Serialization

This covers JSON, Protocol Buffers, and MessagePack for .NET, with a strong focus on AOT compatibility and moving away from Newtonsoft.Json. The comparison tables are genuinely helpful for deciding between formats: use System.Text.Json with source generators for APIs and web clients, Protobuf for gRPC and service-to-service communication where schema evolution matters, and MessagePack when you need compact binary without managing .proto files. The guidance on avoiding BinaryFormatter and reflection-based serializers is spot on. The examples show real patterns like combining multiple JsonSerializerContext instances and handling polymorphic types with JsonDerivedType. If you're still using Newtonsoft.Json or wondering which binary format fits your use case, this gives you concrete decision criteria and working code.

skills.sh installs: 530
GitHub stars: 90
last updated: Aug 21, 2026

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Install

$ npx -y skills add wshaddix/dotnet-skills --skill serialization --agent claude-code

Installs into .claude/skills of the current project.

Files

Serialization in .NET

When to Use This Skill

Use this skill when:

Choosing a serialization format for APIs, messaging, or persistence
Migrating from Newtonsoft.Json to System.Text.Json
Implementing AOT-compatible serialization
Designing wire formats for distributed systems
Optimizing serialization performance

Serialization Format Comparison

Format	Library	AOT-Safe	Human-Readable	Relative Size	Relative Speed	Best For
JSON	System.Text.Json (source gen)	Yes	Yes	Largest	Good	APIs, config, web clients
Protobuf	Google.Protobuf	Yes	No	Smallest	Fastest	Service-to-service, gRPC wire format
MessagePack	MessagePack-CSharp	Yes (with AOT resolver)	No	Small	Fast	High-throughput caching, real-time
JSON	Newtonsoft.Json	No (reflection)	Yes	Largest	Slower	Legacy only -- do not use for AOT