diff --git a/DemoApp/DemoAppJava/app/src/main/java/co/optable/demoappjava/ui/GAMBanner/GAMBannerFragment.java b/DemoApp/DemoAppJava/app/src/main/java/co/optable/demoappjava/ui/GAMBanner/GAMBannerFragment.java
index 46520d1..79065a4 100644
--- a/DemoApp/DemoAppJava/app/src/main/java/co/optable/demoappjava/ui/GAMBanner/GAMBannerFragment.java
+++ b/DemoApp/DemoAppJava/app/src/main/java/co/optable/demoappjava/ui/GAMBanner/GAMBannerFragment.java
@@ -53,6 +53,7 @@ public View onCreateView(@NonNull LayoutInflater inflater,
 
                 targetingDataView.setText(msg.toString());
                 mPublisherAdView.loadAd(adRequest.build());
+                profile();
                 witness();
             });
         });
@@ -77,6 +78,7 @@ public View onCreateView(@NonNull LayoutInflater inflater,
 
             targetingDataView.setText(msg.toString());
             mPublisherAdView.loadAd(adRequest.build());
+            profile();
             witness();
         });
 
@@ -90,9 +92,33 @@ public View onCreateView(@NonNull LayoutInflater inflater,
         return root;
     }
 
+    private void profile() {
+        HashMap<String,Object> traits = new HashMap<String,Object>();
+        traits.put("gender", "F");
+        traits.put("age", 38);
+        traits.put("hasAccount", true);
+
+        MainActivity.OPTABLE
+                .profile(traits)
+                .observe(getViewLifecycleOwner(), result -> {
+                    final StringBuilder msg = new StringBuilder();
+                    msg.append(targetingDataView.getText().toString());
+
+                    if (result.getStatus() == OptableSDK.Status.SUCCESS) {
+                        msg.append("\n\nSuccess calling profile API to set user traits.\n\n");
+                    } else {
+                        msg.append("\n\nOptableSDK Error: " + result.getMessage() + "\n\n");
+                    }
+
+                    targetingDataView.setText(msg.toString());
+                });
+    }
+
     private void witness() {
-        HashMap<String, String> eventProperties = new HashMap<String, String>();
+        HashMap<String,Object> eventProperties = new HashMap<String,Object>();
         eventProperties.put("exampleKey", "exampleValue");
+        eventProperties.put("exampleKey2", 123);
+        eventProperties.put("exampleKey3", false);
 
         MainActivity.OPTABLE
                 .witness("GAMBannerFragment.loadAdButtonClicked", eventProperties)
diff --git a/DemoApp/DemoAppJava/app/src/main/res/layout/fragment_gambanner.xml b/DemoApp/DemoAppJava/app/src/main/res/layout/fragment_gambanner.xml
index 93b9687..b382477 100644
--- a/DemoApp/DemoAppJava/app/src/main/res/layout/fragment_gambanner.xml
+++ b/DemoApp/DemoAppJava/app/src/main/res/layout/fragment_gambanner.xml
@@ -58,8 +58,8 @@
 
     <TextView
         android:id="@+id/targetingDataView"
-        android:layout_width="282dp"
-        android:layout_height="168dp"
+        android:layout_width="291dp"
+        android:layout_height="346dp"
         android:layout_marginTop="100dp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
diff --git a/DemoApp/DemoAppJava/build.gradle b/DemoApp/DemoAppJava/build.gradle
index 76b7630..19b6b0f 100644
--- a/DemoApp/DemoAppJava/build.gradle
+++ b/DemoApp/DemoAppJava/build.gradle
@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.0'
+        classpath 'com.android.tools.build:gradle:4.1.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/DemoApp/DemoAppKotlin/app/src/main/java/co/optable/androidsdkdemo/ui/GAMBanner/GAMBannerFragment.kt b/DemoApp/DemoAppKotlin/app/src/main/java/co/optable/androidsdkdemo/ui/GAMBanner/GAMBannerFragment.kt
index 9cb3f66..af265e1 100644
--- a/DemoApp/DemoAppKotlin/app/src/main/java/co/optable/androidsdkdemo/ui/GAMBanner/GAMBannerFragment.kt
+++ b/DemoApp/DemoAppKotlin/app/src/main/java/co/optable/androidsdkdemo/ui/GAMBanner/GAMBannerFragment.kt
@@ -52,6 +52,7 @@ class GAMBannerFragment : Fragment() {
 
