Backend

Work with MongoDB (document database, BSON documents, aggregation pipelines, Atlas cloud) and PostgreSQL (relational database, SQL queries, psql CLI, pgAdmin).

Use this skill when the user wants to build tool/scripts or achieve a task where using data from the Hugging Face API would help.

Web accessibility end to end: WCAG 2.2 AA, EAA and ADA Title II obligations, audits (axe, pa11y, keyboard, screen reader), the common failures, accessibility…

Authentication and authorization patterns - JWT, OAuth2, sessions, RBAC, ABAC, passkeys, MFA, identity-aware proxies, and Better Auth.

Claude Code internals - hooks, skill frontmatter, headless mode, and extension debugging, current as of June 2026.

Router and composition workflows for Figma via the official Figma MCP: which Figma skill/tool for which job, capture-to-canvas (screenshots or shotcraft crops…

Upgrade a server-rendered Craft CMS/Twig front end: Laravel Mix or Webpack to Vite via craft-vite (manifest, DDEV dev server, HMR, Tailwind v3, legacy builds…

Source, vet, normalize and ship SVG icons for web UI - set selection, licence and trademark traps, currentColor theming, sprite/inline delivery, and…

Kubernetes and Helm in practice: Deployments, Services, probes, resources, autoscaling, disruption budgets, NetworkPolicy, Pod Security Standards, Gateway API…

Prevent and investigate Rust reliability failures in agent-written or human-written code through enforceable API and lint restrictions, ownership and…

Query FRED (Federal Reserve Economic Data) API for 800,000+ economic time series from 100+ sources.

Query and analyze scholarly literature using the OpenAlex database.

CLI-first web scraping & content extraction with optional MCP server.

World-class data science skill for statistical modeling, experimentation, causal inference, and advanced analytics.

Production-ready reinforcement learning algorithms (PPO, SAC, DQN, TD3, DDPG, A2C) with scikit-learn-like API.

Direct REST API access to UniProt.

Generate images on grok.com/imagine with the signed-in Grok session.

Build Solana applications with Helius infrastructure.

Build frontend Solana applications with Phantom Connect SDK and Helius infrastructure.

Read the user's latest X (Twitter) bookmarks as typed data (text, author, metrics, media, links, quoted posts, articles) with a TypeScript SDK that calls X's…

Expert patterns for adding multiplayer to single-player games including client-server architecture, authoritative server design, MultiplayerSynchronizer, lag…

API design patterns for REST, gRPC, and GraphQL.

Analyze Sage's Phoenix/OpenInference trace database (phoenix.db) for the Sage LangGraph multi-agent system.

Cloudflare Workers + Wrangler edge ops: runtime, bindings, local dev, secrets, deploy/CI, Pages-vs-Workers.