Data Validation & Schemas Packages
Runtime data validation and schema-definition libraries for catching malformed input before it reaches your application logic (Zod, Pydantic, Valibot).
Packages in Data Validation & Schemas
Kind
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Zod
TypeScript-first schema validation with static type inference and zero dependencies.
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.
FastAPI
A modern, high-performance Python web framework for building APIs with automatic validation, serialization, and interactive docs.
Ajv
The fastest JSON Schema validator for Node.js and the browser, compiling schemas straight into executable validation code.
prop-types
Runtime type checking for React component props, warning in development when data doesn't match the declared shape.
packaging
Core Python utilities for versions, specifiers, markers, requirements, and metadata
ipaddr.js
A dependency-free JavaScript library for parsing, validating, and manipulating IPv4 and IPv6 addresses.
@hono/zod-validator
Type-safe request validation middleware for Hono, powered by Zod schemas.
zod-to-json-schema
Converts Zod validation schemas into standard JSON Schema, ready for OpenAPI, OpenAI, and JSON Schema draft 7 consumers.
yup
A schema builder for parsing and validating JavaScript and TypeScript values at runtime.
jsonschema
The reference implementation of JSON Schema validation for Python, supporting every draft from 3 to 2020-12.
pydantic-settings
Type-safe application settings management for Python, built on Pydantic models.
validator.js
A dependency-free library of 100+ string validators and sanitizers for Node.js and the browser.
@t3-oss/env-core
Typesafe environment variables for TypeScript, validated at boot with any Standard Schema validator.
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.
attrs
Python classes without boilerplate — generate init, repr, equality, and more from declarative field definitions.
class-transformer
Decorator-based transformation between plain objects and class instances for TypeScript
django-rest-framework
The most widely-used toolkit for building Web APIs on top of Django, with serializers, viewsets, and a built-in browsable API.
Valibot
Modular, type-safe schema validation library with bundle sizes starting under 1KB
json-schema
A lightweight, historical CommonJS implementation of the original JSON Schema draft specifications
joi
The most powerful schema description language and data validator for JavaScript
