aeson VS req

Compare aeson vs req and see what are their differences.


A fast Haskell JSON library (by haskell)


Req is a batteries-included HTTP client for Elixir. (by wojtekmach)
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aeson req
9 3
1,226 838
0.2% -
7.0 9.4
18 days ago about 19 hours ago
Haskell Elixir
BSD 3-clause "New" or "Revised" License -
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of aeson. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-10-24.


Posts with mentions or reviews of req. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2023-08-17.
  • How to implement a disk cache plugin for Elixir's Req HTTP client?
    5 projects | | 17 Aug 2023
    > no error checking at all (I assume it just panics or exception?)

    In Elixir, bang functions per convention will raise on error. `get/2` will return error tuples allowing you to handle errors. In fact, get!/2 just calls get/2 and raises for you[^1].

    > no mention of JSON at all

    Req is the most "batteries included" Elixir HTTP lib out there. I can't speak for Wojtek, but I believe the goal was to make Req extremely easy to use in scripting or things like LiveBook without having to do much work. That being said, the automatic decoding is mentioned in the readme[^2] and the docs[^3].

    > if "body" is JSON, how do you even get the raw body, or can you?

    Per the docs[^3], you can either skip with a `:raw` option, or just build your own request using only the steps you want.

    > just seems over engineered/over fitted whatever you want to call it.

    Fair, but again, this library is designed to be on that end of the spectrum. There are plenty of other libraries further down the stack that you can use. I am partial to Finch[^4], upon which Req is built.

    To address the sibling comment about "Let it Crash", the language allows you to easily recover from crashes, but that is for resiliency, not error handling. In practice you would use the non-bang get/2, pattern match on the response, handle any errors, perhaps use Kernel.get_in/2 to safely traverse the map, etc. The example provided by the author is not "production ready".


  • A Breakdown of HTTP Clients in Elixir
    1 project | | 25 Jul 2023

What are some alternatives?

When comparing aeson and req you can also consider the following projects:


tesla - The flexible HTTP client library for Elixir, with support for middleware and multiple adapters.

alternative-vector - Use vectors with many and some, instead of lists

httpotion - [Deprecated because ibrowse is not maintained] HTTP client for Elixir (use Tesla please)

aeson-utils - Utilities for working with aeson.

httpoison - Yet Another HTTP client for Elixir powered by hackney

req - An HTTP client library

mint - Functional HTTP client for Elixir with support for HTTP/1 and HTTP/2 🌱

aeson-applicative - define To/From JSON instances from one applicative definition

finch - Elixir HTTP client, focused on performance

tmp-postgres - Create temporary postgres instances

swagger-petstore - swagger-codegen contains a template-driven engine to generate documentation, API clients and server stubs in different languages by parsing your OpenAPI / Swagger definition.