YAML to C# Converter

About this tool

Paste a YAML sample and get C# type definitions you can use immediately. Emits classes with auto-properties and `[JsonPropertyName]` attributes for `System.Text.Json`.

When you would use it

• Deserialising in .NET without a custom naming policy
• Bootstrapping models from a real YAML response instead of writing them by hand
• Keeping types in step with an API that has changed

Worked example

id: 4815
name: Ada Lovelace
active: true
score: 91.5
roles:
  - admin
  - editor
address:
  city: London
  postcode: NW1

using System.Collections.Generic;
using System.Text.Json.Serialization;
public class Root
{
    [JsonPropertyName("id")]
    public long Id { get; set; }

    [JsonPropertyName("name")]
    public string Name { get; set; }

    [JsonPropertyName("active")]
    public bool Active { get; set; }

    [JsonPropertyName("score")]
    public double Score { get; set; }

    [JsonPropertyName("roles")]
    public List<string> Roles { get; set; }

    [JsonPropertyName("address")]
    public Address Address { get; set; }

}
public class Address
{
    [JsonPropertyName("city")]
    public string City { get; set; }

    [JsonPropertyName("postcode")]
    public string Postcode { get; set; }

}

Things worth knowing

• Every object in an array is merged when inferring the shape, so a field missing from one item is marked optional rather than assumed to always be present.
• Identical nested shapes are de-duplicated into a single type instead of generating near-duplicates.
• Array element types are named from the singular of the field name, so posts produces a Post type.
• YAML resolves unquoted scalars to types, so no becomes a boolean and 1.10 becomes a number. Quote values you want treated as text.