                 targetingDataView.setText(msg)
                 mPublisherAdView.loadAd(adRequest.build())
+                profile()
                 witness()
             })
         }
@@ -75,6 +76,7 @@ class GAMBannerFragment : Fragment() {
 
             targetingDataView.setText(msg)
             mPublisherAdView.loadAd(adRequest.build())
+            profile()
             witness()
         }
 
@@ -88,11 +90,27 @@ class GAMBannerFragment : Fragment() {
         return root
     }
 
+    private fun profile() {
+        MainActivity.OPTABLE!!
+            .profile(
+                hashMapOf("gender" to "F", "age" to 38, "hasAccount" to true)
+            )
+            .observe(viewLifecycleOwner, Observer { result ->
+                var msg = targetingDataView.text.toString()
+                if (result.status == OptableSDK.Status.SUCCESS) {
+                    msg += "\n\nSuccess calling profile API to set traits on user.\n\n"
+                } else {
+                    msg += "\n\nOptableSDK Error: ${result.message}\n\n"
+                }
+                targetingDataView.setText(msg)
+            })
+    }
+
     private fun witness() {
         MainActivity.OPTABLE!!
             .witness(
                 "GAMBannerFragment.loadAdButtonClicked",
-                hashMapOf("exampleKey" to "exampleValue")
+                hashMapOf("exampleKey" to "exampleValue", "anotherExample" to 123, "foo" to false)
             )
             .observe(viewLifecycleOwner, Observer { result ->
                 var msg = targetingDataView.text.toString()
diff --git a/DemoApp/DemoAppKotlin/app/src/main/res/layout/fragment_gambanner.xml b/DemoApp/DemoAppKotlin/app/src/main/res/layout/fragment_gambanner.xml
index 93b9687..03cafea 100644
--- a/DemoApp/DemoAppKotlin/app/src/main/res/layout/fragment_gambanner.xml
+++ b/DemoApp/DemoAppKotlin/app/src/main/res/layout/fragment_gambanner.xml
@@ -58,8 +58,8 @@
 
     <TextView
         android:id="@+id/targetingDataView"
-        android:layout_width="282dp"
-        android:layout_height="168dp"
+        android:layout_width="281dp"
+        android:layout_height="366dp"
         android:layout_marginTop="100dp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
diff --git a/DemoApp/DemoAppKotlin/build.gradle b/DemoApp/DemoAppKotlin/build.gradle
index 628c5b1..1634bb0 100644
--- a/DemoApp/DemoAppKotlin/build.gradle
+++ b/DemoApp/DemoAppKotlin/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.0'
+        classpath 'com.android.tools.build:gradle:4.1.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
diff --git a/README.md b/README.md
index 683307a..8a81368 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,7 @@ Kotlin SDK for integrating with optable-sandbox from an Android application.
 - [Installing](#installing)
 - [Using](#using)
   - [Identify API](#identify-api)
+  - [Profile API](#profile-api)
   - [Targeting API](#targeting-api)
   - [Witness API](#witness-api)
   - [Integrating GAM360](#integrating-gam360)
@@ -170,6 +171,58 @@ Since the `sendGoogleAdIDBoolean` value provided to `identify()` is `true`, the
 
 The frequency of invocation of `identify` is up to you, however for optimal identity resolution we recommended to call the `identify()` method on your SDK instance every time you authenticate a user, as well as periodically, such as for example once every 15 to 60 minutes while the application is being actively used and an internet connection is available.
 
