diff --git a/Jenkinsfile b/Jenkinsfile
index 479058f..574357f 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -1,20 +1,40 @@
 pipeline {
     agent any
+    environment {
+        GIT_CREDENTIALS = 'jenkins-gitea-karel-token' // the ID of your Jenkins Gitea credentials
+    }
     stages {
-        stage('Build') {
+        stage('Checkout') {
             steps {
-                echo 'Building...'
+                // Clone repo
+                git branch: 'main', credentialsId: env.GIT_CREDENTIALS, url: 'https://git.karel.one/karel/test.git'
             }
         }
-        stage('Test') {
+        stage('Modify File') {
             steps {
-                echo 'Testing...'
+                script {
+                    // Append a line to test.txt (create if it doesn't exist)
+                    def file = 'test.txt'
+                    if (!fileExists(file)) {
+                        writeFile file: file, text: 'This is the first line\n'
+                    } else {
+                        writeFile file: file, text: readFile(file) + "Updated by Jenkins at ${new Date()}\n"
+                    }
+                }
             }
         }
-        stage('Deploy') {
+        stage('Commit & Push') {
             steps {
-                echo 'Deploying...'
+                script {
+                    sh '''
+                        git config user.name "jenkins"
+                        git config user.email "jenkins@example.com"
+                        git add test.txt
+                        git commit -m "Update test.txt from Jenkins"
+                        git push origin main
+                    '''
+                }
             }
         }
     }
-}
+}
\ No newline at end of file