edd

Terminal-based diagram editor for sequence diagrams and flowcharts. Uses vim-style keybindings and modal editing.

What it does

edd edits and converts diagrams between formats (Mermaid, PlantUML, Graphviz, D2). It renders ASCII/Unicode diagrams in the terminal or exports to diagram markup languages.

Supported formats:

• Import: Mermaid, PlantUML, Graphviz DOT, D2, JSON
• Export: ASCII/Unicode, Mermaid, PlantUML, JSON

Diagram types:

• Sequence diagrams (participant interactions over time)
• Flowcharts (box-and-arrow layouts)

Key feature: Jump mode

Press an action key (c, d, e) and labels appear on all elements. Press a label key to select that element. This eliminates arrow key navigation.

Keyboard commands

• c / C - Connect nodes (single/continuous)
• d / D - Delete elements (single/continuous)
• e - Edit element text
• i / I - Insert connections (single/continuous)
• u - Undo
• Ctrl+r - Redo
• t - Toggle diagram type
• :w - Save
• :q - Quit
• :export format [file] - Export to format

Installation

go install github.com/kungfusheep/edd@latest

Usage

Start empty editor:

edd

Edit existing diagram:

edd -i diagram.json
edd -i diagram.mmd     # Auto-detects Mermaid
edd -i diagram.puml    # Auto-detects PlantUML
edd -i diagram.dot     # Auto-detects Graphviz

Render diagram to terminal:

edd diagram.json

Convert between formats:

edd -format mermaid diagram.json > output.mmd
edd -format plantuml diagram.mmd > output.puml
edd -format ascii diagram.puml    # Print to terminal

Batch conversion:

for file in *.puml; do
  edd -format mermaid "$file" > "${file%.puml}.mmd"
done

File format

Diagrams are stored as JSON:

{
  "type": "sequence",
  "nodes": [
    {"id": 0, "text": ["Client"]},
    {"id": 1, "text": ["Server"]}
  ],
  "connections": [
    {"from": 0, "to": 1, "arrow": true, "label": "Request"},
    {"from": 1, "to": 0, "arrow": true, "label": "Response"}
  ]
}

Limitations

• Import support covers basic features only (~20-30% of each format's syntax)
• Keyboard-only (no mouse support)
• No image export (terminal rendering only)
• Sequence diagrams support simple message flows only
• Flowcharts support basic box-and-arrow layouts only

Requirements

• Go 1.19+
• Terminal with Unicode support
• 80+ column width recommended