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Diagram Design

cathrynlavery/diagram-design

Diagram Design is an MIT-licensed skill from Cathryn Lavery of LittleMight that has your agent draw editorial-style diagrams and charts as self-contained HTML with inline SVG. It covers 42 visual types, from architecture and sequence diagrams to Sankey, Wardley and database schema, and can pick up your colors and fonts from your website. It also redraws draw.io, Mermaid and Excalidraw files.

By Cathryn LaveryMIT licenseWorks with 8 agentsDesign and frontend

Facts checked on against the sources listed at the end of this page.

GitHub stars
60,080
Skills in the pack
1
Agents supported
8OpenCode is a manual copy of the skill folder
License
MIT
Last commit
1 day ago21 October 2026
Instruction size
4.2k wordsacross its SKILL.md file

How to install Diagram Design

AgentCommandCopy
Claude Code
/plugin marketplace add cathrynlavery/diagram-design
/plugin install diagram-design@diagram-design

Claude Code leaves auto-update off for third-party marketplaces. Turn it on under /plugin, Marketplaces.

Codex
codex plugin marketplace add cathrynlavery/diagram-design
codex plugin add diagram-design@diagram-design
GitHub Copilot
copilot plugin marketplace add cathrynlavery/diagram-design
copilot plugin install diagram-design@diagram-design

Commands as given in the README on 2 October 2026.

What Diagram Design runs on your machine

Hooks
None found in the repo.
Bundled scripts
Yes. Small Python scripts parse draw.io, Excalidraw and Mermaid input, run a self-check and export SVG. PNG export uses Playwright with Chromium, which you install separately.
Network calls
Only when you ask. Generated diagrams load fonts from Google Fonts when opened in a browser, and brand onboarding fetches a few pages from the website you name. The privacy policy says the plugin has no server, accounts, analytics or telemetry.
API keys needed
None.

These are facts read from the repo, not a security rating. Read the files before you install any skill.

What is inside Diagram Design

Skill or commandWhat it makes the agent do
diagram-designOne skill with reference files for 42 visual types, from architecture and flowcharts to Gantt, Sankey, Wardley maps and UML class diagrams.
/doctorA command that checks the install and setup.
/export-diagramA command that exports a diagram to SVG or PNG.
/import-mermaidA command that redraws a Mermaid source. Matching commands exist for draw.io and Excalidraw files.
/profileA command that saves a brand as a named profile you can attach to a project.

The commands are named for Claude Code, and Pi and Factory Droid load them as prompt templates. The repo ships one skill, and the other entries are its commands.

A good fit for

  • Designers and writers who want diagrams that match a site's colors and fonts
  • Anyone who needs charts and diagrams beyond software architecture, such as Wardley maps, fishbone and kanban
  • Redrawing draw.io, Mermaid or Excalidraw sources at a chosen size and level of detail
  • Agencies that keep a separate brand profile for each client project

Skip it if

  • Diagrams that must be clickable and explorable, since the default output is static
  • Mermaid-only workflows that want the diagram kept as text in a README
  • Machines where Python and Chromium cannot be installed, if you need PNG export

How Diagram Design works

Every visual type comes in minimal light, minimal dark and full-editorial variants. The README says output is static by default, with optional motion modes for ordered explanations that fall back to a complete still frame when reduced motion is requested.

Brand onboarding reads your website's background, text and accent colors and fonts, checks contrast, and writes them as tokens after you approve the change. A saved profile lives in ~/.diagram-design/profiles, and a .diagram-design file in a project picks which one to use. On first use in a new project, the skill pauses and asks if the style guide is still the default.

Works with
Claude Code, Codex, GitHub Copilot, Factory Droid, Pi, Kiro, OpenCode, Claude Cowork

How much context Diagram Design uses

The skill4,221 words in its SKILL.md file
Loaded at startOnly each skill's name and description. The full text loads when a task needs that skill.

Word counts are measured from the repo every day. Reference files a skill loads on demand are not counted.

Is Diagram Design still maintained?

Last commit, 1 day ago
Stars gained in 7 days+4,103
Stars gained in 30 daysShown after 30 days of tracking
Open issues and pull requests41
Forks3,873

Tools Diagram Design works with

Similar skill packs

Questions about Diagram Design

Which agents does Diagram Design support?

Claude Code, Codex, GitHub Copilot, Factory Droid, Pi, Kiro and OpenCode, plus Claude Cowork through an organization marketplace. The README gives a separate install route for each.

Is it free?

Yes. It is MIT licensed.

Does it send my diagrams anywhere?

The privacy policy says the plugin has no server and collects no data. Generated files load Google Fonts when opened in a browser, and brand onboarding fetches the site you name.

How does it match my brand?

Ask it to onboard to your website. It reads the page's colors and fonts, maps them to roles such as paper, ink and accent, checks contrast and shows a diff before writing anything.

Can it convert my existing diagrams?

Yes. It accepts draw.io, Mermaid and Excalidraw scene files and redraws them in its style at a size and detail level you choose.

Sources

Something wrong or out of date? Email [email protected] with a link to the source. Stats come from the public GitHub API and update every day.

For the maker

Add the badge to your README or site. The number updates every day.

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