Skill UI

A comprehensive guide on handling API rate limits and throttling errors (429) when building high-throughput systems, particularly for LLM APIs like OpenRouter. This skill covers best practices, including using exponential backoff, implementing custom client-side rate limiters (Token Bucket), and managing concurrent requests for stable, reliable performance.

Provides comprehensive patterns for creating production-grade client wrappers when integrating with OpenRouter via the OpenAI SDK. This skill covers handling advanced topics such as robust retry mechanisms, structured typing, caching strategies, and middleware implementation. It is essential for developers building stable, reliable SDKs or commercial client libraries that require enterprise-level API robustness.

A comprehensive guide to integrating PayPal into applications, covering all aspects of the payment lifecycle. This skill covers client-side implementations using JavaScript SDK for Express Checkout, server-side API interactions (REST API) for order creation and capture, handling recurring billing via Subscriptions, managing asynchronous updates through IPN/Webhooks, and processing refunds and payouts. Ideal for building robust e-commerce payment gateways.

This guide provides comprehensive instructions for installing and configuring the Perplexity Sonar API authentication. It details setting up the necessary environment variables and using the standard OpenAI client library (for both Node.js and Python) to connect to Perplexity's API endpoint. Learning this process is essential for developers starting a new Perplexity integration, setting up API keys, or verifying API connectivity.

A comprehensive guide and implementation for setting up a fast, cost-effective local development loop for the Perplexity Sonar API. It includes generating type-safe client wrappers, utilizing fixtures for reliable mocking, and establishing a complete test suite with hot-reloading capabilities. This ensures stable development and manages high API call costs during iteration.

Provides a comprehensive workflow for managing feature flags, running A/B/multivariate experiments, and analyzing user cohorts using PostHog. The guide covers implementing flag evaluation both client-side (browser) and server-side (Node.js), and demonstrates how to programmatically set up, track, and query experiment results via API calls (cURL/Bash).

This skill guides the complete setup and configuration of PostHog SDKs for modern applications. It covers best practices for implementing client-side (browser) and server-side (Node.js/Python) event tracking. Users will learn how to install the necessary SDKs via npm or pip, manage environment variables for both Project API Keys and secure Personal API Keys, and initialize the tracking service correctly to ensure accurate and reliable event capture in PostHog.

This guide provides a comprehensive, production-grade architecture for implementing analytics using PostHog. It covers best practices for event taxonomy design, SDK layering (client and server), feature flag management, and integrating the data pipeline (CDP). Ideal for tracking user lifecycle, feature adoption, and revenue in complex web applications.

A comprehensive guide to implementing production-ready patterns for PostHog analytics integration. This includes establishing singleton clients for both server-side (Python/Node) and client-side environments. It provides type-safe event capture utilities, React hooks for handling feature flags (including variants), and the full Next.js App Router setup for robust pageview tracking. Patterns are available for both TypeScript/JavaScript and Python environments.

Diagnoses and fixes Prisma connection pool exhaustion in serverless deployments (Vercel, Lambda, Netlify) by routing through pooling services, limiting client connections, and tuning timeouts to stop P2024/too many connection errors under load.

A comprehensive optimization guide maintained by Vercel, covering 45 rules for React and Next.js. Use this resource when building new components, implementing complex data fetching (client or server-side), refactoring code, or systematically improving bundle size and overall load times for high-performance web applications.

This guide provides production-ready coding patterns for interacting with various built-in Replit services. It covers best practices for setting up singleton clients, implementing robust error handling, and creating type-safe wrappers for Key-Value Database, Object Storage, PostgreSQL, and Auth middleware. Ideal for developers building complex Replit integrations or establishing standardized data access layers.