diff --git a/.github/workflows/nix-build.yml b/.github/workflows/nix-build.yml
index d2e2f12..53efb68 100644
--- a/.github/workflows/nix-build.yml
+++ b/.github/workflows/nix-build.yml
@@ -2,55 +2,35 @@ name: "Nix Build"
 on:
   pull_request:
   push:
-    branches:
-      - development
-      - master
+    branches: [development, master]
 jobs:
-  hooks:
-    runs-on: ubuntu-latest
+  build:
+    name: ${{ matrix.attribute }} / ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+        attribute:
+          - .#devShells.x86_64-linux.default
+          - .#packages.x86_64-linux.default
+          - .#checks.x86_64-linux.pre-commit
     steps:
-    - uses: actions/checkout@v3.0.2
-    - uses: cachix/install-nix-action@v17
-    - uses: cachix/cachix-action@v10
+    - uses: actions/checkout@v2.5.0
+    - uses: cachix/install-nix-action@v18
+      with:
+        extra_nix_config: |
+          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+    - name: free disk space
+      run: |
+        if [[ "${{matrix.os}}" == "ubuntu-latest" ]]
+        then
+          sudo rm -rf /opt
+        fi
+    - uses: cachix/cachix-action@v11
       with:
         name: feedback
-        extraPullNames: validity,sydtest,autodocodec
+        extraPullNames: validity,safe-coloured-text,sydtest,autodocodec
         signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
-    - run: nix-build ci.nix -A pre-commit-check
-
-  shell:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v3.0.2
-    - uses: cachix/install-nix-action@v17
-    - uses: cachix/cachix-action@v10
-      with:
-        name: feedback
-        extraPullNames: validity,sydtest,autodocodec
-        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
-    - run: nix-build ci.nix -A shell
-
-  hoogle:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v3.0.2
-    - uses: cachix/install-nix-action@v17
-    - uses: cachix/cachix-action@v10
-      with:
-        name: feedback
-        extraPullNames: validity,sydtest,autodocodec
-        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
-    - run: nix-build ci.nix -A hoogle
-
-  tests:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v3.0.2
-    - uses: cachix/install-nix-action@v17
-    - uses: cachix/cachix-action@v10
-      with:
-        name: feedback
-        extraPullNames: validity,sydtest,autodocodec
-        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
-    - run: nix-build ci.nix -A release
-
+    - run: nix build "${{matrix.attribute}}"
diff --git a/.gitignore b/.gitignore
index f7204ad..825d540 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ stack.yaml.lock
 result*
 .pre-commit-config.yaml
 .direnv/
+dist-newstyle/
diff --git a/README.md b/README.md
index a5a1175..b9ba3fe 100644
--- a/README.md
+++ b/README.md
@@ -11,23 +11,26 @@ Use the `feedback` command to set up a feedback loop for your work.
 For example, if you are working on a nix build, you might use this feedback loop:
 
 ```
-feedback -- nix-build --no-out-link
+feedback -- nix-build
 ```
 
+Usually `feedback` will correctly figure out which files to watch and which
+files not to watch, but you can also configure this more precisely.
+
 ### Declarative feedback loops
 
 You can declare feedback loops in the `feedback.yaml` configuration file to share them with your team.
-For example, this gives you a [`ci.nix`-based feedback loop](https://cs-syd.eu/posts/2021-04-11-the-ci-nix-pattern):
+For example, this gives you a flake-based feedback loop:
 
-```
+``` yaml
 loops:
-  ci: nix-build ci.nix --no-out-link
+  check: nix flake check -L
 ```
 
 Then you can just run this command, and not have to remember the full incantation:
 
 ```
-feedback ci
+feedback check
 ```
 
 To see the full reference of options of the configuration file, run `feedback --help`.
@@ -38,6 +41,61 @@ When sharing feedback loops with team members, it is important that no one break
 You can use `feedback-test` to test out the feedback loops in a one-shot manner, so you can check that they still work on CI.
 See `feedback-test --help` for more details.
