Full Documentation

A small validation library for .NET that uses a fluent interface and lambda expressions for building validation rules.

Get Started

FluentValidation can be installed using the Nuget package manager or the dotnet CLI.

Install-Package FluentValidation

For ASP.NET Core integration:

Install-Package FluentValidation.AspNetCore

For legacy ASP.NET MVC/WebApi integration:

Install-Package FluentValidation.MVC5
Install-Package FluentValidation.WebApi

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FluentValidation
FluentValidation.AspNetCore
FluentValidation.Mvc5
FluentValidation.WebApi

Example

usingFluentValidation;publicclassCustomerValidator:AbstractValidator<Customer>{publicCustomerValidator(){RuleFor(x =>x.Surname).NotEmpty();RuleFor(x =>x.Forename).NotEmpty().WithMessage("Please specify a first name");RuleFor(x =>x.Discount).NotEqual(0).When(x =>x.HasDiscount);RuleFor(x =>x.Address).Length(20,250);RuleFor(x =>x.Postcode).Must(BeAValidPostcode).WithMessage("Please specify a valid postcode");}privateboolBeAValidPostcode(stringpostcode){// custom postcode validating logic goes here}}varcustomer=newCustomer();varvalidator=newCustomerValidator();ValidationResultresults=validator.Validate(customer);boolsuccess=results.IsValid;IList<ValidationFailure>failures=results.Errors;

Documentation

Documentation can be found on the project site.