diff --git a/core-api/src/main/java/com/optimizely/ab/Optimizely.java b/core-api/src/main/java/com/optimizely/ab/Optimizely.java
index f93214a99..788250528 100644
--- a/core-api/src/main/java/com/optimizely/ab/Optimizely.java
+++ b/core-api/src/main/java/com/optimizely/ab/Optimizely.java
@@ -37,6 +37,7 @@
 import com.optimizely.ab.event.internal.BuildVersionInfo;
 import com.optimizely.ab.event.internal.EventBuilder;
 import com.optimizely.ab.event.internal.payload.EventBatch.ClientEngine;
+import com.optimizely.ab.internal.ControlAttribute;
 import com.optimizely.ab.notification.NotificationCenter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -748,8 +749,8 @@ public UserProfileService getUserProfileService() {
      * {@link ProjectConfig}.
      *
      * @param projectConfig the current project config
-     * @param attributes the attributes map to validate and potentially filter. The reserved key for bucketing id
-     * {@link DecisionService#BUCKETING_ATTRIBUTE} is kept.
+     * @param attributes the attributes map to validate and potentially filter. Attributes which starts with reserved key
+     * {@link ProjectConfig#RESERVED_ATTRIBUTE_PREFIX} are kept.
      * @return the filtered attributes map (containing only attributes that are present in the project config) or an
      * empty map if a null attributes object is passed in
      */
@@ -765,7 +766,7 @@ private Map<String, String> filterAttributes(@Nonnull ProjectConfig projectConfi
         Map<String, Attribute> attributeKeyMapping = projectConfig.getAttributeKeyMapping();
         for (Map.Entry<String, String> attribute : attributes.entrySet()) {
             if (!attributeKeyMapping.containsKey(attribute.getKey()) &&
-                    attribute.getKey() != com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE) {
+                    !attribute.getKey().startsWith(ProjectConfig.RESERVED_ATTRIBUTE_PREFIX)) {
                 if (unknownAttributes == null) {
                     unknownAttributes = new ArrayList<String>();
                 }
diff --git a/core-api/src/main/java/com/optimizely/ab/bucketing/DecisionService.java b/core-api/src/main/java/com/optimizely/ab/bucketing/DecisionService.java
index 2e8ffa9a1..0dc895feb 100644
--- a/core-api/src/main/java/com/optimizely/ab/bucketing/DecisionService.java
+++ b/core-api/src/main/java/com/optimizely/ab/bucketing/DecisionService.java
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2017, Optimizely, Inc. and contributors                        *
+ * Copyright 2017-2018, Optimizely, Inc. and contributors                        *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -24,6 +24,7 @@
 import com.optimizely.ab.config.audience.Audience;
 import com.optimizely.ab.error.ErrorHandler;
 import com.optimizely.ab.internal.ExperimentUtils;
+import com.optimizely.ab.internal.ControlAttribute;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -46,7 +47,6 @@
  */
 public class DecisionService {
 
-    public static final String BUCKETING_ATTRIBUTE = "$opt_bucketing_id";
     private final Bucketer bucketer;
     private final ErrorHandler errorHandler;
     private final ProjectConfig projectConfig;
@@ -130,8 +130,8 @@ public DecisionService(@Nonnull Bucketer bucketer,
 
         if (ExperimentUtils.isUserInExperiment(projectConfig, experiment, filteredAttributes)) {
             String bucketingId = userId;
-            if (filteredAttributes.containsKey(BUCKETING_ATTRIBUTE)) {
-                bucketingId = filteredAttributes.get(BUCKETING_ATTRIBUTE);
+            if (filteredAttributes.containsKey(ControlAttribute.BUCKETING_ATTRIBUTE.toString())) {
+                bucketingId = filteredAttributes.get(ControlAttribute.BUCKETING_ATTRIBUTE.toString());
             }
             variation = bucketer.bucket(experiment, bucketingId);
 
@@ -211,8 +211,8 @@ public DecisionService(@Nonnull Bucketer bucketer,
         // for all rules before the everyone else rule
         int rolloutRulesLength = rollout.getExperiments().size();
         String bucketingId = userId;
-        if (filteredAttributes.containsKey(BUCKETING_ATTRIBUTE)) {
-            bucketingId = filteredAttributes.get(BUCKETING_ATTRIBUTE);
+        if (filteredAttributes.containsKey(ControlAttribute.BUCKETING_ATTRIBUTE.toString())) {
+            bucketingId = filteredAttributes.get(ControlAttribute.BUCKETING_ATTRIBUTE.toString());
         }
         Variation variation;
         for (int i = 0; i < rolloutRulesLength - 1; i++) {
diff --git a/core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java b/core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java
index 4f2689d8f..8a81af72f 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@
 import com.optimizely.ab.error.ErrorHandler;
 import com.optimizely.ab.error.NoOpErrorHandler;
 import com.optimizely.ab.error.RaiseExceptionErrorHandler;
+import com.optimizely.ab.internal.ControlAttribute;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -73,6 +74,7 @@ public String toString() {
     private final String revision;
     private final String version;
     private final boolean anonymizeIP;
+    private final Boolean botFiltering;
     private final List<Attribute> attributes;
     private final List<Audience> audiences;
     private final List<EventType> events;
@@ -100,6 +102,8 @@ public String toString() {
     private final Map<String, Map<String, LiveVariableUsageInstance>> variationToLiveVariableUsageInstanceMapping;
     private final Map<String, Experiment> variationIdToExperimentMapping;
 