 
+## Installation
+
+### Try it out
+
+```
+nix run github:NorfairKing/feedback
+```
+
+### Install globally
+
+Add this to your system flake:
+
+``` nix
+{
+  inputs = {
+    feedback.url = "github:NorfairKing/feedback?ref=flake";
+  };
+  outputs = { nixpkgs, feedback, ... }:
+    let system = "x86_64-linux";
+    in {
+      nixosConfigurations.example = nixpkgs.lib.nixosSystem {
+        inherit system;
+        modules = [
+          { environment.systemPackages = [ feedback.packages.${system}.default ];
+        ];
+      }
+    };
+  };
+}
+```
+
+## Hacking
+
+1. Enter a dev shell
+
+   ```
+   $ nix develop
+   ```
+
+2. Start a feedback loop
+
+   ```
+   feedback istall
+   ```
+
+3. Make your changes
+
+4. Make sure CI will pass
+  
+   ```
+   nix flake check
+   ```
+
+5. Make a PR to `development`.
+
 ## Comparison with other tools
 
 | | feedback | [steeloverseer](https://github.com/schell/steeloverseer) | [watchexec](https://github.com/watchexec/watchexec) | [entr](https://github.com/eradman/entr)
diff --git a/TODO.smos b/TODO.smos
index 7b1dd4a..0780b95 100644
--- a/TODO.smos
+++ b/TODO.smos
@@ -1,8 +1,5 @@
 version: 2.0.0
 value:
-- Configurable debouncing
-- Configurable postponing with --postpone
-- Enter to rerun immediately
 - header: On-busy configuration
   contents: |-
     options:
@@ -13,9 +10,6 @@ value:
     - Send a given signal
 - header: Extension-based filter
   contents: This is simple enough to accomodate
-- Make it possible to use polling
 - header: Make it possible to not use a shell
   contents: also to use  adifferent shell?
 - Make it possible to turn off default ignores
-- Show info if feedback is called without args
-- Autocompletion for the loops, assuming we use the default config
diff --git a/cabal.project b/cabal.project
new file mode 100644
index 0000000..f673831
--- /dev/null
+++ b/cabal.project
@@ -0,0 +1,2 @@
+packages: */*.cabal
+test-show-details: direct
diff --git a/ci.nix b/ci.nix
deleted file mode 100644
index 6a2194c..0000000
--- a/ci.nix
+++ /dev/null
@@ -1,18 +0,0 @@
-let
-  sources = import ./nix/sources.nix;
-  pkgs = import ./nix/pkgs.nix { inherit sources; };
-  pre-commit = import ./nix/pre-commit.nix { inherit sources; };
-
-in
-{
-  release = pkgs.feedbackRelease;
-  pre-commit-check = pre-commit.run;
-  hoogle = pkgs.buildEnv {
-    name = "feedback-hoogle";
-    paths = [ (pkgs.haskellPackages.ghcWithHoogle (ps: pkgs.lib.attrValues pkgs.feedbackPackages)) ];
-  };
-  shell = pkgs.symlinkJoin {
-    name = "shell";
-    paths = (import ./shell.nix { inherit sources pkgs pre-commit; }).buildInputs;
-  };
-}
diff --git a/default.nix b/default.nix
deleted file mode 100644
index 69844cd..0000000
--- a/default.nix
+++ /dev/null
@@ -1,4 +0,0 @@
-let
-  pkgs = import ./nix/pkgs.nix { };
-in
-pkgs.feedbackPackages
diff --git a/feedback.yaml b/feedback.yaml
index ddf52e6..8105b61 100644
--- a/feedback.yaml
+++ b/feedback.yaml
@@ -1,19 +1,12 @@
 loops:
   ci:
     description: Run all of CI
-    command: nix-build ci.nix --no-out-link
+    command: nix flake check
 
   install:
     description: Work on `feedback` and its `--help` page.
