An open-source diagram skill for designer

An open-source diagram skill for Claude Code and other Agent Skills-compatible hosts now ships 39 editorial diagram types in version 2.5.10, adding ten layout grammars including Sankey, fishbone, Wardley map, kanban, user journey, deployment, dependency graph, UML class, story map, and database schema. The skill generates self-contained HTML and SVG with no build step, JavaScript, or external image dependency, and can redraw draw.io, Mermaid, or Excalidraw sources at a chosen format, size, and detail level. Version 2.0 introduced the Loop flywheel with a shared-memory hub, and version 2.3 added semantic system patterns and optional accessible motion while keeping static output as the default.

Editorial diagrams your designer won't hate. New in 2.0 — the Loop: flywheels with a shared-memory hub. The dashed lines are the write-backs. New in 2.3: semantic system patterns and optional accessible motion, while static output stays the default. New in 2.5.10: ten more layout grammars — Sankey, fishbone, Wardley map, kanban, user journey, deployment, dependency graph, UML class, story map, and database schema. 39 editorial diagram types for Claude Code, Codex, Factory Droid, Pi, and Agent Skills-compatible hosts. Self-contained HTML + SVG. No shadows. No Mermaid slop. Semantic patterns describe behavior separately from layout, so a queue, policy trace, or trust boundary can use the nearest existing type without expanding the type count. Static HTML remains the default; optional motion is available for ordered explanations. The skill also redraws draw.io, Mermaid, or Excalidraw sources at a chosen format, size, and detail level. No Figma. No generic rounded boxes. No 30-minute color-picking sessions. I write at littlemight.com https://littlemight.com?utm source=diagram-design&utm medium=readme&utm campaign=github&utm content=intro and run BestSelf.co https://bestself.co?utm source=diagram-design&utm medium=readme&utm campaign=github&utm content=intro on the side . Every time I needed a diagram — an architecture sketch, a flowchart, a pyramid of what matters most — I'd ask Claude and get back a generic rounded-box thing that looked nothing like the rest of the site. I'd either fight with Figma for 30 minutes or just skip the diagram. So I built a Claude Code skill for it. Thirty-nine visual types, editorial quality, matches your brand in 60 seconds by reading your website. The highest-quality move is usually deletion. Every node earns its place. The accent color is reserved for the 1–2 things the reader should look at first. Target density: 4/10. All 39 visual types ship in three static variants: minimal light, minimal dark, and full-editorial. Open any of them directly in a browser. There is no build step, JavaScript, or external image dependency. | Architecture <sub Components + connections</sub | IT current-state <sub Legacy landscape + modernization</sub | Flowchart <sub Decision logic</sub | | Sequence <sub Messages over time</sub | State machine <sub States + transitions</sub | ER / data model <sub Entities + fields</sub | | Timeline <sub Events on an axis</sub | Swimlane <sub Cross-functional flow</sub | Quadrant <sub Two-axis positioning</sub | | Radar / spider <sub Multi-axis comparison</sub | Loop / flywheel <sub Reinforcing cycle + shared hub</sub | Nested <sub Hierarchy by containment</sub | | Tree <sub Parent → children</sub | Org chart <sub Ownership + routing</sub | Layer stack <sub Stacked abstractions</sub | | Venn <sub Set overlap</sub | Pyramid / funnel <sub Ranked hierarchy or drop-off</sub | Bar chart <sub Categorical comparison</sub | | Treemap <sub Part-of-whole by area</sub | Line chart <sub Trends over time</sub | Gantt <sub Tasks + phases on a timeline</sub | | Scatter plot <sub Distribution + correlation</sub | High-Level <sub End-to-end stack on a cluster</sub | Process <sub Multi-actor sequential workflow</sub | | Medallion <sub Multi-tier data storage</sub | Data flow <sub Role-scoped pipeline steps</sub | DP integration <sub Sources → core → consumers</sub | | DP security matrix <sub Per-role access permissions</sub | Sankey <sub Quantities that split + merge</sub | Fishbone <sub Grouped causes → one effect</sub | | Wardley map <sub Value chain × evolution</sub | Kanban <sub Work in progress by state</sub | User journey <sub Stages, actions + sentiment</sub | | Deployment <sub Zones, hosts + artifacts</sub | Dependency graph <sub Fan-in, ranks + cycles</sub | UML class <sub Classes, operations + typed relations</sub | | Story map <sub Backbone × release slices</sub | Database schema <sub Physical tables + column FKs</sub | Polar chart <sub Cyclic magnitude · linear radius</sub | | Waterfall <sub Running total + signed bridges</sub | | | The v2.5.10 release added the final ten types above. Compare their light, dark, and full-editorial variants in the 30-variant contact sheet /cathrynlavery/diagram-design/blob/main/.github/pr-previews/editorial-diagrams-2.5.10.jpg . Browse the live gallery: cathrynlavery.github.io/diagram-design https://cathrynlavery.github.io/diagram-design/ — or open skills/diagram-design/assets/index.html /cathrynlavery/diagram-design/blob/main/skills/diagram-design/assets/index.html locally to flip through all 39 diagrams with light / dark / full-editorial tabs. Claude Code: /plugin marketplace add cathrynlavery/diagram-design /plugin install diagram-design@diagram-design Then enable updates once: run /plugin , open Marketplaces , select diagram-design , and choose Enable auto-update . Claude Code disables auto-update by default for third-party marketplaces; after this toggle, it refreshes the marketplace and installed plugin in the background after startup. Run /reload-plugins when prompted, or let the next session load the update. Codex: codex plugin marketplace add cathrynlavery/diagram-design codex plugin add diagram-design@diagram-design Codex refreshes configured Git marketplaces at startup. To fetch immediately, run codex plugin marketplace upgrade diagram-design and start a new session. GitHub Copilot: copilot plugin marketplace add cathrynlavery/diagram-design copilot plugin install diagram-design@diagram-design Copilot installs the shared Diagram Design skill plus its doctor, export, import, and profile capabilities from the existing repository marketplace. Confirm discovery with copilot skill list or /skills in an interactive session , then ask for a diagram in natural language. To fetch a merged update, run copilot plugin marketplace update diagram-design , then copilot plugin update diagram-design@diagram-design . Factory Droid: droid plugin marketplace add https://github.com/cathrynlavery/diagram-design droid plugin install diagram-design@diagram-design --scope user Droid tracks Git plugins by commit rather than the manifest's display version. To fetch a merged update, run droid plugin marketplace update diagram-design , then droid plugin update diagram-design@diagram-design --scope user , and start a new session. Claude Cowork organization marketplace : Organization GitHub marketplaces currently require a private or internal repository, so first mirror this public repository into one owned by your organization. In Organization settings → Plugins , choose Add plugin → GitHub , connect that mirror, and enable Sync automatically from the marketplace menu. Automatic sync runs when a pull request containing a plugin version bump is merged to the mirror's default branch; direct pushes do not trigger the webhook. Install Diagram Design from the resulting organization marketplace. Pi: pi install https://github.com/cathrynlavery/diagram-design Run /reload in an open Pi session. Pi makes the skill available for matching diagram requests; use /skill:diagram-design to invoke it explicitly. Pi also loads the /export-diagram , /import-mermaid , /import-excalidraw , /profile , and /doctor prompt templates. The unpinned Git install is intentional: Pi has no automatic package refresh, so run pi update --extensions to pull merged updates. Kiro: Import the Agent Skill from the repository subdirectory URL: https://github.com/cathrynlavery/diagram-design/tree/main/skills/diagram-design Kiro copies imported skills into .kiro/skills/ for a workspace or ~/.kiro/skills/ globally, so re-import the URL to pick up updates. Custom agents that declare resources should include skill://diagram-design/ /SKILL.md . OpenCode: Copy or symlink skills/diagram-design/ to .opencode/skills/diagram-design in a project or ~/.config/opencode/skills/diagram-design globally. OpenCode has no Diagram Design marketplace package; copied installs update only when you replace the directory from a newer checkout. One-time migration: an existing standalone npx skills add copy will not start following the Codex marketplace automatically. Remove that standalone copy, then use the Codex marketplace commands above. Likewise, uninstall a personal Cowork copy and reinstall Diagram Design from your organization's marketplace. Future marketplace version bumps then flow through each client's native update path. Managed installs are convenient, but changes to references/style-guide.md may be replaced by package updates. Saved profiles in ~/.diagram-design/profiles/ survive updates, and projects with a .diagram-design marker are unaffected. Clone the repo and install the local path if you plan to customize the working style guide directly: git clone git@github.com:cathrynlavery/diagram-design.git ~/code/diagram-design Pi: register the checkout as a local package pi install ~/code/diagram-design Claude Code: symlink the inner skill ln -s ~/code/diagram-design/skills/diagram-design ~/.claude/skills/diagram-design Other Agent Skills hosts: create only the roots you use mkdir -p ~/.agents/skills ~/.cursor/skills ~/.cline/skills ~/.kiro/skills ~/.config/opencode/skills ~/.copilot/skills ln -s ~/code/diagram-design/skills/diagram-design ~/.agents/skills/diagram-design ln -s ~/code/diagram-design/skills/diagram-design ~/.cursor/skills/diagram-design ln -s ~/code/diagram-design/skills/diagram-design ~/.cline/skills/diagram-design ln -s ~/code/diagram-design/skills/diagram-design ~/.kiro/skills/diagram-design ln -s ~/code/diagram-design/skills/diagram-design ~/.config/opencode/skills/diagram-design ln -s ~/code/diagram-design/skills/diagram-design ~/.copilot/skills/diagram-design The shared skill lives at skills/diagram-design/ . Pi discovers it through the repo's standard skills/ package directory; Claude Code, GitHub Copilot, Codex, Factory Droid, and other Agent Skills-compatible tools use the same files. The whole point: ship editorial-quality diagrams in your colors and typography, not a generic template. Out of the box, diagrams render in a clean jet-black + atomic-tangerine palette white-smoke paper, jet-black ink, atomic-tangerine accent, blue-slate muted, silver hairlines . Good enough to screenshot straight away. But 60 seconds of onboarding is better — the skill will pull your brand from your website and apply it across every diagram. You: "onboard diagram-design to https://yoursite.com" Agent: → fetches the homepage → extracts the dominant palette + font stack → maps detected values to semantic roles: paper, ink, muted, accent, link → shows a proposed diff → writes your tokens to references/style-guide.md You: "yes, apply it" Every new diagram now uses your colors. Your website's paper color becomes the diagram background. Your CTA color becomes the focal accent. Your body font stack becomes the node label family. Brand matching also emits a fidelity receipt: sampled URLs, exact color roles, font families and weights, font source URLs, and any fallback. Public site fonts are used directly and verified after rendering rather than silently replaced with generic system fonts. | Detected from your site | Becomes | |---|---| | <body background | paper token | | Primary text color | ink token | | Secondary / caption text | muted token | | Cards or containers | paper-2 token | | Most-used brand color CTA, link, heading | accent token | | <h1 font family | title font | | <body font family | node-name font | | <code / <pre font | sublabel font | Before writing tokens, the skill verifies WCAG AA contrast on ink over paper . If your site has a color that fails contrast at diagram sizes 9–12px , it proposes an adjusted value and explains why. Every diagram template gives the inline SVG an accessible name and description: role="img" , a resolving aria-labelledby , and first-child <title / <desc slots. IDs are prefixed per diagram and variant, so multiple SVG exports can be safely inlined on one page without duplicate accessible-name IDs. Decorative specimen icons are hidden from assistive technology instead. Prefer to set tokens by hand? Open skills/diagram-design/references/style-guide.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/style-guide.md and edit the table. Everything downstream reads from there — all 39 diagrams, the annotation primitive, and the gallery all inherit semantic role names accent , not eb6c36 . The skill won't silently ship default-skinned diagrams into a branded project. On first use in a new project, it checks if style-guide.md has been customized. If not, it pauses and asks: "This is your first diagram in this project. The style guide is still at the default. Want to run onboarding, paste tokens manually, or proceed with default?" See skills/diagram-design/references/onboarding.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/onboarding.md for the full spec. Onboard a brand once, save the result as a named profile, then add a .diagram-design marker containing profile: <slug to each client project. Marker projects read ~/.diagram-design/profiles/<slug .md directly, so parallel workspaces can use different brands without overwriting a shared installed style-guide.md . The profile library is shared across Claude Code, Codex, Factory Droid, and Pi. Use /diagram-design:profile in Claude Code, /profile in Factory Droid or Pi, or ask in natural language in any host. See profiles.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/profiles.md for the storage, marker, and recovery contract. From a cloned checkout, open the gallery to see all 39 diagrams open skills/diagram-design/assets/index.html macOS xdg-open skills/diagram-design/assets/index.html Linux In Claude Code, Codex, Factory Droid, or Pi, ask: "Make me an architecture diagram of my app: frontend, backend, database, Redis cache." "I need a quadrant showing Q2 projects by impact vs effort." "Give me a sequence of a bearer call with token refresh on 401." branching refresh uses the ALT combined-fragment grammar in type-sequence.md; see skills/diagram-design/assets/example-sequence-oauth.html — not a full authorize-code handshake Operator recipes for editable installs, first diagrams, brand setup, import, export, validation, Windows junctions, and reusable prompts live in docs/cookbook.md /cathrynlavery/diagram-design/blob/main/docs/cookbook.md . Your agent will pick the right type, build the HTML, and save it. You can also start from a template directly: cp skills/diagram-design/assets/template.html my-diagram.html minimal light cp skills/diagram-design/assets/template-full.html my-diagram.html editorial with summary cards cp skills/diagram-design/assets/template-motion.html my-diagram.html optional accessible motion When behavior matters, the skill chooses a semantic pattern first and a visual type second. The eight routed patterns cover fan-in queues and bottlenecks, repeated stage slots, unstructured-input transformation, paired policy traces, secure paved roads, governance catalogs, compensating security layers, and traceable block decomposition. Each pattern defines its triggers, primitives, budget, anti-patterns, static fallback, and nearest visual type in semantic-patterns.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/semantic-patterns.md . Motion is optional and does not create another visual type. animation.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/animation.md defines none , reveal , step , and loop modes with a complete static first frame, deterministic timing, and controls when interaction is available. Reduced-motion output shows the complete static frame and hides/disables playback controls. Motion HTML uses the exact reviewed controller from template-motion.html ; arbitrary or modified inline scripts, remote assets, CSS imports, and executable HTML attributes are rejected. The default is none : ordinary output remains static and script-free. example-policy-trace-animated.html /cathrynlavery/diagram-design/blob/main/skills/diagram-design/assets/example-policy-trace-animated.html is the self-contained interactive example. Already have diagrams in draw.io / diagrams.net, Mermaid, or Excalidraw? Point the skill at the source and it redraws them — same content, this design system, at whatever the destination needs. A 12-node draw.io file redrawn at balanced detail for a blog post. The source's six pastel fills became one accent; its hand-dragged coordinates became a 4px grid. /diagram-design:import-drawio platform.drawio /diagram-design:import-drawio platform.drawio --size=slide-16x9 --detail=simplified --audience=executive /diagram-design:import-drawio platform.drawio --detail=faithful --format=png --page=all /diagram-design:import-mermaid README.md --diagram=all /diagram-design:import-mermaid architecture.mmd --size=slide-16x9 --detail=simplified /diagram-design:import-excalidraw whiteboard.excalidraw --size=slide-16x9 --detail=simplified Or just ask: "redraw this drawio file for my deck" , "make this Mermaid block editorial" , "make this whiteboard sketch presentable" , or "この Mermaid をスライド用にきれいにして" . Reads the common containers draw.io writes — .drawio , .drawio.xml , .drawio.png embedded diagram , and .drawio.svg — including compressed payloads that look like base64 garbage in an editor. For Mermaid, it accepts .mmd , .mermaid , and one or more fenced mermaid blocks in Markdown. For Excalidraw, it accepts .excalidraw and .excalidraw.json scene files not .excalidraw.png / .excalidraw.svg exports . It parses text only: no rendering, JavaScript, browser, network, or followed click targets. The point isn't conversion, it's fitting the output to where it's going . Same source file, three different diagrams: | Dial | Options | What it changes | |---|---|---| | Format | html · svg · png · html+png | The deliverable. SVG for Figma, PNG for slides, HTML for the web. | | Size | doc-inline · doc-wide · slide-16x9 · slide-4x3 · social-og · social-square · print-a4-landscape · print-letter-landscape · fit | The viewBox and the type ramp — a projected slide gets 16px node names, not 12px. | | Detail | faithful ≤24 nodes, zoned · balanced ≤12 · simplified ≤7 | How much of the source survives, via a fixed degrade ladder — decorations, then duplicates, then leaf clusters, then infrastructure. | | Audience | engineer · mixed · executive | The wording , not the count. Auth Service / JWT · RS256 · :8443 → Auth Service / token check → Sign-in . | Every import ends with a fidelity ledger — what got merged, collapsed, or dropped. You know the source; you'd notice anyway. Detail: balanced · 12 source nodes → 8 drawn Collapsed: "Token valid?" decision → edge label on Gateway → Auth Dropped: 1 sticky note "legacy path, to be retired" — unconnected in source Kept in full: the request path Web/Mobile → Gateway → Orders → Postgres What never carries over: source or renderer coordinates, source palette, source fonts, draw.io's diagonal connector spaghetti, Mermaid's automatic layout, or Excalidraw's hand-drawn geometry. What always does: components, relationships, grouping, and direction. See references/import-drawio.