqwest --search status --search-spec name,signature
```
By default the query matches name, doc, and signature domains, case-insensitively.
Use `--search-spec` to select domains (e.g., `--search-spec name,path` or
`--search-spec doc`). Add `--search-case-sensitive` for exact case matching, or
`--direct-match-only` to keep container matches collapsed.
Search respects `--private`, feature flags, and syntax highlighting.
## Listing
Use `--list` to print a concise catalog of crate items instead of rendering
Rust code. Each line reports the item kind and its fully qualified path:
```sh
# Survey the high-level structure of tokio without emitting code
ruskel tokio --list
crate crate
module crate::sync
struct crate::sync::Mutex
trait crate::io::AsyncRead
```
Combine `--list` with `--search` to filter the catalog using the same domain
controls. The listing honours `--private`, feature flags, and paging choices,
but conflicts with `--raw`.
---
## MCP Server
Ruskel can run as a Model Context Protocol (MCP) server for coding agents.
### Running as MCP Server
To start Ruskel in MCP server mode:
```bash
ruskel --mcp
```
This starts the server on stdout, exposing a single `ruskel` tool.
### MCP Configuration
For Codex CLI, Claude Code, or other coding agents:
```json
{
"mcpServers": {
"ruskel": {
"command": "ruskel",
"args": ["--mcp"]
}
}
}
```
### Tool Parameters
The `ruskel` tool accepts the following JSON parameters:
#### Required
- `target` (string): The crate/module to generate a skeleton for.
#### Optional
- `frontmatter` (boolean, default: true): Include comment frontmatter.
- `search` (string | null, default: null): Restrict output to matches for this query.
- `search_spec` (array of strings | null, default: null): Search domains (name, doc, signature,
path). Defaults to name, doc, signature.
- `search_case_sensitive` (boolean, default: false): Require exact-case matches when searching.
- `direct_match_only` (boolean, default: false): Only render direct matches, not expanded containers.
- `no_default_features` (boolean, default: false): Disable default features.
- `all_features` (boolean, default: false): Enable all features.
- `features` (array of strings, default: []): Features to enable.
---
## libruskel library
The underlying library can be used directly:
```rust
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(())
}
```
---
## Community
Want to contribute? Have ideas or feature requests? Come tell us about it on
[Discord](https://discord.gg/fHmRmuBDxF).