Frequently asked questions

Using DiagramaHub

Which diagram languages are supported?

Mermaid, PlantUML, D2 and DBML, plus the freehand whiteboard. Mermaid is drawn in your browser; PlantUML, D2 and DBML are drawn by the Kroki service that runs inside the same installation. See Diagram types.

Can I turn a diagram into another language?

Yes, with the editor's AI-assisted conversion, which shows the result side by side before applying it. You need an AI provider configured. See The editor.

How do I get my diagrams out of DiagramaHub?

Each diagram exports to PNG, SVG, PDF or Markdown, and a whole project or folder exports as a ZIP. You can also import ZIP archives, diagram files and Excalidraw drawings. See Export and import.

Who can see a diagram I share?

Anyone with the link; if the link is protected, they also need the access code. Links can expire after 5, 10 or 30 days or never, and you can revoke them. See Sharing diagrams.

Artificial intelligence

Does the AI cost anything?

DiagramaHub doesn't charge for or resell AI: you use your own API key (BYOL) for Gemini, OpenAI, Claude, DeepSeek or MiniMax, and your provider bills you directly.

What is sent to the AI provider, and where is my API key stored?

Only when you use an AI feature, the backend sends your provider the request and the diagram context. The key is stored encrypted in the database and the API never returns it in full. See AI assistant and Protections.

The AI returned a diagram that doesn't render. What now?

For Mermaid and D2 the chat validates the code and, if it fails, asks the model to fix it (you can turn this off in the AI settings). A reply cut off for length is not applied and you get a notice. See AI assistant.

Account

I forgot my password

Request a recovery link from the sign-in screen. It requires the instance operator to have set up email delivery. See Your account and security.

I lost the phone with my authenticator app

Sign in with one of your recovery codes (each works once) or with the email code if you have it enabled. If you have neither, an instance administrator can reset your MFA. See Your account and security.

Self-host

Does running it on my server cost anything?

No. The software is open source under Apache 2.0. Your instance's plans, limits and prices are yours to define; Stripe payments are optional. See Plans and limits.

What do I need to install it?

Docker with Docker Compose. You can use the MongoDB the installation starts or an external one. See Self-host and Installation.

How do I upgrade to a new version?

Back up the database, read the release notes and follow Maintenance and upgrades.

Something doesn't work in my installation

Check Troubleshooting. If it's a bug, open an issue on GitHub; if it's a vulnerability, report it privately as described in Security.