Firebase JWT validation

CrazyValidators enables easy validation of attributs of an ActiveModel class, such as alphanumericality, presence in a Blacklist.

A ruby interface over the DataValidation service.

Includes optional reader/writer delegation and unobtrusive errors validation

Write self-documenting parameter validation and type-casting in your API actions. Docs and development at https://github.com/ozydingo/despecable.

Adds a Rails-esque validation method for use in Rails 3 with ActiveRecord or DataMapper

Transform database constraint errors into activerecord validation errors

Hash validation for 'options'-like methods.

Paper-thin Facebook validation and signed request parsing Rails plugin

Dr Nic's Magic Models - Invisible validations, assocations and Active Record models themselves!

Mutations gem interface implemented with `dry-rb`’s validation schemas.

Dependency-free object validation library for Ruby 1.8.7+

Reliable contract definition, data validation, and type checking for Ruby.

Advanced ActiveModel email validation with MX lookups, domain blacklisting and disposable email blocking

A simple, localizable EachValidator for email address fields in ActiveRecord 3.0.

Ruby Library for the mailboxlayer API, a web service that email validation & verification, https://mailboxlayer.com/

error_messages_for_helper provides a simple helper to show ActiveRecord validation errors (just like old helper error_messages_for for Rails-2.3.x).

100% exclusive message for any ActiveModel validation error.

It provides basic command line tools for simply defining things like cross validations, factorial experimental design and basic statistics. All of this can be run in a distributed manner.

A simple hash validator that allows you to do complex validations with custom error messages.