# Diagrams and images

## Drawing diagrams

BookStack has **diagrams.net** (formerly drawio) built in. This is the killer feature for documenting how systems connect.

### How to insert one

1. In the editor toolbar, click the diagrams button.
2. A drawio window opens. Draw your diagram.
3. Click **Save**. The diagram is embedded but stays editable — click it later to re-open.

### What to draw

- System architecture (boxes = services, arrows = data flows)
- Sequence diagrams (who calls whom)
- Data flow between JSON feeds and the websites that consume them
- Deployment diagrams

## Images

Drag-and-drop images into the editor. They upload automatically.

## Code and JSON

Use the code block button (`</>`) and pick the language. All syntax-highlighted.