diff --git a/README.md b/README.md
index beabd272cb4aa1cc6429d8cff1599fe4d450768f..542c44d7227dd6fd6a4a0a7dbbc147c5624dde9e 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,30 @@ The fields `device` and `channel` are mandatory and `incremental` is an optional
 - The contents should be read as: Upgrades from major version 9 to major version 9 and to major version 10 are allowed. Upgrades from major version 10 to major version 10 and to major version 11 are allowed.
 - Current version is always available as an upgrade (if a more recent build is found), even if file is not available (for backwards compatibility too).
 
+## How to set incremental rollout percentage in build config file
+
+- You can specify incremental rollout rules by adding values in `config.json` file. You can add the file only if you want percentage incremental rollout for a build.
+- The format of file name will be : `<BUILD_NAME>.zip.config.json`
+
+```shell
+$ cd builds/full/test/guacamoleb/
+$ tree
+.
+├── e.x.xx-xxyyzz-guacamoleb.zip # the full ROM zip file
+└── e.x.xx-xxyyzz-guacamoleb.zip.config.json # the ROM build.config.json file
+```
+
+- E.g. : Suppose builds for "guacamoleb" devices are stored at "/mnt/rom/builds/full/test/guacamoleb". The file "/mnt/rom/builds/full/test/guacamoleb/e.x.xx-xxyyzz-guacamoleb.zip.config.json" should then have contents like:
+```json
+    { 
+        "rollout": {
+            "percentage": 20
+        }   
+    }
+```
+- The `percentage` value must be between 0 to 100. Do not add `%` sign after the value. 
+- The `config.json` file is not mandatory. In case it does not exist, a build will consider a 100% rollout percentage.
+
 ### ONLY for LineageOS 15.x and newer
 
 If you are willing to use this project on top of your LineageOS 15.x ( or newer ) ROM builds, you may have noticed that the file named `build.prop` have been removed inside your ZIP file, and has been instead integrated within your `system.new.dat` file, which is basically an ext4 image ( you can find out more here: https://source.android.com/devices/tech/ota/block ).
diff --git a/src/CmOta.php b/src/CmOta.php
index 8df8c54b2b3f8db3b2ec8bcd2f103aa663d037a9..d04591ff76dbaa7a71ab98bcaaf7a6893cb4d623 100644
--- a/src/CmOta.php
+++ b/src/CmOta.php
@@ -110,25 +110,26 @@
 
             // LineageOS new API
             Flight::route('/api/v1/@deviceType/@romType(/@incrementalVersion)', function ( $deviceType, $romType, $incrementalVersion ){
-              Flight::builds()->setPostData(
-                array(
-                  'params' => array(
-                    'device' => $deviceType,
-                    'channels' => array(
-                      $romType,
-                    ),
-                    'source_incremental' => $incrementalVersion,
-                  ),
-                )
-              );
-
-              $ret = array(
-                  'id' => null,
-                  'response' => Flight::builds()->get(),
-                  'error' => null
-              );
-
-              Flight::json($ret);
+                Flight::builds()->setPostData(
+                    array(
+                      'params' => array(
+                        'device' => $deviceType,
+                        'channels' => array(
+                          $romType,
+                        ),
+                        'source_incremental' => $incrementalVersion,
+                      ),
+                    )
+                  );
+    
+                  $ret = array(
+                      'id' => null,
+                      'response' => Flight::builds()->get(),
+                      'error' => null
+                  );
+    
+                  Flight::json($ret);
+    
             });
         }
 
diff --git a/src/Helpers/Build.php b/src/Helpers/Build.php
index a2e8e70ea142c4d53cf6ad55c603c3c412d9fe4d..f3061a5796d3c76c5d759f39de998d6715844af5 100644
--- a/src/Helpers/Build.php
+++ b/src/Helpers/Build.php
@@ -38,6 +38,7 @@
         private $incremental = '';
         private $filePath = '';
         private $buildProp = '';
+        private $confProp = '';
         private $uid = null;
         private $size = '';
         private $logger = null;
@@ -82,6 +83,7 @@
             // - builds/CURRENT_ZIP_FILE.zip/system/build.prop
             // - builds/CURRENT_ZIP_FILE.zip.prop ( which must exist )
             $this->buildProp = explode("\n", @file_get_contents($this->getPropFilePath()));
+            $this->confProp = $this->getConfProp();
             // Try to fetch build.prop values. In some cases, we can provide a fallback, in other a null value will be given
             $this->timestamp = intval($this->getBuildPropValue('ro.build.date.utc') ?? filemtime($this->filePath));
             $this->incremental = $this->getBuildPropValue('ro.build.version.incremental') ?? '';
@@ -510,4 +512,48 @@
         {
             return is_callable($func) && false === stripos(ini_get('disable_functions'), $func);
         }
-    }
+
+        /**
+         * Check if the current build is valid with multiple conditions
+         * @param type $params The params dictionary inside the current POST request
+         * @return boolean True if valid, False if not.
+         */
+        public function includeInResults($params)
+        {
+            return $this->isValid($params) && $this->checkRollout();
+        }
+
+        /**
+         * Return the correct config file path (depending of version)
+         * @return string
+         */
+        private function getConfigFilePath()
+        {
+            return file_exists($this->filePath . '.config.json') ? $this->filePath . '.config.json' : '';
+        }
+
+        /**
+         * Return the all values from config file path
+         * @return JSON if valid otherwise null
+         */
+        private function getConfProp(){
+            $configFilePath = $this->getConfigFilePath();
+            return ($configFilePath) ?  json_decode( file_get_contents($configFilePath) , true) : array();
+        }
+
+        /**
+         * Return if rollout successful or not for a build
+         * @return boolean
+         */
+        public function checkRollout()
+        {
+            $rolloutpercentage = isset($this->confProp['rollout']['percentage']) ? $this->confProp['rollout']['percentage'] : 100;
+            if ($rolloutpercentage >= 0 && $rolloutpercentage < 100) {
+                $rand_number = rand(0, 100);
+                if ($rand_number > $rolloutpercentage) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
\ No newline at end of file
diff --git a/src/Helpers/Builds.php b/src/Helpers/Builds.php
index fb2ce2bbeeff8f5a92207eb647904d7bbfdeb089..4fa87802f5a0961cf333ecf8189e63b96c9ce03a 100644
--- a/src/Helpers/Builds.php
+++ b/src/Helpers/Builds.php
@@ -203,8 +203,8 @@
                         } else {
                             $build = new Build($file, $dir, $this->logger);
                         }
-
-                        if ($build->isValid($this->postData['params'])) {
+                        
+                        if ($build->includeInResults($this->postData['params'])) {
                             array_push($this->builds, $build);
                             if (!empty($this->postData['params']) && strcmp($this->postData['params']['source_incremental'], $build->getIncremental()) == 0) {
                                 $this->currentBuild = $build;