diff --git a/cabal.project b/cabal.project
new file mode 100644
index 0000000..e6fdbad
--- /dev/null
+++ b/cabal.project
@@ -0,0 +1 @@
+packages: .
diff --git a/default.nix b/default.nix
index f714d7a..c6e23fa 100644
--- a/default.nix
+++ b/default.nix
@@ -1,22 +1,20 @@
-{ mkDerivation, aeson, base, bytestring, case-insensitive, hedgehog
-, lifted-base, monad-control, opaleye, postgresql-simple
-, product-profunctors, profunctors, scientific, semigroupoids
-, stdenv, tasty, tasty-hedgehog, text, time, tmp-postgres, uuid
-}:
-mkDerivation {
-  pname = "rel8";
-  version = "0.1.0.0";
-  src = ./.;
-  libraryHaskellDepends = [
-    aeson base bytestring case-insensitive opaleye postgresql-simple
-    product-profunctors profunctors scientific semigroupoids text time
-    uuid
-  ];
-  testHaskellDepends = [
-    base bytestring case-insensitive hedgehog lifted-base monad-control
-    postgresql-simple scientific tasty tasty-hedgehog text time
-    tmp-postgres uuid
-  ];
-  description = "Hey! Hey! Can u rel8?";
-  license = stdenv.lib.licenses.bsd2;
+let 
+  haskellNix = import (import ./nix/sources.nix)."haskell.nix" {};
+
+  nixpkgsSrc = haskellNix.sources.nixpkgs-2009;
+
+  nixpkgsArgs = haskellNix.nixpkgsArgs;
+
+  compiler-nix-name = "ghc8103";
+
+  pkgs = import nixpkgsSrc nixpkgsArgs;
+
+in 
+pkgs.haskell-nix.project {
+  inherit compiler-nix-name;
+
+  src = pkgs.haskell-nix.haskellLib.cleanGit {
+    name = "rel8";
+    src = ./.;
+  };
 }
diff --git a/jobs.nix b/jobs.nix
index 883f649..42bc5a5 100644
--- a/jobs.nix
+++ b/jobs.nix
@@ -1,2 +1,5 @@
-let pkgs = import ./nix/pkgs.nix;
-in { rel8 = pkgs.haskellPackages.rel8; }
+let project = import ./.;
+in { 
+  rel8 = project.hsPkgs.components.library; 
+  tests = project.hsPkgs.components.checks.tests; 
+}
diff --git a/nix/overlays.nix b/nix/overlays.nix
deleted file mode 100644
index 4b947ef..0000000
--- a/nix/overlays.nix
+++ /dev/null
@@ -1,3 +0,0 @@
-[
-  (import ./overlays/haskell-packages.nix)
-]
diff --git a/nix/overlays/haskell-packages.nix b/nix/overlays/haskell-packages.nix
deleted file mode 100644
index 8f79fc3..0000000
--- a/nix/overlays/haskell-packages.nix
+++ /dev/null
@@ -1,40 +0,0 @@
-self:
-super:
-
-let
-  inherit (self) haskell haskellPackages;
-
-  inherit (haskellPackages) callCabal2nix;
-
-  inherit (haskell.lib) addBuildTool appendConfigureFlag packagesFromDirectory;
-
-  inherit (super.lib) composeExtensions;
-
-  pkgs = self;
-
-  WError =
-    drv: appendConfigureFlag drv "--ghc-option=-Werror";
-
-  configurations =
-    self: super: {
-      rel8 = addBuildTool (WError (callCabal2nix "rel8" (builtins.path { path = ../../.; name = "rel8"; }) {})) pkgs.postgresql;
-    };
-
-in
-{
-  haskellPackages =
-    super.haskellPackages.override
-      (
-        old:
-          {
-            overrides =
-              composeExtensions
-                (old.overrides or (_: _: {}))
-                (
-                  composeExtensions
-                    (packagesFromDirectory { directory = ./haskell-packages; })
-                    configurations
-                );
-          }
-      );
-}
diff --git a/nix/overlays/haskell-packages/opaleye.nix b/nix/overlays/haskell-packages/opaleye.nix
deleted file mode 100644
index d09a562..0000000
--- a/nix/overlays/haskell-packages/opaleye.nix
+++ /dev/null
@@ -1,30 +0,0 @@
-{ mkDerivation, aeson, base, base16-bytestring, bytestring
-, case-insensitive, containers, contravariant, dotenv, hspec
-, hspec-discover, multiset, postgresql-simple, pretty
-, product-profunctors, profunctors, QuickCheck, scientific
-, semigroups, stdenv, text, time, time-locale-compat, transformers
-, uuid, void
-}:
-mkDerivation {
-  pname = "opaleye";
-  version = "0.7.1.0";