+### Profile API
+
+To associate key value traits with the user's device, for eventual audience assembly, you can call the profile API as follows:
+
+#### Kotlin
+
+```kotlin
+import co.optable.android_sdk.OptableSDK
+import my.org.app.MainActivity
+import android.util.Log
+...
+MainActivity.OPTABLE!!
+    .profile(hashMapOf("gender" to "F", "age" to 38, "hasAccount" to true))
+    .observe(viewLifecycleOwner, Observer { result ->
+        if (result.status == OptableSDK.Status.SUCCESS) {
+            Log.i("Profile API Success... ")
+        } else {
+            // result.status is OptableSDK.Status.ERROR
+            // result.message is the error message
+            Log.e("Profile API Error: ${result.message}")
+        }
+    })
+```
+
+#### Java
+
+```java
+import co.optable.android_sdk.OptableSDK;
+import co.optable.demoappjava.MainActivity;
+import android.util.Log;
+import java.util.HashMap;
+...
+HashMap<String,Object> traits = new HashMap<String,Object>();
+traits.put("gender", "F");
+traits.put("age", 38);
+traits.put("hasAccount", true);
+
+MainActivity.OPTABLE
+    .profile(traits)
+    .observe(getViewLifecycleOwner(), result -> {
+        if (result.getStatus() == OptableSDK.Status.SUCCESS) {
+            Log.i(null, "Profile API Success... ");
+        } else {
+            // result.getStatus() is OptableSDK.Status.ERROR
+            // result.getMessage() is the error message
+            Log.e(null, "Profile API Error: " + result.getMessage());
+        }
+    });
+```
+
+The specified traits are associated with the user's device and can be used for matching during audience assembly. The traits are of type `OptableProfileTraits` which is an alias for `HashMap<String,Any>` (or `HashMap<String,Object>` in Java), and should consist only of key-value pairs where the key is a string and the value is either a string, number, or boolean.
+
 ### Targeting API
 
 To get the targeting key values associated by the configured sandbox with the device in real-time, you can call the `targeting` API as follows:
@@ -299,7 +352,7 @@ import co.optable.demoappjava.MainActivity;
 import android.util.Log;
 import java.util.HashMap;
 ...
-HashMap<String, String> eventProperties = new HashMap<String, String>();
+HashMap<String,Object> eventProperties = new HashMap<String,Object>();
 eventProperties.put("exampleKey", "exampleValue");
 
 MainActivity.OPTABLE
@@ -315,7 +368,7 @@ MainActivity.OPTABLE
     });
 ```
 
-The specified event type and properties are associated with the logged event and which can be used for matching during audience assembly. The optional witness event properties are of type `OptableWitnessProperties` which is an alias for `HashMap<String,String>`, and should consist only of string key-value pairs.
+The specified event type and properties are associated with the logged event and which can be used for matching during audience assembly. The optional witness event properties are of type `OptableWitnessProperties` which is an alias for `HashMap<String,Any>` (or `HashMap<String,Object>` in Java), and should consist only of key-value pairs where the key is a string and the value is either a string, number, or boolean.
 
 ### Integrating GAM360
 
@@ -432,7 +485,7 @@ override fun onCreate(savedInstanceState: Bundle?) {
 }
 ```
 
