liblastfm: Lastfm API interface

This is a package candidate release! Here you can preview how this package release will appear once published to the main package index (which can be accomplished via the 'maintain' link below). Please note that once a package has been published to the main package index it cannot be undone! Please consult the package uploading documentation for more information.


Provides interface to Lastfm REST API, supports XML and JSON formats.

[Skip to ReadMe]


Versions0.0.1.0,,,,,,,,,,,,,,,,,,,,,, 0.5.0, 0.5.1, 0.6.0, 0.6.1, 0.7.0
Dependenciesaeson, base (>=3 && <5), bytestring, cereal, containers (>=0.5), contravariant, crypto-api, http-conduit (>=1.9), http-types, network, pureMD5, semigroups, tagged, text, void [details]
AuthorMatvey Aksenov, Dmitry Malikov
MaintainerMatvey Aksenov <>
CategoryNetwork APIs
Source repositoryhead: git clone
UploadedTue Dec 31 18:31:36 UTC 2013 by MatveyAksenov



Maintainers' corner

For package maintainers and hackage trustees

Readme for liblastfm-

[back to package description]


Hackage Build Status Build Status

Complete API interface to service. Documentation is available in two flavours:

General introduction

liblastfm provides Applicative interface for constructing requests. Also, it handles all machinery needed to prepare request for sending:

Once request is ready, liblastfm may send it and get you back a response. Response format might be:


To install either use hackage:

% cabal install liblastfm

Or git:

% git clone
% cd liblastfm
% cabal install


Suppose, you need to use API method. First find it in liblastfm: Tag would be the name of the module and search would be the name of function. Here it is. So import a couple of modules:

ghci> import Network.Lastfm -- a bunch of useful utilities
ghci> import qualified Network.Lastfm.Tag as Tag -- for

Now you may you applicative <*> for required and <* or *> for optional parameters to construct desired request: <*> tag "russian-folk" <* limit 3 <*> apiKey "29effec263316a1f8a97f753caaa83e0" <* json

To send constructed request use lastfm:

ghci> lastfm $ <*> tag "russian-folk" <* limit 10 <*> apiKey "29effec263316a1f8a97f753caaa83e0" <* json
Just (Object fromList [("results",Object fromList [("tagmatches", ...

How to parse responses is described in wiki.


Q: I'm getting the following error. How do I fix it?

> Artist.getInfo <*> artist "Pink Floyd" <*> apiKey "29effec263316a1f8a97f753caaa83e0"

    Couldn't match expected type `Data.Text.Lazy.Internal.Text'
                with actual type `[Char]

A: This means you haven't OverloadedStrings extension enabled. To enable it (either one works):

Q: I'm getting the following error. How do I fix it?

> lastfm (Artist.getInfo <*> artist "Pink Floyd" <*> apiKey "29effec263316a1f8a97f753caaa83e0")

    No instance for (Network.Lastfm.Response.Supported f0)
      arising from a use of `lastfm'
    The type variable `f0' is ambiguous
    Possible fix: add a type signature that fixes these type variable(s)
    Note: there are several potential instances:
      instance Network.Lastfm.Response.Supported 'XML
        -- Defined at src/Network/Lastfm/Response.hs:66:10
      instance Network.Lastfm.Response.Supported 'JSON
        -- Defined at src/Network/Lastfm/Response.hs:51:10

A: This error message indicates that GHC cannot infer response format for Request. To fix it, add use json or xml helpers, depending on your needs

> lastfm (Artist.getInfo <*> artist "Pink Floyd" <*> apiKey "29effec263316a1f8a97f753caaa83e0" <* json)
Just (Object fromList [("artist" ...
> lastfm (Artist.getInfo <*> artist "Pink Floyd" <*> apiKey "29effec263316a1f8a97f753caaa83e0" <* xml)
"<?xml version=\"1.0\" ...