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/import-drawio.md , references/import-mermaid.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/import-mermaid.md , references/import-excalidraw.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/import-excalidraw.md , and references/output-spec.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/output-spec.md . Diagrams ship as self-contained HTML, but you can export the diagram itself for Figma, slides, or social cards. Use the slash command for your agent: Pi: /export-diagram path/to/diagram.html /export-diagram path/to/diagram.html --svg-only /export-diagram path/to/diagram.html --png-only --scale=3 /export-diagram path/to/diagram.html --registry Claude Code: /diagram-design:export-diagram path/to/diagram.html /diagram-design:export-diagram path/to/diagram.html --svg-only /diagram-design:export-diagram path/to/diagram.html --png-only --scale=3 /diagram-design:export-diagram path/to/diagram.html --registry Or just ask in natural language: "Export this diagram as SVG and PNG." "Save my-diagram.html as PNG." - SVG — extracts the <svg node and injects Google Fonts so it renders standalone in browsers, Figma, and Illustrator. - PNG — rasterizes the diagram via Playwright at 2× by default. One-time setup: pip install playwright && playwright install chromium . Both formats are diagram-only — editorial cards and headers from -full variants aren't included. For a screenshot of the full editorial layout, use your browser's print-to-PDF or full-page screenshot. See skills/diagram-design/references/export.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/export.md for the full procedure. - --registry — for diagrams using the traceable block decomposition /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/semantic-patterns.md pattern, also emits <basename .registry.json , a structured projection of every block's data-block- metadata. Combine with either raster format or run alone. See skills/diagram-design/references/export-registry.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/export-registry.md . For motion-enabled HTML, export the explicit final state: open ?motion=static , wait for document.fonts.ready , and confirm the motion root has data-frame="static" before capture. Use ?motion=step&step=N only when a named intermediate frame was requested. Progressive disclosure. SKILL.md routes behavior first when needed, then layout. Semantic, type, and animation references load only when relevant. diagram-design/ ├── .agents/plugins/marketplace.json — Codex marketplace catalog ├── .claude-plugin/ — Claude marketplace + plugin manifest ├── .codex-plugin/ — Codex plugin manifest ├── .factory-plugin/ — Factory Droid marketplace + plugin manifest ├── commands/ │ ├── export-diagram.md — plugin export command │ ├── import-drawio.md — plugin draw.io import command │ ├── import-mermaid.md — plugin Mermaid import command │ ├── import-excalidraw.md — plugin Excalidraw import command │ ├── profile.md — plugin client-profile command │ └── doctor.md — plugin environment diagnostics command ├── prompts/ │ ├── export-diagram.md — Pi /export-diagram prompt template │ ├── import-mermaid.md — Pi Mermaid import prompt template │ ├── import-excalidraw.md — Pi Excalidraw import prompt template │ ├── profile.md — Pi /profile prompt template │ └── doctor.md — Pi /doctor diagnostics prompt template ├── skills/ │ └── diagram-design/ │ ├── SKILL.md — philosophy, selection guide, checklist │ ├── references/ — loaded only when a type or primitive is chosen │ │ ├── style-guide.md — single source of truth for colors + fonts │ │ ├── semantic-patterns.md — behavior patterns independent of layout │ │ ├── animation.md — optional motion + accessibility contract │ │ ├── onboarding.md — the URL-to-tokens flow │ │ ├── profiles.md — named client profiles + project markers │ │ ├── import-drawio.md — draw.io redraw procedure │ │ ├── import-mermaid.md — Mermaid redraw procedure │ │ ├── import-excalidraw.md — Excalidraw redraw procedure │ │ ├── output-spec.md — format × size × detail level │ │ ├── export.md — SVG / PNG export + sizing │ │ ├── export-registry.md — block-metadata JSON sidecar export │ │ ├── type-architecture.md │ │ ├── type-flowchart.md │ │ ├── type-sequence.md │ │ ├── type-state.md │ │ ├── type-er.md │ │ ├── type-timeline.md │ │ ├── type-swimlane.md │ │ ├── type-quadrant.md │ │ ├── type-nested.md │ │ ├── type-tree.md │ │ ├── type-org-chart.md │ │ ├── type-layers.md │ │ ├── type-venn.md │ │ ├── type-pyramid.md │ │ ├── type-sankey.md │ │ ├── type-fishbone.md │ │ ├── type-wardley.md │ │ ├── type-kanban.md │ │ ├── type-journey.md │ │ ├── type-deployment.md │ │ ├── type-dependency.md │ │ ├── type-uml-class.md │ │ ├── type-story-map.md │ │ ├── type-db-schema.md │ │ ├── primitive-annotation.md │ │ ├── primitive-sketchy.md │ │ └── primitive-terminal.md │ ├── scripts/ │ │ ├── drawio