+    public final static String RESERVED_ATTRIBUTE_PREFIX = "$opt_";
+
     /**
      *  Forced variations supersede any other mappings.  They are transient and are not persistent or part of
      * the actual datafile. This contains all the forced variations
@@ -123,6 +127,7 @@ public ProjectConfig(String accountId, String projectId, String version, String
         this(
                 accountId,
                 anonymizeIP,
+                null,
                 projectId,
                 revision,
                 version,
@@ -140,6 +145,7 @@ public ProjectConfig(String accountId, String projectId, String version, String
     // v4 constructor
     public ProjectConfig(String accountId,
                          boolean anonymizeIP,
+                         Boolean botFiltering,
                          String projectId,
                          String revision,
                          String version,
@@ -157,6 +163,7 @@ public ProjectConfig(String accountId,
         this.version = version;
         this.revision = revision;
         this.anonymizeIP = anonymizeIP;
+        this.botFiltering = botFiltering;
 
         this.attributes = Collections.unmodifiableList(attributes);
         this.audiences = Collections.unmodifiableList(audiences);
@@ -285,6 +292,30 @@ private List<Experiment> aggregateGroupExperiments(List<Group> groups) {
         return groupExperiments;
     }
 
+    /**
+     * Checks is attributeKey is reserved or not and if it exist in attributeKeyMapping
+     * @param attributeKey
+     * @return AttributeId corresponding to AttributeKeyMapping, AttributeKey when it's a reserved attribute and
+     * null when attributeKey is equal to BOT_FILTERING_ATTRIBUTE key.
+     */
+    public String getAttributeId(ProjectConfig projectConfig, String attributeKey) {
+        String attributeIdOrKey = null;
+        com.optimizely.ab.config.Attribute attribute = projectConfig.getAttributeKeyMapping().get(attributeKey);
+        boolean hasReservedPrefix = attributeKey.startsWith(RESERVED_ATTRIBUTE_PREFIX);
+        if (attribute != null) {
+            if (hasReservedPrefix) {
+                logger.warn("Attribute {} unexpectedly has reserved prefix {}; using attribute ID instead of reserved attribute name.",
+                        attributeKey, RESERVED_ATTRIBUTE_PREFIX);
+            }
+            attributeIdOrKey = attribute.getId();
+        } else if (hasReservedPrefix) {
+            attributeIdOrKey = attributeKey;
+        } else {
+            logger.debug("Unrecognized Attribute \"{}\"", attributeKey);
+        }
+        return attributeIdOrKey;
+    }
+
     public String getAccountId() {
         return accountId;
     }
@@ -305,6 +336,10 @@ public boolean getAnonymizeIP() {
         return anonymizeIP;
     }
 
+    public Boolean getBotFiltering() {
+        return botFiltering;
+    }
+
     public List<Group> getGroups() {
         return groups;
     }
@@ -540,6 +575,7 @@ public String toString() {
                 ", revision='" + revision + '\'' +
                 ", version='" + version + '\'' +
                 ", anonymizeIP=" + anonymizeIP +
+                ", botFiltering=" + botFiltering +
                 ", attributes=" + attributes +
                 ", audiences=" + audiences +
                 ", events=" + events +
diff --git a/core-api/src/main/java/com/optimizely/ab/config/parser/JsonConfigParser.java b/core-api/src/main/java/com/optimizely/ab/config/parser/JsonConfigParser.java
index 5dc33d0df..593fa56ae 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/parser/JsonConfigParser.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/parser/JsonConfigParser.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -81,14 +81,18 @@ public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParse
 
             List<FeatureFlag> featureFlags = null;
             List<Rollout> rollouts = null;
+            Boolean botFiltering = null;
             if (datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString())) {
                 featureFlags = parseFeatureFlags(rootObject.getJSONArray("featureFlags"));
                 rollouts = parseRollouts(rootObject.getJSONArray("rollouts"));
+                if(rootObject.has("botFiltering"))
+                    botFiltering = rootObject.getBoolean("botFiltering");
             }
 
             return new ProjectConfig(
                     accountId,
                     anonymizeIP,
+                    botFiltering,
                     projectId,
                     revision,
                     version,
diff --git a/core-api/src/main/java/com/optimizely/ab/config/parser/JsonSimpleConfigParser.java b/core-api/src/main/java/com/optimizely/ab/config/parser/JsonSimpleConfigParser.java
index e0bb745d6..c4784b5c4 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/parser/JsonSimpleConfigParser.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/parser/JsonSimpleConfigParser.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -83,14 +83,18 @@ public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParse
 
             List<FeatureFlag> featureFlags = null;
             List<Rollout> rollouts = null;
+            Boolean botFiltering = null;
             if (datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString())) {
                 featureFlags = parseFeatureFlags((JSONArray) rootObject.get("featureFlags"));
                 rollouts = parseRollouts((JSONArray) rootObject.get("rollouts"));
+                if(rootObject.containsKey("botFiltering"))
+                    botFiltering = (Boolean) rootObject.get("botFiltering");
             }
 
             return new ProjectConfig(
                     accountId,
                     anonymizeIP,
+                    botFiltering,
                     projectId,
                     revision,
                     version,
@@ -103,6 +107,8 @@ public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParse
                     liveVariables,
                     rollouts
             );
+        } catch (RuntimeException ex){
+            throw new ConfigParseException("Unable to parse datafile: " + json, ex);
         } catch (Exception e) {
             throw new ConfigParseException("Unable to parse datafile: " + json, e);
         }
diff --git a/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigGsonDeserializer.java b/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigGsonDeserializer.java
index c9718d851..c556b9063 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigGsonDeserializer.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigGsonDeserializer.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -82,16 +82,20 @@ public ProjectConfig deserialize(JsonElement json, Type typeOfT, JsonDeserializa
 
