mermaid-diagram

name mermaid-diagram description Generate Mermaid diagrams from user requirements. Supports flowcharts, sequence diagrams, class diagrams, ER diagrams, Gantt charts, and 18 more diagram types. argument-hint [diagram description or requirements] allowed-tools Bash(*), Read, Write, Edit, Glob, Grep Mermaid Diagram Generator Generate high-quality Mermaid diagram code based on user requirements, with file output and verification. Constants OUTPUT_DIR = figures/ — Output directory for all generated files MAX_ITERATIONS = 3 — Maximum refinement rounds for syntax errors Workflow: MUST EXECUTE ALL STEPS Step 0: Pre-flight Check # Create output directory mkdir -p figures Step 1: Understand Requirements & Select Diagram Type Parse the input: $ARGUMENTS Analyze user description to determine the most suitable diagram type Read the corresponding syntax reference documentation (see Diagram Type Reference below) If the diagram involves mathematical notation (formulas, equations, Greek letters, subscripts, superscripts, fractions, matrices, etc.), apply the math syntax rules from the Math Formulas in Diagrams section below Identify all components, connections, and data flow Plan the diagram structure Step 2: Read Documentation Select the appropriate diagram type based on the use case. Use your built-in knowledge of Mermaid syntax, or fetch up-to-date docs via the context7 MCP server if needed. Type Use Cases Flowchart Processes, decisions, steps Sequence Diagram Interactions, messaging, API calls Class Diagram Class structure, inheritance, associations State Diagram State machines, state transitions ER Diagram Database design, entity relationships Gantt Chart Project planning, timelines Pie Chart Proportions, distributions Mindmap Hierarchical structures, knowledge graphs Timeline Historical events, milestones Git Graph Branches, merges, versions Quadrant Chart Four-quadrant analysis Requirement Diagram Requirements traceability C4 Diagram System architecture (C4 model) Sankey Diagram Flow, conversions XY Chart Line charts, bar charts Block Diagram System components, modules Packet Diagram Network protocols, data structures Kanban Task management, workflows Architecture Diagram System architecture Radar Chart Multi-dimensional comparison Treemap Hierarchical data visualization User Journey User experience flows ZenUML Sequence diagrams (code style) Configuration & Themes Theming - Custom colors and styles Directives - Diagram-level configuration Layouts - Layout direction and spacing Configuration - Global settings Math - LaTeX math support (see Math Formulas in Diagrams section below) Step 3: Generate Mermaid Code & Save Files Generate the Mermaid code following the reference specification, then save TWO files: File 1: figures/<diagram-name>.mmd — Raw Mermaid source The .mmd file contains ONLY the raw Mermaid code (no markdown fences). Example: flowchart TD A[Start] --> B{Condition} B -->|Yes| C[Execute] B -->|No| D[End] C --> D File 2: figures/<diagram-name>.md — Markdown with embedded Mermaid The .md file wraps the same code in a mermaid code block for preview rendering, plus a title and description. Example: # Diagram Title Brief description of what this diagram shows. ​ ```mermaid flowchart TD A[Start] --> B{Condition} B -->|Yes| C[Execute] B -->|No| D[End] C --> D ​``` Naming convention : Use a descriptive kebab-case name derived from the user's request (e.g., auth-flow , system-architecture , database-er ). Step 4: Verify Mermaid Syntax (MANDATORY) Claude MUST verify the generated Mermaid code by running the Mermaid CLI ( mmdc ). # Check if mermaid-cli is available if command -v mmdc &> /dev/null; then # Render to PNG to verify syntax is correct mmdc -i figures/<diagram-name>.mmd -o figures/<diagram-name>.png -b transparent echo "✅ Syntax valid — PNG rendered to figures/<diagram-name>.png" else # Try npx as fallback npx -y @mermaid-js/mermaid-cli@latest -i figures/<diagram-name>.mmd -o figures/<diagram-name>.png -b transparent echo "✅ Syntax valid — PNG rendered to figures/<diagram-name>.png" fi If the verification fails: Read the error message carefully Fix the syntax issue in both .mmd and .md files Re-run verification Repeat up to MAX_ITERATIONS (3) times Step 5: Claude STRICT Visual Review & Scoring (MANDATORY) After successful rendering, Claude MUST read the generated PNG and perform a STRICT review: ## Claude's STRICT Review of < diagram-name > ### What I See [Describe the rendered diagram in DETAIL - every block, every arrow, every label] ### Files Generated - `figures/<diagram-name>.mmd` — Raw Mermaid source - `figures/<diagram-name>.md` — Markdown with embedded diagram - `figures/<diagram-name>.png` — Rendered PNG (if mmdc available) ### ═══════════════════════════════════════════════════════════════ ### STRICT VERIFICATION CHECKLIST (ALL must pass for score ≥ 9) ### ═══════════════════════════════════════════════════════════════ #### A. File Correctness - [ ] `.mmd` file contains valid Mermaid syntax (no markdown fences) - [ ] `.md` file has the mermaid code wrapped in ```mermaid``` fences - [ ] `.mmd` and `.md` contain IDENTICAL Mermaid code - [ ] Diagram renders without errors (via mmdc) #### B. Arrow Correctness Verification (CRITICAL - any failure = score ≤ 6) Check EACH arrow: - [ ] Arrow 1: [Source] → [Target] — Does it point to the CORRECT target? - [ ] Arrow 2: [Source] → [Target] — Does it point to the CORRECT target? - [ ] ... (check ALL arrows) #### C. Block Content Verification (any failure = score ≤ 7) Check EACH block/node: - [ ] Block 1 "[Name]": Has correct label? Content correct? - [ ] Block 2 "[Name]": Has correct label? Content correct? - [ ] ... (check ALL blocks) #### D. Completeness - [ ] All components from user requirements are present - [ ] All connections/arrows are correct - [ ] Node labels are meaningful and match requirements #### E. Visual Quality - [ ] Layout is clean and readable - [ ] Color scheme is professional (not rainbow) - [ ] Text is readable at normal zoom - [ ] Proper spacing (not cramped, not sparse) - [ ] Data flow is traceable in 5 seconds ### ═══════════════════════════════════════════════════════════════ ### Issues Found (BE SPECIFIC) 1. [Issue 1]: [EXACTLY what is wrong] → [How to fix] 2. [Issue 2]: [EXACTLY what is wrong] → [How to fix] ### Score: X/10 ### Score Breakdown Guide: - **10** : Perfect. No issues. Publication-ready. - **9** : Excellent. Minor issues that don't affect understanding. - **8** : Good but has noticeable issues (layout, styling). - **7** : Usable but has clear problems (wrong arrows, missing labels). - **6** : Has arrow direction errors or missing major components. - **1-5** : Major issues. Unacceptable. ### Verdict [ ] ACCEPT (score ≥ 9 AND all critical checks pass) [ ] FIX (score < 9 OR any critical check fails — list EXACT fixes needed) If FIX: apply corrections to both .mmd and .md files, re-render, and re-verify. Loop until ACCEPT or MAX_ITERATIONS reached. Step 6: Final Output Summary When accepted, present to user: ✅ Mermaid diagram generated successfully! Files: figures/<diagram-name>.mmd — Raw Mermaid source (use with mmdc, editors, CI) figures/<diagram-name>.md — Markdown preview (renders on GitHub, VS Code, etc.) figures/<diagram-name>.png — Rendered image (if mmdc was available) To re-render manually: mmdc -i figures/<diagram-name>.mmd -o figures/<diagram-name>.png Architecture Diagram Best Practices When generating architecture-beta diagrams, apply these layout techniques for complex diagrams: Use Junctions for Layout Control Think of the diagram as an invisible grid. Use junction nodes as virtual anchor points on that grid to precisely control where each component is placed. This is especially useful when a direct edge between two services produces unexpected