Show HN: DeepDiagram – Open source AI diagram generator (Draw.io, Mermaid)

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DeepDiagram: Open source AI diagram generator (Draw.io, Mermaid, ECharts)

Hi everyone,

I built DeepDiagram because I was tired of AI tools generating static images (PNG/JPG) for diagrams. If the AI gets one detail wrong, you can't easily fix it.

I wanted a tool that generates editable code and renders it interactively.

It is an open-source web platform using a Multi-Agent architecture (React 19 + LangGraph). A Router analyzes your intent and directs it to a specialized agent (e.g., Draw.io expert, Flowchart expert, or Data Viz expert).

📺 Demos

Mind Map & Data Charts (ECharts):

Draw.io Generation (XML based):

Mermaid Diagrams:

🛠 Tech Stack

Orchestration: LangGraph (Python) for the ReAct loop.
Frontend: React 19, Vite, TailwindCSS, Zustand.
Backend: FastAPI (Python 3.10+).
Streaming: SSE (Server-Sent Events) for real-time preview.
Rendering: React Flow, Apache ECharts, Mermaid.js, Draw.io (Atlas theme).

✨ Key Features

Draw.io Agent: Generates compatible XML. You can edit the result directly in the canvas.
Data Chart Agent: Turns raw data into interactive ECharts (Bar/Line/Pie).
Mermaid Agent: Supports Sequence, Gantt, Class diagrams, etc.
Branching & History: AI isn't perfect, so I added a Git-like branching system. You can "retry" messages or navigate back to previous states to fix errors.