diff --git a/.gitignore b/.gitignore
index febbcdd..8b7ca09 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,4 +13,7 @@ cabal.sandbox.config
 .*.swp
 *.log
 *.dump-hi
+.direnv/
+.envrc
 dist-newstyle/
+result/
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..db382ba
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1695360818,
+        "narHash": "sha256-JlkN3R/SSoMTa+CasbxS1gq+GpGxXQlNZRUh9+LIy/0=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "e35dcc04a3853da485a396bdd332217d0ac9054f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..c537278
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,82 @@
+{
+  description = "mat-chalmers goes flakes";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  nixConfig.allow-import-from-derivation = true; # cabal2nix uses IFD
+
+  outputs = { self, nixpkgs, flake-utils }:
+    let
+      ghcVer = "ghc945";
+      makeHaskellOverlay = overlay: final: prev: {
+        haskell = prev.haskell // {
+          packages = prev.haskell.packages // {
+            ${ghcVer} = prev.haskell.packages."${ghcVer}".override (oldArgs: {
+              overrides =
+                prev.lib.composeExtensions (oldArgs.overrides or (_: _: { }))
+                  (overlay prev);
+            });
+          };
+        };
+      };
+
+      out = system:
+        let
+          pkgs = import nixpkgs {
+            inherit system;
+            overlays = [ self.overlays.default ];
+            config.allowBroken = true;
+          };
+
+        in
+        {
+          packages = rec {
+            default = mat;
+            mat = pkgs.haskell.packages.${ghcVer}.mat;
+          };
+
+          checks = {
+            inherit (self.packages.${system}) mat;
+          };
+
+          # for debugging
+          # inherit pkgs;
+
+          devShells.default =
+            let haskellPackages = pkgs.haskell.packages.${ghcVer};
+            in
+            haskellPackages.shellFor {
+              packages = p: [ self.packages.${system}.mat ];
+              withHoogle = true;
+              buildInputs =
+                [ pkgs.docker ] ++
+                (with haskellPackages; [
+                  haskell-language-server
+                  cabal-install
+                ]);
+              # Change the prompt to show that you are in a devShell
+              # shellHook = "export PS1='\\e[1;34mdev > \\e[0m'";
+            };
+        };
+    in
+    flake-utils.lib.eachDefaultSystem out // {
+      # this stuff is *not* per-system
+      overlays = {
+        default = makeHaskellOverlay (prev: hfinal: hprev:
+          let hlib = prev.haskell.lib; in
+          {
+            mat = hprev.callCabal2nix "mat" ./. { };
+
+            # here's how to do hacks to the package set
+            # don't run the test suite
+            # fast-tags = hlib.dontCheck hprev.fast-tags;
+            #
+            # don't check version bounds
+            # friendly = hlib.doJailbreak hprev.friendly;
+          });
+      };
+    };
+}
diff --git a/mat-chalmers.cabal b/mat-chalmers.cabal
index 03b9b10..d20044a 100644
--- a/mat-chalmers.cabal
+++ b/mat-chalmers.cabal
@@ -1,3 +1,4 @@
+cabal-version: 3.0
 name: mat-chalmers
 version: 0.1.0.0
 license: MIT
@@ -6,7 +7,6 @@ author: Adam Sandberg Eriksson
 maintainer: adam@sandbergericsson.se
 category: Web
 build-type: Simple
-cabal-version: >=1.10
 Tested-With: GHC ==9.4.5
 data-files:
            static/style.css
@@ -38,7 +38,7 @@ library
                , css-text >= 0.1.3.0 && < 0.2
                , exceptions >= 0.10.5 && < 0.11.0
                , heredoc == 0.2.0.0
-               , http-client >= 0.7.14 && < 0.8
+               , http-client >= 0.7.13.1 && < 0.8
                , http-client-tls >= 0.3.6.1 && <= 0.4
                , logging-effect >= 1.4.0 && <= 2.0
                , microlens-platform >= 0.4.3.3 && < 0.5
@@ -61,7 +61,7 @@ executable mat-chalmers
                , base
                , bytestring
                , file-embed
-               , http-client-tls
+               , http-client-tls >= 0.3.5.3
                , microlens-platform
                , logging-effect
                , mtl
@@ -83,4 +83,4 @@ Test-Suite test-mat
                , hspec >= 2.10.10 && < 3.0
                , HUnit >= 1.6.2.0 && < 2.0
                , text
-               , thyme
+               , thyme >= 0.3.5.5
diff --git a/shell.nix b/shell.nix
deleted file mode 100644
index 84e1ccf..0000000
--- a/shell.nix
+++ /dev/null
@@ -1,44 +0,0 @@
-{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:
-
-let
-
-  inherit (nixpkgs) pkgs;
-
-  f = { mkDerivation, aeson, base, bytestring, css-text, errors
-      , exceptions, file-embed, heredoc, http-client, http-client-tls
-      , logging-effect, lucid, microlens-platform, mtl, old-locale
-      , prettyprinter, safe, scotty, stdenv, text, thyme, time, wai-extra
-      , wai-middleware-static-embedded
-      }:
-      mkDerivation {
-        pname = "mat-chalmers";
-        version = "0.1.0.0";
-        src = ./.;
-        isLibrary = true;
-        isExecutable = true;
-        buildTools = [ haskellPackages.cabal-install ];
-        enableSeparateDataOutput = true;
-        libraryHaskellDepends = [
-          aeson base bytestring css-text errors exceptions file-embed heredoc
-          http-client logging-effect lucid microlens-platform mtl old-locale
-          prettyprinter safe text thyme
-        ];
-        executableHaskellDepends = [
-          base bytestring file-embed http-client-tls logging-effect
-          microlens-platform mtl scotty time wai-extra
-          wai-middleware-static-embedded
-        ];
-        license = stdenv.lib.licenses.mit;
-      };
-
-  haskellPackages = if compiler == "default"
-                       then pkgs.haskellPackages
-                       else pkgs.haskell.packages.${compiler};
-
-  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;
-
-  drv = variant (haskellPackages.callPackage f {});
-
-in
-
-  if pkgs.lib.inNixShell then drv.env else drv