What problem does it solve? Multi-service interaction bugs are typically discovered during debugging rather than design because teams skip documenting how components actually communicate. This Skill closes that gap by generating Mermaid sequence diagrams for every critical cross-component flow before implementation begins. ## Core Features & Use Cases - Critical Flow Identification: Reads the HLD Container diagram and spec REQ-NNN entries to find flows crossing 3+ components, auth boundaries, retries, or async messaging. - Full Mermaid Syntax Coverage: Produces sequenceDiagram blocks using alt/else, loop, par, opt, critical, and break control flow, plus sync, async, and error arrow types. - Reviewer Loop: Dispatches a sequence-diagram-reviewer agent against the generated artifact and iterates fixes until all Critical findings pass. - Use Case: While writing the HLD for a checkout feature, generate sequence diagrams covering JWT validation, payment critical regions with timeout and decline paths, idempotency checks, and async order.created event publishing, saved to .ai/YYYY-MM-DD-<feature-slug>/lld/. ## Quick Start Ask the AI to generate sequence diagrams for the critical flows in your current feature's HLD and spec, covering happy paths, error paths, and auth boundaries.
