DEPRECATED AND REPLACED BY https://github.com/Brandon689/eBay.API
C# api for eBay with some sqlite database store. It is a few years old and I will make a better version.
But it is usable for common features or to inspect how XML SOAP API can be implemented.
The official C# SDK for ebay is 15 years old and closed source, that was the original motivation to make this.
The exact XML requests to the api are poorly documented so you can test the http request body yourself and see what it needs. For example uploading pictures to EPS