-    script: |
-      set -x
-      stack install :feedback \
-        --fast --no-nix --system-ghc --with-hpack hpack
-      ~/.local/bin/feedback --help
+    command: cabal run feedback:feedback -- --help
 
   test:
     description: Work on `feedback-test`
-    script: |
-      stack install :feedback-test \
-        --fast --no-nix --system-ghc --with-hpack hpack
-      ~/.local/bin/feedback-test --debug ci
+    command: cabal run feedback:feedback-test
diff --git a/feedback/default.nix b/feedback/default.nix
new file mode 100644
index 0000000..44314fa
--- /dev/null
+++ b/feedback/default.nix
@@ -0,0 +1,25 @@
+{ mkDerivation, autodocodec, autodocodec-yaml, base, bytestring
+, conduit, containers, envparse, fsnotify, lib
+, optparse-applicative, path, path-io, pretty-show
+, safe-coloured-text, safe-coloured-text-layout
+, safe-coloured-text-terminfo, text, time, typed-process, unix
+, unliftio, yaml
+}:
+mkDerivation {
+  pname = "feedback";
+  version = "0.0.0.0";
+  src = ./.;
+  isLibrary = true;
+  isExecutable = true;
+  libraryHaskellDepends = [
+    autodocodec autodocodec-yaml base bytestring conduit containers
+    envparse fsnotify optparse-applicative path path-io pretty-show
+    safe-coloured-text safe-coloured-text-layout
+    safe-coloured-text-terminfo text time typed-process unix unliftio
+    yaml
+  ];
+  executableHaskellDepends = [ base ];
+  homepage = "https://github.com/NorfairKing/feedback#readme";
+  description = "Declarative feedback loop manager";
+  license = lib.licenses.gpl3Only;
+}
diff --git a/feedback/src/Feedback/Common/Process.hs b/feedback/src/Feedback/Common/Process.hs
index d32cdb9..5e7b586 100644
--- a/feedback/src/Feedback/Common/Process.hs
+++ b/feedback/src/Feedback/Common/Process.hs
@@ -58,7 +58,7 @@ makeProcessConfigFor RunSettings {..} = do
   pure $
     setStdout inherit
       . setStderr inherit
-      . setStdin closed -- TODO make this configurable?
+      . setStdin nullStream -- TODO make this configurable?
       . setEnv envForProcess
       . maybe id (setWorkingDir . fromAbsDir) runSettingWorkingDir
       $ shell commandString
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..c60d230
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,148 @@
+{
+  "nodes": {
+    "autodocodec": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1666331698,
+        "narHash": "sha256-VrONoycKv3lOwN/oKet3Pix96aFNgK+PmLevzBgSsgY=",
+        "owner": "NorfairKing",
+        "repo": "autodocodec",
+        "rev": "fdc5171d0f904613b6a8b986a909c7a8ade4d2f1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NorfairKing",
+        "ref": "flake",
+        "repo": "autodocodec",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1667077288,
+        "narHash": "sha256-bdC8sFNDpT0HK74u9fUkpbf1MEzVYJ+ka7NXCdgBoaA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "6ee9ebb6b1ee695d2cacc4faa053a7b9baa76817",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1668281765,
+        "narHash": "sha256-6Tuj9CZ9HacMk7FJ8sF9XSVTBnUhVzlSY40Jo1krIaQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "c5091eec689acc45d4d818109236da31d3685ca2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-22.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1668266328,
+        "narHash": "sha256-+nAW+XR8nswyEnt5IkQlkrz9erTcQWBVLkhtNHxckFw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "5ca8e2e9e1fa5e66a749b39261ad6bd0e07bc87f",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1667992213,
+        "narHash": "sha256-8Ens8ozllvlaFMCZBxg6S7oUyynYx2v7yleC5M0jJsE=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "ebcbfe09d2bd6d15f68de3a0ebb1e4dcb5cd324b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "autodocodec": "autodocodec",
+        "nixpkgs": "nixpkgs",
+        "pre-commit-hooks": "pre-commit-hooks",
+        "safe-coloured-text": "safe-coloured-text",
+        "sydtest": "sydtest",
+        "validity": "validity"
+      }
+    },
+    "safe-coloured-text": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1666332070,
+        "narHash": "sha256-Jvx1599QUkgzPhdvSOrxEKKBXF42eYv26EgXwM+RguU=",
+        "owner": "NorfairKing",
+        "repo": "safe-coloured-text",
+        "rev": "df6d65d1afb0140d081b685b411dcfe03ae6f789",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NorfairKing",
