Development skills.

Create distinctive, production-grade frontend interfaces with high design quality. Use when building web components, pages, artifacts, posters, or applications. Generates creative, polished UI code that avoids generic AI aesthetics.

Use the Claude API effectively: messages endpoint, streaming, tool use, vision, prompt caching, batches, files. Use when the user is building against the Anthropic API or troubleshooting requests.

Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Supports Python (FastMCP) and Node/TypeScript (MCP SDK).

Build self-contained interactive web artifacts (single-file HTML+CSS+JS apps) like calculators, visualisers, mini-tools and demos. Use when the user wants a runnable web artifact rather than a full project.

Systematically debug failing code: form hypotheses, isolate variables, add targeted logging, run minimal reproductions. Use when the user is stuck on a bug.

Build interactive data visualisations with D3.js: bar charts, line charts, scatter plots, geographic maps, force-directed graphs. Use when the user wants custom, code-driven charts beyond Chart.js.

Build and deploy Cloudflare Workers / Pages: Hono routing, D1 SQLite, KV, R2, Durable Objects, secrets, wrangler. Use when the user is on the Cloudflare edge.

Perform a thoughtful code review: correctness, readability, performance, security, tests. Use when the user pastes a diff or PR and wants critical feedback.

Build with the Next.js App Router: server components, route handlers, server actions, streaming, middleware, layouts. Use when the user works on a Next.js 13+ project.

Drive headless and headed browsers with Playwright: navigate, fill forms, take screenshots, scrape, and run end-to-end tests. Use whenever the user wants to automate a browser.

Run a thorough technical SEO audit on a website: meta titles, descriptions, canonicals, sitemap, structured data, internal linking, Core Web Vitals. Use when the user wants to improve organic traffic.

Design and iterate on prompts and prompt templates with structured testing. Use when the user is shipping a feature that depends on LLM behaviour and needs reliable outputs.

Author end-to-end and integration tests for web applications using Playwright, Cypress and the like. Use when the user wants to add tests, debug flaky behaviour, or set up CI test pipelines.

Run safe, idiomatic git operations: rebases, interactive rebase, cherry-picks, conflict resolution, bisect, history rewriting. Use when the user is debugging a tricky git situation.

Design schemas, write performant queries, debug query plans, manage migrations, and operate PostgreSQL safely. Use when the user is working with a Postgres database.

Read EXPLAIN plans, find missing indexes, rewrite slow queries, and suggest schema changes. Use when the user has a slow SQL query in any major dialect.

Write clear API reference docs and tutorials from OpenAPI specs or source code. Use when the user is launching or maintaining a public API.

Generate user-facing changelogs from git history or PR lists. Use when the user is preparing a release and needs human-readable change notes.

Produce a production-grade Dockerfile and docker-compose setup for an existing project: multi-stage builds, small images, healthchecks, secrets handling.

Build React Native apps with Expo: navigation, native modules, EAS build pipelines, deployment to App Store and Play Store. Use whenever the user works on a mobile app with Expo.

Drive the iOS simulator from Claude: launch apps, interact with UI, take screenshots, inspect view hierarchies. Use when building or QAing iOS apps locally.

Write and debug Kubernetes manifests: Deployments, Services, Ingress, ConfigMaps, Secrets, HPA. Use when the user is operating workloads on Kubernetes.

Write idiomatic React hooks: dependency arrays, custom hooks, useReducer, useMemo, suspense. Use when the user is working with React functional components.

Refactor code safely with small, testable steps: extract function, rename, simplify conditionals, eliminate duplication. Use when the user wants to improve code without changing behaviour.

Design, debug and explain regular expressions with test cases. Use when the user needs a regex written, understood, or fixed.

Author and refactor Terraform/OpenTofu modules. Use when the user is provisioning AWS, GCP, Azure or Cloudflare infrastructure as code.

Write TypeScript that satisfies strict mode and noUncheckedIndexedAccess. Use when the user wants type-safe code without `any`, or is migrating a JS project to TS.

Manipulate large JSON files with jq, Python and surgical patches. Use when the user needs to slice, restructure or merge JSON.