Open Source Packages
Libraries, frameworks, tools, and SDKs used by the apps in this directory — scored the same way as the apps themselves.
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Zod
TypeScript-first schema validation with static type inference and zero dependencies.
React Hook Form
Performant, flexible React forms built on hooks with minimal re-renders and built-in validation.
Pydantic
Data validation and settings management using Python type hints, backed by a Rust core.
@hookform/resolvers
Official React Hook Form adapters that plug 20+ schema-validation libraries — Zod, Yup, Joi, Valibot, ArkType and more — straight into useForm's resolver.
Ajv
The fastest JSON Schema validator for Node.js and the browser, compiling schemas straight into executable validation code.
validator.js
A dependency-free library of 100+ string validators and sanitizers for Node.js and the browser.
jsonschema
The reference implementation of JSON Schema validation for Python, supporting every draft from 3 to 2020-12.
ajv-formats
ajv-formats: JSON Schema Format Validators for Ajv v8+
class-validator
Decorator-based property validation for TypeScript and JavaScript classes, on both Node.js and the browser.
validator
Go struct and field validation using reflection-based tags, with cross-field, cross-struct, and nested slice/array/map diving support.
Formik
Formik: Build React Forms Without the Tears - Docs & Guide
Valibot
Modular, type-safe schema validation library with bundle sizes starting under 1KB
joi
The most powerful schema description language and data validator for JavaScript
email-validator
Robust email address syntax and deliverability validation for Python
@apidevtools/swagger-parser
Parses, validates, and dereferences Swagger 2.0 and OpenAPI 3.x specs in Node.js and browsers
zod-validation-error
Turns raw Zod validation issues into clear, human-readable error messages.
express-validator
A chainable Express middleware that wraps validator.js to validate and sanitize incoming request data with minimal boilerplate.
msgspec
A fast, zero-cost serialization and validation library for JSON, MessagePack, YAML, and TOML in Python.
validators
A Python library for validating strings — emails, URLs, IPs, and more — without defining a schema.
jsonschema
A high-performance JSON Schema validator for Rust with Python, Ruby, and WASM bindings
utf-8-validate
Native addon that validates UTF-8 buffers at C++ speed, with a pure-JS fallback for unsupported platforms.
vee-validate
Template-based form validation library for Vue.js with Composition API support
govalidator
A comprehensive Go package of string, numeric, and struct validators and sanitizers, modeled on validator.js.
cron-validator
A zero-dependency TypeScript library that validates cron expression strings, with support for seconds, aliases, blank days, and nth-weekday syntax.
