gsd-2

Synthesize the current conversation into a milestone brief (PRD). Writes to `M###-CONTEXT.md` by default, or files a GitHub issue only with explicit user confirmation. Use when asked to "turn this into a PRD", "draft a milestone brief", "capture this context", "write it up", or when enough has been discussed to commit the plan to paper. Does not interview — it synthesizes what is already known.

Collaborative document authoring workflow for proposals, technical specs, decision docs, README sections, ADRs, and long-form prose that must work for fresh readers. Use when asked to "write the docs", "draft a proposal", "write a spec", "write an RFC", "write the README", or when a document needs to be understandable by someone without this session's context. Three stages: gather context, iterate on structure, reader-test for a stranger.

Comprehensive web quality audit covering performance, accessibility, SEO, and best practices. Use when asked to "audit my site", "review web quality", "run lighthouse audit", "check page quality", or "optimize my website".

Block completion claims until verification evidence has been produced in the current message. Use before marking a task/slice/milestone complete, before creating a commit or PR, before saying "it works" or "tests pass", and any time you are about to claim work is done. The rule is: evidence before claims, always — running the verification must happen now, not "earlier in the session". Fresh output or no claim.

UI/UX best practices for web interfaces. Use when reviewing animations, CSS, audio, typography, UX patterns, prefetching, or icon implementations. Covers 11 categories from animation principles to typography. Outputs file:line findings.

Test-driven development with red-green-refactor loops built around vertical slices (tracer bullets), not horizontal layers. Use when asked to "use TDD", "write test-first", "red-green-refactor", "build this with tests", or whenever a feature has a clear observable contract and would benefit from tests that outlive refactors. Complements the bundled test and add-tests skills — use this for the discipline, use those for the mechanics.

Package findings from a completed spike into a durable, project-local skill that auto-loads on future similar work. Reads the most recent `.gsd/workflows/spikes/` directory, interviews the user briefly on what's reusable, then writes `.claude/skills/<name>/SKILL.md`. Use when asked to "wrap up the spike", "package this as a skill", "make this reusable", "turn findings into a skill", or at the end of the synthesize phase of `/gsd start spike`. Closes the parity gap with GSD v1's `/gsd-spike-wrap-up`.

Threat-model-driven security review of a change, feature, or subsystem. Runs a STRIDE-style pass (Spoofing, Tampering, Repudiation, Info disclosure, Denial of service, Elevation of privilege), examines the actual code, and produces a filing-ready report with severity, exploit scenario, and concrete remediation. Use when asked to "security review", "threat model", "check for vulnerabilities", "audit this for security", "secure this", or before shipping any change that touches auth, input handling, data access, or external surfaces.

Review code changes for security, performance, bugs, and quality. Reviews staged changes, unstaged changes, specific commits, or PR-ready diffs.

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

Add agent-first observability to code — structured logs, health endpoints, failure-state persistence, and explicit failure modes — so the next agent hitting a problem at 3am has the signals it needs to diagnose. Use when asked to "add logging", "add observability", "add metrics", "debug later", "make this observable", or when building/refactoring a subsystem that will run unattended (auto-mode engine, background jobs, servers, watchers). Operationalizes VISION.md's "agent-first observability" principle.

Design engineering principles for making interfaces feel polished. Use when building UI components, reviewing frontend code, implementing animations, hover states, shadows, borders, typography, micro-interactions, enter/exit animations, or any visual detail work. Triggers on UI polish, design details, "make it feel better", "feels off", stagger animations, border radius, optical alignment, font smoothing, tabular numbers, image outlines, box shadows.

Lint and format code. Auto-detects ESLint, Biome, Prettier, or language-native formatters and runs them with auto-fix. Reports remaining issues with actionable suggestions.

