servant-server

A family of combinators for defining webservices APIs and serving them

http://haskell-servant.github.io/

Version on this page:	0.4.4
LTS Haskell 24.56:	0.20.3.0@rev:5
Stackage Nightly 2026-08-24:	0.20.3.0@rev:5
Latest on Hackage:	0.20.3.0@rev:5

See all snapshots servant-server appears in

BSD-3-Clause licensed by Alp Mestanogullari, Sönke Hahn, Julian K. Arni

Maintained by [email protected]

This version can be pinned in stack with:servant-server-0.4.4@sha256:52732d28512dc87c2bb6a57a9142198480edf4b474975a073bcaa6f11ff16e14,3584

Module documentation for 0.4.4

Servant
- Servant.Server
  - Servant.Server.Internal
    - Servant.Server.Internal.Enter
    - Servant.Server.Internal.ServantErr
- Servant.Utils
  - Servant.Utils.StaticFiles

Depends on 21 packages(full list with versions):

Used by 3 packages in nightly-2015-08-16(full list with versions):

servant-jquery, servant-JuicyPixels, servant-server

servant-server

servant

This library lets you implement an HTTP server with handlers for each endpoint of a servant API, handling most of the boilerplate for you.

Getting started

We’ve written a Getting Started guide that introduces the core types and features of servant. After this article, you should be able to write your first servant webservices, learning the rest from the haddocks’ examples.

Repositories and Haddocks

The core servant package - docs
Implementing an HTTP server for a webservice API with servant-server - docs
(Haskell) client-side function generation with servant-client - docs
(Javascript) client-side function generation with servant-jquery - docs
API docs generation with servant-docs - docs

Changes

0.4.1

Bump attoparsec upper bound to < 0.14
Bump wai-app-static upper bound to < 3.2
Bump either upper bound to < 4.5

0.4

Delete now is like Get, Post, Put, and Patch and returns a response body
Add a RouteMismatch constructor for arbitrary HTTP response codes (https://github.com/haskell-servant/servant-server/pull/22)
Add support for the Patch combinator
Support for Accept/Content-type headers and for the content-type aware combinators in servant-0.4
Export toApplication from Servant.Server (https://github.com/haskell-servant/servant-server/pull/29)
Support other Monads than just EitherT (Int, String) IO (https://github.com/haskell-servant/servant-server/pull/21)
Make methods return status code 204 if they return () (https://github.com/haskell-servant/servant-server/issues/28)
Add server support for response headers
Use ServantErr instead of (Int,String) in EitherT handlers
Add errXXX functions for HTTP errors with sensible default reason strings
Add enter function for applying natural transformations to handlers

0.2.4

Added support for matrix parameters, see e.g. http://www.w3.org/DesignIssues/MatrixURIs.html
Add support for serializing based on Accept header (https://github.com/haskell-servant/servant-server/issues/9)
Ignore trailing slashes (https://github.com/haskell-servant/servant-server/issues/5)

0.2.3

Fix consuming request body issue (https://github.com/haskell-servant/servant/issues/3)
Make code sample in Servant.Server complete