+        "ref": "flake",
+        "repo": "safe-coloured-text",
+        "type": "github"
+      }
+    },
+    "sydtest": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1666335564,
+        "narHash": "sha256-RUAQuAaCCF+bFXWKQV9lx3Caj9pHp7l5NGnMfBaK05I=",
+        "owner": "NorfairKing",
+        "repo": "sydtest",
+        "rev": "56eb625a7603652f475d0cfd4af50b700e9a5d1e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NorfairKing",
+        "ref": "flake",
+        "repo": "sydtest",
+        "type": "github"
+      }
+    },
+    "validity": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1666331942,
+        "narHash": "sha256-xKqunzWw3w7OaKSatckNxn7gCKtusjaj9szhgBWQwAc=",
+        "owner": "NorfairKing",
+        "repo": "validity",
+        "rev": "dc24b655564beaa6750e390e37e64f8b0b67e18f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NorfairKing",
+        "ref": "flake",
+        "repo": "validity",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..b2ea061
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,80 @@
+{
+  description = "feedback";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs?ref=nixos-22.05";
+    pre-commit-hooks.url = "github:cachix/pre-commit-hooks.nix";
+    validity.url = "github:NorfairKing/validity?ref=flake";
+    validity.flake = false;
+    autodocodec.url = "github:NorfairKing/autodocodec?ref=flake";
+    autodocodec.flake = false;
+    safe-coloured-text.url = "github:NorfairKing/safe-coloured-text?ref=flake";
+    safe-coloured-text.flake = false;
+    sydtest.url = "github:NorfairKing/sydtest?ref=flake";
+    sydtest.flake = false;
+  };
+
+  outputs =
+    { self
+    , nixpkgs
+    , pre-commit-hooks
+    , validity
+    , safe-coloured-text
+    , sydtest
+    , autodocodec
+    }:
+    let
+      system = "x86_64-linux";
+      pkgsFor = nixpkgs: import nixpkgs {
+        inherit system;
+        config.allowUnfree = true;
+        overlays = [
+          self.overlays.${system}
+          (import (autodocodec + "/nix/overlay.nix"))
+          (import (safe-coloured-text + "/nix/overlay.nix"))
+          (import (sydtest + "/nix/overlay.nix"))
+          (import (validity + "/nix/overlay.nix"))
+        ];
+      };
+      pkgs = pkgsFor nixpkgs;
+
+    in
+    {
+      overlays.${system} = import ./nix/overlay.nix;
+      packages.${system}.default = pkgs.feedback;
+      checks.${system} = {
+        package = self.packages.${system}.default;
+        shell = self.devShells.${system}.default;
+        pre-commit = pre-commit-hooks.lib.${system}.run {
+          src = ./.;
+          hooks = {
+            hlint.enable = true;
+            hpack.enable = true;
+            ormolu.enable = true;
+            nixpkgs-fmt.enable = true;
+            nixpkgs-fmt.excludes = [ ".*/default.nix" ];
+            cabal2nix.enable = true;
+          };
+        };
+      };
+      devShells.${system}.default = pkgs.haskellPackages.shellFor {
+        name = "feedback-shell";
+        packages = p: [ p.feedback ];
+        withHoogle = true;
+        doBenchmark = true;
+        buildInputs = with pkgs; [
+          feedback
+          niv
+          zlib
+          cabal-install
+        ] ++ (with pre-commit-hooks;
+          [
+            hlint
+            hpack
+            nixpkgs-fmt
+            ormolu
+            cabal2nix
+          ]);
+        shellHook = self.checks.${system}.pre-commit.shellHook + pkgs.feedback.shellHook;
+      };
+    };
+}
diff --git a/nix/overlay.nix b/nix/overlay.nix
index 5a4d9a6..d13b360 100644
--- a/nix/overlay.nix
+++ b/nix/overlay.nix
@@ -1,84 +1,55 @@
-final: previous:
+final: prev:
 with final.lib;
 with final.haskell.lib;
-
-let
-  sources = import ./sources.nix;
-in
 {
-  feedbackPackages =
-    let
-      feedbackPkg = name:
-        overrideCabal
-          (
-            final.haskellPackages.callCabal2nixWithOptions name
-              (final.gitignoreSource (../. + "/${name}"))
-              "--no-hpack"
-              { }
-          )
-          (old: {
-            doBenchmark = true;
-            doHaddock = true;
-            doCoverage = false;
-            doHoogle = true;
-            doCheck = false; # Only check the release version.
