Integrate FaultLens from .NET today. Angular SDK is in development.

Current SDK status

Prerequisites

Before integrating, make sure you have:

• An active FaultLens workspace with at least one project created.
• A project API key from Project Settings -> API Keys.
• Your ingest base URL, shown in the same project settings surface.

.NET SDK

The recommended .NET path is the public SDK package. Use it when you want the supported client surface for exception capture and delivery behavior.

dotnet add package FaultLens.Sdk

Initialize the client

var client = new FaultLensClient(
    new FaultLensOptions(
        apiKey: "YOUR_PROJECT_API_KEY",
        environment: "production",
        release: "1.0.0")
);

Capture exceptions

try
{
    throw new InvalidOperationException("Something broke");
}
catch (Exception ex)
{
    client.CaptureException(ex);
}

ASP.NET Core setup

If you are wiring FaultLens into an ASP.NET Core application, register the options and typed client early, then capture exceptions at the middleware or service layer where context is strongest.

appsettings.json

{
  "FaultLens": {
    "ApiKey": "fl_proj_your_key_here",
    "Environment": "production",
    "Release": "1.4.2",
    "BaseUrl": "https://api.faultlens.in"
  }
}

Program.cs

builder.Services.Configure<FaultLensOptions>(
    builder.Configuration.GetSection("FaultLens"));

builder.Services.AddHttpClient<FaultLensClient>((sp, client) =>
{
    var opts = sp.GetRequiredService<IOptions<FaultLensOptions>>().Value;
    client.BaseAddress = opts.BaseUrl;
    client.Timeout = TimeSpan.FromSeconds(5);
});

Direct ingest fallback

The direct ingest API is still useful when you need lower-level control, want to prototype a custom runtime, or are bridging Angular before the SDK is released.

Minimal custom client shape

using System.Net.Http.Json;

public sealed class FaultLensClient
{
    private readonly HttpClient _http;

    public FaultLensClient(HttpClient http)
    {
        _http = http;
    }

    public async Task CaptureExceptionAsync(Exception ex, CancellationToken ct = default)
    {
        var payload = new
        {
            eventId = Guid.NewGuid().ToString(),
            timestamp = DateTimeOffset.UtcNow,
            environment = "production",
            platform = "dotnet",
            sdk = new { name = "faultlens-dotnet", version = "1.0.0" },
            exception = new
            {
                type = ex.GetType().FullName ?? ex.GetType().Name,
                message = ex.Message
            }
        };

        using var request = new HttpRequestMessage(HttpMethod.Post, "api/events/ingest")
        {
            Content = JsonContent.Create(payload)
        };

        request.Headers.Add("X-API-Key", "fl_proj_your_key_here");
        await _http.SendAsync(request, ct);
    }
}

Breadcrumbs

Breadcrumbs capture the trail leading into an exception. They help FaultLens show what happened just before a failure rather than only showing the final exception record.

Breadcrumb example

var breadcrumbs = new[]
{
    new
    {
        timestamp = DateTimeOffset.UtcNow,
        type = "log",
        level = "info",
        category = "order",
        message = "Order validation passed"
    },
    new
    {
        timestamp = DateTimeOffset.UtcNow,
        type = "http",
        level = "info",
        category = "payment",
        message = "Payment gateway responded OK"
    }
};

Angular SDK status

The Angular SDK is currently in development. The intent is to support Angular-native exception capture, route-aware breadcrumbs, and a cleaner integration surface than manual event posting.

If you are planning an Angular integration and want to align with the in-progress SDK direction, contact support@faultlens.in.

Payload reference

Complete field reference for POST /api/events/ingest. Authentication is via X-API-Key: fl_proj_....

Minimal example payload

POST /api/events/ingest
X-API-Key: fl_proj_your_key_here
Content-Type: application/json

{
  "eventId": "a3f1c2d4-8b7e-4f3a-9c12-1d2e3f4a5b6c",
  "timestamp": "2026-04-01T10:42:00.000Z",
  "environment": "production",
  "platform": "dotnet",
  "release": "1.4.2",
  "sdk": { "name": "faultlens-dotnet", "version": "1.0.0" },
  "exception": {
    "type": "System.NullReferenceException",
    "message": "Object reference not set to an instance of an object."
  }
}