Philiprehberger.ApiErrorStandardizer 0.1.8

dotnet add package Philiprehberger.ApiErrorStandardizer --version 0.1.8
                    
NuGet\Install-Package Philiprehberger.ApiErrorStandardizer -Version 0.1.8
                    
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="Philiprehberger.ApiErrorStandardizer" Version="0.1.8" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="Philiprehberger.ApiErrorStandardizer" Version="0.1.8" />
                    
Directory.Packages.props
<PackageReference Include="Philiprehberger.ApiErrorStandardizer" />
                    
Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.
paket add Philiprehberger.ApiErrorStandardizer --version 0.1.8
                    
#r "nuget: Philiprehberger.ApiErrorStandardizer, 0.1.8"
                    
#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.
#:package Philiprehberger.ApiErrorStandardizer@0.1.8
                    
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.
#addin nuget:?package=Philiprehberger.ApiErrorStandardizer&version=0.1.8
                    
Install as a Cake Addin
#tool nuget:?package=Philiprehberger.ApiErrorStandardizer&version=0.1.8
                    
Install as a Cake Tool

Philiprehberger.ApiErrorStandardizer

CI NuGet Last updated

Middleware for consistent, structured JSON API error responses.

Installation

dotnet add package Philiprehberger.ApiErrorStandardizer

Usage

Register the middleware early in your pipeline in Program.cs:

using Philiprehberger.ApiErrorStandardizer;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.UseErrorStandardizer();

app.MapGet("/example", () =>
{
    throw new KeyNotFoundException("User not found");
});

app.Run();

When an unhandled exception is thrown, the middleware returns a structured JSON response:

{
  "error": "NotFound",
  "message": "User not found",
  "statusCode": 404,
  "traceId": "0HN4CMFQ8G5RI:00000001"
}

Custom Exception Mapping

Map your own exception types to specific HTTP status codes:

app.UseErrorStandardizer(options =>
{
    options.ExceptionStatusMap[typeof(InsufficientFundsException)] = 402;
    options.ExceptionStatusMap[typeof(RateLimitException)] = 429;
    options.IncludeStackTrace = false;
    options.IncludeTraceId = true;
});

Built-in Exception Mappings

Exception Type Status Code
ArgumentException 400 Bad Request
ArgumentNullException 400 Bad Request
ArgumentOutOfRangeException 400 Bad Request
UnauthorizedAccessException 401 Unauthorized
KeyNotFoundException 404 Not Found
InvalidOperationException 409 Conflict
NotImplementedException 501 Not Implemented
All other exceptions 500 Internal Server Error

Custom mappings in ExceptionStatusMap take precedence over built-in defaults.

API

ApiError

Property Type Description
Error string The error type or category
Message string Human-readable error description
StatusCode int HTTP status code
TraceId string? Request trace identifier (if enabled)
ValidationErrors IDictionary<string, string[]>? Field-level validation errors

ErrorStandardizerOptions

Property Type Default Description
IncludeStackTrace bool false Include stack trace in responses
IncludeTraceId bool true Include trace ID from request context
ExceptionStatusMap Dictionary<Type, int> empty Custom exception-to-status-code mappings

ApplicationBuilderExtensions

Method Description
UseErrorStandardizer(Action<ErrorStandardizerOptions>?) Adds the error standardizer middleware to the pipeline

Development

dotnet build src/Philiprehberger.ApiErrorStandardizer.csproj --configuration Release

Support

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License

MIT

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.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • net8.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
0.1.8 112 4/1/2026
0.1.7 107 3/25/2026
0.1.6 107 3/23/2026
0.1.5 109 3/23/2026
0.1.4 120 3/16/2026
0.1.3 112 3/16/2026
0.1.2 115 3/16/2026
0.1.1 112 3/13/2026
0.1.0 110 3/13/2026