expect

Use when editing .tsx/.jsx/.css/.html, React components, pages, routes, forms, styles, or layouts. Also when asked to test, verify, validate, QA, find bugs, check for issues, or fix expect-cli failures.

Systematic evidence-based debugging using runtime logs. Generates hypotheses, instruments code with NDJSON logs, guides reproduction, analyzes log evidence, and iterates until root cause is proven with cited log lines. Use when the user reports a bug, unexpected behavior, or asks to debug an issue.

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

Write and improve agent skills (SKILL.md files). Use when creating new skills, refactoring existing ones, debugging why an agent ignores instructions, or improving compliance. Covers prompt structure, TDD for skills, description optimization, and rationalization bulletproofing.

Enforces Effect-TS patterns for services, errors, layers, and atoms. Use when writing code with Effect.Service, Schema.TaggedError, Layer composition, or effect-atom React components.

Portable Effect patterns for robust promise execution. Use when wrapping async operations with timeouts, retries, tagged errors, caching, concurrency, pattern matching, or tracing - all designed to resolve to a plain Promise via Effect.runPromise.

Perform code reviews. Use when reviewing pull requests, examining code changes, or providing feedback on code quality. Covers security, performance, testing, and design review.

Simplify and refine recently modified code while preserving functionality. Use when asked to "deslop", "clean up code", "simplify code", or after making changes that could benefit from refinement.