extract.py — draw.io → structured IR │ │ ├── mermaid extract.py — Mermaid → structured IR │ │ ├── excalidraw extract.py — Excalidraw → structured IR │ │ └── self check.py — packaged output self-check runs installed │ └── assets/ │ ├── index.html — live gallery, tabbed │ ├── template .html — scaffolds for new diagrams │ ├── example-<type .html — 3 variants × 39 types │ ├── example-loop-terminal.html │ ├── example-quadrant-consultant.html │ ├── example-import-drawio.html │ ├── example-import-mermaid.html │ ├── example-import-excalidraw.html │ ├── example-policy-trace-animated.html │ └── example-sequence-oauth .html ├── scripts/ │ ├── build-readme-thumbs.py — regenerates docs/screenshots/thumbs/ │ ├── bump-plugin-version.py — synchronized Claude/Codex/Factory version bump │ ├── render-canonical-screenshots.py — deterministic 39-type PNG catalog renderer │ ├── verify-screenshot-freshness.py — source + screenshot digest gate │ ├── verify-plugin-package.py — version + marketplace package gate │ ├── test-plugin-package.py — adversarial package-gate tests │ ├── lint-render.py — Chromium rendered-layout checker │ ├── verify-doctor.py — doctor diagnostics contract gate │ ├── test-verify-doctor.py — doctor diagnostics adversarial tests │ ├── verify-polar.py — quantitative polar encoding gate │ ├── test-verify-polar.py — polar gate adversarial tests │ ├── verify-sankey.py — Sankey conservation + geometry gate │ ├── test-verify-sankey.py — Sankey gate adversarial tests │ ├── verify-waterfall.py — waterfall running-total + bridge gate │ ├── test-verify-waterfall.py — waterfall gate adversarial tests │ ├── test-verify-docs-sync.py — docs/routing-surface gate tests │ └── fixtures/ │ ├── sample-flowchart.mmd │ ├── sample-readme-with-mermaid.md │ ├── sample-adversarial.mmd │ ├── sample-whiteboard.excalidraw │ └── sample-adversarial.excalidraw ├── docs/cookbook.md — operator recipes for editable installs and common tasks ├── docs/adr/ — short records of settled design decisions ├── docs/screenshots/ — full-resolution images + source-digest manifest.json └── docs/screenshots/thumbs/ — generated WebP previews the README renders This keeps the agent's working context tight: routine diagrams load one type reference; behavior-rich diagrams add the routed semantic reference; animation adds its contract only when selected. Before submitting a new example, run python3 scripts/lint-skin.py <your-new-example.html . The repository-wide check python3 scripts/lint-skin.py --all --baseline covers examples and templates and must stay green. CI separately verifies semantic routing, animated-example structure, animated skin, every shipped motion asset, and adversarial mutations of the controller contract, reporting later gate outcomes even when an earlier gate fails. Semantic routing must pass python3 scripts/verify-semantic-motion.py --markdown-only ; the animated example has a separate --example-only gate. Every shipped motion template/example must also pass python3 scripts/verify-motion.py --shipped . The linter's a11y category rejects diagram SVGs without a resolving accessible name, an empty or misplaced title/description, or unsafe bare title / desc IDs. It also pins the exact reviewed motion controller and rejects remote assets, CSS @import , non-fragment CSS url , and executable attributes such as onclick or srcdoc . If you touch the draw.io import path, python3 scripts/verify-drawio-import.py must also pass — it drives the real extractor against scripts/fixtures/sample-architecture.drawio in all four container formats and checks the references stay in sync. If you touch the Mermaid import path, python3 scripts/verify-mermaid-import.py must also pass — it covers all supported grammars, multi-block Markdown, adversarial labels, trust-boundary behavior, resource caps, named failures, and reference/command wiring. If you touch the Excalidraw import path, python3 scripts/verify-excalidraw-import.py must also pass — it covers scene parsing, bound labels, groups and frames, adversarial labels, trust-boundary behavior, resource caps, named failures, and reference/command wiring. Label placement is gated geometrically: python3 scripts/verify-geometry.py --all fails CI when a label mask overlaps a node declared later in the document, because the node fill would clip the text at render time. python3 scripts/test-verify-geometry.py keeps that checker honest in both directions. Diagrams using the traceable block decomposition pattern get a structural gate on top of that: python3 scripts/verify-block-registry.py --all fails CI on a duplicate data-block-id , a data-block-parent that doesn't resolve to another block in the same file, a cycle in the parent chain, a blank data-block-id , or a missing or blank data-block-name — the same defects that would make --registry 's exported JSON see export-registry.