This skill extends `accessibility-patterns` with screen reader testing, automated testing, and accessible component patterns. Load `accessibility-patterns` first.

Web Accessibility (WCAG 2.2): key success criteria (contrast, keyboard, focus, ARIA), ARIA patterns (aria-label/labelledby/describedby, roles, live regions, state attributes), keyboard navigation (focus trap, skip links, roving tabindex), screen reader testing (NVDA/VoiceOver/TalkBack), automated testing (axe-core, axe-playwright, jest-axe), and accessible component patterns (modals, tables, forms, data visualizations).

Agent evolution closes the continuous-learning feedback loop: validated instincts flow from sessions into agent instructions, making agents smarter over time without touching the versioned agent files in the repo.

This skill extends `agent-reliability` with common mistakes and how to fix them. Load `agent-reliability` first.

Agent Reliability Patterns: retry with exponential backoff and jitter, timeout hierarchies (tool < agent < workflow), fallback chains, circuit breaker for agent calls, cost control (token budgets, model tiering), rate limiting, and observability (what to log per agent call).

Data & product analytics workflow: event taxonomy design, instrumentation (Segment, PostHog, Mixpanel, Amplitude, GA4), analytics pipelines, funnel and retention analysis, and dashboard design. Complements observability (infrastructure metrics) with product/user behavior tracking.

This skill extends `android-patterns` with performance optimization and reference guide. Load `android-patterns` first.

For Kafka/NATS/SQS event interfaces and multi-consumer contract validation with Pact. For the core REST/OpenAPI workflow (steps 1-5), see `api-contract` first.

This skill extends `api-design` with implementation patterns and anti-patterns. Load `api-design` first.

API documentation best practices — OpenAPI spec (paths, components, examples, x-webhooks), docs-as-code CI/CD, platform selection (Mintlify/Redoc/Scalar), interactive playgrounds, changelog automation with conventional commits.

Cursor and offset pagination, filtering operators, multi-field sorting, full-text search, and sparse fieldsets for REST APIs.

arc42 architecture documentation template (all 12 sections) combined with C4 diagrams (Context, Container, Component, Deployment) in PlantUML. The standard for architecture documentation in this setup. Maps each section to the Claude skills that help fill it.

Turn a raw topic, note dump, or vague idea into a sharp brief before writing begins. Good briefs prevent rewrites.

Asynchronous processing patterns: job queues (BullMQ, Celery, asynq), scheduled cron jobs, event-driven pub/sub, dead letter queues, retry with exponential backoff, and idempotency. Covers TypeScript, Python, and Go.

Idiomatic Bash scripting patterns: script structure, argument parsing, error handling, logging, temp files, parallel execution, and portability. Use when writing or reviewing shell scripts.

Bash script testing with BATS (Bash Automated Testing System): test structure, assertions, setup/teardown, mocking external commands, CI integration, and coverage strategies.

C programming patterns (C11/C17): opaque pointer encapsulation, error handling via return codes and out-parameters, resource cleanup with goto, memory management discipline (malloc/free pairing, double-free prevention), safe string functions (snprintf, fgets, strncpy), Makefile patterns with auto-dependencies, bit manipulation, and AddressSanitizer/Valgrind integration. Use when writing or reviewing C code.

> This skill extends [cpp-coding-standards](../cpp-coding-standards/SKILL.md) with concurrency, templates/concepts, standard library, enumerations, naming, performance, and the full checklist.

The clarc Way — opinionated end-to-end software development methodology. 8-stage pipeline from idea to shipped code: /idea → /evaluate → /explore → /prd → /plan → /tdd → /code-review → commit. Activate when a user asks how to structure their workflow, which commands to use, or when to use clarc.

CLI tool design patterns for Node.js (yargs/commander), Python (click/typer/argparse), Go (cobra/pflag), and Rust (clap). Covers argument design, subcommand structure, interactive prompts (inquirer/Ratatui), progress bars, exit codes, stdin/stdout/stderr composability, and --json output. Use when building any command-line tool.