Litho Turns a Codebase Into Markdown Docs and C4 Diagrams

Keeping documentation in step with a codebase is the chore nobody wants to own. Litho takes that job off your hands: it's a Rust-based tool that reads a project and writes the documentation itself, diagrams included.

It works at four levels at once: the overall system, its containers, the individual components, and the code inside them. Wire it into CI and those docs regenerate on every commit.

How Litho Generates Documentation

Litho scans a codebase and pulls out comments, structures, and the relationships between them. From that, it produces Markdown documentation and C4 diagrams automatically, so the written page and the architecture drawing come out of a single pass rather than two separate jobs.

Beyond the code itself, Litho can take PDFs, existing Markdown, and SQL files as extra context. It uses that material to generate database diagrams, and it inspects Git history to show how the architecture changed over time.

Why Keeping Docs in Sync Matters

Most teams write architecture docs once and then watch them drift out of date. Because Litho reads the code and the Git history instead of a separate document, its output moves with the repository. Hooked into CI, the documentation refreshes on each commit instead of waiting for someone to remember it exists.