The frontend is built with Next.js and React Flow to render the interactive diagrams that users explore.

A live demo is available at docflow.software, with the option to test your own repositories on the free tier.

Under the hood, DocFlow uses a NestJS backend with BullMQ for indexing, and combines structural code parsing with PostgreSQL and pgvector for hybrid search, citing exact file paths and lines.

DocFlow automates mapping of backend repositories to reveal database schemas, REST endpoints, and authorization logic, creating a comprehensive view of how backends are wired.

A line-cited architecture chat explains authentication tracing with exact source lines (for example src/user/auth.middleware.ts:14-31) and a route protection table across modules such as UserModule, ProfileModule, and ArticleModule.

The tool works across full-stack and backend frameworks, demonstrated using the nestjs-realworld-example-app repository to show versatility.

The Backend API explorer scans NestJS controllers and lists multiple REST endpoints (GET, POST, PUT, DELETE), linking routes to source files like src/article/article.controller.ts and src/user/user.controller.ts.

The author invites feedback on diagram aesthetics and on additional extractions users would find helpful when inspecting unfamiliar backends.

A real bug is identified: PUT /articles/:slug and DELETE /articles/:slug authenticate via middleware but do not check the author's userId in the service, exposing an authorization gap.

Interactive database schema visualization shows six tables (user, article, comment, tag, follows, article_favorites_user) with keys and relationships displayed via a React Flow graph.