H2 is an embeddable RDBMS written in Java.

A long-form article / blog post — masthead, hero image placeholder, article body with figures and pull quotes, author byline, related posts. Use when the brief asks for "blog", "article", "post", "essay", or "case study".

Use when the user wants to write a blog post about a feature, product change, PR, git diff, or any technical topic - accepts marketing briefs, PRs, git refs, codebase paths, or freeform descriptions as input

Use whenever writing, editing, or reviewing markup or UI code — HTML, JSX/TSX, Vue/Svelte/Angular templates, web components, email HTML, or CSS that affects text size, color, focus, motion, layout order, or hit area. Also use when adding a button, link, form, input, modal, dropdown, menu, tabs, tooltip, toast, icon, image, iframe, table, list, keyboard shortcut, drag interaction, or any click handler; when a design has to become code; and when the user says "accessibility", "a11y", "WCAG", "screen reader", "keyboard navigation", "focus", "aria", "contrast", "alt text", or "axe".

Establish architecture-as-code practice using C4 modeling and Structurizr DSL. Use after bootstrap-project, when establishing architecture documentation, or when migrating from diagram-based to code-based architecture.

Translate and sync bilingual user documentation between docs/zh/ and docs/en/ following the source-of-truth rules in docs/AGENTS.md.

Bootstrap a new project at a chosen graduation tier (t0 minimum, t1 decision-tracked, t2 full pattern language) following AI-Assisted Project Orchestration best practices. Use when starting a new software project, promoting an existing project to a higher tier, or converting an existing project for AI-assisted development.