CSharpEssentials.LoggerHelper.Sink.Seq 5.2.6

CSharpEssentials.LoggerHelper.Sink.Seq

Seq centralized structured log server integration for CSharpEssentials.LoggerHelper.

Targets: net8.0 · net9.0 · net10.0 — Part of the CSharpEssentials.LoggerHelper ecosystem. Install only the sinks you need.

Install

dotnet add package CSharpEssentials.LoggerHelper
dotnet add package CSharpEssentials.LoggerHelper.Sink.Seq

Quick Setup — JSON

Add to appsettings.json:

{
  "LoggerHelper": {
    "ApplicationName": "MyApp",
    "Routes": [
      { "Sink": "Seq", "Levels": ["Information", "Warning", "Error", "Fatal"] }
    ],
    "Sinks": {
      "Seq": {
        "ServerUrl": "http://localhost:5341",
        "ApiKey": "your-api-key"
      }
    }
  }
}

// Program.cs
builder.Services.AddLoggerHelper(builder.Configuration);

var app = builder.Build();
app.UseLoggerHelper();   // ← required: activates sinks and registers middleware

ApiKey is optional for local development. A local Seq instance (single-user, no auth) works with ApiKey omitted entirely.

Quick Setup — Fluent API

builder.Services.AddLoggerHelper(b => b
    .WithApplicationName("MyApp")
    .AddRoute("Seq", LogEventLevel.Information, LogEventLevel.Warning, LogEventLevel.Error, LogEventLevel.Fatal)
    .ConfigureSeq(s => {
        s.ServerUrl = "http://localhost:5341";
        s.ApiKey    = "your-api-key";   // omit for local no-auth Seq
    })
);

var app = builder.Build();
app.UseLoggerHelper();   // ← required

What You'll See

Log events appear in the Seq web UI at http://localhost:5341 with full structured property support — filter, search, and alert on any property value:

2026-06-01 14:23:01 [INF] Order 42 placed by usr_99
  OrderId    = 42
  UserId     = "usr_99"
  TenantId   = "acme"
  ApplicationName = "MyApp"

All properties set via BeginScope or call-site parameters are indexed and searchable in Seq's SQL-like query language:

-- Seq filter examples
ApplicationName = 'MyApp' and @Level = 'Error'
TenantId = 'acme' and OrderId > 100

Configuration Options

Quick Local Setup with Docker

The fastest way to run Seq locally:

docker run -d --name seq \
  -e ACCEPT_EULA=Y \
  -p 5341:80 \
  datalust/seq

Open the Seq UI at http://localhost:5341. No API key needed for local single-user mode.

For Seq Cloud or a production server, generate an API key in Settings → API Keys and set it in ApiKey.

Troubleshooting

Links

• Seq — Structured log server
• Seq Documentation
• Documentation
• CSharpEssentials.LoggerHelper (core)
• GitHub Repository
• MIT License