Validit

Validit is a software library and framework for data validation used in software development to verify that inputs, configurations, and datasets conform to defined constraints. It provides a schema-driven approach in which developers declare validation rules for structured data, enabling consistent validation across applications, APIs, and data pipelines. The engine supports primitive types, nested objects, arrays, and optional fields, with features such as type coercion, default values, conditional rules, asynchronous validators, and detailed error reporting. It is designed to be language-agnostic in concept, with bindings that allow usage in multiple programming environments.

Origin and development: Validit began as an open-source project in 2017 created by a group of developers seeking a common validation layer for diverse stacks. Over time it gained additional bindings, documentation, and a plugin system, promoting community contributions and collaboration. Official releases are distributed via public repositories with active issue tracking and continuous integration.

Features and architecture: At its core, Validit comprises a core validation engine, a schema registry that stores definitions, and adapters that connect to data sources or transport layers. It supports a declarative schema syntax inspired by JSON Schema and custom validators through a plugin mechanism. The architecture emphasizes composability, allowing validators to be composed into reusable rules and reused across contexts. Performance considerations include streaming validation for large payloads and memoization for repeated checks, along with clear, actionable error messages.

Usage and reception: Users typically define a schema that describes the expected shape and constraints of data and then run data through the validator before further processing. In practice, Validit has been adopted by projects ranging from small web services to larger pipelines, with praise for its expressive rules and extensibility, and critique regarding its learning curve for simple validation tasks.

See also: JSON Schema, Joi, Cerberus.