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.