         List<FeatureFlag> featureFlags = null;
         List<Rollout> rollouts = null;
+        Boolean botFiltering = null;
         if (datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString())) {
             Type featureFlagsType = new TypeToken<List<FeatureFlag>>() {}.getType();
             featureFlags = context.deserialize(jsonObject.getAsJsonArray("featureFlags"), featureFlagsType);
             Type rolloutsType = new TypeToken<List<Rollout>>() {}.getType();
             rollouts = context.deserialize(jsonObject.get("rollouts").getAsJsonArray(), rolloutsType);
+            if(jsonObject.has("botFiltering"))
+                botFiltering = jsonObject.get("botFiltering").getAsBoolean();
         }
 
         return new ProjectConfig(
                 accountId,
                 anonymizeIP,
+                botFiltering,
                 projectId,
                 revision,
                 version,
diff --git a/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigJacksonDeserializer.java b/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigJacksonDeserializer.java
index 6ebd3c4ec..76cac7412 100644
--- a/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigJacksonDeserializer.java
+++ b/core-api/src/main/java/com/optimizely/ab/config/parser/ProjectConfigJacksonDeserializer.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -76,16 +76,20 @@ public ProjectConfig deserialize(JsonParser parser, DeserializationContext conte
 
         List<FeatureFlag> featureFlags = null;
         List<Rollout> rollouts = null;
+        Boolean botFiltering = null;
         if (datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString())) {
             featureFlags = mapper.readValue(node.get("featureFlags").toString(),
                    new TypeReference<List<FeatureFlag>>() {});
             rollouts = mapper.readValue(node.get("rollouts").toString(),
                     new TypeReference<List<Rollout>>(){});
+            if (node.hasNonNull("botFiltering"))
+                botFiltering = node.get("botFiltering").asBoolean();
         }
 
         return new ProjectConfig(
                 accountId,
                 anonymizeIP,
+                botFiltering,
                 projectId,
                 revision,
                 version,
diff --git a/core-api/src/main/java/com/optimizely/ab/event/internal/EventBuilder.java b/core-api/src/main/java/com/optimizely/ab/event/internal/EventBuilder.java
index 20206d343..96f8161d9 100644
--- a/core-api/src/main/java/com/optimizely/ab/event/internal/EventBuilder.java
+++ b/core-api/src/main/java/com/optimizely/ab/event/internal/EventBuilder.java
@@ -17,7 +17,6 @@
 package com.optimizely.ab.event.internal;
 
 import com.optimizely.ab.annotations.VisibleForTesting;
-import com.optimizely.ab.bucketing.DecisionService;
 import com.optimizely.ab.config.EventType;
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.ProjectConfig;
@@ -32,6 +31,7 @@
 import com.optimizely.ab.event.internal.serializer.DefaultJsonSerializer;
 import com.optimizely.ab.event.internal.serializer.Serializer;
 import com.optimizely.ab.internal.EventTagUtils;
+import com.optimizely.ab.internal.ControlAttribute;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import javax.annotation.Nonnull;
@@ -44,7 +44,6 @@
 
 public class EventBuilder {
     private static final Logger logger = LoggerFactory.getLogger(EventBuilder.class);
-    static final String ATTRIBUTE_KEY_FOR_BUCKETING_ATTRIBUTE = "optimizely_bucketing_id";
     static final String EVENT_ENDPOINT = "https://logx.optimizely.com/v1/events";
     static final String  ACTIVATE_EVENT_KEY = "campaign_activated";
 
@@ -118,17 +117,25 @@ public LogEvent createConversionEvent(@Nonnull ProjectConfig projectConfig,
     private List<Attribute> buildAttributeList(ProjectConfig projectConfig, Map<String, String> attributes) {
         List<Attribute> attributesList = new ArrayList<Attribute>();
 
-        Map<String, com.optimizely.ab.config.Attribute> attributeMap = projectConfig.getAttributeKeyMapping();
         for (Map.Entry<String, String> entry : attributes.entrySet()) {
-            com.optimizely.ab.config.Attribute projectAttribute = attributeMap.get(entry.getKey());
-            Attribute attribute = new Attribute((projectAttribute != null ? projectAttribute.getId() : null),
-                    entry.getKey(), Attribute.CUSTOM_ATTRIBUTE_TYPE, entry.getValue());
-
-            if (entry.getKey() == DecisionService.BUCKETING_ATTRIBUTE) {
-                attribute = new Attribute(com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE,
-                        ATTRIBUTE_KEY_FOR_BUCKETING_ATTRIBUTE, Attribute.CUSTOM_ATTRIBUTE_TYPE, entry.getValue());
+            String attributeId = projectConfig.getAttributeId(projectConfig, entry.getKey());
+            if(attributeId != null) {
+                Attribute attribute = new Attribute(attributeId,
+                        entry.getKey(),
+                        Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                        entry.getValue());
+                attributesList.add(attribute);
             }
+        }
 
+        //checks if botFiltering value is not set in the project config file.
+        if(projectConfig.getBotFiltering() != null) {
+            Attribute attribute = new Attribute(
+                    ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                    ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                    Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                    projectConfig.getBotFiltering()
+            );
             attributesList.add(attribute);
         }
 
diff --git a/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Attribute.java b/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Attribute.java
index 71e93adba..74580cc1c 100644
--- a/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Attribute.java
+++ b/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Attribute.java
@@ -26,13 +26,13 @@ public class Attribute {
     String entityId;
     String key;
     String type;
-    String value;
+    Object value;
 
     public Attribute() {
 
     }
 
-    public Attribute(String entityId, String key, String type, String value) {
+    public Attribute(String entityId, String key, String type, Object value) {
         this.entityId = entityId;
         this.key = key;
         this.type = type;
@@ -63,7 +63,7 @@ public void setType(String type) {
         this.type = type;
     }
 