-  sha256 = "c65faccdc01207d94500198b3ec33db7daaa25daae28d47f234b9ad6926f9644";
-  revision = "3";
-  editedCabalFile = "14y8nnng9307wb1mafzdr2fmn37cwyfpw9sby8lf9sj467rvghrq";
-  libraryHaskellDepends = [
-    aeson base base16-bytestring bytestring case-insensitive
-    contravariant postgresql-simple pretty product-profunctors
-    profunctors scientific semigroups text time time-locale-compat
-    transformers uuid void
-  ];
-  testHaskellDepends = [
-    aeson base bytestring containers contravariant dotenv hspec
-    hspec-discover multiset postgresql-simple product-profunctors
-    profunctors QuickCheck semigroups text time transformers uuid
-  ];
-  testToolDepends = [ hspec-discover ];
-  doCheck = false;
-  homepage = "https://github.com/tomjaguarpaw/haskell-opaleye";
-  description = "An SQL-generating DSL targeting PostgreSQL";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/overlays/haskell-packages/tmp-postgres.nix b/nix/overlays/haskell-packages/tmp-postgres.nix
deleted file mode 100644
index 8a46087..0000000
--- a/nix/overlays/haskell-packages/tmp-postgres.nix
+++ /dev/null
@@ -1,35 +0,0 @@
-{ mkDerivation, ansi-wl-pprint, async, base, base64-bytestring
-, bytestring, containers, criterion, cryptohash-sha1, deepseq
-, directory, generic-monoid, hspec, mtl, network, port-utils
-, postgres-options, postgresql-simple, process, stdenv, stm
-, temporary, transformers, unix
-}:
-mkDerivation {
-  pname = "tmp-postgres";
-  version = "1.34.1.0";
-  sha256 = "98514428edaf527cc464cb9a30df89c6168c858e039ab1baf8293471196c3ba2";
-  isLibrary = true;
-  isExecutable = true;
-  libraryHaskellDepends = [
-    ansi-wl-pprint async base base64-bytestring bytestring containers
-    cryptohash-sha1 deepseq directory generic-monoid port-utils
-    postgres-options postgresql-simple process stm temporary
-    transformers unix
-  ];
-  executableHaskellDepends = [
-    async base directory postgres-options postgresql-simple process
-    temporary
-  ];
-  testHaskellDepends = [
-    async base containers directory generic-monoid hspec mtl network
-    port-utils postgres-options postgresql-simple process temporary
-    unix
-  ];
-  benchmarkHaskellDepends = [
-    base criterion deepseq postgres-options postgresql-simple temporary
-  ];
-  doCheck = false;
-  homepage = "https://github.com/jfischoff/tmp-postgres#readme";
-  description = "Start and stop a temporary postgres";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/pkgs.nix b/nix/pkgs.nix
deleted file mode 100644
index b3aab0d..0000000
--- a/nix/pkgs.nix
+++ /dev/null
@@ -1,7 +0,0 @@
-import (builtins.fetchTarball {
-  name = "nixos-20.03";
-  url = "https://github.com/nixos/nixpkgs/archive/0d0660fde3bb53a3d013b65e5e141eb11d1efb82.tar.gz";
-  sha256 = "13qpa916qq1kqvfj8q4zkmnfnbh2kpx0nxxg04nblai0smz97820";
-}) {
-  overlays = import ./overlays.nix;
-}
diff --git a/nix/sources.json b/nix/sources.json
new file mode 100644
index 0000000..bd2440b
--- /dev/null
+++ b/nix/sources.json
@@ -0,0 +1,38 @@
+{
+  "haskell.nix": {
+    "branch": "circuithub",
+    "description": "Alternative Haskell Infrastructure for Nixpkgs",
+    "homepage": "https://input-output-hk.github.io/haskell.nix",
+    "owner": "circuithub",
+    "repo": "haskell.nix",
+    "rev": "2902f9b49484a87afb0e1a33b1d88a2c7b8ca0a0",
+    "sha256": "0a01g5b46z5yaf2mnl415hc4lciwiyqhj22qhgwgwd261w4068iy",
+    "type": "tarball",
+    "url": "https://github.com/circuithub/haskell.nix/archive/2902f9b49484a87afb0e1a33b1d88a2c7b8ca0a0.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": "ba57d5a29b4e0f2085917010380ef3ddc3cf380f",
+    "sha256": "1kpsvc53x821cmjg1khvp1nz7906gczq8mp83664cr15h94sh8i4",
+    "type": "tarball",
