Scotty

A Haskell web framework inspired by Ruby's Sinatra, using WAI and Warp.

{-# LANGUAGE OverloadedStrings #-}
import Web.Scotty

main = scotty 3000 $
    get "/:word" $ do
        beam <- pathParam "word"
        html $ mconcat ["<h1>Scotty, ", beam, " me up!</h1>"]

Scotty is the cheap and cheerful way to write RESTful, declarative web applications.

• A page is as simple as defining the verb, URL pattern, and Text content.
• It is template-language agnostic. Anything that returns a Text value will do.
• Conforms to the web application interface (WAI).
• Uses the very fast Warp webserver by default.

As for the name: Sinatra + Warp = Scotty.

Examples

Run /basic.hs to see Scotty in action:

runghc examples/basic.hs

Setting phasers to stun... (port 3000) (ctrl-c to quit)

Or equivalently with stack:

stack exec -- scotty-basic

Once the server is running you can interact with it with curl or a browser:

curl localhost:3000

foobar

curl localhost:3000/foo_query?p=42

<h1>42</h1>

Additionally, the examples directory shows a number of concrete use cases, e.g.

• exception handling
• global state
• configuration
• cookies
• file upload
• session
• WAI middlewares (logging, header validation)
• and more

More Information

Tutorials and related projects can be found in the Scotty wiki.

Contributing

Feel free to ask questions or report bugs on the Github issue tracker.

Github issues are now (September 2023) labeled, so newcomers to the Haskell language can start with easy fix ones and gradually progress to new features, bugs and R&D :)

Package versions

Scotty adheres to the Package Versioning Policy.

FAQ

• Fails to compile regex-posix on Windows
  • If you are using stack, add the following parameters to stack.yaml:

    •   extra-deps:
        - regex-posix-clib-2.7
        flags:
          regex-posix:
            _regex-posix-clib: true
      

  • If you are using cabal, update the constraints section of cabal.project.local as follows:

    • constraints:
        regex-posix +_regex-posix-clib 
      

Contributors

Copyright

(c) 2012-Present, Andrew Farmer and Scotty contributors