-    public String getValue() {
+    public Object getValue() {
         return value;
     }
 
diff --git a/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Decision.java b/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Decision.java
index 8c3341a47..b5af81da9 100644
--- a/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Decision.java
+++ b/core-api/src/main/java/com/optimizely/ab/event/internal/payload/Decision.java
@@ -18,8 +18,6 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
-import java.util.Objects;
-
 public class Decision {
     @JsonProperty("campaign_id")
     String campaignId;
diff --git a/core-api/src/main/java/com/optimizely/ab/internal/ControlAttribute.java b/core-api/src/main/java/com/optimizely/ab/internal/ControlAttribute.java
new file mode 100644
index 000000000..d1c3278c5
--- /dev/null
+++ b/core-api/src/main/java/com/optimizely/ab/internal/ControlAttribute.java
@@ -0,0 +1,34 @@
+/**
+ *
+ *    Copyright 2018, Optimizely and contributors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package com.optimizely.ab.internal;
+
+public enum ControlAttribute {
+    BOT_FILTERING_ATTRIBUTE("$opt_bot_filtering"),
+    USER_AGENT_ATTRIBUTE("$opt_user_agent"),
+    BUCKETING_ATTRIBUTE("$opt_bucketing_id");
+
+    private final String key;
+
+    ControlAttribute(String key) {
+        this.key = key;
+    }
+
+    @Override
+    public String toString() {
+        return key;
+    }
+}
diff --git a/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java b/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
index f08e8561f..20baeb674 100644
--- a/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
@@ -37,6 +37,7 @@
 import com.optimizely.ab.event.LogEvent;
 import com.optimizely.ab.event.internal.EventBuilder;
 import com.optimizely.ab.internal.LogbackVerifier;
+import com.optimizely.ab.internal.ControlAttribute;
 import com.optimizely.ab.notification.ActivateNotificationListener;
 import com.optimizely.ab.notification.NotificationCenter;
 import com.optimizely.ab.notification.NotificationListener;
@@ -179,7 +180,7 @@ public static Collection<Object[]> data() throws IOException {
     private static final String genericUserId = "genericUserId";
     private static final String testUserId = "userId";
     private static final String testBucketingId = "bucketingId";
-    private static final String testBucketingIdKey = DecisionService.BUCKETING_ATTRIBUTE;
+    private static final String testBucketingIdKey = ControlAttribute.BUCKETING_ATTRIBUTE.toString();
 
     private int datafileVersion;
     private String validDatafile;
diff --git a/core-api/src/test/java/com/optimizely/ab/bucketing/DecisionServiceTest.java b/core-api/src/test/java/com/optimizely/ab/bucketing/DecisionServiceTest.java
index e8f2359fa..0b65e9f91 100644
--- a/core-api/src/test/java/com/optimizely/ab/bucketing/DecisionServiceTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/bucketing/DecisionServiceTest.java
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2017, Optimizely, Inc. and contributors                        *
+ * Copyright 2017-2018, Optimizely, Inc. and contributors                        *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -26,6 +26,7 @@
 import com.optimizely.ab.error.ErrorHandler;
 import com.optimizely.ab.internal.LogbackVerifier;
 
+import com.optimizely.ab.internal.ControlAttribute;
 import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
@@ -1050,7 +1051,7 @@ public void getVariationBucketingId() throws Exception {
         when(bucketer.bucket(experiment, "bucketId")).thenReturn(expectedVariation);
 
         Map<String, String> attr = new HashMap<String, String>();
-        attr.put(DecisionService.BUCKETING_ATTRIBUTE, "bucketId");
+        attr.put(ControlAttribute.BUCKETING_ATTRIBUTE.toString(), "bucketId");
         // user excluded without audiences and whitelisting
         assertThat(decisionService.getVariation(experiment, genericUserId, attr), is(expectedVariation));
 
@@ -1068,7 +1069,7 @@ public void getVariationForRolloutWithBucketingId() {
         String bucketingId = "user_bucketing_id";
         String userId = "user_id";
         Map<String, String> attributes = new HashMap<String, String>();
-        attributes.put(DecisionService.BUCKETING_ATTRIBUTE, bucketingId);
+        attributes.put(ControlAttribute.BUCKETING_ATTRIBUTE.toString(), bucketingId);
 
         Bucketer bucketer = mock(Bucketer.class);
         when(bucketer.bucket(rolloutRuleExperiment, userId)).thenReturn(null);
diff --git a/core-api/src/test/java/com/optimizely/ab/config/ProjectConfigTest.java b/core-api/src/test/java/com/optimizely/ab/config/ProjectConfigTest.java
index 609dfddba..2d64e71fe 100644
--- a/core-api/src/test/java/com/optimizely/ab/config/ProjectConfigTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/config/ProjectConfigTest.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
  */
 package com.optimizely.ab.config;
 
+import ch.qos.logback.classic.Level;
 import com.optimizely.ab.config.audience.AndCondition;
 import com.optimizely.ab.config.audience.Condition;
 import com.optimizely.ab.config.audience.NotCondition;
@@ -37,7 +38,10 @@
 import static org.junit.Assert.assertEquals;
 
