diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..96f1e2f
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,12 @@
+{ pkgs ? import <nixpkgs> { } }:
+let
+  myPkgs = import ./pkgs { inherit pkgs; };
+  myPatchedPkgs = import ./patches { pkgs = pkgs // myPkgs; };
+in
+{
+  modules = import ./modules;
+  overlays = {
+    pkgs = import ./pkgs/overlay.nix;
+    patches = import ./patches/overlay.nix;
+  };
+} // myPkgs // myPatchedPkgs
diff --git a/modules/default.nix b/modules/default.nix
new file mode 100644
index 0000000..2c63c08
--- /dev/null
+++ b/modules/default.nix
@@ -0,0 +1,2 @@
+{
+}
diff --git a/patches/default.nix b/patches/default.nix
new file mode 100644
index 0000000..9a59815
--- /dev/null
+++ b/patches/default.nix
@@ -0,0 +1,8 @@
+{ pkgs }:
+let
+  # self is not included here to avoid recursion.
+  callPackage = pkgs.lib.callPackageWith pkgs;
+  self = rec {
+  };
+in
+self
diff --git a/patches/overlay.nix b/patches/overlay.nix
new file mode 100644
index 0000000..2959fa1
--- /dev/null
+++ b/patches/overlay.nix
@@ -0,0 +1,4 @@
+self: super:
+
+{
+}
diff --git a/pkgs/default.nix b/pkgs/default.nix
new file mode 100644
index 0000000..9ef3fcf
--- /dev/null
+++ b/pkgs/default.nix
@@ -0,0 +1,13 @@
+{ pkgs, lib ? pkgs.lib }:
+let
+  callPackage = lib.callPackageWith (pkgs // self);
+  callPackageWithMerged = attrName: f: extraArgs:
+    let
+      mergedSubset = pkgs.${attrName} // self.${attrName};
+      subsetArgs = builtins.listToAttrs [{ name = attrName; value = mergedSubset; }];
+    in
+    callPackage f (subsetArgs // extraArgs);
+  self = rec {
+  };
+in
+self
diff --git a/pkgs/overlay.nix b/pkgs/overlay.nix
new file mode 100644
index 0000000..ce39825
--- /dev/null
+++ b/pkgs/overlay.nix
@@ -0,0 +1,3 @@
+self: super:
+{
+}