-            hyperlinkSource = false;
-            enableLibraryProfiling = false;
-            enableExecutableProfiling = false;
 
-            configureFlags = (old.configureFlags or [ ]) ++ [
-              # Optimisations
-              "--ghc-options=-O2"
-              # Extra warnings
-              "--ghc-options=-Wall"
-              "--ghc-options=-Wincomplete-uni-patterns"
-              "--ghc-options=-Wincomplete-record-updates"
-              "--ghc-options=-Wpartial-fields"
-              "--ghc-options=-Widentities"
-              "--ghc-options=-Wredundant-constraints"
-              "--ghc-options=-Wcpp-undef"
-              "--ghc-options=-Werror"
-              "--ghc-options=-optP-Wno-nonportable-include-path" # For macos
-            ];
-            # Ugly hack because we can't just add flags to the 'test' invocation.
-            # Show test output as we go, instead of all at once afterwards.
-            testTarget = (old.testTarget or "") + " --show-details=direct";
-          });
-      feedbackPkgWithComp =
-        exeName: name:
-        generateOptparseApplicativeCompletion exeName (feedbackPkg name);
-      feedbackPkgWithOwnComp = name: feedbackPkgWithComp name name;
-    in
-    {
-
-      "feedback" = feedbackPkgWithOwnComp "feedback";
-    };
-
-  feedbackReleasePackages = mapAttrs
-    (_: pkg: justStaticExecutables (doCheck pkg))
-    final.feedbackPackages;
-
-
-  feedbackRelease =
-    final.symlinkJoin {
-      name = "feedback-release";
-      paths = attrValues final.feedbackReleasePackages;
-      passthru.shellHook = ''
-        ${final.feedbackReleasePackages.feedback}/bin/feedback
+  feedback = (justStaticExecutables final.haskellPackages.feedback).overrideAttrs (old: {
+    passthru = (old.passthru or { }) // {
+      shellHook = ''
+        ${final.haskellPackages.feedback}/bin/feedback
       '';
     };
+  });
 
-  feedback = final.feedbackRelease;
+  haskellPackages = prev.haskellPackages.override (old: {
+    overrides = composeExtensions (old.overrides or (_: _: { })) (
+      self: super:
+        {
+          feedback = generateOptparseApplicativeCompletion "feedback" (
+            buildFromSdist (overrideCabal
+              (
+                self.callPackage
+                  ../feedback
+                  { }
+              )
+              (old: {
+                doBenchmark = true;
+                doHaddock = true;
+                doCoverage = false;
+                doHoogle = true;
+                hyperlinkSource = false;
+                enableLibraryProfiling = false;
+                enableExecutableProfiling = false;
 
-  haskellPackages =
-    previous.haskellPackages.override (
-      old:
-      {
-        overrides =
-          composeExtensions (old.overrides or (_: _: { })) (
-            self: super:
-              final.feedbackPackages
-          );
-      }
+                configureFlags = (old.configureFlags or [ ]) ++ [
+                  # Optimisations
+                  "--ghc-options=-O2"
+                  # Extra warnings
+                  "--ghc-options=-Wall"
+                  "--ghc-options=-Wincomplete-uni-patterns"
+                  "--ghc-options=-Wincomplete-record-updates"
+                  "--ghc-options=-Wpartial-fields"
+                  "--ghc-options=-Widentities"
+                  "--ghc-options=-Wredundant-constraints"
+                  "--ghc-options=-Wcpp-undef"
+                  "--ghc-options=-Werror"
+                  "--ghc-options=-optP-Wno-nonportable-include-path" # For macos
+                ];
+                # Ugly hack because we can't just add flags to the 'test' invocation.
+                # Show test output as we go, instead of all at once afterwards.