 
+import com.optimizely.ab.internal.LogbackVerifier;
+import com.optimizely.ab.internal.ControlAttribute;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -49,6 +53,9 @@ public class ProjectConfigTest {
 
     private ProjectConfig projectConfig;
 
+    @Rule
+    public LogbackVerifier logbackVerifier = new LogbackVerifier();
+
     @Before
     public void initialize() {
         projectConfig = ProjectConfigTestUtils.validProjectConfigV3();
@@ -143,7 +150,7 @@ public void verifyGetLiveVariableIdToExperimentsMapping() throws Exception {
         expectedLiveVariableIdToExperimentsMapping.put("7", Collections.singletonList(groupedExpWithVariables));
 
         assertThat(projectConfig.getLiveVariableIdToExperimentsMapping(),
-                   is(expectedLiveVariableIdToExperimentsMapping));
+                is(expectedLiveVariableIdToExperimentsMapping));
     }
 
     /**
@@ -185,12 +192,13 @@ public void verifyGetVariationToLiveVariableUsageInstanceMapping() throws Except
         expectedVariationToLiveVariableUsageInstanceMapping.put("281", groupedVariation281VariableValues);
 
         assertThat(projectConfig.getVariationToLiveVariableUsageInstanceMapping(),
-                   is(expectedVariationToLiveVariableUsageInstanceMapping));
+                is(expectedVariationToLiveVariableUsageInstanceMapping));
     }
 
     /**
      * Asserts that anonymizeIP is set to false if not explicitly passed into the constructor (in the case of V2
      * projects).
+     *
      * @throws Exception
      */
     @Test
@@ -202,23 +210,23 @@ public void verifyAnonymizeIPIsFalseByDefault() throws Exception {
     /**
      * Invalid User IDs
 
-     User ID is null
-     User ID is an empty string
-     Invalid Experiment IDs
+      User ID is null
+      User ID is an empty string
+      Invalid Experiment IDs
 
-     Experiment key does not exist in the datafile
-     Experiment key is null
-     Experiment key is an empty string
-     Invalid Variation IDs [set only]
+      Experiment key does not exist in the datafile
+      Experiment key is null
+      Experiment key is an empty string
+      Invalid Variation IDs [set only]
 
-     Variation key does not exist in the datafile
-     Variation key is null
-     Variation key is an empty string
-     Multiple set calls [set only]
+      Variation key does not exist in the datafile
+      Variation key is null
+      Variation key is an empty string
+      Multiple set calls [set only]
 
-     Call set variation with different variations on one user/experiment to confirm that each set is expected.
-     Set variation on multiple variations for one user.
-     Set variations for multiple users.
+      Call set variation with different variations on one user/experiment to confirm that each set is expected.
+      Set variation on multiple variations for one user.
+      Set variations for multiple users.
      */
     /* UserID test */
     @Test
@@ -227,6 +235,7 @@ public void setForcedVariationNullUserId() {
         boolean b = projectConfig.setForcedVariation("etag1", null, "vtag1");
         assertFalse(b);
     }
+
     @Test
     @SuppressFBWarnings("NP")
     public void getForcedVariationNullUserId() {
@@ -237,6 +246,7 @@ public void getForcedVariationNullUserId() {
     public void setForcedVariationEmptyUserId() {
         assertFalse(projectConfig.setForcedVariation("etag1", "", "vtag1"));
     }
+
     @Test
     public void getForcedVariationEmptyUserId() {
         assertNull(projectConfig.getForcedVariation("etag1", ""));
@@ -248,6 +258,7 @@ public void getForcedVariationEmptyUserId() {
     public void setForcedVariationNullExperimentKey() {
         assertFalse(projectConfig.setForcedVariation(null, "testUser1", "vtag1"));
     }
+
     @Test
     @SuppressFBWarnings("NP")
     public void getForcedVariationNullExperimentKey() {
@@ -259,6 +270,7 @@ public void setForcedVariationWrongExperimentKey() {
         assertFalse(projectConfig.setForcedVariation("wrongKey", "testUser1", "vtag1"));
 
     }
+
     @Test
     public void getForcedVariationWrongExperimentKey() {
         assertNull(projectConfig.getForcedVariation("wrongKey", "testUser1"));
@@ -269,6 +281,7 @@ public void setForcedVariationEmptyExperimentKey() {
         assertFalse(projectConfig.setForcedVariation("", "testUser1", "vtag1"));
 
     }
+
     @Test
     public void getForcedVariationEmptyExperimentKey() {
         assertNull(projectConfig.getForcedVariation("", "testUser1"));
@@ -345,4 +358,38 @@ public void setForcedVariationMultipleUsers() {
         assertNull(projectConfig.getForcedVariation("etag2", "testUser2"));
 
