7 refactoring skills for Claude Code — 66 techniques, 23 code smells from refactoring.guru
Skill Claude CodeCodex
Use when reviewing code for object creation problems or structural composition issues — covers all 12 GoF Creational (5) and Structural (7) patterns with intent, red flags, and refactoring cross-references.
Skill Claude CodeCodex
Use when reviewing code for quality issues, when code feels hard to change or understand, when preparing for refactoring, or when a module has grown unwieldy.
Skill Claude CodeCodex needs its repo
Use when designing or reviewing developer tooling, monorepo structure, dev environments, onboarding flows, or internal platforms — covers Monorepo tooling (Nx/Turborepo), dev containers, golden path / platform engineering, local-prod parity, fast feedback loops, DX-first API design, developer onboarding, and DX…
Skill Claude CodeCodex
Use when instrumenting distributed systems or reviewing tracing code — covers OpenTelemetry auto and manual instrumentation, span design, context propagation (W3C TraceContext, B3), sampling strategies (head, tail, probabilistic, rate-limiting), trace-based testing, exemplars, and anti-patterns (over-instrumentation…
Skill Claude CodeCodex
Use when designing or reviewing domain models — covers Bounded Contexts, Context Mapping, Aggregate Root, Value Objects vs Entities, Domain Events, Ubiquitous Language, Repository pattern, Domain vs Application Services, and DDD anti-patterns (anemic domain model, feature envy) with examples in TypeScript, Java, Go…
Skill Claude CodeCodex
Use when reviewing code for error handling correctness — covers Result/Either types, Exception hierarchies, Error propagation, Retry with backoff, Circuit breaker, Fail-fast, Graceful degradation, Error boundaries, Null Object/Optional, and Dead Letter Queue with red flags and fix strategies across TypeScript, Go…
Skill Claude CodeCodex
Use when designing or reviewing systems that store state as an immutable sequence of events — covers Event Sourcing fundamentals, CQRS, projections and read models, snapshot strategy, aggregate replay, event schema evolution and upcasting, eventual consistency, idempotency, and anti-patterns across TypeScript, Java…
Skill Claude CodeCodex
Use when designing or reviewing feature flag systems, progressive delivery pipelines, A/B testing infrastructure, or rollout strategies — covers feature toggles, canary/blue-green/ring deployments, percentage rollouts, kill switches, flag lifecycle, targeting rules, user segments, experiment design, and anti-patterns…
Skill Claude CodeCodex
Use when designing or reviewing file upload and media processing systems — covers presigned URL direct-to-storage uploads, resumable uploads (tus/S3 multipart), upload security pipeline (MIME magic bytes, virus scanning, quarantine), async media processing (thumbnails, transcoding, webhooks), image optimization…
Skill Claude CodeCodex
Use when reviewing Go code — covers goroutine leak detection, context propagation rules, error handling patterns (sentinel vs typed vs wrapped), slice/map pitfalls, interface design, nil traps, and common anti-patterns. Load alongside review-accuracy-calibration to ensure findings are well-calibrated before posting…
Skill Claude CodeCodex
Use when reviewing or designing GraphQL and gRPC APIs — covers schema design and evolution, N+1/DataLoader batching, subscriptions, Protobuf field numbering, gRPC streaming modes, breaking-change detection, anti-patterns, and code review signals across TypeScript, Go, and Java.
Skill Claude CodeCodex needs its repo
Use when building or reviewing internationalized applications — covers message externalization, ICU MessageFormat, CLDR plural rules, Intl.DateTimeFormat/NumberFormat, RTL layout with CSS logical properties, Intl.Collator for locale-correct sorting, translation workflow, pseudo-localization testing, and i18n…
Skill Claude CodeCodex
Use when reviewing Java code — covers null safety and Optional misuse, Stream API pitfalls, concurrency hazards (synchronized scope, CompletableFuture, ThreadLocal), resource management via try-with-resources, generics and type erasure traps, immutability patterns, and common Java anti-patterns. Load alongside…
Skill Claude CodeCodex
Use when reviewing code for language-specific correctness — covers idiomatic patterns, common anti-idioms, and code review red flags for TypeScript/JavaScript, Python, Java, Go, Rust, and C++, with before/after examples and a quick reference table.
Skill Claude CodeCodex
Use when designing or reviewing event-driven systems — covers Point-to-Point vs Pub/Sub, Competing Consumers, delivery guarantees (at-most-once, at-least-once, exactly-once), Transactional Outbox, Dead Letter Queues, Kafka partition design and consumer groups, message ordering and idempotency, backpressure, and…
Skill Claude CodeCodex
Use when designing or reviewing microservice architectures — covers Saga (choreography vs orchestration), Bulkhead, API Gateway, Circuit Breaker, Retry with Backoff, Fallback and graceful degradation, Health Probes, Service Mesh/Sidecar, and resilience anti-patterns (retry storm, cascading failure, thundering herd)…
Skill Claude CodeCodex
Use when planning or reviewing monolith decomposition, service extraction, or database migration — covers Strangler Fig, Anti-Corruption Layer, Branch by Abstraction, Database Decomposition (Expand-Contract, dual-write), Change Data Capture (Debezium, AWS DMS), and migration anti-patterns across TypeScript, Go, and…
Skill Claude CodeCodex
Use when designing or reviewing multi-tenant systems — covers tenant isolation strategies (RLS, schema-per-tenant, DB-per-tenant), tenant context propagation, tenant-aware caching, tenant lifecycle management, shared vs isolated infrastructure tradeoffs, and multi-tenant anti-patterns across TypeScript, Go, Python…
Skill Claude CodeCodex
Use when reviewing code for observability correctness — covers Structured Logging, Log Levels, Distributed Tracing, Metrics (counters/gauges/histograms), Health Checks, Alerting, Correlation IDs, and Audit Trails with red flags and fix strategies across TypeScript, Python, Java, and Go.
Skill Claude CodeCodex
Use when you need end-to-end examples of detecting a code smell, identifying the underlying anti-pattern, selecting a refactoring technique, and applying the appropriate design pattern — each walkthrough traces the full diagnostic flow with before/after TypeScript code.
Skill Claude CodeCodex
Use when reviewing a PR for performance regressions, when a service is slow under load, when database query times are spiking, or when CPU or memory usage is growing unexpectedly.
Skill Claude CodeCodex
Use when starting a PR review and you need the end-to-end orchestration of all review skills into one complete workflow. This is the capstone skill that sequences every component skill into a principled, time-boxed process from PR load to verdict.
Skill Claude CodeCodex
Python-specific code review guide for AI reviewers. Covers mutable defaults, type hints, GIL and concurrency patterns, import anti-patterns, Pythonic idioms, and exception handling. Load alongside review-accuracy-calibration to calibrate confidence before posting Python findings.
Skill Claude CodeCodex
Use when designing or reviewing real-time communication — covers WebSocket lifecycle, Server-Sent Events, long polling, protocol selection, connection manager, horizontal scaling with Redis Pub/Sub, auth at upgrade, backpressure, and real-time anti-patterns with TypeScript and Go examples.
At most 3 mods per repository are shown here, and a mod shipped inside a plugin is left to that plugin's page — the rest are on their repository pages: