LanguageExt.Net.Http 0.1.0-alpha-2

LanguageExt HTTP

A functional wrapper around HttpClient intended to integrate into LangagueExt V5 based workflows.

Provides the expected methods (get, post, delete, etc.) returning Http<HttpResponseMessage>, an "Http Monad"

Rationale

If you're already convinced of the general preferability of the functional approach, you probably don't need this Rationale section.

If you're not convinced but curious, check out the code cleanup project, noting the differences between the functional and imperative approaches, not just in total lines of code, but also the greater simplicity[^1] of nearly every part of the functional approach.

I may create a more dedicated "literate coding" style writeup of the above in the future (as of 10/23/2025), but for now hopefully the code can speak for iself.

[^1] Simplicity in the Rich Hickey sense of the word, it may not be easy at first if you're not familiar with the concepts!

Usage

// add to GlobalUsings as appropriate
using LanguageExt.Net;
using static LanguageExt.Net.Http;

The Http monad implements and thus gives us

• Monad, for basic sequencing and composition, Bind (with LINQ syntax) and Traverse being the bread and butter of most of what you'll do
• Fallible, for generalizable and modular error handling
• MonadUnliftIO for not only lifting arbitrary IO operations (such as debuggings), but also access to Retry, Fork, Repeat and related goodes
• Readable, to enable threading of an HttpClient throughout the application
  • If you need to thread CancellationToken as well, you can utilize IO's built-in EnvIO

You can refer to the examples to see most of the above in action.

However, since a concrete Http type is an obstacle to composition in large applications, nearly every method in this library has both an Http-based and generalized version, for exmaple

• "The basics" (get, post, delete, etc.), can be generalized to any MonadIO that implements Readable for an Env that implements this library's HasHttpClient interface
• parseUri can be generalized to any Fallible Applicative
• Response parsing methods such as readContentAsStream can be generalized to any MonadIO

Testing

Mocking HttpClients is a thorn in many peoples sides, so this library provides a Http.client method that, given a Func<HttpResponseMessage, HttpResponseMessage> ( or other overload ) handles all of the nasty business of dealing with an HttpMessageHandler for you.

client combined with the natural structure of the "reader monad pattern" this follows should enable much smoother mocking of http functionality in general.

Copyright 2025 Michael Marsh