     }
+
+    @Test
+    public void getAttributeIDWhenAttributeKeyIsFromAttributeKeyMapping() {
+        ProjectConfig projectConfig = ProjectConfigTestUtils.validProjectConfigV4();
+        String attributeID = projectConfig.getAttributeId(projectConfig, "house");
+        assertEquals(attributeID, "553339214");
+    }
+
+    @Test
+    public void getAttributeIDWhenAttributeKeyIsUsingReservedKey() {
+        ProjectConfig projectConfig = ProjectConfigTestUtils.validProjectConfigV4();
+        String attributeID = projectConfig.getAttributeId(projectConfig, "$opt_user_agent");
+        assertEquals(attributeID, ControlAttribute.USER_AGENT_ATTRIBUTE.toString());
+    }
+
+    @Test
+    public void getAttributeIDWhenAttributeKeyUnrecognizedAttribute() {
+        ProjectConfig projectConfig = ProjectConfigTestUtils.validProjectConfigV4();
+        String invalidAttribute = "empty";
+        String attributeID = projectConfig.getAttributeId(projectConfig, invalidAttribute);
+        assertNull(attributeID);
+        logbackVerifier.expectMessage(Level.DEBUG, "Unrecognized Attribute \""+invalidAttribute+"\"");
+    }
+
+    @Test
+    public void getAttributeIDWhenAttributeKeyPrefixIsMatched() {
+        ProjectConfig projectConfig = ProjectConfigTestUtils.validProjectConfigV4();
+        String attributeWithReservedPrefix = "$opt_test";
+        String attributeID = projectConfig.getAttributeId(projectConfig, attributeWithReservedPrefix);
+        assertEquals(attributeID,"583394100");
+        logbackVerifier.expectMessage(Level.WARN, "Attribute "+attributeWithReservedPrefix +" unexpectedly" +
+                " has reserved prefix $opt_; using attribute ID instead of reserved attribute name.");
+    }
+
 }
\ No newline at end of file
diff --git a/core-api/src/test/java/com/optimizely/ab/config/ValidProjectConfigV4.java b/core-api/src/test/java/com/optimizely/ab/config/ValidProjectConfigV4.java
index c43f73c1d..19a65dcba 100644
--- a/core-api/src/test/java/com/optimizely/ab/config/ValidProjectConfigV4.java
+++ b/core-api/src/test/java/com/optimizely/ab/config/ValidProjectConfigV4.java
@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2017, Optimizely and contributors
+ *    Copyright 2017-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ public class ValidProjectConfigV4 {
     // simple properties
     private static final String     ACCOUNT_ID = "2360254204";
     private static final boolean    ANONYMIZE_IP = true;
+    private static final boolean    BOT_FILTERING = true;
     private static final String     PROJECT_ID = "3918735994";
     private static final String     REVISION = "1480511547";
     private static final String     VERSION = "4";
@@ -44,6 +45,10 @@ public class ValidProjectConfigV4 {
     public  static final String     ATTRIBUTE_NATIONALITY_KEY = "nationality";
     private static final Attribute  ATTRIBUTE_NATIONALITY = new Attribute(ATTRIBUTE_NATIONALITY_ID, ATTRIBUTE_NATIONALITY_KEY);
 
+    private static final String     ATTRIBUTE_OPT_ID = "583394100";
+    public  static final String     ATTRIBUTE_OPT_KEY = "$opt_test";
+    private static final Attribute  ATTRIBUTE_OPT = new Attribute(ATTRIBUTE_OPT_ID, ATTRIBUTE_OPT_KEY);
+
     // audiences
     private static final String     CUSTOM_DIMENSION_TYPE = "custom_dimension";
     private static final String     AUDIENCE_GRYFFINDOR_ID = "3468206642";
@@ -1027,6 +1032,7 @@ public static ProjectConfig generateValidProjectConfigV4() {
         List<Attribute> attributes = new ArrayList<Attribute>();
         attributes.add(ATTRIBUTE_HOUSE);
         attributes.add(ATTRIBUTE_NATIONALITY);
+        attributes.add(ATTRIBUTE_OPT);
 
         // list audiences
         List<Audience> audiences = new ArrayList<Audience>();
@@ -1073,6 +1079,7 @@ public static ProjectConfig generateValidProjectConfigV4() {
         return new ProjectConfig(
                 ACCOUNT_ID,
                 ANONYMIZE_IP,
+                BOT_FILTERING,
                 PROJECT_ID,
                 REVISION,
                 VERSION,
diff --git a/core-api/src/test/java/com/optimizely/ab/event/internal/EventBuilderTest.java b/core-api/src/test/java/com/optimizely/ab/event/internal/EventBuilderTest.java
index b976bed29..879386a44 100644
--- a/core-api/src/test/java/com/optimizely/ab/event/internal/EventBuilderTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/event/internal/EventBuilderTest.java
@@ -1,3 +1,19 @@
+/**
+ *
+ *    Copyright 2016-2018, Optimizely and contributors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
 package com.optimizely.ab.event.internal;
 
 import com.google.gson.FieldNamingPolicy;
@@ -16,6 +32,7 @@
 import com.optimizely.ab.event.LogEvent;
 import com.optimizely.ab.event.internal.payload.Decision;
 import com.optimizely.ab.event.internal.payload.EventBatch;
+import com.optimizely.ab.internal.ControlAttribute;
 import com.optimizely.ab.internal.ReservedEventKey;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -33,11 +50,7 @@
 
 import static com.optimizely.ab.config.ProjectConfigTestUtils.validProjectConfigV2;
 import static com.optimizely.ab.config.ProjectConfigTestUtils.validProjectConfigV4;
-import static com.optimizely.ab.config.ValidProjectConfigV4.AUDIENCE_GRYFFINDOR_VALUE;
-import static com.optimizely.ab.config.ValidProjectConfigV4.EVENT_BASIC_EVENT_KEY;
-import static com.optimizely.ab.config.ValidProjectConfigV4.EVENT_PAUSED_EXPERIMENT_KEY;
-import static com.optimizely.ab.config.ValidProjectConfigV4.MULTIVARIATE_EXPERIMENT_FORCED_VARIATION_USER_ID_GRED;
-import static com.optimizely.ab.config.ValidProjectConfigV4.PAUSED_EXPERIMENT_FORCED_VARIATION_USER_ID_CONTROL;
+import static com.optimizely.ab.config.ValidProjectConfigV4.*;
 import static junit.framework.Assert.assertNotNull;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.Matchers.closeTo;
@@ -85,25 +98,93 @@ public EventBuilderTest(int datafileVersion,
         this.validProjectConfig = validProjectConfig;
     }
 
