What problem does it solve? Complex system relationships, ownership boundaries, state transitions, and failure paths are hard to reason about from prose alone, leading to missed defects like auth gaps, tenant leaks, and retry duplication. This Skill turns Mermaid diagrams into a structured engineering reasoning and defect-prevention tool. ## Core Features & Use Cases - Diagram-first defect discovery: Draw current and target paths before coding, then inspect for red flags such as missing owners, hidden writes, HITL bypasses, and circular dependencies. - Diagram type selection guide: Decision table mapping development questions to the right Mermaid type (flowchart, sequence, state, ER, C4, architecture, Gantt, and more), with local syntax references for each. - Lifecycle integration: Mandatory diagram passes for task discovery, file planning, implementation, PR review, and post-merge/incident analysis, including failure and recovery branches. - Use Case: Before implementing an AI proposal-to-approval workflow, draw the sequence diagram showing the human review gate, server revalidation, and idempotent write, catching a potential AI self-approval path before any code is written. ## Quick Start Ask the agent to draw current-state and target-state Mermaid diagrams for the task you are planning, including auth boundaries and failure branches.