+                testTarget = (old.testTarget or "") + " --show-details=direct";
+              })));
+        }
     );
+  });
 }
diff --git a/nix/pkgs.nix b/nix/pkgs.nix
deleted file mode 100644
index c1fa8c8..0000000
--- a/nix/pkgs.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-{ sources ? import ./sources.nix
-}:
-import sources.nixpkgs {
-  overlays =
-    [
-      (final: previous: { inherit (import sources.gitignore { inherit (final) lib; }) gitignoreSource; })
-      (import (sources.autodocodec + "/nix/overlay.nix"))
-      (import (sources.safe-coloured-text + "/nix/overlay.nix"))
-      (import (sources.sydtest + "/nix/overlay.nix"))
-      (import (sources.validity + "/nix/overlay.nix"))
-      (import ./overlay.nix)
-    ];
-  config.allowUnfree = true;
-}
diff --git a/nix/pre-commit.nix b/nix/pre-commit.nix
deleted file mode 100644
index a5ad66a..0000000
--- a/nix/pre-commit.nix
+++ /dev/null
@@ -1,21 +0,0 @@
-{ sources ? import ./sources.nix }:
-let
-  pre-commit-hooks = import sources.pre-commit-hooks;
-in
-{
-  run = pre-commit-hooks.run {
-    src = ../.;
-    hooks = {
-      hlint.enable = true;
-      hpack.enable = true;
-      nixpkgs-fmt.enable = true;
-      ormolu.enable = true;
-    };
-  };
-  tools = with pre-commit-hooks; [
-    hlint
-    hpack
-    nixpkgs-fmt
-    ormolu
-  ];
-}
diff --git a/nix/sources.json b/nix/sources.json
deleted file mode 100644
index fba086d..0000000
--- a/nix/sources.json
+++ /dev/null
@@ -1,98 +0,0 @@
-{
-    "autodocodec": {
-        "branch": "master",
-        "description": "self(auto)- documenting encoders and decoders",
-        "homepage": "",
-        "owner": "NorfairKing",
-        "repo": "autodocodec",
-        "rev": "98135d2b24c4c52f56f53c6650a169aeec61c7f1",
-        "sha256": "0srbn65343a213690samf7pf2q0kvnngpv6wn0srm57dpv0f68hn",
-        "type": "tarball",
-        "url": "https://github.com/NorfairKing/autodocodec/archive/98135d2b24c4c52f56f53c6650a169aeec61c7f1.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "gitignore": {
-        "branch": "master",
-        "description": "Nix functions for filtering local git sources",
-        "homepage": "",
-        "owner": "hercules-ci",
-        "repo": "gitignore.nix",
-        "rev": "a20de23b925fd8264fd7fad6454652e142fd7f73",
-        "sha256": "07vg2i9va38zbld9abs9lzqblz193vc5wvqd6h7amkmwf66ljcgh",
-        "type": "tarball",
-        "url": "https://github.com/hercules-ci/gitignore.nix/archive/a20de23b925fd8264fd7fad6454652e142fd7f73.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "niv": {
-        "branch": "master",
-        "description": "Easy dependency management for Nix projects",
-        "homepage": "https://github.com/nmattia/niv",
-        "owner": "nmattia",
-        "repo": "niv",
-        "rev": "82e5cd1ad3c387863f0545d7591512e76ab0fc41",
-        "sha256": "090l219mzc0gi33i3psgph6s2pwsc8qy4lyrqjdj4qzkvmaj65a7",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/82e5cd1ad3c387863f0545d7591512e76ab0fc41.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs": {
-        "branch": "nixos-22.05",
-        "description": "Nix Packages collection",
-        "homepage": "",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "a82127cea64fd801c5e138ae23dfd444ec1e06d1",
-        "sha256": "07i03bwpk5s6daqc5s1v02zfjzmvl5sz8s3xccg9akcbn9phyn2s",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/a82127cea64fd801c5e138ae23dfd444ec1e06d1.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "pre-commit-hooks": {
-        "branch": "master",
-        "description": "Seamless integration of https://pre-commit.com git hooks with Nix.",
-        "homepage": "",
-        "owner": "cachix",
-        "repo": "pre-commit-hooks.nix",
-        "rev": "521a524771a8e93caddaa0ac1d67d03766a8b0b3",
-        "sha256": "16qfrylk41r7gc7g4352hxz7b3vk9w7bc6893apmmr6yy08ra0m9",
-        "type": "tarball",
-        "url": "https://github.com/cachix/pre-commit-hooks.nix/archive/521a524771a8e93caddaa0ac1d67d03766a8b0b3.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "safe-coloured-text": {
-        "branch": "master",
-        "description": null,
-        "homepage": "https://cs-syd.eu/posts/2021-03-07-safe-coloured-text",
-        "owner": "NorfairKing",
-        "repo": "safe-coloured-text",
-        "rev": "675cb01fce5f46718416d7746de5b856ed90a63f",
-        "sha256": "18lf28k51f24smkyba0dfv1hqz3jxfqr81w70zjvbw77z5q0vxf6",