+    /**
+     * Verify {@link com.optimizely.ab.event.internal.payload.EventBatch} event creation
+     */
+    @Test
+    public void createImpressionEventPassingUserAgentAttribute() throws Exception {
+        // use the "valid" project config and its associated experiment, variation, and attributes
+        Experiment activatedExperiment = validProjectConfig.getExperiments().get(0);
+        Variation bucketedVariation = activatedExperiment.getVariations().get(0);
+        Attribute attribute = validProjectConfig.getAttributes().get(0);
+        String userId = "userId";
+        Map<String, String> attributeMap = new HashMap<String, String>();
+        attributeMap.put(attribute.getKey(), "value");
+        attributeMap.put(ControlAttribute.USER_AGENT_ATTRIBUTE.toString(), "Chrome");
+        Decision expectedDecision = new Decision(activatedExperiment.getLayerId(), activatedExperiment.getId(), bucketedVariation.getId(), false);
+        com.optimizely.ab.event.internal.payload.Attribute feature = new com.optimizely.ab.event.internal.payload.Attribute(attribute.getId(),
+                attribute.getKey(), com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                "value");
+        com.optimizely.ab.event.internal.payload.Attribute userAgentFeature = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.USER_AGENT_ATTRIBUTE.toString(),
+                ControlAttribute.USER_AGENT_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                "Chrome");
+
+        com.optimizely.ab.event.internal.payload.Attribute botFilteringFeature = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
+
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(userAgentFeature, feature, botFilteringFeature);
+        else
+            expectedUserFeatures = Arrays.asList(userAgentFeature, feature);
+
+        LogEvent impressionEvent = builder.createImpressionEvent(validProjectConfig, activatedExperiment, bucketedVariation,
+                userId, attributeMap);
+
+        // verify that request endpoint is correct
+        assertThat(impressionEvent.getEndpointUrl(), is(EventBuilder.EVENT_ENDPOINT));
+
+        EventBatch eventBatch = gson.fromJson(impressionEvent.getBody(), EventBatch.class);
+
+        // verify payload information
+        assertThat(eventBatch.getVisitors().get(0).getVisitorId(), is(userId));
+        assertThat((double) eventBatch.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getTimestamp(), closeTo((double)System.currentTimeMillis(), 1000.0));
+        assertFalse(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0).getIsCampaignHoldback());
+        assertThat(eventBatch.getAnonymizeIp(), is(validProjectConfig.getAnonymizeIP()));
+        assertThat(eventBatch.getProjectId(), is(validProjectConfig.getProjectId()));
+        assertThat(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0), is(expectedDecision));
+        assertThat(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0).getCampaignId(),
+                is(activatedExperiment.getLayerId()));
+        assertThat(eventBatch.getAccountId(), is(validProjectConfig.getAccountId()));
+        assertThat(eventBatch.getVisitors().get(0).getAttributes(), is(expectedUserFeatures));
+        assertThat(eventBatch.getClientName(), is(EventBatch.ClientEngine.JAVA_SDK.getClientEngineValue()));
+        assertThat(eventBatch.getClientVersion(), is(BuildVersionInfo.VERSION));
+        assertNull(eventBatch.getVisitors().get(0).getSessionId());
+    }
+
     /**
      * Verify {@link com.optimizely.ab.event.internal.payload.EventBatch} event creation
      */
     @Test
     public void createImpressionEvent() throws Exception {
         // use the "valid" project config and its associated experiment, variation, and attributes
-        ProjectConfig projectConfig = validProjectConfigV2();
-        Experiment activatedExperiment = projectConfig.getExperiments().get(0);
+        Experiment activatedExperiment = validProjectConfig.getExperiments().get(0);
         Variation bucketedVariation = activatedExperiment.getVariations().get(0);
-        Attribute attribute = projectConfig.getAttributes().get(0);
+        Attribute attribute = validProjectConfig.getAttributes().get(0);
         String userId = "userId";
         Map<String, String> attributeMap = Collections.singletonMap(attribute.getKey(), "value");
         Decision expectedDecision = new Decision(activatedExperiment.getLayerId(), activatedExperiment.getId(), bucketedVariation.getId(), false);
         com.optimizely.ab.event.internal.payload.Attribute feature = new com.optimizely.ab.event.internal.payload.Attribute(attribute.getId(),
                 attribute.getKey(), com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 "value");
-        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures = Collections.singletonList(feature);
+        com.optimizely.ab.event.internal.payload.Attribute botFilteringFeature = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
 
-        LogEvent impressionEvent = builder.createImpressionEvent(projectConfig, activatedExperiment, bucketedVariation,
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(feature, botFilteringFeature);
+        else
+            expectedUserFeatures = Arrays.asList(feature);
+
+        LogEvent impressionEvent = builder.createImpressionEvent(validProjectConfig, activatedExperiment, bucketedVariation,
                 userId, attributeMap);
 
