TypeSafeId

A modern, type-safe implementation of TypeID version 0.3 for .NET. TypeIds are globally unique, K-sortable identifiers that combine a human-readable prefix with a UUIDv7 encoded in Crockford Base32.

Here's an example of a TypeID of type user:

  user_01h455vb4pex5vsknk084sn02q
  └──┘ └────────────────────────┘
  type    uuid suffix (base32)

It's corresponding type-safe id type could be TypeId<User>.

Features

• ✨ Type-safe - Generic TypeId<TEntity> provides compile-time safety
• ⚡ Fast - See benchmarks for performance details
• 🔤 Human-readable - Prefixes make identifiers self-describing (e.g., user_01h455vb4pex5vsknk084sn02q)
• ⏱️ K-sortable - UUIDv7 based, preserves insertion order
• 🚀 AOT Compatible - Ready for Native AOT compilation
• 🔗 ASP.NET Core Integration - Route constraints and model binding
• 💾 Entity Framework Core Support - Value converters for database storage

Installation

# Core library
dotnet add package TypeSafeId

# ASP.NET Core extensions
dotnet add package TypeSafeId.AspNetCore

# Entity Framework Core extensions
dotnet add package TypeSafeId.EntityFrameworkCore

Quick Start

Strongly-Typed TypeIds

This is the preferred id type. Use it when you know the type of id in advance.

// Define your entity types
record User(TypeId<User> Id, string Name);

// By default, the prefix is derived from the type name (lowercase, "_" separated)
var user = new User(
    Id: TypeId.Create<User>(),
    Name: "John Doe"
);
Console.WriteLine(user.Id); // user_01h455vb4pex5vsknk084sn02q

// Customize the prefix with the TypeId attribute
[TypeId("prd")]
record Product(TypeId<Product> Id, string Name);

var product = new Product(
    Id: TypeId.Create<Product>(),
    Name: "Widget"
);
Console.WriteLine(product.Id); // prd_01h455vb4pex5vsknk084sn02q

Non-Typed Usage

Use non-typed TypeId if you do not know the type of id.

using TypeSafeId;

// Create a TypeId with a prefix
var userId = TypeId.Create("user");
Console.WriteLine(userId); // user_01h455vb4pex5vsknk084sn02q

// Parse from string
var parsed = TypeId.Parse("user_01h455vb4pex5vsknk084sn02q");

ASP.NET Core Integration

Add TypeId routing support in your application:

using TypeSafeId;

var builder = WebApplication.CreateBuilder(args);

// Register TypeId route constraints
builder.Services.AddTypeIdRouting();

var app = builder.Build();

// Use TypeId in route parameters
app.MapGet("/users/{userId:typeid}", (TypeId<User> userId) =>
{
    return Results.Ok(new { UserId = userId });
});

app.MapGet("/products/{productId:typeid}", (TypeId<Product> productId) =>
{
    return Results.Ok(new { ProductId = productId });
});

app.Run();

record User(TypeId<User> Id, string Name);

[TypeId("prd")]
record Product(TypeId<Product> Id, string Name);

Entity Framework Core Integration

Use TypeId value converters for database storage:

using Microsoft.EntityFrameworkCore;
using TypeSafeId;

public class AppDbContext : DbContext
{
    public DbSet<User> Users { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        // Store as string
        modelBuilder.Entity<User>()
            .Property(u => u.Id)
            .HasTypeIdToStringConversion();

        // Or store as bytes for better performance
        modelBuilder.Entity<User>()
            .Property(u => u.Id)
            .HasTypeIdToBytesConversion();
    }
}

record User
{
    public TypeId<User> Id { get; init; }
    public string Name { get; set; } = string.Empty;
}

JSON Serialization

TypeIds serialize naturally with System.Text.Json:

using System.Text.Json;
using TypeSafeId;

var user = new User(
    Id: TypeId.Create<User>(),
    Name: "Jane Doe"
);

var json = JsonSerializer.Serialize(user);
// {"Id":"user_01h455vb4pex5vsknk084sn02q","Name":"Jane Doe"}

var deserialized = JsonSerializer.Deserialize<User>(json);

Format Specification

TypeIds follow the official specification:

• Format: [prefix_]<base32-encoded-uuid>
• Prefix: Optional, lowercase letters (a-z) and underscores, max 63 characters
• Separator: Single underscore _ (when prefix is present)
• UUID: UUIDv7 encoded in Crockford Base32 (26 characters)
• Total Length: 26 characters (no prefix) or prefix length + 1 + 26

Examples

user_01h455vb4pex5vsknk084sn02q     # With prefix "user"
order_01h455vb4pex5vsknk084sn02r    # With prefix "order"
01h455vb4pex5vsknk084sn02s          # Without prefix

Related Projects

This implementation is inspired by and builds upon:

• firenero/TypeId - Another .NET TypeId implementation
• UUIDNext - High-performance UUID generation library for .NET, used for UUIDv7 generation

License

MIT License - See LICENSE file for details

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.