- #### Java
+#### Java
 
 ```java
 @Override
diff --git a/android_sdk/src/main/java/co/optable/android_sdk/OptableSDK.kt b/android_sdk/src/main/java/co/optable/android_sdk/OptableSDK.kt
index 22b01ac..a71bb30 100644
--- a/android_sdk/src/main/java/co/optable/android_sdk/OptableSDK.kt
+++ b/android_sdk/src/main/java/co/optable/android_sdk/OptableSDK.kt
@@ -25,17 +25,23 @@ import java.security.MessageDigest
  */
 typealias OptableIdentifyInput = List<String>
 
+/*
+ * Profile API expects user traits:
+ */
+typealias OptableProfileTraits = HashMap<String,Any>
+
 /*
  * Witness API expects event properties:
  */
-typealias OptableWitnessProperties = HashMap<String, String>
+typealias OptableWitnessProperties = HashMap<String,Any>
 
 /*
- * Identify and Witness APIs usually just return {}... Void would be better but that results in
- * retrofit2 error when parsing response, even when the API responded successfully, since {} is
- * technically a HashMap:
+ * Identify, Profile, and Witness APIs usually just return {}... Void would be better but that
+ * results in retrofit2 error when parsing response, even when the API responded successfully,
+ * since {} is technically a HashMap:
  */
 typealias OptableIdentifyResponse = HashMap<Any,Any>
+typealias OptableProfileResponse = HashMap<Any,Any>
 typealias OptableWitnessResponse = HashMap<Any,Any>
 
 /*
@@ -181,6 +187,44 @@ class OptableSDK @JvmOverloads constructor(context: Context, host: String, app:
         }
     }
 
+    /*
+     *  profile(traits) calls the Optable Sandbox "profile" API in order to associate the
+     *  specified keyvalue OptableProfileTraits 'traits', which can be subsequently used for
+     *  audience assembly.
+     *
+     *  It is asynchronous, so the caller may call observe() on the returned LiveData and expect
+     *  an instance of Response<OptableProfileResponse> in the result. Success can be checked by
+     *  comparing result.status to OptableSDK.Status.SUCCESS. Note that result.data!! will point
+     *  to an empty HashMap on success, and can therefore be ignored.
+     */
+    fun profile(traits: OptableProfileTraits):
+            LiveData<Response<OptableProfileResponse>> {
+        val liveData = MutableLiveData<Response<OptableProfileResponse>>()
+        val client = this.client
+
+        GlobalScope.launch {
+            val response = client.Profile(traits)
+            when (response) {
+                is EdgeResponse.Success -> {
+                    liveData.postValue(Response.success(response.body))
+                }
+                is EdgeResponse.ApiError -> {
+                    liveData.postValue(Response.error(response.body))
+                }
+                is EdgeResponse.NetworkError -> {
+                    liveData.postValue(Response.error(
+                        Response.Error("NetworkError", "None")))
+                }
+                is EdgeResponse.UnknownError -> {
+                    liveData.postValue(Response.error(
+                        Response.Error("UnknownError", "None")))
+                }
+            }
+        }
+
+        return liveData
+    }
+
     /*
      *  targeting() calls the Optable Sandbox "targeting" API, which returns the key-value targeting
      *  data matching the user/device/app.
diff --git a/android_sdk/src/main/java/co/optable/android_sdk/core/Client.kt b/android_sdk/src/main/java/co/optable/android_sdk/core/Client.kt
index 4fb732c..65f38dc 100644
--- a/android_sdk/src/main/java/co/optable/android_sdk/core/Client.kt
+++ b/android_sdk/src/main/java/co/optable/android_sdk/core/Client.kt
@@ -82,6 +82,14 @@ class Client(private val config: Config, private val context: Context) {
         return edgeService!!.Identify(this.config.app, idList)
     }
 
+    suspend fun Profile(traits: OptableProfileTraits):
+            EdgeResponse<OptableProfileResponse, OptableSDK.Response.Error>
+    {
+        val profileBody = HashMap<String,Any>()
+        profileBody.put("traits", traits)
+        return edgeService!!.Profile(this.config.app, profileBody)
+    }
+
     suspend fun Targeting():
             EdgeResponse<OptableTargetingResponse, OptableSDK.Response.Error>
     {
diff --git a/android_sdk/src/main/java/co/optable/android_sdk/edge/EdgeService.kt b/android_sdk/src/main/java/co/optable/android_sdk/edge/EdgeService.kt
index 5fb56d4..0106f5f 100644
--- a/android_sdk/src/main/java/co/optable/android_sdk/edge/EdgeService.kt
+++ b/android_sdk/src/main/java/co/optable/android_sdk/edge/EdgeService.kt
@@ -16,6 +16,11 @@ interface EdgeService {
     suspend fun Identify(@Path("app") app: String, @Body idList: OptableIdentifyInput):
             EdgeResponse<OptableIdentifyResponse, OptableSDK.Response.Error>
 
+    @POST("/{app}/profile")
+    suspend fun Profile(@Path("app") app: String,
+                        @Body profileBody: HashMap<String,Any>):
+            EdgeResponse<OptableProfileResponse, OptableSDK.Response.Error>
+
     @GET("/{app}/targeting")
     suspend fun Targeting(@Path("app") app: String):
             EdgeResponse<OptableTargetingResponse, OptableSDK.Response.Error>