Yesod Web Framework

An advanced web framework using the Haskell programming language. Featuring:

• safety & security guaranteed at compile time
• developer productivity: tools for all your basic web development needs
• raw performance
  • fast, compiled code
  • techniques for constant-space memory consumption
• asynchronous IO
  • this is built in to the Haskell programming language (like Erlang)

Getting Started

Learn more about Yesod on its main website. If you want to get started using Yesod, we strongly recommend the quick start guide, based on the Haskell build tool stack.

Here's a minimal example!

{-# LANGUAGE OverloadedStrings, QuasiQuotes, TemplateHaskell, TypeFamilies #-}

import Yesod

data App = App -- Put your config, database connection pool, etc. in here.

-- Derive routes and instances for App.
mkYesod "App" [parseRoutes|
/ HomeR GET
|]

instance Yesod App -- Methods in here can be overridden as needed.

-- The handler for the GET request at /, corresponds to HomeR.
getHomeR :: Handler Html
getHomeR = defaultLayout [whamlet|Hello World!|]

main :: IO ()
main = warp 3000 App

To read about each of the concepts in use above (routing, handlers, linking, JSON), in detail, visit Basics in the Yesod book.

Hacking on Yesod

Yesod consists mostly of four repositories:

git clone --recurse-submodules http://github.com/yesodweb/shakespeare
git clone --recurse-submodules http://github.com/yesodweb/persistent
git clone --recurse-submodules http://github.com/yesodweb/wai
git clone --recurse-submodules http://github.com/yesodweb/yesod

Each repository can be built with stack build.