positioning. Instead of connecting services directly: lb:R --> L:scim lb:R --> L:webapi Route through junctions to control vertical/horizontal placement: junction j_lb_r lb:R -- L:j_lb_r junction j_scim_l j_lb_r:T -- B:j_scim_l j_scim_l:R --> L:scim junction j_webapi_l j_lb_r:B -- T:j_webapi_l j_webapi_l:R --> L:webapi Place junctions on all four sides of components to anchor them logically on the grid. Use Edges out of Groups for Floating Components For services that have no logical connection to other nodes (e.g. a deployment tool, a monitoring agent), use a junction combined with the {group} modifier to position them without adding a semantically incorrect edge: junction j_acd_t j_algolia_proc_b{group}:B -- T:j_acd_t j_acd_t:B -- T:acd This anchors acd below its intended neighbor without implying a real relationship. CVPR/ICLR/NeurIPS Style Guide (for Academic Diagrams) When the diagram is intended for academic papers, apply these style standards: Visual Standards Clean white background — No decorative patterns or gradients (unless subtle) Sans-serif fonts — Arial, Helvetica, or Computer Modern; minimum 14pt Subtle color palette — Not rainbow colors; use 3-5 coordinated colors Print-friendly — Must be readable in grayscale (many reviewers print papers) Professional borders — Thin (2-3px), solid colors, not flashy Layout Standards Horizontal flow — Left-to-right is the standard for pipelines Clear grouping — Use subtle background boxes to group related modules Consistent sizing — Similar components should have similar sizes Balanced whitespace — Not cramped, not sparse Arrow Standards (MOST CRITICAL) Thick strokes — 4-6px minimum (thin arrows disappear when printed) Clear arrowheads — Large, filled triangular heads Dark colors — Black or dark gray (#333333); avoid colored arrows Labeled — Every arrow should indicate what data flows through it No crossings — Reorganize layout to avoid arrow crossings CORRECT DIRECTION — Arrows must point to the RIGHT target! Color Palette (Academic Professional) Inputs : Green (#10B981 / #34D399) Encoders : Blue (#2563EB / #3B82F6) Fusion : Purple (#7C3AED / #8B5CF6) Outputs : Orange (#EA580C / #F97316) Arrows : Black or dark gray (#333333 / #1F2937) Background : Pure white (#FFFFFF) What to AVOID Rainbow color schemes (too many colors) Thin, hairline arrows Heavy drop shadows or glowing effects 3D effects / perspective Excessive decorative icons Small text that's unreadable when printed Math Formulas in Diagrams (KaTeX) Mermaid supports rendering mathematical expressions via KaTeX (v10.9.0+). When the diagram content involves math (formulas, equations, Greek letters, subscripts/superscripts, fractions, matrices, operators, etc.), use KaTeX notation instead of plain-text approximations. Supported Diagram Types for Math Math rendering with $$...$$ is supported in: Flowcharts ( flowchart / graph ) — in node labels and edge labels Sequence Diagrams — in participant aliases, messages, and notes Syntax Rules Wrap math expressions in $$ delimiters inside quoted strings: A["$$x^2$$"] -->|"$$\sqrt{x+3}$$"| B("$$\frac{1}{2}$$") Node labels with math MUST be quoted — use ["$$...$$"] or ("$$...$$") : scaledDot["$$\text{softmax}\left(\frac{QK^T}{\sqrt{d_k}}\right)V$$"] Mix text and math by placing $$ only around the math portion: layer1["Linear Layer $$W_1 x + b_1$$"] Use \text{} for non-math text inside a $$ block: node["$$\text{Attention}(Q, K, V)$$"] Common Math Patterns for ML/Science Diagrams Concept KaTeX Syntax Renders As Subscript $$W_Q$$ W_Q Superscript $$x^2$$ x² Fraction $$\frac{QK^T}{\sqrt{d_k}}$$ QK^T / sqrt(d_k) Greek letters $$\alpha, \beta, \gamma$$ α, β, γ Square root $$\sqrt{d_k}$$ √d_k Summation $$\sum_{i=1}^{n} x_i$$ Σx_i Matrix $$\begin{bmatrix} a & b \\ c & d \end{bmatrix}$$ 2x2 matrix Softmax $$\text{softmax}(z_i)$$ softmax(z_i) Norm $$||x||_2$$ ‖x‖₂ Hat/tilde $$\hat{y}, \tilde{x}$$ ŷ, x̃