This gem provides immutability validation. This is different from `readonly: true` stuff because it sets the error.

rack-oidc-api provides a JWT validation middleware which automatically discovers the settings supported by a given OIDC provider, and validates the token against the published keys.

Use the ActiveRecord mimicking API to write into CM and enjoy all the benefits of callbacks, validations and permission checking

PIC is a pattern matching library, like regular expressions, based on Cobol edited pictures. It's advantage over regular expressions is it more concise syntax which geared specifically toward validation of user input.

iTunes In-App Purchase and Subscription Receipt Analysis and Validation

This is useful when you want to define optional validations for a resource and keep it valid.

JsonValidation validates JSON according to a JSON Schema.

This gem allows you to create dynamic classes (models) based on a JSON Schema, providing validations and being compliant with ActiveModel.

JsonColumn is a simple HashWithIndifferentAccess with a ._schema method. It makes it easier to deal with json, jsonb postgresql column. It provide validation with josn-schema

A Ruby Gem For Chinese Mainland Personal ID Card Validation

Normalize dry-validation and ActiveModel errors to the universal format

Logobox translates ICO of the company into appropriate logo url at logobox.cz\nIt can check that the logo is uploaded and make the ICO validation.

An ActiveModel validator that consolidates multiple password validations.

Gem for validating complex JSON payloads in a functional way

It's a simple tool that provides helper methods for credit card number validations using Luhn Algorithm.

Generates Rails models from the target database... magically! Validations and associations included.

A mail gem based validator for rails

This RubyGem allows you to prevent particular database fields from being changed after an Active Record object is created. A validation error occurs on updates if an attribute of a model object is different from its value in the database.

A Guilded (http://github.com/midas/guilded/tree/master) component that highlights form fields when they are selected or when they have a validation error.

Tiny plugin for MongoMapper to sanitize strings before validation.