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/export-registry.md misrepresent the tree it claims to describe. python3 scripts/test-verify-block-registry.py keeps that checker honest in both directions. Treemaps get a second geometric gate, because their whole claim is that area is the encoding: python3 scripts/verify-treemap.py --all fails CI when a cell's share of the drawn area doesn't match the value printed inside it, or when a label overruns the cell it names. It measures area error as a relative figure — an absolute one passes exactly the small cells most likely to be wrong. python3 scripts/test-verify-treemap.py keeps it honest in both directions. Waterfalls get the same treatment, because their whole claim is that the running total is conserved: python3 scripts/verify-waterfall.py --all fails CI when the declared start, deltas, and end don't reconcile, when a bridge bar is drawn anywhere other than its two running levels on the shared scale, when a carry connector is missing or sits at the wrong level, when a delta prints without an explicit sign, or when the two directions collapse into one fill. python3 scripts/test-verify-waterfall.py keeps it honest in both directions. Docs and routing surfaces are themselves gated: python3 scripts/verify-docs-sync.py fails CI if the SKILL.md description loses a type's lexical hook, the gallery can't reach a shipped example, the README tree names a file that doesn't exist, a relative reference link is broken, a scanner-visible support path is not shipped inside the skill package, or any command/prompt surface drifts from its routed reference. python3 scripts/test-verify-docs-sync.py exercises those newer checks adversarially, including the strict-bundler behavior used by Hermes Agent. The skill also ships skills/diagram-design/scripts/self check.py — a distilled output checker installed agents can run on their own generated diagrams; python3 scripts/test-self-check.py keeps it honest. Settled design decisions why one pinned controller, why patterns never add types, the autoplay policy, the SKILL.md byte cap, why label placement is verified geometrically, and why client profiles use marker-first resolution live as short ADRs in docs/adr/ — read them before relitigating one, add one when you settle a new policy. All pull requests and pushes are automatically validated across Linux, Windows, and macOS runners via GitHub Actions CI .github/workflows/ci.yml . lint-skin.py reads the source. lint-render.py renders it — headless Chromium reports what actually got painted, which catches content cut off by the SVG viewport, collapsed SVGs, horizontal page overflow, missing local assets and JS errors. Both run in CI on every pull request. pip install playwright && playwright install chromium same dep as PNG export python3 scripts/lint-render.py --self-test checks the checks python3 scripts/lint-render.py --all examples and templates python3 scripts/lint-render.py <your-new-example.html python3 scripts/lint-render.py --fonts --all measure with the real webfonts Clipping is measured by paint, not geometry: getBoundingClientRect on an SVG child ignores stroke width, markers and filter bleed, and knows nothing about clip-path or overflow: visible , so it both misses real clipping and invents clipping that isn't there. Instead each SVG is screenshot as authored and again with its overflow released, and the two are diffed — ink that appears outside was being cut off. Releases are staged — the SVG alone, then each clipping ancestor — so a wrapper release can't mask spill at the SVG's own edge, and an SVG authored overflow: visible inside a clipping wrapper is still checked. --self-test asserts all of that on 23 cases, over half of them cases that must not be flagged, and it also asserts the DOM is byte-identical after measuring. No golden images, so there is nothing to re-record and no PNGs in the repo. Network is cut at the browser's resolver, which covers WebSockets and anything else that bypasses request routing, with request routing as a second layer; --fonts excludes exactly the two Google Fonts hostnames and allows them only over HTTPS. Since the oracle is pixels, CI pins Playwright and its Chromium build rather than installing whatever is newest. Font metrics differ between the default run and --fonts . With network blocked — the default, and what CI runs — text is laid out in the fallback faces, not Instrument Serif and Geist. That is deterministic and machine-independent, which is what a linter needs, but it is not what your reader sees. Run --fonts --all locally when you care whether real text fits its box. At startup, the agent sees only the skill name and description. When a request matches, it loads SKILL.md ; semantic, type, and animation references are pulled in only when relevant. | You ask for… | Agent loads | |---|---| | "Make me a flowchart" | SKILL.md + references/type-flowchart.md | | "Build an architecture diagram" | SKILL.md + references/type-architecture.md | | "Compare why these two