Welcome to GenDI Discussions!

[schivei]

🎉 Introducing GenDI — compile-time dependency injection for .NET

Hey everyone! 👋

I'm excited to share GenDI, an open-source C# source generator that makes dependency
injection in .NET cleaner, faster, and AOT-ready — without sacrificing any of the power you
expect from Microsoft DI.

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The problem it solves

Every time you add a dependency to a service, you're forced to:

1. Add a constructor parameter
2. Declare a private backing field
3. Write an assignment in the constructor body

For two or three dependencies that's fine. For real-world services with five, six, or more
dependencies it becomes noise — pure maintenance overhead that distracts from actual business
logic.

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The GenDI way

// Instead of this...
public class OrderProcessor
{
    private readonly IOrderRepository _repo;
    private readonly IPaymentGateway _payment;
    private readonly IEmailService _email;
    private readonly ILogger<OrderProcessor> _logger;

    public OrderProcessor(
        IOrderRepository repo, IPaymentGateway payment,
        IEmailService email, ILogger<OrderProcessor> logger)
    {
        _repo = repo; _payment = payment;
        _email = email; _logger = logger;
    }
}

// ...write this
[Injectable<IOrderProcessor>(ServiceLifetime.Scoped)]
public class OrderProcessor : IOrderProcessor
{
    [Inject] public required IOrderRepository Repo { get; init; }
    [Inject] public required IPaymentGateway Payment { get; init; }
    [Inject] public required IEmailService Email { get; init; }
    [Inject] public required ILogger<OrderProcessor> Logger { get; init; }
}

One [Inject] property per dependency. No fields, no constructor, no assignments. GenDI
generates all the wiring code at compile time.

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Key highlights

• 🔖 Attribute-first: mark services with [Injectable], contracts with [ServiceInjection]
• ⚡ ~19× faster startup than reflection-based assembly scanning
• 🏗️ NativeAOT and trimming compatible out of the box
• 🔑 Keyed services via [Inject(Key = "...")] or [FromKeyedServices]
• 🧪 Compile-time safety: the required keyword ensures every dependency is wired
• 📦 Zero lock-in: Microsoft DI is still the runtime container — GenDI is purely additive

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Benchmarks

Strategy	Mean startup	Allocated
Manual (no GenDI)	1.842 μs	5.21 KB
GenDI constructor injection	2.007 μs	5.68 KB
GenDI property injection	2.031 μs	5.71 KB
Reflection scanner	37.901 μs	14.54 KB

Property injection and constructor injection are within noise — so you can pick the clean
ergonomic style without any performance penalty.

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Get started

dotnet add package GenDI

• 📖 Docs: https://elton.schivei.nom.br/GenDI
• 💻 GitHub: https://github.com/schivei/GenDI
• 📦 NuGet: https://www.nuget.org/packages/GenDI

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Roadmap

We have a big list of ideas coming — analyzers, [InjectOptional], decorator pattern
auto-wiring, GenDI.Testing, Blazor WASM validation, dotnet new templates and more.
Check the full roadmap.

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I'd love your feedback! Have you dealt with constructor bloat in your .NET projects? What
features would make GenDI more useful for you? Drop a comment below 👇

And if you'd like to contribute or sponsor the project:

• 🤝 Contributing guide
• ❤️ Sponsor on GitHub