SharpYaml is a high-performance .NET YAML parser, emitter, and object serializer - NativeAOT ready.
Note: SharpYaml v3 is a major redesign with breaking changes from v2. It uses a System.Text.Json-style API with YamlSerializer, YamlSerializerOptions, and resolver-based metadata (IYamlTypeInfoResolver). See the migration guide for details.
✨ Features
System.Text.Json-style API: familiar surface with YamlSerializer, YamlSerializerOptions, YamlTypeInfo<T>
Low-level access: full scanner, parser, emitter, and syntax tree APIs for advanced YAML processing
NativeAOT and trimming oriented (IsAotCompatible, IsTrimmable)
📐 Requirements
SharpYaml targets net8.0, net10.0, and netstandard2.0.
Consuming the NuGet package works on any runtime that supports netstandard2.0 (including .NET Framework) or modern .NET (net8.0+).
Building SharpYaml from source requires the .NET 10 SDK (C# 14).
📦 Install
dotnet add package SharpYaml
SharpYaml ships the source generator in-package (analyzers/dotnet/cs) - no extra package needed.
🚀 Quick Start
using SharpYaml;
// Serialize
var yaml = YamlSerializer.Serialize(new { Name = "Ada", Age = 37 });
// Deserialize
var person = YamlSerializer.Deserialize<Person>(yaml);
Options
var options = new YamlSerializerOptions
{
PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
WriteIndented = true,
IndentSize = 4,
DefaultIgnoreCondition = YamlIgnoreCondition.WhenWritingNull,
};
var yaml = YamlSerializer.Serialize(config, options);
var model = YamlSerializer.Deserialize<MyConfig>(yaml, options);
By default, PropertyNamingPolicy is null, meaning CLR member names are used as-is for YAML mapping keys (same default as System.Text.Json).
Source Generation
Declare a context with [JsonSerializable] roots:
using System.Text.Json.Serialization;
using SharpYaml.Serialization;
[JsonSerializable(typeof(MyConfig))]
internal partial class MyYamlContext : YamlSerializerContext { }
Then consume generated metadata:
var context = MyYamlContext.Default;
var yaml = YamlSerializer.Serialize(config, context.MyConfig);
var roundTrip = YamlSerializer.Deserialize(yaml, context.MyConfig);
Reflection Control
Reflection fallback can be disabled globally before first serializer use:
When reflection is disabled, POCO/object mapping requires metadata (use generated YamlTypeInfo<T>, the overloads that accept a YamlSerializerContext, or pass MyYamlContext.Default.Options to an options-based overload). Primitive scalars and untyped containers (object, Dictionary<string, object>, List<object>, object[]) still work without reflection.
When publishing with NativeAOT (PublishAot=true), the SharpYaml NuGet package disables reflection-based serialization by default.
You can override the default by setting the following MSBuild property in your app project:
In the included benchmarks, SharpYaml is typically ~2x to ~15x faster than YamlDotNet and uses ~2x to ~9x less memory allocations, depending on the scenario (POCO vs generic vs source-generated).
