Skill UI

Master the art of building robust, production-grade LLM chains using LangChain Expression Language (LCEL). This guide covers advanced composition patterns, including sequential, parallel, and conditional branching chains. It also details prompt templating, structured output parsing (JSON/Zod), and context injection, enabling the creation of complex, multi-step AI pipelines.

This guide provides minimal working examples demonstrating the LangChain Expression Language (LCEL). It shows how to chain together diverse components—such as prompts, LLMs, and output parsers—using simple pipe syntax (e.g., .pipe() or |). Ideal for developers starting a new LangChain project, understanding core AI workflow patterns, or mastering structured data output.

Practical reference to validate and correct n8n expressions, covering {{ }} usage, $json/$node/$now/$env variables, webhook payload access, and common pitfalls so workflow authors write error-free automations.

Polars is a blazing fast in-memory DataFrame library based on Apache Arrow that replaces pandas for 1-100GB workloads, offering expression-based lazy execution, parallel operators, and rich I/O for ETL pipelines.

Performs static security analysis on GitHub Actions workflows that incorporate AI coding agents (e.g., Claude, Gemini, OpenAI). This skill helps identify critical data flow vulnerabilities, such as where attacker-controlled input can reach AI agent prompts or internal systems via CI/CD pipelines, going beyond simple expression checks.

This skill assists developers in understanding, writing, and validating EAS workflow YAML files for Expo projects. It provides comprehensive guidance on CI/CD pipelines, job definitions, triggers, and expression syntax, ensuring configurations are accurate and up-to-date by referencing official Expo schemas. Use this when automating builds or deployments via EAS.

This is an expert guide for writing, debugging, and validating complex expressions within n8n workflows. It covers core variables such as $json, $node, $now, and $env, detailing how to correctly access nested data from current nodes, previous nodes, and webhook payloads. Learn best practices for handling data structures, managing variable scopes, and avoiding common syntax errors to ensure reliable workflow automation.

This skill provides advanced debugging capabilities for failing Power Automate cloud flows using the FlowStudio MCP server. Unlike the limited status codes from the standard Graph API, this tool gives agents deep, action-level inputs and outputs, allowing users to find the true root cause of failures. It is essential for diagnosing complex issues like expression failures, connector authentication errors, or internal run errors.

A comprehensive methodology for pinpointing the root cause of complex bugs, regressions, or unexpected behavior in large codebases. Techniques include binary search debugging, Git bisect for tracking regressions across commits, strategic data/control flow logging, component isolation, and advanced breakpoint strategies (conditional breakpoints, watch expressions). Ideal for scenarios where the bug source is unclear or difficult to reproduce.

An expert guide covering advanced exploitation techniques for Expression Language (EL) injection across multiple Java frameworks, including Spring (SpEL), Struts2 (OGNL), and JSP/JSF (Java EL). Details detection methods, sandbox bypasses, and real-world CVE chains for Remote Code Execution (RCE).

A comprehensive reference guide detailing modern and idiomatic PHP coding standards. It covers best practices across various topics, including type safety (strict typing, union types), object-oriented programming (constructor promotion, enums, match expressions), efficient array handling, robust error handling (exceptions), and modern string manipulation functions. Ideal for developers looking to upgrade legacy PHP code to modern, clean, and performant standards.

This tool diagnoses and validates complex cron expressions (e.g., crontab, Kubernetes CronJob) to prevent silent scheduling failures. It identifies five common pitfalls: impossible dates, misunderstood OR semantics, resource spikes, uneven step drift, and leap year issues. Users can check the syntax, understand the true meaning, and calculate future execution times reliably.