CoreSystem.Correlation 1.1.0

⚡ CoreSystem.Correlation

Correlation ID propagation middleware for ASP.NET Core.

CoreSystem.Correlation is a lightweight, standalone library that accepts or issues a correlation identifier per request, exposes it via HttpContext.Items, and enriches log scopes with it. It can also be composed with CoreSystem.Observability.

✨ Features

• ✅ Accepts a client-provided correlation header (configurable name)
• ✅ Generates a reliable Guid-based ID otherwise
• ✅ Exposes the ID via HttpContext.Items[CoreCorrelationConstants.HttpContextItemKey]
• ✅ Echoes the ID back in the response headers
• ✅ Enriches log scopes with a correlationId property
• ✅ Input validation (length + character allowlist)
• ✅ IOptions/IConfiguration binding
• ✅ Standalone — no dependency on CoreSystem.Observability

📦 Installation

dotnet add package CoreSystem.Correlation

🚀 Quick Start

Register the services:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddCoreCorrelation(); // or builder.Services.AddCoreCorrelation(o => o.MaximumLength = 64);

var app = builder.Build();

Add the middleware:

app.UseCoreCorrelationId(); // after UseRouting/UseCors, before endpoints

Read the current ID anywhere in the pipeline:

app.MapGet("/ping", (HttpContext ctx) =>
    Results.Ok(ctx.Items[CoreCorrelationConstants.HttpContextItemKey]));

⚙ Configuration

Bind from the Core:Correlation configuration section:

builder.Services.AddCoreCorrelation(builder.Configuration);

🏗 Architecture

Client Request
     │
     ▼
CorrelationIdMiddleware
     │
     ├── validates / generates id
     ├── context.Items["CoreSystem.CorrelationId"]
     ├── logger scope (correlationId)
     ▼
Request pipeline

Each request gets one ID for its whole pipeline. The value flows through HttpContext.Items and log scopes so application code can attach it to logs and downstream calls without HTTP-specific knowledge.

📖 Documentation

The full documentation includes:

• Getting Started
• Configuration
• Log enrichment
• Composing with CoreSystem.Observability
• Architecture

Visit the GitHub repository for the complete documentation.

🤝 Contributing

Issues, discussions and pull requests are welcome.

📄 License

Released under the MIT License.