What problem does it solve? Mermaid diagrams in plans, MR descriptions, and review comments often fail to render, break in dark mode, or exceed host size budgets, leaving readers with parse errors or hidden content. This Skill provides authoring rules, per-type guidance, and a render-and-look validation loop so diagrams survive both GitLab and GitHub renderers. ## Core Features & Use Cases - Diagram selection guidance: Decides whether a diagram is worth drawing at all and picks the right type (flowchart, sequenceDiagram, stateDiagram-v2, erDiagram) for the content. - Cross-renderer authoring rules: Enforces syntax that works on both GitLab and GitHub, including quoting labels, avoiding pinned themes, and respecting GitLab's 2000-character page budget. - Validation loop: Renders each diagram with mermaid-cli through a validator subagent that reports render status and clarity before the diagram ships. - Use Case: When writing an MR description that explains a retry race between services, use this Skill to draft a sequence diagram, validate it renders correctly, and inline it in the description. ## Quick Start Ask the AI to create a Mermaid sequence diagram showing the checkout flow and validate it renders before adding it to the MR description.
