Overview

Availability: C# 11 / .NET 7 Properties can be marked required to indicate that they must be present in the JSON payload for deserialization to succeed. Otherwise, Deserialize methods throw a JsonException.

Techniques for Marking Fields/Properties

1. Add the required modifier to the field/property (C# 11)
2. Annotate the property with JsonRequiredAttribute (.NET 7) a. Use this technique if the requirement should only apply to deserialization.
3. Modify the JsonPropertyInfo.IsRequired property of the contract model (.NET 7)

Example

public class Person 
{
	public required string Name { get; set; }
	public int Age { get; set; }
}

or:

[JsonRequired]
public string Name { get; set; }