OpenFlowKit

OpenFlowKit is an open-source diagramming studio that runs in the browser and can be self-hosted. It draws architecture diagrams from handwritten, coded, or agent-assisted inputs, and can map a GitHub repository into a visual network of services with links back to source code. The tool emphasizes local-first operation, no mandatory sign-up, and ownership of data. It is free and MIT-licensed, with options for private repos and offline use.

OpenFlowKit supports multiple ways to work: drawing on a shared canvas, typing diagram definitions, and using an agent to generate or modify the diagram. It lets users paste Mermaid, D2, or Structurizr to import code-based diagrams and then edit them visually. The system aims to keep the code and the canvas in sync while offering export options for various formats.

Users can map GitHub repositories to diagrams by reading public repos or private ones on the user’s machine with local tooling. The product shows an integrated path from code to architecture, allowing clicking parts to see underlying files and line numbers. It also supports private mapping on the user’s device without uploading data to a server.

It provides a shared link option for viewing, as well as editable links that keep data within the URL. The platform emphasizes no account is required to start and a focus on keeping work on the user’s device unless explicitly shared.

Use cases

• Map a GitHub repo to understand system architecture and dependencies
• Create diagrams from code and export for docs
• Collaborate with an agent to design or refine diagrams