Packages

Express.js middleware for configuring Cross-Origin Resource Sharing (CORS) headers. Handles the browser's same-origin policy by setting Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, and related CORS headers on HTTP responses. Supports whitelist-based origin validation, preflight OPTIONS request handling, credential cookies, and dynamic per-request origin configuration. Part of the expressjs GitHub organization.

Express.js middleware for validating and sanitizing request data (body, params, query, headers, cookies). Built on top of validator.js. Provides a chainable API: body('email').isEmail().normalizeEmail(), param('id').isUUID(), query('page').isInt({min: 1}). Validation results collected via validationResult() or matchedData(). The de-facto standard for Express.js request validation.

Tiny (3.9kB), fast Node.js library for terminal string styling with ANSI colors. Drop-in alternative to chalk with a chainable API and automatic NO_COLOR/FORCE_COLOR environment variable support. Uses template literal tags and a chainable API. Notably faster than chalk in benchmarks and has zero dependencies.

Fast Python JSON library written in Rust. orjson is 3-10x faster than the standard library json module for serialization and deserialization. Natively serializes Python dataclasses, datetime, numpy arrays, UUID, and Pydantic models without custom encoders. Drop-in replacement for json.dumps/json.loads with better performance and native type support.

Comprehensive Python static code analyzer — checks for errors, enforces coding standards, and detects code smells. pylint features: error detection (undefined names, wrong types, attribute errors), convention violations (PEP 8, naming), refactoring hints (too-many-arguments, too-complex), warning detection, score out of 10, message categorization (C/R/W/E/F), --disable/--enable for selective rules, pylintrc/pyproject.toml configuration, plugin system (pylint-django, pylint-celery), --output-format for CI integration, --fail-under for quality gates, and --jobs for parallel linting. More thorough than flake8 but slower.

Strips ANSI escape codes (color codes, cursor movement, formatting) from strings. Essential utility for processing terminal output that may contain color codes — logging terminal output to files, testing CLI output, measuring string display width, or displaying colored terminal output in non-ANSI contexts. Maintained by the chalk team. ESM-only since v7.

End-to-end type-safe RPC framework for TypeScript. tRPC generates TypeScript types from server-side router definitions and shares them with the client — no code generation, no schema files. Calling a server procedure from the client has full TypeScript autocomplete for inputs and outputs. Works as HTTP/JSON under the hood. Designed for TypeScript monorepos (Next.js, T3 stack).

Blazing-fast structured logging library for Go from Uber. Provides two interfaces: Logger (zero-allocation, maximum performance) and SugaredLogger (more convenient, slightly slower). Outputs structured JSON logs ideal for log aggregation platforms (Datadog, ELK, Loki). 4-10x faster than other Go structured loggers.

Content-focused web framework using Islands Architecture to ship zero JavaScript by default. Astro renders HTML at build time (SSG) or request time (SSR) with components from any UI framework (React, Vue, Svelte, Solid). Island components selectively hydrate only interactive parts. Optimized for content sites, documentation, blogs, and marketing pages.

Microsoft Azure's managed IoT hub service for bidirectional communication between IoT devices and cloud applications, with device twins, direct methods, and built-in message routing to Azure services.

Open banking API platform providing PSD2-compliant account information and payment initiation services for Dutch banks, with an MCP server for agent-driven banking integration.

Cloud CI/CD platform with a REST API (v2) for triggering pipelines, monitoring jobs, managing artifacts, and programmatic pipeline control for GitHub, GitLab, and Bitbucket repositories.

Modern Android Jetpack replacement for SharedPreferences. DataStore provides two APIs: Preferences DataStore (key-value pairs, no schema) and Proto DataStore (typed Protocol Buffer schema, requires .proto file). Key advantages over SharedPreferences: Kotlin coroutines and Flow for async access (no blocking main thread), ACID transactions, handles exceptions properly (SharedPreferences silently swallows IOExceptions), and Kotlin DSL API. Part of Android Jetpack, recommended by Google for all new Android key-value storage.

HTTP request logger middleware for Node.js. Logs HTTP request details (method, URL, status, response time, content length) to stdout or a stream in configurable formats. Part of the expressjs GitHub organization. Built-in formats: combined (Apache-style), common, dev (colored console), short, tiny. Custom format tokens available. Essential for access logging in Express applications during development and production.

Polymarket prediction markets MCP server enabling AI agents to query Polymarket — the popular blockchain-based prediction market platform. Enables reading market prices (probability estimates), querying active markets by topic, monitoring specific predictions, and integrating crowd wisdom from prediction markets into AI forecasting and decision-support workflows.

Type-safe ORM for TypeScript/Node.js with a declarative schema, auto-generated query client, and built-in migration runner supporting PostgreSQL, MySQL, SQLite, and MongoDB.

Adobe's library of React hooks for building accessible UI components. Implements ARIA patterns, keyboard navigation, focus management, and internationalization for 40+ component types (buttons, dialogs, menus, date pickers, etc.). Headless — no styles, pure behavior and accessibility logic. The accessibility-first alternative to Radix UI with more comprehensive ARIA pattern coverage and internationalization support from Adobe's enterprise experience.

Official, opinionated Redux toolset for efficient Redux development. Redux Toolkit (RTK) eliminates Redux boilerplate by providing createSlice (reducers + actions in one), createAsyncThunk (async actions), and RTK Query (data fetching and caching). Uses Immer internally for immutable state updates via mutable syntax. The recommended way to use Redux in new React projects.

The de-facto standard synchronous Python HTTP library offering a simple, human-friendly API for making web requests.

React data fetching library using the stale-while-revalidate (SWR) HTTP caching strategy. useSWR hook returns cached data immediately (stale), then fetches fresh data in the background (revalidate). Features: automatic revalidation on focus, interval polling, deduplication of concurrent requests, pagination, mutation, and optimistic updates. Lighter alternative to TanStack Query from Vercel — focused and minimal.