Nedo.AspNet.Exception.AspNetCore 1.0.0

Nedo.AspNet.Exception.AspNetCore

ASP.NET Core integration: IExceptionHandler that emits the platform-standard Nedo.AspNet.ApiContracts.Responses.BaseResponse<T> envelope (RFC 9457 problem+json) for any thrown Nedo or stock .NET exception, plus DI extensions and optional middleware fallback.

dotnet add package Nedo.AspNet.Exception.AspNetCore

Relationship to Nedo.AspNet.ApiContracts

This package depends on Nedo.AspNet.ApiContracts (≥ 2.0.0) and emits the same envelope as every other endpoint on the platform. It subsumes AddGlobalExceptionHandler() — do NOT call both.

- builder.Services.AddGlobalExceptionHandler();
+ builder.Services.AddNedoExceptions();

Same wire shape; the 11-prefix ErrorCodes taxonomy replaces the small ad-hoc set (ERR-NF-001, ERR-AUTH-001, …).

Quickstart

using Nedo.AspNet.Exception.AspNetCore;

builder.Services.AddNedoExceptions(opts =>
{
    opts.IncludeExceptionDetails = builder.Environment.IsDevelopment();
    // Format defaults to ResponseFormat.ApiContracts; switch to NedoLegacyEnvelope for brownfield frontends.
    // MaskServerErrors defaults to true (5xx leak suppression); MapStockExceptions defaults to true.
});

// Customize the RFC 9457 `type` URI base globally (Nedo.AspNet.ApiContracts setting):
Nedo.AspNet.ApiContracts.Responses.ProblemTypes.BaseUri = "https://errors.example.com/";

var app = builder.Build();
app.UseNedoExceptions();

Response shape

A thrown NotFoundException("User 42 not found") becomes:

{
  "success": false,
  "type":    "urn:nedo:problems:ERR-RES-NF",
  "title":   "Not Found",
  "status":  404,
  "detail":  "User 42 not found",
  "instance": "/users/42",
  "code":    "ERR-RES-NF",
  "info": {
    "transaction_id": "00-…",
    "timestamp":      "2026-05-02 12:34:56 UTC",
    "operation_type": "Exception",
    "trace_id":       "…",
    "span_id":        "…"
  }
}

The exception's Metadata dictionary surfaces in errors[0].data (4xx only). IValidationException failures populate errors[0].error_details.form_errors / field_errors. ServiceUnavailableException carries retry_after_seconds / estimated_end_at in errors[0].data plus the Retry-After HTTP header.

5xx responses are masked by default — real code, detail, metadata, and custom IResponseInfoContributor output are stripped from the wire and replaced with ERR-SRV + a generic message; full detail goes to the server log keyed by transaction_id. See docs/06-aspnetcore-integration.md for the full security model.