+    "url": "https://github.com/nmattia/niv/archive/ba57d5a29b4e0f2085917010380ef3ddc3cf380f.tar.gz",
+    "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+  },
+  "nixpkgs": {
+    "branch": "nixos-20.09",
+    "description": "Nix Packages collection",
+    "homepage": null,
+    "owner": "nixos",
+    "repo": "nixpkgs",
+    "rev": "6e7f25001fe6874f7ae271891f709bbf50a22c45",
+    "sha256": "1x04j4351pqiqbpkq6g308mxcvb5aqnwv8l2vmlxkgvq5phzky7z",
+    "type": "tarball",
+    "url": "https://github.com/nixos/nixpkgs/archive/6e7f25001fe6874f7ae271891f709bbf50a22c45.tar.gz",
+    "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+  }
+}
diff --git a/nix/sources.nix b/nix/sources.nix
new file mode 100644
index 0000000..b64b8f8
--- /dev/null
+++ b/nix/sources.nix
@@ -0,0 +1,148 @@
+# This file has been generated by Niv.
+
+let
+
+  #
+  # The fetchers. fetch_<type> fetches specs of type <type>.
+  #
+
+  fetch_file = pkgs: spec:
+    if spec.builtin or true then
+      builtins_fetchurl { inherit (spec) url sha256; }
+    else
+      pkgs.fetchurl { inherit (spec) url sha256; };
+
+  fetch_tarball = pkgs: name: spec:
+    let
+      ok = str: ! builtins.isNull (builtins.match "[a-zA-Z0-9+-._?=]" str);
+      # sanitize the name, though nix will still fail if name starts with period
+      name' = stringAsChars (x: if ! ok x then "-" else x) "${name}-src";
+    in
+      if spec.builtin or true then
+        builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
+      else
+        pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
+
+  fetch_git = spec:
+    builtins.fetchGit { url = spec.repo; inherit (spec) rev ref; };
+
+  fetch_local = spec: spec.path;
+
+  fetch_builtin-tarball = name: throw
+    ''[${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
+  #
+
+  # The set of packages used when specs are fetched using non-builtins.
+  mkPkgs = sources:
+    let
+      sourcesNixpkgs =
+        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {};
+      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 spec
+    else if spec.type == "tarball" then fetch_tarball pkgs name spec
+    else if spec.type == "git" then fetch_git 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_${saneName}";
+    in
+      if ersatz == "" then drv else ersatz;
+
+  # Ports of functions for older nix versions
+
+  # a Nix version of mapAttrs if the built-in doesn't exist
+  mapAttrs = builtins.mapAttrs or (
+    f: set: with builtins;
+    listToAttrs (map (attr: { name = attr; value = f attr set.${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));
+  concatStrings = builtins.concatStringsSep "";
+
+  # fetchTarball version that is compatible between all the versions of Nix
+  builtins_fetchTarball = { url, name, sha256 }@attrs:
+    let
+      inherit (builtins) lessThan nixVersion fetchTarball;
+    in
+      if lessThan nixVersion "1.12" then
+        fetchTarball { inherit name url; }
+      else
+        fetchTarball attrs;
+
+  # fetchurl version that is compatible between all the versions of Nix
+  builtins_fetchurl = { url, sha256 }@attrs:
+    let
+      inherit (builtins) lessThan nixVersion fetchurl;
+    in
+      if lessThan nixVersion "1.12" then
+        fetchurl { inherit url; }
+      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)
+    , pkgs ? mkPkgs sources
+    }: 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
index 5b74dac..1501765 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,2 +1,8 @@
-let pkgs = import ./nix/pkgs.nix;
-in pkgs.haskellPackages.rel8.env
+let
+  hsPkgs = import ./default.nix {};
+in
+  hsPkgs.shellFor {
+    withHoogle = true;
+    tools = { cabal = "3.2.0.0"; haskell-language-server = "latest"; };
+    exactDeps = true;
+  }