-        "type": "tarball",
-        "url": "https://github.com/NorfairKing/safe-coloured-text/archive/675cb01fce5f46718416d7746de5b856ed90a63f.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "sydtest": {
-        "branch": "master",
-        "description": "A modern testing framework for Haskell with good defaults and advanced testing features.",
-        "homepage": "",
-        "owner": "NorfairKing",
-        "repo": "sydtest",
-        "rev": "130de92053c1c3d60a8f45d509210415ffbea530",
-        "sha256": "1873sjmmxfmf2iig5p1ka0y7n7n1zmiv92d6pq4cyc9a2f10184a",
-        "type": "tarball",
-        "url": "https://github.com/NorfairKing/sydtest/archive/130de92053c1c3d60a8f45d509210415ffbea530.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "validity": {
-        "branch": "master",
-        "description": "Validity and validity-based testing",
-        "homepage": "https://www.youtube.com/watch?v=eIs9qNh17SM",
-        "owner": "NorfairKing",
-        "repo": "validity",
-        "rev": "8373ac5f0f02ad66f1b83c9bf572290430e84062",
-        "sha256": "04rs2hq9xz9y8w5zpc15zazm8dcbkd5kryh4cy7yww187jgp0saq",
-        "type": "tarball",
-        "url": "https://github.com/NorfairKing/validity/archive/8373ac5f0f02ad66f1b83c9bf572290430e84062.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    }
-}
diff --git a/nix/sources.nix b/nix/sources.nix
deleted file mode 100644
index 3f84104..0000000
--- a/nix/sources.nix
+++ /dev/null
@@ -1,177 +0,0 @@
-# This file has been generated by Niv.
-
-let
-
-  #
-  # The fetchers. fetch_<type> fetches specs of type <type>.
-  #
-
-  fetch_file = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-    if spec.builtin or true then
-      builtins_fetchurl { inherit (spec) url sha256; name = name'; }
-    else
-      pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
-
-  fetch_tarball = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-    if spec.builtin or true then
-      builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
-    else
-      pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
-
-  fetch_git = name: spec:
-    let
-      ref =
-        if spec ? ref then spec.ref else
-        if spec ? branch then "refs/heads/${spec.branch}" else
-        if spec ? tag then "refs/tags/${spec.tag}" else
-        abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
-    in
-    builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
-
-  fetch_local = spec: spec.path;
-
-  fetch_builtin-tarball = name: throw
-    ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=tarball -a builtin=true'';
-
-  fetch_builtin-url = name: throw
-    ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=file -a builtin=true'';
-
-  #
-  # Various helpers
-  #
-
-  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
-  sanitizeName = name:
-    (
-      concatMapStrings (s: if builtins.isList s then "-" else s)
-        (
-          builtins.split "[^[:alnum:]+._?=-]+"
-            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
-        )
-    );
-
-  # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources: system:
-    let
-      sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
-      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
-      hasThisAsNixpkgsPath = <nixpkgs> == ./.;
-    in
-    if builtins.hasAttr "nixpkgs" sources
-    then sourcesNixpkgs
-    else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
-      import <nixpkgs> { }
-    else
-      abort
-        ''
-          Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
-          add a package called "nixpkgs" to your sources.json.
-        '';
-
-  # The actual fetching function.
-  fetch = pkgs: name: spec:
-
-    if ! builtins.hasAttr "type" spec then
-      abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file pkgs name spec
-    else if spec.type == "tarball" then fetch_tarball pkgs name spec
-    else if spec.type == "git" then fetch_git name spec
-    else if spec.type == "local" then fetch_local spec
-    else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
-    else if spec.type == "builtin-url" then fetch_builtin-url name
-    else
-      abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
-
-  # If the environment variable NIV_OVERRIDE_${name} is set, then use
-  # the path directly as opposed to the fetched source.
