iris: Haskell CLI framework

[ cli, framework, library, mpl, program ] [ Propose Tags ]

Haskell CLI framework. See for more details.

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Dependencies ansi-terminal (>=0.11 && <0.12), base (>=4.14 && <4.17), bytestring (>=0.10 && <0.12), colourista (>=0.1 && <0.2), directory (>=1.3 && <1.4), iris, mtl (>=2.2 && <2.4), optparse-applicative (>=0.17 && <0.18), process (>=1.6 && <1.7), text (>=1.2 && <2.1), unliftio-core (>=0.2 && <0.3) [details]
License MPL-2.0
Copyright 2022 Dmitrii Kovanikov
Author Dmitrii Kovanikov
Maintainer Dmitrii Kovanikov <>
Category CLI, Framework
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Source repo head: git clone
Uploaded by shersh at 2022-08-08T17:54:42Z
Distributions NixOS:
Reverse Dependencies 1 direct, 0 indirect [details]
Executables iris-example
Downloads 53 total (7 in the last 30 days)
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Readme for iris-

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GitHub CI Hackage MPL-2.0 license

Iris is a Haskell framework for building CLI applications that follow Command Line Interface Guidelines.

🌈 Iris (/ˈaɪrɪs/) is a Greek goddess associated with communication, messages, the rainbow, and new endeavors.

Iris changing her workflow and hair colour depending on the time of day.

ℹ️ DISCLAIMER #1: Currently, Iris is in experimental phase and mostly for early adopters. It may lack documentation or have significant breaking changes. We appreciate anyone's help in improving the documentation! At the same time, the maintainers will strive to provide helpful migration guides.

ℹ️ DISCLAIMER #2: Iris is developed and maintained in free time by volunteers. The development may continue for decades or may stop tomorrow. You can use GitHub Sponsorship to support the development of this project.


Iris development is guided by the following principles:

  1. Support Command Line Interface Guidelines. Features or changes that violate these guidelines are not accepted in the project.

  2. Beginner-friendliess. Haskell beginners should be able to build CLI applications with Iris. Hence, the implementation of Iris API that uses less fancy Haskell features are preferred. When the complexity is justified, the cost of introducing this extra complexity should be mitigated by having better documentation.

  3. Reasonable batteries-included. Iris is not trying to be minimalistic as possible, it strives to provide out-of-the-box solutions for most common problems. But at the same time, we don't want to impose unnecessary heavy dependencies.

  4. Excellent documentation. Iris documentation should be as helpful as possible in using the framework.

    NOTE: Currently, Iris may lack documentation but there's an ongoing effort to improve the situation.

🧱 Iris focuses solely on CLI applications. If you're interested in building TUI app with Haskell, check out brick.


CLI apps built with Iris offer the following features for end users:

  • Automatic detection of colouring support in the terminal
  • Ability to check required external tools if you need e.g. curl or git
  • Support for standard CLI options out-of-the-box:
    • --help
    • --version
    • --numeric-version: helpful for detecting required tools versions
    • --no-input: for disabling all interactive features
  • Utilities to open files in a browser

How to use?

iris is compatible with the following GHC versions - supported versions

In order to start using iris in your project, you will need to set it up with these steps:

  1. Add the dependency on iris in your project's .cabal file. For this, you should modify the build-depends section according to the below section:

      , base ^>= LATEST_SUPPORTED_BASE
      , iris ^>= LATEST_VERSION
  2. To use this package, refer to the below example.

    {-# LANGUAGE GeneralizedNewtypeDeriving #-}
    module Main (main) where
    import Control.Monad.IO.Class (MonadIO (..))
    import qualified Iris
    newtype App a = App
        { unApp :: Iris.CliApp () () a
        } deriving newtype
            ( Functor
            , Applicative
            , Monad
            , MonadIO
    appSettings :: Iris.CliEnvSettings () ()
    appSettings = Iris.defaultCliEnvSettings
        { Iris.cliEnvSettingsHeaderDesc = "Iris usage example"
        , Iris.cliEnvSettingsProgDesc = "A simple 'Hello, world!' utility"
    app :: App ()
    app = liftIO $ putStrLn "Hello, world!"
    main :: IO ()
    main = Iris.runCliApp appSettings $ unApp app

For contributors

Check for contributing guidelines.


To build the project and run the tests locally, you can use either cabal or stack.

See the First time section if you don't have Haskell development environment locally.


Build the project:

cabal build all

Run all unit tests:

cabal test --enable-tests --test-show-details=direct


Build the project:

stack build --test --no-run-tests

Run all unit tests:

stack test

First time

If this is your first time dealing with Haskell tooling, we recommend using GHCup.

During the installation, GHCup will suggest you installing all the necessary tools. If you have GHCup installed but miss some of the tooling for some reason, type the following commands in the terminal:

ghcup install ghc 8.10.7
ghcup set     ghc 8.10.7
ghcup install cabal

If you are using Linux or macOS, you may find ghcup tui command a more attractive option.