Automate Your Architecture Docs: Litho Generates C4 Diagrams Straight From Your Codebase

You know the feeling. You inherit a codebase with no documentation, or you find a README that's three years out of date, or you spend a whole afternoon updating architecture diagrams only to have them become irrelevant after the next refactor. Keeping documentation in sync with code is a losing battle for most teams. Litho, a Rust-powered tool also called deepwiki-rs, aims to change that by automatically generating professional C4 model documentation directly from your source code.

What It Does

Litho is an AI-driven documentation generation engine. It analyzes your codebase and produces architecture documentation structured around the C4 model, which means you get context diagrams, container diagrams, component diagrams, and code-level documentation all generated for you. The project is written in Rust, and it's available as a crate on crates.io. It's designed to work with any codebase, scanning your source files and using AI to interpret the structure, relationships, and responsibilities of each component.

The output is not just a wall of text. You get formatted documentation with diagrams that illustrate how pieces of your system relate to one another. The idea is that you run Litho against your repository, and it produces a wiki-like set of documents that stay current because you can regenerate them whenever your code changes.

Why It's Cool

The C4 model is a well-established way to document software architecture, but it's rarely used in practice because it's tedious to maintain. Litho addresses that pain point directly by making the generation process automatic.

• It solves the stale documentation problem. Most documentation tools require manual updates. Litho generates docs from your actual code, so when you refactor or add features, you can regenerate and your docs reflect reality. No more explaining to new hires that the architecture diagram is "mostly accurate except for the database layer."

• It uses a structured, professional format. Instead of dumping a bunch of markdown files with inconsistent formatting, Litho produces C4 model documentation. That means you get hierarchical diagrams that show system context, containers, components, and code-level details. It's the same format used by enterprise architecture tools, but without the manual effort.

• It's built with Rust. The README specifically highlights "high-performance" as a design goal. Rust gives you fast parsing and processing, which matters when you're scanning a large monorepo with thousands of files. You're not waiting around for documentation to generate.

• It fills a real gap in the developer tooling ecosystem. There are linters, formatters, and test runners that keep your code healthy. But documentation? That's usually left to manual effort or half-hearted automation. Litho treats documentation generation as a first-class CI step, something you can run alongside your tests.

How to Try It

Litho is distributed through crates.io, so you'll need Rust installed. If you don't have Rust yet, you can get it from rustup.rs.

Install the tool with cargo:

cargo install deepwiki-rs

Once installed, you can point it at your project. The exact usage command isn't detailed in the README excerpt, but the repository at github.com/sopaco/deepwiki-rs contains documentation in both English and Chinese under the docs directory. You'll find setup instructions, configuration options, and examples there.

For a quick start, clone the repo and check the docs:

git clone https://github.com/sopaco/deepwiki-rs.git
cd deepwiki-rs
cargo run -- --help

The project is actively maintained, with CI workflows and regular releases. If you run into issues, the GitHub issues page is the place to start.

Final Thoughts

Litho isn't going to replace the need for human-written design documents or architectural decision records. But for the kind of documentation that describes what your code actually does and how it connects, this tool could save you a lot of time. It's best suited for teams that want to maintain up-to-date architecture docs without dedicating a person to the task. If you're tired of explaining your system's architecture to new team members using a whiteboard and hand-waving, give Litho a try.

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