FastIDs.TypeId 1.0.0

dotnet add package FastIDs.TypeId --version 1.0.0                
NuGet\Install-Package FastIDs.TypeId -Version 1.0.0                
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="FastIDs.TypeId" Version="1.0.0" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add FastIDs.TypeId --version 1.0.0                
#r "nuget: FastIDs.TypeId, 1.0.0"                
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install FastIDs.TypeId as a Cake Addin
#addin nuget:?package=FastIDs.TypeId&version=1.0.0

// Install FastIDs.TypeId as a Cake Tool
#tool nuget:?package=FastIDs.TypeId&version=1.0.0                


NuGet Version

High-performance C# implementation of TypeId.

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

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

Why another library?

This implementation is comparable or faster (sometimes 3x faster) in all common scenarios than other .NET implementations. It also allocates up to 5x less memory, reducing GC pressure.

See the Benchmarks wiki for more details.

Why should you care?

You may think that generating, parsing, or serializing a single TypeId is very fast regardless of the implementation. To some degree, that's true. But small inefficiencies accumulate quickly, and they are very hard to spot in a large system. Most likely, there are millions of IDs parsed and serialized across your whole application daily. There is no single place with "slow" performance to spot in the profiler, so it's very hard to notice these inefficiencies.

GC is another important factor. If every small library generates tons of short-lived objects for no reason, the GC will trigger much more frequently, impacting your whole application. The tricky part? There is nothing you can do about it because the memory is allocated inside 3rd party code.

There is no reason to use inefficient building blocks in your application. With this library, you get the same high-level, easy-to-use API. You don't have to deal with "weird" performance-oriented approaches. However, I plan to expose additional performance-oriented APIs in the near future for those who need them.


Install from NuGet:


The library exposes two types optimized for slightly different use-cases. For better understanding refer to TypeId vs TypeIdDecoded section in wiki.

This readme covers the basic operation you need to know to use the library.


using FastIDs.TypeId;

Creating a TypeId

TypeId can be generated using static methods of TypeId and TypeIdDecoded classes. Both have the same API and will create an instance of TypeIdDecoded struct. Examples in this section only use TypeId for simplicity.

Generate new ID:

var typeIdDecoded = TypeId.New("prefix");

It's also possible to create a TypeID without a prefix by passing the empty string:

var typeIdDecodedWithoutPrefix = TypeId.New("");

Note: If the prefix is empty, the separator _ is omitted in the string representation.

Create TypeId from existing UUIDv7:

Guid uuidV7 = new Guid("01890a5d-ac96-774b-bcce-b302099a8057");
var typeIdDecoded = TypeId.FromUuidV7("prefix", uuidV7);

Both TypeId.New(prefix) and TypeId.FromUuidV7(prefix, guid) validate provided prefix. You can skip this validation by using overloads with bool validateType parameter set to false. The best case to do so is when you're 100% sure your prefix is correct and you want to squeeze extra bits of performance.

var typeIdDecoded = TypeId.New("prefix", false) // skips validation and creates a valid TypeId instance.

var invalidTypeIdDecoded = TypeId.New("123", false) // doesn't throw FormatException despite invalid type provided
var shouldThrowIdDecoded = TypeId.New("123") // throws FormatException

Conversion between TypeId and TypeIdDecoded

Convert TypeIdDecoded to TypeId:

TypeId typeId = typeIdDecoded.Encode();

Convert TypeId to TypeIdDecoded:

TypeIdDecoded typeIdDecoded = typeId.Decode();

TypeId serialization to string

All the following examples assume that there is a typeId variable created this way:

TypeId typeId = TypeId.FromUuidV7("type", new Guid("01890a5d-ac96-774b-bcce-b302099a8057")).Encode();

Get string representation

string typeIdString = typeId.ToString();
// returns "type_01h455vb4pex5vsknk084sn02q" (without quotes)

It's possible to get only type:

ReadOnlySpan<char> typeSpan = typeId.Type;
string type = typeSpan.ToString();
// both are "type" (without quotes)

It's also possible to get only the suffix:

ReadOnlySpan<char> suffixSpan = typeId.Suffix;
string suffix = suffixSpan.ToString();
// both are "01h455vb4pex5vsknk084sn02q" (without quotes)

Note: if TypeID doesn't have a type (i.e. type is an empty string), values returned from Suffix and ToString() are equal.

