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Just a simple question as I'm studying the various class libraries available in .NET. I noticed that there's a System.Net.Http namespace and a System.Web.Http namespace.

  • What purpose(s) do both namespaces serve?
  • What were the motivations for creating two seemingly ambiguous namespaces?
  • Is there any history I should know about or is one of the namespaces "deprecated"?

System.Net.Http, System.Web.Http

user2864740
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Alexander Trauzzi
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5 Answers5

34

System.Net.Http is for client-side HTTP programming. System.Web.Http is for server-side HTTP programming.

Max Toro
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    Is that naming convention supposed to be intuitive? – DLeh May 14 '14 at 20:33
  • @DLeh Only if you've done work with other System.Net or System.Web namespaces, e.g. System.Net.Mail or System.Web.Mvc. – Max Toro May 14 '14 at 20:39
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    I wondered about this question when I discovered that my server code uses both namespaces. Specifically I'm using System.Net.Http.HttpResponseMessage in my server. So... I shouldn't be using that class in my server? – steve Apr 22 '16 at 15:29
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    If this answer were true or accurate, then HttpResponseMessage would be define in System.Web.Http as opposed to System.Net.Http. The fact is; none of these explanations clearly describe or illuminate reasonable explanations of the differences nor the purposes of both existing nor is there a reasonable explanation of a clear separation of functionality to facility. – Jim Sep 01 '19 at 04:11
19

System.Net.Http relates to network programming while System.Web.Http relates specifically to programming for the web.

jmcilhinney
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  • Is any aspect of System.Web IIS/ASP.NET specific? – Alexander Trauzzi Feb 10 '14 at 01:25
  • System.Web.Http and System.Net.Http are specifically implementations of the ASP.NET Web API. http://www.asp.net/web-api – jmcilhinney Feb 10 '14 at 01:34
  • Does that preclude them from being used in non-IIS non-ASP.NET Owin apps? – Alexander Trauzzi Feb 10 '14 at 01:48
  • You can use whatever types are useful in any situation that they are useful in. Certainly types that are members of System.Web and System.Net are not limited ASP.NET apps. System.Web.Http and System.Net.Http are specifically dedicated to Web API though. I've never used them so I'm not 100% sure but that suggests to me that they would only be useful in a Web API scenario. That may include clients too though, which would often not be ASP.NET apps hosted in IIS. – jmcilhinney Feb 10 '14 at 03:35
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    Hmm. Isn't HTTP specific to the web? Or am I demonstrating my ignorance? I can't say your answer is wrong, but I'm not convinced you're right. I also wonder about the answer from Max Toro. Is that right? In addition to this? Instead of this? Or neither? – steve Apr 22 '16 at 15:25
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    I don't see how this answer provides any clarity at all – cambunctious May 07 '18 at 23:58
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    "The net" and "the web" are both used to refer to the Internet. This redundancy/interchangeability is presumably why the question was asked in the first place – Kyle Delaney Nov 13 '18 at 00:25
  • @KyleDelaney, using "the web" to refer to the internet is incorrect because there is more to the internet than just the world wide web. Also, I didn't say "the net". I said "network programming", which applies to any network and not just the internet. I guess my answer overestimates the computer literacy of many who want to be programmers these days. Given how many people seem incapable of even using a search engine, I guess that I should keep my expectations low. At least the OP did accept this answer so it apparently helped them. – jmcilhinney Nov 13 '18 at 00:26
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    All of the more recent answers below are excellent and you should read them ALSO. As always, there is a little more to it. :) – Jeremy Farrance May 15 '21 at 16:26
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"System.Web.Http" is used for creating WebAPIs.

"System.Net.Http" is used for consuming WebAPIs (using HttpClient class)

Tasos K.
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Reyan Chougle
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10

From my experience, the separation between the two namespaces becomes clear when you look at the difference between self hosted webapi services vs IIS-hosted. Self hosted only requires System.Http, whilst IIS hosted needs both. See Difference between "MapHttpRoute" and "MapRoute"? for a similar discussion and useful links.

So, the reason there are two is so that you can create a self-hosted web service that doesn't depend on the entire ASP.NET stack.

Neither of them are deprecated.

I haven't seen an official Microsoft explanation for this, but that's the best I've been able to find.

Community
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Dan Ling
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9

System.Web heavily depends on IIS web server, which can only be hosted on a Windows machine. As Microsoft is heading to open source and is starting to support multiple platforms like Linux and Mac, they need to extract their functionality which will be independent of IIS server. As a result, System.Net is independent of IIS features and is deployable to different platforms.

catfood
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Nauty
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    Assuming this is correct, this is the most clear and concise answer. I immediately know I want to run on non-IIS servers, so I should avoid System.Web. – Francisco d'Anconia May 31 '22 at 16:40