Valibot is a modular, type-safe schema validation library for TypeScript with zero external dependencies. It provides a comprehensive set of schemas (string, number, object, array, union, etc.), validation actions (email, minLength, regex, etc.), transformation actions (toNumber, toUpperCase, parseJson, etc.), and composition methods (pipe, fallback, forward, cache). The library is tree-shakeable, supports both sync and async validation, and achieves 100% test coverage. Its architecture follows a consistent action/schema object pattern with a `~run` method for runtime validation and extensive TypeScript generics for type inference (InferInput, InferOutput, InferIssue). The repository is a monorepo containing the core library, a documentation website built with Qwik, a codemod for migrating from Zod to Valibot, a JSON Schema conversion package, and an i18n package for localized error messages. The primary entry point is `library/src/index.ts`, which re-exports all schemas, actions, methods, and utilities. Data flows involve defining schemas, optionally piping actions, and then calling `parse` or `safeParse` to validate input against the schema. The library implements the Standard Schema specification for interoperability.
Bundlephobia is a production web application that analyzes the bundle-size cost of npm packages by performing real builds with a bundler. It exposes a public REST API (endpoints for size, exports, history, trends, similar packages) and a rich Next.js frontend with interactive visualizations (treemaps, trends charts, export analysis). The architecture is microservice-oriented: a main Koa/Next.js server orchestrates requests, a Fastify build-service executes package builds with timeout and profiling, a cache-service backed by Firebase and LRU memory stores results, and an installation-service deduplicates npm installs with lease-based concurrency control. The system also includes a separate Kotlin/Gradle sub-project for JVM package analysis (Maven, Android AAR/JAR) and a curated similar-packages catalog maintained via automated AI research workflows. External dependencies include npm registry, GitHub API, Algolia, Contentful, and Amplitude analytics. Key design patterns include a language-agnostic analysis gateway with adapter registration, a middleware pipeline for request processing (caching, rate-limiting, error handling), typed service contracts using Zod schemas, and a queue service with priority and cancellation. The codebase demonstrates strong engineering practices with extensive unit and e2e tests, custom Oxlint lint rules enforcing internal TypeScript standards, and CI/CD automation for package recommendation updates and JVM releases. While primarily an application, the repository also contains data-research elements: a curated similar-packages catalog with weighted tags, trends analysis merging npm downloads and GitHub stars, and automated library research scripts that propose catalog updates. These are integrated into the application's recommendation features.