hyperbole

Interactive HTML apps using type-safe serverside Haskell

https://github.com/seanhess/hyperbole

LTS Haskell 24.52:0.4.3
Stackage Nightly 2026-07-28:0.7.1
Latest on Hackage:0.7.1

See all snapshots hyperbole appears in

BSD-3-Clause licensed by Sean Hess
Maintained by [email protected]
This version can be pinned in stack with:hyperbole-0.7.1@sha256:c931005e36ea44b1e84a868111b2d2098334c006fffee10d2d7990d676038227,6642

Module documentation for 0.7.1

Hyperbole

Hackage Version

Create interactive HTML applications with type-safe serverside Haskell. Inspired by HTMX, Elm, and Phoenix LiveView.

▶️ Simple Example

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeFamilies #-}

module Main where

import Data.Text (Text)
import Web.Atomic.CSS (border, (~))
import Web.Hyperbole

main :: IO ()
main = do
  run 3000 $ do
    liveApp quickStartDocument (runPage page)

page :: (Hyperbole :> es) => Page es '[Message]
page = do
  pure $ do
    hyper Message1 $ messageView "Hello"
    hyper Message2 $ messageView "World!"

data Message = Message1 | Message2
  deriving (Generic, ViewId)

instance HyperView Message es where
  data Action Message
    = Louder Text
    deriving (Generic, ViewAction)

  update (Louder msg) = do
    let new = msg <> "!"
    pure $ messageView new

messageView :: Text -> View Message ()
messageView msg = do
  button (Louder msg) ~ border 1 $ text msg

Documentation

Visit hyperbole.live for documentation and live examples. Also see the Hackage Documentation

Getting Started with Cabal

Create a new application:

$ mkdir myapp
$ cd myapp
$ cabal init

Add hyperbole and text as dependencies to the .cabal file:

    build-depends:
        base
      , hyperbole
      , atomic-css
      , text

    default-language: GHC2021

Paste the above example into Main.hs, then run it:

$ cabal run

Visit http://localhost:3000 to view the application

Learn More

In the Wild

The NSO uses Hyperbole to manage Level 2 Data pipelines for the DKIST telescope

Contributors

Changes

Revision history for hyperbole

0.7.1 – 2026-07.01

Features:

  • Accept multipart form file uploads with good default security settings

Improvements:

  • trigger and pushEvent now send to the client immediately instead of waiting for the action to finish
  • Added cookieSecure option to Session class
  • Deprecated toActionInput in favor of inputValue - Instead of partially applying a constructor, inputs are read with a function similar to forms
  • Web.Hyperbole.Data.Param was unnecessary and removed. Everything uses ToJSON and FromJSON as an intermediate encoding
  • moved OAuth2 to sub-package to allow for dependencies on cryptography libraries
  • Embedded Haddock docs will work even in projects that depend on hyperbole

Breaking Changes:

  • Actions with input like search, onInput and dropdown should now use an action with no arguments. Get the value using inputValue instead
  • ToParam and FromParam are no longer used. Use the generic implementation of ToJSON and FromJSON instead

Maintenance:

0.6.0 – 2026-01-15

Improvements:

  • ViewState - built in threaded state, defaults to (), for folks who really miss Elm
  • Concurrency Controls - Drop vs Replace for overlapping updates
  • pushUpdate - server push an update to an arbitrary view
  • Long-running actions can be interrupted / cancelled
  • https://hyperbole.live now has inline documentation, code snippets, and live examples

Breaking Changes:

  • A few functions now require state, such as trigger and target

0.5.0 – 2025-09-26

Improvements

  • trigger actions in other views
  • Javascript FFI
    • window.Hyperbole - API available from custom JS. runAction allows JS to trigger actions
    • pushEvent - send events to JS from the server
  • Documents
    • Choose to configure with View DocumentHead () instead of ByteString -> ByteString
    • quickStartDocument
    • Live Reload
  • Websocket - ping keepalive
  • New form fields: radio, select
  • Web.Hyperbole.Effect.OAuth2 - Authentication
  • Web.Hyperbole.Effect.GenRandom - Simple random effect used by OAuth2
  • Error handling, custom errors
  • Examples
    • Many additions and improvements
    • External Stylesheet TodoMVC
    • OAuth2 example

Breaking Changes / Improvements

  • Web.Atomic.CSS overhauled, and is now opt-in. Use new @ and ~ operators to apply attributes and styles
  • Web.Hyperbole.Data.Param - unified param encoding for Forms, ViewId, ViewAction, Sessions, Queries
  • Web.Hyperbole.Data.Encoding - encoding for ViewId, ViewAction
  • Web.Hyperbole.Data.URI - Standardize on Network.URI, extra utilities to manage paths
  • trigger: required refactor of Page type alias to support type-checking: Eff es (Page '[]) is now Page es '[]

0.4.3 – 2025-01-31

  • Bug fixes and improvements

0.4.2 – 2025-01-21

  • Cleaner HyperView class (@cgeorgii)
    • data family Action
    • update
  • Type-safe resolution of HyperViews
  • Record-based Forms
  • High-level sessions and query params
  • Events: onLoad, onClick onInput, onSubmit, onDblClick, onKeyDown, onKeyUp
  • Major refactoring
  • Nix build and CI (@Skyfold)
  • New Examples Live: https://docs.hyperbole.live
  • New Examples Added:
    • TodoMVC
    • Forms - Simple
    • DataTable
    • Search - Filters
    • Search - Autocomplete

0.3.6 – 2024-05-21

  • First version. Released on an unsuspecting world.