Prepare a clean cross-session handoff so the next agent (or you tomorrow) can pick up exactly where you left off. Writes a focused `continue.md` in the active slice directory and ensures `STATE.md` + summary artifacts are current. Use when asked to "hand off", "prepare handoff", "pause work", "bookmark this", "I'll come back to this later", before running out of context budget, or at the end of a long session with unfinished work. Closes the v1 `/gsd-pause-work` parity gap.

Relentless sequential interview that stress-tests a plan or design until every decision branch is resolved. Use when the user wants to "grill me", "stress-test the plan", "interrogate my design", "resolve the decision tree", or whenever a plan feels hand-wavy, under-specified, or carries hidden coupling that planning phases must surface before execution. Pairs with the discuss phase and blocks execution until alignment is reached.

Install and configure the GitHub CLI (gh) for AI agent environments where gh may not be pre-installed and git remotes use local proxies instead of github.com. Provides auto-install script with SHA256 verification and GITHUB_TOKEN auth with anonymous fallback. Use when gh command not found, shutil.which("gh") returns None, need GitHub API access (issues, PRs, releases, workflow runs), or repository operations fail with "failed to determine base repo" error. Documents required -R flag for all gh commands in proxy environments. Includes project management: GitHub Projects V2 (gh project), milestones (REST API), issue stories (lifecycle and templates), and label taxonomy management.

Work with GitHub Actions CI/CD workflows - read live syntax, monitor runs, and debug failures. Use when writing, running, or debugging GitHub Actions workflows.

Create distinctive, production-grade frontend interfaces with high design quality. Use this skill when the user asks to build web components, pages, artifacts, posters, or applications (examples include websites, landing pages, dashboards, React components, HTML/CSS layouts, or when styling/beautifying any web UI). Generates creative, polished code and UI design that avoids generic AI aesthetics.

Post-mortem a failed GSD auto-mode run. Traces from symptom to root cause using `.gsd/activity/*.jsonl`, `.gsd/journal/YYYY-MM-DD.jsonl`, `.gsd/metrics.json`, and `.gsd/auto.lock`. Produces a filing-ready bug report with file:line references and a concrete fix suggestion. Use when asked to "forensics", "post-mortem", "why did auto-mode fail", "trace the stuck loop", "debug the crash", after `/gsd forensics` is invoked, or when a session ended in an unexpected terminal state. Reads existing artifacts — does NOT re-run anything.

Produce 3+ radically different designs for a module, API, or interface, compare them in prose, and synthesize a recommendation. Use when asked to "design an interface", "shape this API", "design it twice", "explore module boundaries", or when planning a new deep module and the first idea is unlikely to be the best. Based on "Design It Twice" from A Philosophy of Software Design — the value is the contrast, not the first draft.

Plan, batch, and verify dependency upgrades safely. Triages outdated packages into risk tiers, upgrades in order (dev/minor/patch first, runtime majors last), verifies each batch before moving on, and produces an auditable commit sequence. Use when asked to "upgrade deps", "bump packages", "update node_modules", "fix vulnerabilities", "upgrade React/Node/TypeScript", or after `/gsd start dep-upgrade`. Complements the dep-upgrade workflow template with execution-level rigor.

Break a plan or milestone brief into independently-grabbable vertical slices (tracer bullets). Produces slices in `M###-ROADMAP.md` by default, or GitHub issues only with explicit user confirmation. Use when asked to "break this into slices", "decompose the plan", "vertical slices", "break into issues", or when a plan is ready but needs task-level decomposition. Prefers many thin slices over few thick ones; marks dependency order explicitly.

Deep analysis debugging mode for complex issues. Activates methodical investigation protocol with evidence gathering, hypothesis testing, and rigorous verification. Use when standard troubleshooting fails or when issues require systematic root cause analysis.

Conversational guide for creating valid YAML workflow definitions. Use when asked to "create a workflow", "new workflow definition", "build a workflow", "workflow YAML", "define workflow steps", or "workflow from template".

Expert guidance for creating, writing, building, and refining GSD skills. Use when working with SKILL.md files, authoring new skills, improving existing skills, or understanding skill structure and best practices.