var typeId = TypeId.FromUuidV7("", new Guid("01890a5d-ac96-774b-bcce-b302099a8057")).Encode();
Console.WriteLine($"{typeId.Suffix.ToString()} == {typeId.ToString()}");
// prints: "01h455vb4pex5vsknk084sn02q == 01h455vb4pex5vsknk084sn02q" (without quotes)

TypeIdDecoded serialization to string

All the following examples assume that there is a typeIdDecoded variable created this way:

TypeIdDecoded typeIdDecoded = TypeId.FromUuidV7("type", new Guid("01890a5d-ac96-774b-bcce-b302099a8057"));

Get string representation

string typeIdString = typeIdDecoded.ToString();
// returns "type_01h455vb4pex5vsknk084sn02q" (without quotes)

It's possible to get only type:

string type = typeIdDecoded.Type;
// returns "type" (without quotes)

It's also possible to get only the suffix:

string suffix = typeIdDecoded.GetSuffix();
// returns "01h455vb4pex5vsknk084sn02q" (without quotes)

Span<char> suffixSpan = stackalloc char[26];
int charsWritten = typeIdDecoded.GetSuffix(suffixSpan);
// `charsWritten` is 26, and `suffixSpan` contains "01h455vb4pex5vsknk084sn02q" (without quotes)

Note: if TypeID doesn't have a type (i.e. type is an empty string), values returned from GetSuffix() and ToString() are equal.

var typeIdDecoded = TypeId.FromUuidV7("", new Guid("01890a5d-ac96-774b-bcce-b302099a8057"));
Console.WriteLine($"{typeIdDecoded.GetSuffix()} == {typeIdDecoded.ToString()}");
// prints: "01h455vb4pex5vsknk084sn02q == 01h455vb4pex5vsknk084sn02q" (without quotes)


String representation can only be parsed into TypeId.

Parse existing string representation to the TypeId instance:

TypeId typeId = TypeId.Parse("type_01h455vb4pex5vsknk084sn02q");

The Parse(string input) method will throw a FormatException in case of incorrect format of the passed value. Use the TryParse(string input, out TypeId result) method to avoid throwing the exception:

if (TypeId.TryParse("type_01h455vb4pex5vsknk084sn02q", out TypeId typeId))
    // TypeId is successfully parsed here.
    // Unable to parse TypeId from the provided string.

Match type

Both TypeId and TypeIdDecoded have the same API for checking if the type equals the provided value.

bool isSameType = typeId.HasType("your_type"); // also has overload for ReadOnlySpan<char>


Both TypeId and TypeIdDecoded structs implement the IEquatable<T> interface with all its benefits:

  • typeId.Equals(other) or typeId == other to check if IDs are same.
  • !typeId.Equals(other) or typeId != other to check if IDs are different.
  • Use TypeId as a key in Dictionary or HashSet.

UUIDv7 component operations

TypeIdDecoded provides the API for accessing the UUIDv7 component of the TypeID.

Get Guid:

Guid uuidv7 = typeIdDecoded.Id;

Get the creation timestamp (part of the UUIDv7 component):

DateTimeOffset timestamp = typeIdDecoded.GetTimestamp();

Json Serialization

NuGet packages are available for working with JSON.

You can use the extension method ConfigureForTypeId on the JsonSerializerSettings type for Json.Net or on the JsonSerializerOptions type for System.Text.Json to automatically serialize a TypeId or a TypeIdDecoded to a string.

If you are using SwashBuckle, you will need to configure your service as follows:

builder.Services.AddSwaggerGen(c =>
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "api", Version = "v1" });

    c.MapType(typeof(TypeId), () => new OpenApiSchema { Type = "string", Example = new OpenApiString("prefix_01h93ech7jf5ktdwg6ye383x34") });
    c.MapType(typeof(TypeIdDecoded), () => new OpenApiSchema { Type = "string", Example = new OpenApiString("prefix_01h93ech7jf5ktdwg6ye383x34") });
Product Compatible and additional computed target framework versions.
.NET net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (2)

Showing the top 2 NuGet packages that depend on FastIDs.TypeId:

Package Downloads

System.Text.Json serialization helpers for FastIDs.TypeId


Json.NET serialization helpers for FastIDs.TypeId

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated
1.0.0 3,535 4/15/2024
0.2.3 4,230 8/15/2023
0.2.2 219 7/22/2023
0.2.1 158 7/11/2023