Show HN: Nino – Fastest C# serializer, safe on untrusted input, also TS/Go/Rust

The fastest binary serializer for C#. Source-generated, zero-allocation, thread-safe and safe on untrusted input. For .NET, Unity, Godot and HybridCLR, with the same bytes on every platform and runtime, Go, Rust and TypeScript included. 🌐 Website · 🚀 Getting Started · What's new in v4 · Benchmarks · 中文 Why Nino Fastest. Up to 7.2× faster serialization than MemoryPack, and up to 9.5× faster deserialization into existing objects. Benchmarks Safe on untrusted input. Crafted bytes cannot crash the process, read past the input, allocate out of proportion or name a type to create; every invalid input throws one NinoDataException. Untrusted data Zero allocation. Serialize into an IBufferWriter, deserialize into existing or pooled objects: nothing allocated per call, thread-safe, with no locks on the hot path. Zero allocation Everything at compile time. No reflection, no IL emit, no registration, no init call: works on IL2CPP, Native AOT and HybridCLR hot updates, and compiles up to 221× faster than v3. Platforms The same bytes everywhere. Identical bytes on every runtime and CPU, and from Go, Rust and TypeScript through the code nino-gen writes for your types. Other languages Rich types that evolve. Polymorphism without tags, keyed and version-tolerant types, reference tracking, every BCL collection. Supported types Mistakes caught as you type. 33 analyzer diagnostics, many with a one-click fix. Analyzers dotnet add package Nino --prerelease # .NET and Godot: the runtime and the generator openupm add com.jasonxudeveloper.nino # Unity 2022.3+ Nino v4 is a prerelease, so --prerelease is required: without it NuGet installs 3.9.x, which cannot read or write v4 data. Optional packages: Nino.Immutable (System.Collections.Immutable), Nino.AspNetCore (MVC formatters, Minimal API bodies and results), Nino.Codegen (your types as TypeScript, Go or Rust after each build; Nino.Codegen.Tool is the same as the nino-gen command). Installation for .NET, Unity and Godot. Quick start using Nino.Core; [NinoType] public sealed class Order { public long Id; public string Customer; public List Lines; } byte[] bytes = NinoSerializer.Serialize(order); Order copy = NinoDeserializer.Deserialize(bytes); NinoDeserializer.Deserialize(bytes, ref copy); // fills the same instance in place Polymorphism needs no tags: a value declared as its base is read back as its runtime type. [NinoType] public abstract class Message { public int Seq; } [NinoType] public sealed class Chat : Message { public string Text; } byte[] bytes = NinoSerializer.Serialize(new Chat { Text = "hi" }); Message msg = NinoDeserializer.Deserialize(bytes); // a Chat again Next: your first types, evolving data, reference tracking, pooling and the advanced guides. AI coding assistants Nino ships a skill for Claude Code, Codex, Cursor, Copilot and other agents: npx skills add JasonXuDeveloper/Nino The nino-serialization skill teaches your assistant to declare [NinoType]s, pick the format for data that outlives a release, use the fast and zero-allocation forms, and fix every NINO diagnostic. The docs are written for models too: llms.txt, llms-full.txt, and every page as Markdown (add .md to its URL). Benchmarks BenchmarkDotNet 0.15.8, .NET 10.0.14, server GC, Intel Xeon 6973P-C 3.54 GHz; Nino v4 and MemoryPack 1.21.4 in one run, Nino 3.3.13 from NuGet directly before it on the same machine. Payloads are about the same size (SimpleClass: 1,069 bytes in v4, 1,152 in v3, 1,148 in MemoryPack). Every case and the method: docs/v4-benchmarks.md; the notes of each release carry that release's numbers. Every case, Arm64, MessagePack and protobuf-net: .NET benchmarks; Unity with Burst; Go, Rust and TypeScript. Arrays of tuples and structs and string conversion use AVX-512, AVX2, SSSE3, Arm64 and WebAssembly SIMD (Burst kernels in Unity), with portable code writing the same bytes elsewhere: SIMD. Built for Compared with MemoryPack MemoryPack's README now calls it "a high-performance serialization format for trusted data only" (MemoryPack README); Nino is built for data from network peers and user files (details). While benchmarking we found three types MemoryPack 1.21.4 does not round-trip (BigInteger, BitArray on .NET 10, tuples between runtimes); Nino writes them by value. The full comparison covers them, what MemoryPack has that Nino does not, and how to switch. Also compared: MessagePack and protobuf-net. v4 vs v3 v4 is a rewrite of the runtime and the generator. Its binary format is not compatible with v3. Everything new: what's new in v4, the changelog and the migration guide; internals are in docs/v4-design.md. Contributing Issues and pull requests are welcome. CONTRIBUTING.md covers building, the test matrix and releasing. MIT License · Made by JasonXuDeveloper