---
title: Logging API
slug: commerce-connect-15/docs/logging-api
docTags: 
createdAt: 2026-07-30T20:34:40.000Z
---

Optimizely includes a logging API that abstracts writing log messages from the system. Logging is useful when you troubleshoot and locate application problems.

Optimizely Commerce Connect uses `EPiServer.Logging`, which works as a façade for the logging framework in .NET Core (`Microsoft.Extensions.Logging`). To manage the configuration and output of the logger, refer to the API of the implementing framework. See [Logging in .NET Core](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/logging/?view=aspnetcore-5.0).

Use the logging API defined in .NET Core for custom logging in Optimizely.