policy requests differ" | SKILL.md + references/semantic-patterns.md + references/type-flowchart.md | | "Animate that policy trace" | Prior selection + references/animation.md | | "Onboard this skill to my site" | SKILL.md + references/onboarding.md + references/style-guide.md | | "Use my saved Acme client profile" | SKILL.md + references/profiles.md + ~/.diagram-design/profiles/acme.md | | "Add an editorial callout to this diagram" | SKILL.md + references/primitive-annotation.md | | "Give me a hand-drawn version" | SKILL.md + references/primitive-sketchy.md | | "Give me a terminal / CLI-window version" | SKILL.md + references/primitive-terminal.md | | "Redraw this .drawio file for my deck" | SKILL.md + references/import-drawio.md + references/output-spec.md + the chosen type's reference | | "Redraw this Mermaid block for my deck" | SKILL.md + references/import-mermaid.md + references/output-spec.md + the chosen type's reference | | "Redraw this Excalidraw sketch for my deck" | SKILL.md + references/import-excalidraw.md + references/output-spec.md + the chosen type's reference | | Routine static diagram-making any of the 39 visual types | Only SKILL.md + that one type's reference | No matter how many types exist, the agent only reads the one you need. Add a new type tomorrow and nothing else changes. - A routine request "make me a flowchart" loads SKILL.md plus exactly one type reference — nothing else. - Before drawing, the agent states the chosen type, pattern, size, and planned cuts, then renders. - The output is one .html file that opens double-clicked, offline, with no network requests beyond Google Fonts. - Screen readers announce the diagram's title and description; prefers-reduced-motion shows the complete static frame. - python3 skills/diagram-design/scripts/self check.py <file prints OK on the generated file. - After brand onboarding, new diagrams use your site's paper, ink, accent, and fonts — with a fidelity receipt naming each. If any of these fail, that's a bug worth filing. One accent color, 1–2 focal elements per diagram. Three font families: Instrument Serif title + italic callouts , Geist sans node names , Geist Mono technical sublabels . 1px hairline borders, no shadows, max border-radius 10px. Every coord, width, and gap divisible by 4 — non-negotiable, it's what keeps the diagrams from feeling AI-generated. Mono is for technical content ports, URLs, field types , not a blanket "dev" aesthetic. Coral-tinted focal nodes draw the eye to the 1–2 things that matter. Full spec in SKILL.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/SKILL.md 5-design-system . - Annotation callout — italic Instrument Serif + dashed Bézier leader, for editorial asides that sit in the margins. See skills/diagram-design/references/primitive-annotation.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/primitive-annotation.md . - Sketchy filter — SVG turbulence + displacement map for a hand-drawn variant. Good for essays, not for technical docs. See skills/diagram-design/references/primitive-sketchy.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/primitive-sketchy.md . - Icon set — 87 monochrome IT/cloud icons laptop, phone, user, server, database, Docker, Kubernetes, AWS, Azure, GitHub, Postgres… for richer architecture and sequence diagrams. Stroked icons from Tabler Icons https://tabler.io/icons MIT ; brand silhouettes from Simple Icons https://simpleicons.org CC0 . Each icon uses currentColor so it inherits the editorial skin or your onboarded brand. See skills/diagram-design/references/primitive-icons.md /cathrynlavery/diagram-design/blob/main/skills/diagram-design/references/primitive-icons.md ; browse the gallery /cathrynlavery/diagram-design/blob/main/skills/diagram-design/assets/icons.html . Regenerate with python scripts/build-icons.py . - Quick unicode diagrams for tweets or terminal output → wiretext-style skill. - Lists of anything → a table or bullets. - Before/after comparisons → a table. - One-shape "diagrams" — a single box with a label → just write the sentence. Before drawing, ask: would a reader learn more from this than from a well-written paragraph? If no, don't draw. Contributions are welcome — new diagram types, import grammar support, examples, docs, and tooling. See CONTRIBUTING.md /cathrynlavery/diagram-design/blob/main/CONTRIBUTING.md for the validation gates and workflows, and CODE OF CONDUCT.md /cathrynlavery/diagram-design/blob/main/CODE OF CONDUCT.md for community standards. Made by Cathryn Lavery — founder of BestSelf.co https://bestself.co?utm source=diagram-design&utm medium=readme&utm campaign=github&utm content=bio . I write about AI, entrepreneurship, and designing nice-looking things at littlemight.com https://littlemight.com?utm source=diagram-design&utm medium=readme&utm campaign=github&utm content=bio — blog + newsletter. If this is useful, star the repo and come say hi on X https://x.com/cathrynlavery .