needs-architecture

To generate system architecture documentation from an existing codebase, the Skill reverse-engineers repository structure, feature designs, and ADRs to produce a cohesive architecture document. It outputs an AsciiDoc file containing prose sections and C4 diagrams reflecting the current project state.

A living architecture document is an up-to-date system design reference that evolves with your project. It stays current by operating in update mode, analyzing new feature designs and ADRs after development to regenerate the architecture documentation with version metadata.

Yes, you can create C4 diagrams with Mermaid automatically. The Skill analyzes your repository state and outputs C4 diagrams via Mermaid to communicate system context, containers, and components directly within the generated architecture documentation.

Yes, this architecture documentation tool supports greenfield development. It operates in a greenfield mode that synthesizes constraints and feature designs to establish the initial system architecture document before coding begins.

The best way to maintain ADRs and architecture docs in sync is to use an automated update tool that inspects both. This Skill analyzes your ADRs and repository state to regenerate the architecture document, ensuring your system design reflects current technical decisions.

A limitation of reverse-engineering architecture from code is that the output quality depends on available artifacts. The Skill relies on inspecting existing feature designs, ADRs, and codebase structure, so sparse documentation or missing constraints will result in a less cohesive architecture document.