diff --git a/README.md b/README.md
index a495df0..a3b748b 100644
--- a/README.md
+++ b/README.md
@@ -1,16 +1,30 @@
-# nim-e2e-reliability
-Nim implementation of the e2e reliability protocol
+# nim-sds
+
+Nim implementation of the e2e reliability protocol.
+
+## Quick start
+
+```bash
+# Build the shared library
+nix build '.?submodules=1#libsds'
+
+# Run tests
+nix develop '.?submodules=1' --command nim test sds.nims
+
+# Clean the Nix store
+nix run '.#clean'
+```
 
 ## Building
 
-### Nix (recommended)
+### Desktop
 
-Build the shared library:
 ```bash
 nix build --print-out-paths '.?submodules=1#libsds'
 ```
 
-Build for Android:
+### Android
+
 ```bash
 nix build --print-out-paths '.?submodules=1#libsds-android-arm64'
 nix build --print-out-paths '.?submodules=1#libsds-android-amd64'
@@ -18,14 +32,15 @@ nix build --print-out-paths '.?submodules=1#libsds-android-x86'
 nix build --print-out-paths '.?submodules=1#libsds-android-arm'
 ```
 
-### Development shell
+<details>
+<summary>Development shell</summary>
 
 Enter the dev shell (sets up vendored dependencies automatically):
 ```bash
 nix develop '.?submodules=1'
 ```
 
-Then build directly with nim:
+Then build directly with Nim:
 ```bash
 # Linux
 nim libsdsDynamicLinux sds.nims
@@ -42,12 +57,15 @@ nim libsdsStaticWindows sds.nims
 
 Run tests:
 ```bash
-nimble test
+nim test sds.nims
 ```
 
 The built library is output to `build/`.
 
-### Android (without Nix)
+</details>
+
+<details>
+<summary>Android (without Nix)</summary>
 
 Download the latest Android NDK. For example, on Ubuntu with Intel:
 
@@ -82,3 +100,12 @@ ARCH=arm64 ANDROID_ARCH=aarch64-linux-android ARCH_DIRNAME=aarch64-linux-android
 | arm | `arm` | `armv7a-linux-androideabi` | `arm-linux-androideabi` |
 
 The library is output to `build/libsds.so`.
+
+</details>
+
+## Maintenance
+
+```bash
+# Clean unreferenced Nix store packages
+nix run '.#clean'
+```
diff --git a/flake.lock b/flake.lock
index cc4a595..1ca4043 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,27 +1,5 @@
 {
   "nodes": {
-    "nimbusBuildSystem": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1769685810,
-        "narHash": "sha256-mANqcQcRXb08ZR8WF6SoyVrL/nXUePtMZfpNx25BlLI=",
-        "ref": "refs/heads/master",
-        "rev": "0e7a764edae92b224326b3700f062702489ce2b4",
-        "revCount": 238,
-        "submodules": true,
-        "type": "git",
-        "url": "file:./vendor/nimbus-build-system"
-      },
-      "original": {
-        "submodules": true,
-        "type": "git",
-        "url": "file:./vendor/nimbus-build-system"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1757590060,
@@ -40,7 +18,6 @@
     },
     "root": {
       "inputs": {
-        "nimbusBuildSystem": "nimbusBuildSystem",
         "nixpkgs": "nixpkgs"
       }
     }
diff --git a/flake.nix b/flake.nix
index 40989bb..b2a930b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -7,19 +7,12 @@
   };
 
   inputs = {
-    # We are pinning the commit because ultimately we want to use same commit across different projects.
-    # A commit from nixpkgs 24.11 release : https://github.com/NixOS/nixpkgs/tree/release-24.11
+    # Pinned commit from nixpkgs 24.11 release (provides Nim 2.2.4).
+    # https://github.com/NixOS/nixpkgs/tree/release-24.11
     nixpkgs.url = "github:NixOS/nixpkgs?rev=0ef228213045d2cdb5a169a95d63ded38670b293";
-    # Used only for its pinned Nim compiler package.
-    # The build system itself (Makefiles, env.sh) is NOT used — we call nimble directly.
-    # WARNING: Remember to update commit and use 'nix flake update' to update flake.lock.
-    nimbusBuildSystem = {
-      url = "git+file:./vendor/nimbus-build-system?submodules=1";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
   };
 
-  outputs = { self, nixpkgs, nimbusBuildSystem }:
+  outputs = { self, nixpkgs }:
     let
       stableSystems = [
         "x86_64-linux" "aarch64-linux"
@@ -49,10 +42,9 @@
     in rec {
       packages = forAllSystems (system: let
         pkgs = pkgsFor.${system};
-        nim = nimbusBuildSystem.packages.${system}.nim;
 
         buildTargets = pkgs.callPackage ./nix/default.nix {
-          inherit stableSystems nim;
+          inherit stableSystems;
           src = self;
         };
 
@@ -76,8 +68,18 @@
       }) targets));
 
       devShells = forAllSystems (system: {
-        default = pkgsFor.${system}.callPackage ./nix/shell.nix {
-          inherit (nimbusBuildSystem.packages.${system}) nim;
+        default = pkgsFor.${system}.callPackage ./nix/shell.nix {};
+      });
+
+      # nix run '.#clean' — garbage-collect the Nix store
+      apps = forAllSystems (system: {
+        clean = {
+          type = "app";
+          program = toString (pkgsFor.${system}.writeShellScript "nix-clean" ''
+            echo "Removing old Nix generations and unreferenced packages..."
+            nix-collect-garbage -d
+            echo "Done."
+          '');
         };
       });
     };
diff --git a/vendor/nimbus-build-system b/vendor/nimbus-build-system
deleted file mode 160000
index 0e7a764..0000000
--- a/vendor/nimbus-build-system
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 0e7a764edae92b224326b3700f062702489ce2b4