diff --git a/environmentManager/index.js b/environmentManager/index.js
index 5723551..0a9aeb2 100644
--- a/environmentManager/index.js
+++ b/environmentManager/index.js
@@ -1,10 +1,11 @@
 const settings = require('../utils/parserConfigs')();
-const { validEnvironment, validEnvironmentConfig, isString, throwError } = require('../utils/parserConfigs/validators');
+const { validEnvironment, validEnvironmentConfig, isString, throwError, validFlagSets } = require('../utils/parserConfigs/validators');
 const { getSplitFactory } = require('../sdk');
 const { obfuscate } = require('../utils/utils');
 const SPLIT_EVALUATOR_ENVIRONMENTS = 'SPLIT_EVALUATOR_ENVIRONMENTS';
 const SPLIT_EVALUATOR_AUTH_TOKEN = 'SPLIT_EVALUATOR_AUTH_TOKEN';
 const SPLIT_EVALUATOR_API_KEY = 'SPLIT_EVALUATOR_API_KEY';
+const DEFAULT_AUTH_TOKEN = 'DEFAULT_AUTH_TOKEN';
 
 const EnvironmentManagerFactory = (function(){
   /**
@@ -29,13 +30,16 @@ const EnvironmentManagerFactory = (function(){
     }
 
     _initializeEnvironments(){
+
+      let defaultEnvironment = false;
       // If environments envVar is not defined, it creates an environment with auth_token and api_key envVars
       if (!process.env.SPLIT_EVALUATOR_ENVIRONMENTS) {
+        defaultEnvironment = true;
         const AUTH_TOKEN = process.env.SPLIT_EVALUATOR_AUTH_TOKEN;
         // If auth_token envVar is not defined, means that openapi security tag should not be added
         if (!AUTH_TOKEN) {
           this.requireAuth = false;
-          process.env.SPLIT_EVALUATOR_AUTH_TOKEN = 'splitToken';
+          process.env.SPLIT_EVALUATOR_AUTH_TOKEN = DEFAULT_AUTH_TOKEN;
         }
         process.env.SPLIT_EVALUATOR_ENVIRONMENTS = `[{
           "AUTH_TOKEN": "${process.env[SPLIT_EVALUATOR_AUTH_TOKEN]}",
@@ -45,11 +49,17 @@ const EnvironmentManagerFactory = (function(){
 
       const environmentConfigs = validEnvironmentConfig(SPLIT_EVALUATOR_ENVIRONMENTS);
 
+      if (!defaultEnvironment && settings.sync && settings.sync.splitFilters) {
+        throwError('Flag sets must be defined in SPLIT_EVALUATOR_ENVIRONMENTS, initialization aborted');
+        process.exit(0);
+      }
+
       environmentConfigs.forEach(environment => {
 
         validEnvironment(environment);
         const authToken = environment['AUTH_TOKEN'];
         const apiKey = environment['API_KEY'];
+        const maybeFlagSets = environment['FLAG_SET_FILTER'];
         settings.core.authorizationKey = apiKey;
 
         if(!isString(authToken)) {
@@ -60,6 +70,14 @@ const EnvironmentManagerFactory = (function(){
           throwError(`There are two or more environments with the same authToken '${authToken}' `);
         }
 
+        if (!defaultEnvironment) {
+          const flagSets = validFlagSets(maybeFlagSets);
+          settings.sync = {
+            ...settings.sync,
+            splitFilters: flagSets,
+          };
+        }
+
         const { factory, telemetry, impressionsMode} = getSplitFactory(settings);
 
         // Creates an environment for authToken
@@ -105,7 +123,7 @@ const EnvironmentManagerFactory = (function(){
     }
 
     getFactory(authToken) {
-      if (!this.requireAuth) authToken = 'splitToken';
+      if (!this.requireAuth) authToken = DEFAULT_AUTH_TOKEN;
       return this._environments[authToken].factory;
     }
 
@@ -122,7 +140,7 @@ const EnvironmentManagerFactory = (function(){
     }
 
     getTelemetry(authToken) {
-      if (!this.requireAuth) authToken = 'splitToken';
+      if (!this.requireAuth) authToken = DEFAULT_AUTH_TOKEN;
       const environment = this.getEnvironment(authToken);
       const telemetry = environment.telemetry;
       const stats = {
@@ -152,7 +170,7 @@ const EnvironmentManagerFactory = (function(){
     }
 
     updateLastEvaluation(authToken) {
-      if (!this.requireAuth) authToken = 'splitToken';
+      if (!this.requireAuth) authToken = DEFAULT_AUTH_TOKEN;
       this._environments[authToken].lastEvaluation = new Date().toJSON();
     }
 
diff --git a/utils/mocks/index.js b/utils/mocks/index.js
index f422881..d357b5b 100644
--- a/utils/mocks/index.js
+++ b/utils/mocks/index.js
@@ -74,10 +74,6 @@ const storage = {
 };
 
 const sync = {
-  splitFilters: [{
-    type: 'byName',
-    values: ['split_name_1', 'split_name_2'],
-  }],
   impressionsMode: 'NONE',
   enabled: false,
 };
diff --git a/utils/parserConfigs/validators.js b/utils/parserConfigs/validators.js
index 3edff3a..7cdc880 100644
--- a/utils/parserConfigs/validators.js
+++ b/utils/parserConfigs/validators.js
@@ -86,6 +86,15 @@ const validGlobalConfig = (globalParam) => {
   }
 };
 
+const validFlagSets = (maybeFlagSets) => {
+  if (!maybeFlagSets) return;
+  if (!isString(maybeFlagSets)) {
+    throwError('you passed an invalid flag set, flag sets must be comma separated a string list');
+    return;
+  }
+  return [{type: 'bySet', values: maybeFlagSets.split(',')}];
+};
+
 module.exports = {
   throwError,
   validUrl,
@@ -96,4 +105,5 @@ module.exports = {
   validEnvironment,
   validEnvironmentConfig,
   validGlobalConfig,
+  validFlagSets,
 };
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