Golden Examples
Use before writing a git commit message, Japanese UI copy or app strings (ボタン/エラーメッセージ等の文言), code review comments, or a completion report to the user — match the approved style samples first; also when unsure how formal/verbose Japanese app text should be, or how to phrase a review finding.
Feature Flow
Full spec-driven workflow for substantial features or refactors that span multiple files/modules. Combines OpenSpec's propose→apply→archive pipeline with agent-skills' planning, TDD, incremental implementation, and multi-axis review. Produces spec/design/tasks artifacts, drives a review-fix loop, and ends with shipping verification. Use when the change is non-trivial, touches multiple layers, or…
Flutter Dev Playbook
Use when writing, refactoring, or debugging Flutter/Dart app code (widgets, Riverpod, Bloc, setState, platform channel, pubspec) — before adding a screen, choosing state management, measuring performance, adding a plugin, or preparing a release build. Also when facing jank/dropped frames, rebuild storms, release mode crash (tree shaking / AOT-only), MissingPluginException, or "works in debug but…
Dispatching Subagents
Use when about to spawn or delegate work to a subagent (Agent/Task tool), choosing a model tier (haiku/sonnet/opus) for a task, writing a delegation prompt, deciding whether something should be delegated at all, verifying a delegated result, or after a delegated task failed twice and needs escalation.
Go Concurrency Playbook
Use when designing or debugging high-concurrency Go services — before adding a goroutine pool / worker pool, wiring backpressure or a bounded channel, choosing errgroup vs WaitGroup, adding rate limit / load shedding / circuit breaker, tuning GOMAXPROCS in containers, or sizing a connection pool; also when facing OOM under load, rising goroutine count, lock contention, p99 latency spikes, retry s…
Harness Writing
Use when 要為新專案或既有專案建立專屬的 harness 開發流程（階段化閘門 + 專案契約制度），或用戶說「建 harness」「導入開發流程框架」「幫這個專案定契約」。適用於任何語言/stack 的 repo。
Thinking Kernel
Use when working in a technical domain with no existing playbook, writing new coding guidelines / review criteria / checklists from scratch, judging whether a verification method actually proves a claim (test passed but does it count?), or when repeated fixes keep failing and the direction feels wrong. Domain-agnostic reasoning moves that generate concrete decision criteria for any field — not ti…
Frontend Web Playbook
Use when writing, refactoring, or debugging React/Next.js frontend code (App Router, Server/Client Components, hooks, Tailwind/CSS Modules) — before adding a component, choosing where state lives, wiring data fetching, or preparing a production deploy; or when facing hydration mismatch, NEXT_PUBLIC_ env leaks, excessive re-render, bundle size bloat, CLS, SEO/metadata gaps, or XSS via dangerouslyS…
Android Dev Playbook
Use when writing, refactoring, or debugging Android app code (Kotlin, Jetpack Compose, Gradle, ProGuard/R8) — before adding a feature, touching build config or proguard-rules, preparing a release/AAB, or when facing release-only crashes, ClassNotFoundException after minify, lifecycle leaks, ANR, or excessive recomposition.
Agent Design
Use when creating a new custom agent/subagent definition (.claude/agents/*.md), auditing or rewriting existing agent definitions, deciding whether a task deserves a dedicated agent vs general-purpose with a good prompt, choosing an agent's tools whitelist or model tier, or when delegated agents keep going off-scope, dumping full transcripts back, or overlapping each other's roles.
Backend Server Playbook
Use when designing, writing, refactoring, or debugging backend server code (REST API, Node.js/TypeScript, Go) — before adding an endpoint, designing an error/response envelope, choosing pagination, writing a DB migration or query, touching auth (session/JWT), hashing passwords, handling secrets, or preparing a deploy; also when facing N+1 queries, race conditions, IDOR/broken access control, SSRF…
Ios Dev Playbook
Use when writing, refactoring, or debugging iOS app code (Swift, SwiftUI, Swift Concurrency, Xcode) — before adding a feature, choosing state ownership (@State / @Observable / @Environment), touching MainActor/actor/Sendable, preparing a TestFlight/App Store build, or when facing App Store review rejection, provisioning profile errors, missing dSYM / unsymbolicated crashes, data races, or continu…
Rag Playbook
Use when building or debugging RAG / semantic search / retrieval systems — before choosing a vector store (pgvector, Qdrant, Milvus, Elasticsearch), designing chunking, embedding models, hybrid search (BM25 + vector), HNSW indexing, or a reranker; or when facing bad recall, "retrieved the wrong docs", LLM answers wrong despite good docs, stale index, post-filter emptying top-k, metadata filtering…