Frontend

Guidance for implementing encoders/compressors that must produce output compatible with an existing decoder/decompressor. This skill applies when tasked with writing compression algorithms, arithmetic coders, entropy encoders, or any encoder that must be the inverse of a given decoder implementation.

Analyze and optimize application performance including bundle size, render performance, and API response times. Use when investigating slow pages or optimizing production builds.

Guidance for filtering JavaScript and XSS attack vectors from HTML while preserving original formatting. This skill should be used when tasks involve removing script content, sanitizing HTML, filtering XSS payloads, or creating security filters that must preserve the original document structure unchanged.

Guidance for Bayesian Network DAG structure recovery, parameter learning, and causal intervention tasks. This skill should be used when tasks involve recovering DAG structure from observational data, learning Bayesian Network parameters, performing causal interventions (do-calculus), or generating samples from modified networks. Applies to tasks mentioning Bayesian networks, DAG recovery, structure learning, causal inference, or interventional distributions.

Guide for extracting code or pseudocode from images using OCR and implementing it correctly. This skill should be used when tasks involve reading code, pseudocode, or algorithms from images (PNG, JPG, screenshots) and executing or implementing the extracted logic.

Guidance for bypassing HTML/JavaScript sanitization filters in security testing contexts. This skill should be used when tasked with finding XSS filter bypasses, testing HTML sanitizers, or exploiting parser differentials between server-side filters and browsers. Applies to CTF challenges, authorized penetration testing, and security research involving HTML injection and JavaScript execution through sanitization bypasses.

Create or update Next.js server actions for blog and analytics functionality. Use when adding form handlers, data mutations, or server-side logic in the web app.

Guidance for setting up Git repositories with automatic web deployment via post-receive hooks. This skill applies when configuring bare Git repositories, setting up web servers to serve pushed content, creating Git hooks for deployment automation, or implementing push-to-deploy workflows.

Business Logic Focus audit worker (L3). Detects tests that validate framework/library behavior (Prisma, Express, bcrypt, JWT, axios, React hooks) instead of OUR code. Returns findings with REMOVE decisions.

Guidance for extracting structured data from log files using regular expressions. This skill applies when parsing logs to extract dates, IP addresses, timestamps, or other structured patterns, especially when multiple conditions must be combined (e.g., "find the last date on lines containing an IP"). Use this skill for complex regex construction involving lookaheads, anchors, and pattern composition.

Use when implementing features or fixing bugs - enforces RED-GREEN-REFACTOR cycle requiring tests to fail before writing code

Guidance for implementing minimal GPT-2 inference in constrained environments (code golf challenges). This skill should be used when implementing neural network inference from scratch, parsing binary checkpoint formats, implementing BPE tokenization, or working on code golf challenges involving ML models. Covers verification strategies and common pitfalls for checkpoint parsing and model inference.

Recommend appropriate HeroUI components for new features and ensure proper usage. Use when implementing new UI features or migrating from shadcn/ui to HeroUI.

Guidance for building digital logic circuits that compute composite functions like Fibonacci of integer square root. This skill applies when implementing combinational and sequential logic in gate-level simulators, particularly when combining algorithms (like isqrt and Fibonacci) under resource constraints (gate counts, simulation steps). Use for circuit synthesis, HDL-style logic design, or gate-level algorithm implementation tasks.

This skill provides guidance for merging data from multiple heterogeneous sources (CSV, JSON, Parquet, XML, etc.) into unified output formats with conflict detection and resolution. Use when tasks involve combining data from different file formats, field mapping between schemas, priority-based conflict resolution, or generating merged datasets with conflict reports.

Guide for building CompCert, the formally verified C compiler, from source. This skill should be used when compiling, building, or installing CompCert, or when working with Coq-based software that has strict dependency version requirements. Covers OCaml/opam setup, Coq version compatibility, memory management, and common build pitfalls.

Application lifecycle audit worker (L3). Checks bootstrap initialization order, graceful shutdown, resource cleanup, signal handling, liveness/readiness probes. Returns findings with severity, location, effort, recommendations.

Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Codex's capabilities with specialized knowledge, workflows, or tool integrations.

Guides architects on when and how to use goal-seeking agents as a design pattern. This skill helps evaluate whether autonomous agents are appropriate for a given problem, how to structure their objectives, integrate with goal_agent_generator, and reference real amplihack examples like AKS SRE automation, CI diagnostics, pre-commit workflows, and fix-agent pattern matching.

Use when building RAG systems, vector databases, or knowledge-grounded AI applications requiring semantic search, document retrieval, or context augmentation.