Diagramagic – SVG Diagram Generation

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Generate and edit SVG diagrams using svg++ and the diagramagic CLI tool. Perfect for creating rich, detailed diagrams with minimal layout math.

Sby Skills Guide Bot
DevelopmentIntermediate
107/24/2026
Claude Code
#svg-diagrams#auto-layout#visualization#graph-layout#diagramming

Recommended for

Our review

This skill enables generating and editing SVG diagrams using the svg++ language and diagramagic CLI tool, with automatic layout extensions.

Strengths

  • Simplifies creation of complex diagrams by automating positioning and routing.
  • Supports multiple layout types (flex, graph with layered, radial, circular layouts).
  • Allows rich diagrams with multi-line text, labeled arrows, and sub-file inclusion.
  • Iterative workflow with PNG rendering for verification before final SVG compilation.

Limitations

  • Requires Graphviz system installation for circular and radial layouts.
  • SVG files can become large with many includes and subgraphs.
  • Learning curve to master svg++ syntax and layout rules.
When to use it

Use this skill when you need precise, detailed technical diagrams (architectures, flows, dependency graphs) where automated layout saves time.

When not to use it

Avoid it for very simple diagrams or quick sketches where manual SVG entry is faster, or if you cannot install Graphviz.

Security analysis

Safe
Quality score88/100

The skill only instructs using the 'diagramagic' CLI tool with safe commands (cheatsheet, patterns, render, compile). No destructive actions, exfiltration, or arbitrary command execution are instructed.

No concerns found

Examples

Create a flowchart
Create a diagram showing the request flow from client to server with authentication and database. Use layered graph layout with ortho routing.
Design a system architecture
Design a system architecture diagram for a microservice application with a gateway, three services, and a message queue. Use flex layout for the overall structure and include detailed service cards.
Auto-layout dependency graph
Create a circular layout graph illustrating the dependency relationships between the modules in our application.

name: diagramagic description: Generate and edit SVG diagrams using svg++ and the diagramagic CLI allowed-tools: Bash(diagramagic *), Read, Write, Glob

diagramagic — svg++ Diagram Skill

Diagramagic helps LLMs create better, larger diagrams more easily by keeping SVG familiar and adding minimal layout extensions.

You generate diagrams using svg++ (SVG with diag: layout extensions) and the diagramagic CLI tool.

Setup (first use per session)

Run these commands and use their output as your syntax reference:

  • !diagramagic cheatsheet
  • !diagramagic patterns

Workflow (required)

  1. Create or edit a .svg++ file
  2. Run diagramagic render <file>.svg++ to generate PNG
  3. View the PNG to verify correctness
  4. If incorrect, fix the source and render again
  5. When satisfied, run diagramagic compile <file>.svg++ for final SVG

Quality Standard

You are writing SVG. The diag: extensions handle layout and sizing — they do not replace your responsibility to create rich, detailed, information-dense diagrams. Write with the same visual quality and detail you would if generating raw SVG. The diag: features save you from coordinate math, not from doing the actual design work.

Layout Rules

  • Use <diag:diagram> root with xmlns="http://www.w3.org/2000/svg" and xmlns:diag="https://diagramagic.ai/ns"
  • Use diag:flex for layout structure (stacks, rows, grids of cards) — but fill those containers with rich, detailed content
  • Use diag:graph for auto-layout when topology matters (flowcharts, dependency graphs) — but treat it as scaffolding, not the complete design
  • Choose graph layout deliberately:
    • layout="layered" for flowcharts, request pipelines, dependency chains
    • layout="radial" for hub-and-spoke systems
    • layout="circular" for peer/cyclic systems
  • Choose routing deliberately:
    • routing="auto" as default
    • routing="ortho"/"polyline" for dense technical diagrams where readability matters most
    • routing="curved" for lighter conceptual diagrams; avoid it for dense feedback-heavy graphs
  • Keep graph nodes content-rich (title + details), not just single-line labels
  • For title+body graph nodes, set diag:node gap="6" to gap="12" to avoid cramped text blocks
  • If graph output gets crowded, split into multiple subgraphs with diag:include or switch to a hybrid flex + arrows structure
  • Use diag:wrap="true" on <text> for multi-line text (wrapping is a text feature, not a diag:node feature)
  • Use diag:arrow with id-tagged elements for connectors
  • Use label-rotate="horizontal" for readable arrow/edge labels by default; use follow only when line-following text is intentionally desired
  • Use diag:anchor for precise named points (sequence diagrams, etc.)
  • Use diag:include to compose large diagrams from sub-files
  • Use diag:template when you have 3+ visually identical elements (e.g., entity cards, service boxes)
  • Mix raw SVG freely: <rect>, <line>, <circle>, <path> for decorative elements, region backgrounds, custom shapes
  • Do NOT stop at first compile — iterate until the render matches intent
  • layout="circular" and layout="radial" require system Graphviz (dot) on PATH; layered layout can fall back if unavailable

Error Recovery

  • E_PARSE_XML: fix malformed XML and retry
  • E_SVGPP_SEMANTIC: fix svg++ structure/ids and retry
  • E_INCLUDE_ID_COLLISION: rename conflicting ids between parent and included files
  • E_GRAPH_UNKNOWN_NODE: ensure every diag:edge from/to id exists as a diag:node in the same graph
  • E_GRAPH_SELF_EDGE: remove or redesign self-referential diag:edge (from == to)
  • E_GRAPH_TOO_LARGE: split the graph into smaller sections or compose with diag:include
  • Always attempt at least one fix before asking for help
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