The API is pretty old and is written in C#, I tried debugging the API calls with mitmproxy.

This is the successful API call (manually uploading file)successful API call

but when I tried curling it, it gave me this error which is apparently a common error from the C# language (that's how I'm able to know that the API is written in C#) "Sequence contains no element" im not sure but i think it's got something to do with SQL


I also tried insomnia and postman but it came to the same ending

same ending

so what is it that I can do to reverse engineer this file uploading API? It'd be perfect if you could briefly explain it so that I may understand and do better for the next API reverse engineering that I might do THANK YOU!!!!

sources: https://products.aspose.app/video/compress

please ask for more sources, I don't know what screenshot is necessary for me to put here.

  • please do point out if there are any mistakes that I did so that I may correct them for my future questions. Commented Feb 19, 2023 at 8:33
  • This is .NET LINQ, yes, which can be used for SQL but almost certainly isn't here. You're giving the API an empty list when it's not expecting one, or e.g. it's generating an empty list from the data you've POSTed because you've left something out. Could that be the actual file upload? I don't know the tool, but it looks like you're actually posting a file upload in the first one but sending no data for the other two.
    – Rup
    Commented Feb 20, 2023 at 1:49
  • I found out I did actually miss something out, apparently I didn't pay enough attention to the successful call (manual), I've fixed it, but I don't know how to close this post. Commented Feb 20, 2023 at 14:39


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