diff --git a/app/src/main/java/com/campusaula/edbole/kanban_clone_android/ui/CollaboratorAddActivity.kt b/app/src/main/java/com/campusaula/edbole/kanban_clone_android/ui/CollaboratorAddActivity.kt
new file mode 100644
index 0000000..e68042e
--- /dev/null
+++ b/app/src/main/java/com/campusaula/edbole/kanban_clone_android/ui/CollaboratorAddActivity.kt
@@ -0,0 +1,126 @@
+package com.campusaula.edbole.kanban_clone_android.ui
+
+import android.content.Intent
+import android.os.Bundle
+import android.util.Log
+import android.util.Patterns
+import android.widget.Button
+import android.widget.EditText
+import android.widget.Toast
+import androidx.activity.enableEdgeToEdge
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.lifecycle.lifecycleScope
+import com.campusaula.edbole.kanban_clone_android.R
+import com.campusaula.edbole.kanban_clone_android.network.ApiService
+import com.campusaula.edbole.kanban_clone_android.network.RetrofitInstance
+import com.google.android.material.floatingactionbutton.FloatingActionButton
+import kotlinx.coroutines.launch
+
+class CollaboratorAddActivity : AppCompatActivity() {
+
+    private lateinit var api: ApiService
+
+    private lateinit var returnActionButton: FloatingActionButton
+    private lateinit var collaboratorEmailInput: EditText
+    private lateinit var addCollaboratorButton: Button
+
+    private var projectId: Int = -1
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContentView(R.layout.activity_collaborator_add)
+        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
+            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
+            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
+            insets
+        }
+
+        api = RetrofitInstance.getRetrofit(applicationContext).create(ApiService::class.java)
+
+        // Get project ID from intent
+        projectId = intent.getIntExtra("project_id", -1)
+
+        if (projectId == -1) {
+            Toast.makeText(this, "Error: Invalid project ID", Toast.LENGTH_SHORT).show()
+            finish()
+            return
+        }
+
+        // Initialize views
+        returnActionButton = findViewById(R.id.returnActionButton)
+        collaboratorEmailInput = findViewById(R.id.collaboratorEmailInput)
+        addCollaboratorButton = findViewById(R.id.addCollaboratorButton)
+
+        // Set up button listeners
+        returnActionButton.setOnClickListener {
+            finish()
+
+            val intent = Intent(this@CollaboratorAddActivity, ProjectDetailActivity::class.java)
+            intent.putExtra("project_id", projectId)
+            startActivity(intent)
+
+        }
+
+        addCollaboratorButton.setOnClickListener {
+            addCollaborator()
+        }
+    }
+
+    private fun addCollaborator() {
+        val user_email = collaboratorEmailInput.text.toString().trim()
+
+        // Validate email
+        if (user_email.isEmpty()) {
+            Toast.makeText(this, "Email cannot be empty", Toast.LENGTH_SHORT).show()
+            return
+        }
+
+        if (!Patterns.EMAIL_ADDRESS.matcher(user_email).matches()) {
+            Toast.makeText(this, "Please enter a valid email address", Toast.LENGTH_SHORT).show()
+            return
+        }
+
+        lifecycleScope.launch {
+            try {
+                Log.d("CollaboratorAddActivity", "Adding collaborator: $user_email")
+                val emailBody = mapOf("user_email" to user_email)
+                val response = api.addProjectCollaborator(projectId, emailBody)
+
+                if (response.isSuccessful) {
+                    Log.d("CollaboratorAddActivity", "Collaborator added successfully")
+                    Toast.makeText(
+                        this@CollaboratorAddActivity,
+                        "Collaborator added successfully",
+                        Toast.LENGTH_SHORT
+                    ).show()
+                    setResult(RESULT_OK)
+                    finish()
+
+                    // Reopen ProjectDetailActivity to show the new collaborator
+                    val intent = Intent(this@CollaboratorAddActivity, ProjectDetailActivity::class.java)
+                    intent.putExtra("project_id", projectId)
+                    startActivity(intent)
+                } else {
+                    val errorBody = response.errorBody()?.string()
+                    Log.e("CollaboratorAddActivity", "Error adding collaborator: $errorBody")
+                    Toast.makeText(
+                        this@CollaboratorAddActivity,
+                        "Error adding collaborator: ${response.code()}",
+                        Toast.LENGTH_SHORT
+                    ).show()
+                }
+            } catch (e: Exception) {
+                Log.e("CollaboratorAddActivity", "Exception adding collaborator: ${e.message}")
+                Toast.makeText(
+                    this@CollaboratorAddActivity,
+                    "Failed to add collaborator: ${e.message}",
+                    Toast.LENGTH_SHORT
+                ).show()
+            }
+        }
+    }
+}
+
diff --git a/app/src/main/res/layout/activity_collaborator_add.xml b/app/src/main/res/layout/activity_collaborator_add.xml
new file mode 100644
index 0000000..b31ddce
--- /dev/null
+++ b/app/src/main/res/layout/activity_collaborator_add.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/main"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".ui.CollaboratorAddActivity">
+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/returnActionButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="@dimen/fab_margin_end"
+        android:layout_marginBottom="@dimen/fab_margin_bottom"
+        android:contentDescription="Return"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:srcCompat="@android:drawable/ic_menu_revert" />
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:orientation="vertical"
+        android:paddingBottom="@dimen/bottom_padding_for_fab">
+
+        <TextView
+            android:id="@+id/titleLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="Add Collaborator"
+            android:textSize="@dimen/text_size_title"
+            android:textStyle="bold"
+            android:padding="@dimen/padding_standard"
+            android:layout_marginTop="@dimen/margin_tiny" />
+
+        <TextView
+            android:id="@+id/collaboratorEmailLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="Email Address:"
+            android:textSize="@dimen/text_size_subtitle"
+            android:textStyle="bold"
+            android:layout_marginTop="@dimen/margin_medium"
+            android:paddingLeft="@dimen/padding_standard"
+            android:paddingRight="@dimen/padding_standard" />
+
+        <EditText
+            android:id="@+id/collaboratorEmailInput"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="Enter collaborator email"
+            android:inputType="textEmailAddress"
+            android:padding="@dimen/padding_standard"
+            android:layout_marginLeft="@dimen/margin_standard"
+            android:layout_marginRight="@dimen/margin_standard"
+            android:layout_marginTop="@dimen/margin_small" />
+
+        <Button
+            android:id="@+id/addCollaboratorButton"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="Add Collaborator"
+            android:backgroundTint="@color/primary_green"
+            android:layout_marginTop="@dimen/margin_large"
+            android:layout_marginLeft="@dimen/margin_standard"
+            android:layout_marginRight="@dimen/margin_standard" />
+
+    </LinearLayout>
+
+</androidx.constraintlayout.widget.ConstraintLayout>