-  replace = name: drv:
-    let
-      saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
-      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
-    in
-    if ersatz == "" then drv else
-      # this turns the string into an actual Nix path (for both absolute and
-      # relative paths)
-    if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
-
-  # Ports of functions for older nix versions
-
-  # a Nix version of mapAttrs if the built-in doesn't exist
-  mapAttrs = builtins.mapAttrs or (
-    f: set: with builtins;
-    listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set))
-  );
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1);
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
-  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
-  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
-  concatMapStrings = f: list: concatStrings (map f list);
-  concatStrings = builtins.concatStringsSep "";
-
-  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else { };
-
-  # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchTarball;
-    in
-    if lessThan nixVersion "1.12" then
-      fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-    else
-      fetchTarball attrs;
-
-  # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchurl;
-    in
-    if lessThan nixVersion "1.12" then
-      fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-    else
-      fetchurl attrs;
-
-  # Create the final "sources" from the config
-  mkSources = config:
-    mapAttrs
-      (
-        name: spec:
-          if builtins.hasAttr "outPath" spec
-          then
-            abort
-              "The values in sources.json should not have an 'outPath' attribute"
-          else
-            spec // { outPath = replace name (fetch config.pkgs name spec); }
-      )
-      config.sources;
-
-  # The "config" used by the fetchers
-  mkConfig =
-    { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then { } else builtins.fromJSON (builtins.readFile sourcesFile)
-    , system ? builtins.currentSystem
-    , pkgs ? mkPkgs sources system
-    }: rec {
-      # The sources, i.e. the attribute set of spec name to spec
-      inherit sources;
-
-      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
-      inherit pkgs;
-    };
-
-in
-mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); }
diff --git a/shell.nix b/shell.nix
deleted file mode 100644
index 1ff4ae6..0000000
--- a/shell.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-{ sources ? import ./nix/sources.nix
-, pkgs ? import ./nix/pkgs.nix { inherit sources; }
-, pre-commit ? import ./nix/pre-commit.nix { inherit sources; }
-}:
-pkgs.haskell.lib.buildStackProject {
-  name = "feedback-shell";
-  buildInputs = with pkgs; [
-    (import sources.niv { }).niv
-    zlib
-  ] ++ pre-commit.tools;
-}
diff --git a/stack.yaml b/stack.yaml
deleted file mode 100644
index 6070f0b..0000000
--- a/stack.yaml
+++ /dev/null
@@ -1,64 +0,0 @@
-resolver: lts-19.6
-
-packages:
-- feedback
-
-ghc-options:
-  "$locals": -Wall -Wincomplete-uni-patterns -Wincomplete-record-updates -Wpartial-fields -Widentities -Wredundant-constraints -Wcpp-undef
-
-extra-deps:
-- github: NorfairKing/safe-coloured-text
-  commit: 675cb01fce5f46718416d7746de5b856ed90a63f
-  subdirs:
-    - safe-coloured-text
-    - safe-coloured-text-layout
-    - safe-coloured-text-terminfo
-- github: NorfairKing/sydtest
-  commit: 130de92053c1c3d60a8f45d509210415ffbea530
-  subdirs:
-    - sydtest
-- github: NorfairKing/autodocodec
-  commit: 98135d2b24c4c52f56f53c6650a169aeec61c7f1
-  subdirs:
-    - autodocodec
-    - autodocodec-schema
-    - autodocodec-yaml
-- github: NorfairKing/validity
-  commit: 8373ac5f0f02ad66f1b83c9bf572290430e84062
-  subdirs:
-    - genvalidity
-    - genvalidity-aeson
-    - genvalidity-bytestring
-    - genvalidity-containers
-    - genvalidity-criterion
-    - genvalidity-path
-    - genvalidity-persistent
-    - genvalidity-property
-    - genvalidity-scientific
-    - genvalidity-sydtest
-    - genvalidity-sydtest-aeson
-    - genvalidity-sydtest-hashable
-    - genvalidity-sydtest-lens
-    - genvalidity-sydtest-persistent
-    - genvalidity-text
-    - genvalidity-time
-    - genvalidity-unordered-containers
-    - genvalidity-uuid
-    - genvalidity-vector
-    - validity
-    - validity-aeson
-    - validity-bytestring
-    - validity-containers
-    - validity-path
-    - validity-persistent
-    - validity-primitive
-    - validity-scientific
-    - validity-text
-    - validity-time
-    - validity-unordered-containers
-    - validity-uuid
-    - validity-vector
-
-nix:
-  enable: true
-  shell-file: shell.nix