A framework of packages for building Haskell applications
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Peter J. Jones b870f7f5fc
Make it easier to generate new certificates
1 week ago
crypto Make it easier to generate new certificates 1 week ago
opaleye Rename Opaleye -> Database, add helper function 2 months ago
validation validation: Add `HasValidLength' instance for `NonEmpty' 2 months ago
.envrc Update for NixOS 19.09 3 months ago
.gitignore Fix a couple typos, improve the shell.nix file 7 months ago
LICENSE Add Iolaus.Opaleye.Config 8 months ago
README.md Typo 2 months ago
default.nix Initial import of the iolaus-validations library 2 months ago



A set of packages that aim to take care of the 20% overlap between all of the Haskell applications that you write.


This collection of packages uses the “MTL + Classy Optics” style of composing the major components of an application.

For more information we highly recommend the talk by George Wilson entitled Next Level MTL with Classy Optics.


  • crypto: Simplified cryptography operations.

  • opaleye: Database queries and schema migrations.

  • validation: Data validation