ASP.NET Core diagnostics

ApiLens

Why an ASP.NET Core request was slow or failed

NuvyntraLabs.NET.ApiLens · 0.1.0

Developer-first runtime diagnostics for ASP.NET Core. ApiLens reads System.Diagnostics and explains one request: endpoint time, EF Core commands, and outbound HttpClient calls. It does not replace OpenTelemetry, ASP.NET Core metrics, or a production observability backend.

GitHub Documentation nuget.org

Install

dotnet add package NuvyntraLabs.NET.ApiLens.AspNetCore
dotnet add package NuvyntraLabs.NET.ApiLens.EntityFrameworkCore
dotnet add package NuvyntraLabs.NET.ApiLens.Http

Version 0.1.0 targets net10.0 and is on nuget.org. Publishing is pipeline-only. Do not dotnet nuget push from a local clone. Downloads for the five packages are on the .NET libraries NuGet stats.

Register

builder.Services.AddApiLens();
builder.Services.AddApiLensEntityFrameworkCore();
builder.Services.AddApiLensHttp();
app.UseApiLens();

Call UseApiLens() before endpoints so the middleware wraps the request. Step-by-step: Getting started.

What a request shows

ApiLens stores a timeline for each MVC or minimal API request, attributes overlapping work as a share of wall-clock time, and flags a repeated SQL shape as a possible N+1. The dashboard is served only in Development. SQL parameter values, request bodies, response bodies, and HTTP query strings are never stored.

The time model and the N+1 rule are on the request timeline.

Capture

Surface	Development	Production
Dashboard	On, unless EnableDashboard is false	Off
SQL text	Stored after literal redaction	Dropped after grouping
Parameter values	Never read	Never read
Request and response bodies	Never stored	Never stored
HTTP query strings	Not stored (host and status only)	Not stored
Exception text	Type name only	Type name only

Packages

NuvyntraLabs.NET.ApiLens
Timeline, attribution, N+1, explain rules, and the in-memory ring. No ASP.NET reference.
NuvyntraLabs.NET.ApiLens.AspNetCore
AddApiLens and UseApiLens for MVC and minimal APIs, plus the dashboard gate.
NuvyntraLabs.NET.ApiLens.EntityFrameworkCore
EF Core CommandExecuted and CommandError on the active request.
NuvyntraLabs.NET.ApiLens.Http
Outbound HttpClient timings. Factory clients use a handler. Other clients use the System.Net.Http diagnostic listener.
NuvyntraLabs.NET.ApiLens.UI
Embedded dashboard page. Referenced by the ASP.NET Core package.

Package boundaries: Packages.

Sample

dotnet run --project samples/ApiLens.Sample

GET /api/orders runs a deliberate per-row query loop. The dashboard is at /_apilens.

Discussion

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