         // verify that request endpoint is correct
@@ -115,12 +196,12 @@ public void createImpressionEvent() throws Exception {
         assertThat(eventBatch.getVisitors().get(0).getVisitorId(), is(userId));
         assertThat((double) eventBatch.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getTimestamp(), closeTo((double)System.currentTimeMillis(), 1000.0));
         assertFalse(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0).getIsCampaignHoldback());
-        assertThat(eventBatch.getAnonymizeIp(), is(projectConfig.getAnonymizeIP()));
-        assertThat(eventBatch.getProjectId(), is(projectConfig.getProjectId()));
+        assertThat(eventBatch.getAnonymizeIp(), is(validProjectConfig.getAnonymizeIP()));
+        assertThat(eventBatch.getProjectId(), is(validProjectConfig.getProjectId()));
         assertThat(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0), is(expectedDecision));
         assertThat(eventBatch.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0).getCampaignId(),
                 is(activatedExperiment.getLayerId()));
-        assertThat(eventBatch.getAccountId(), is(projectConfig.getAccountId()));
+        assertThat(eventBatch.getAccountId(), is(validProjectConfig.getAccountId()));
         assertThat(eventBatch.getVisitors().get(0).getAttributes(), is(expectedUserFeatures));
         assertThat(eventBatch.getClientName(), is(EventBatch.ClientEngine.JAVA_SDK.getClientEngineValue()));
         assertThat(eventBatch.getClientVersion(), is(BuildVersionInfo.VERSION));
@@ -134,7 +215,7 @@ public void createImpressionEvent() throws Exception {
     @Test
     public void createImpressionEventIgnoresUnknownAttributes() throws Exception {
         // use the "valid" project config and its associated experiment, variation, and attributes
-        ProjectConfig projectConfig = validProjectConfigV2();
+        ProjectConfig projectConfig = validProjectConfig;
         Experiment activatedExperiment = projectConfig.getExperiments().get(0);
         Variation bucketedVariation = activatedExperiment.getVariations().get(0);
 
@@ -268,7 +349,121 @@ public void createConversionEvent() throws Exception {
         com.optimizely.ab.event.internal.payload.Attribute feature = new com.optimizely.ab.event.internal.payload.Attribute(attribute.getId(), attribute.getKey(),
                 com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 AUDIENCE_GRYFFINDOR_VALUE);
-        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures = Collections.singletonList(feature);
+        com.optimizely.ab.event.internal.payload.Attribute feature2 = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
+
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(feature, feature2);
+        else
+            expectedUserFeatures = Arrays.asList(feature);
+
+        assertEquals(conversion.getVisitors().get(0).getAttributes(), expectedUserFeatures);
+        assertThat(conversion.getVisitors().get(0).getSnapshots().get(0).getDecisions(), containsInAnyOrder(expectedDecisions.toArray()));
+        assertEquals(conversion.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getEntityId(), eventType.getId());
+        assertEquals(conversion.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getKey(), eventType.getKey());
+        assertEquals(conversion.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getRevenue(), null);
+        assertTrue(conversion.getVisitors().get(0).getAttributes().containsAll(expectedUserFeatures));
+        assertTrue(conversion.getVisitors().get(0).getSnapshots().get(0).getEvents().get(0).getTags().equals(eventTagMap));
+        assertFalse(conversion.getVisitors().get(0).getSnapshots().get(0).getDecisions().get(0).getIsCampaignHoldback());
+        assertEquals(conversion.getAnonymizeIp(), validProjectConfig.getAnonymizeIP());
+        assertEquals(conversion.getClientName(), EventBatch.ClientEngine.JAVA_SDK.getClientEngineValue());
+        assertEquals(conversion.getClientVersion(), BuildVersionInfo.VERSION);
+    }
+
+    /**
+     * Verify {@link com.optimizely.ab.event.internal.payload.EventBatch} event creation
+     * passing User Agent reserved attribute in attribute map and to check it exist in visitors.attributes
+     */
+    @Test
+    public void createConversionEventPassingUserAgentAttribute() throws Exception {
+        // use the "valid" project config and its associated experiment, variation, and attributes
+        Attribute attribute = validProjectConfig.getAttributes().get(0);
+        EventType eventType = validProjectConfig.getEventTypes().get(0);
+        String userId = "userId";
+
+        Bucketer mockBucketAlgorithm = mock(Bucketer.class);
+
+        List<Experiment> allExperiments = validProjectConfig.getExperiments();
+        List<Experiment> experimentsForEventKey = validProjectConfig.getExperimentsForEventKey(eventType.getKey());
+
+        // Bucket to the first variation for all experiments. However, only a subset of the experiments will actually
+        // call the bucket function.
+        for (Experiment experiment : allExperiments) {
+            when(mockBucketAlgorithm.bucket(experiment, userId))
+                    .thenReturn(experiment.getVariations().get(0));
+        }
+        DecisionService decisionService = new DecisionService(
+                mockBucketAlgorithm,
+                mock(ErrorHandler.class),
+                validProjectConfig,
+                mock(UserProfileService.class)
+        );
+
+        Map<String, String> attributeMap = new HashMap<String, String>();
+        attributeMap.put(attribute.getKey(), AUDIENCE_GRYFFINDOR_VALUE);
+        attributeMap.put(ControlAttribute.USER_AGENT_ATTRIBUTE.toString(), "Chrome");
+        Map<String, Object> eventTagMap = new HashMap<String, Object>();
+        eventTagMap.put("boolean_param", false);
+        eventTagMap.put("string_param", "123");
+        Map<Experiment, Variation> experimentVariationMap = createExperimentVariationMap(
+                validProjectConfig,
+                decisionService,
+                eventType.getKey(),
+                userId,
+                attributeMap);
+        LogEvent conversionEvent = builder.createConversionEvent(
+                validProjectConfig,
+                experimentVariationMap,
+                userId,
+                eventType.getId(),
+                eventType.getKey(),
+                attributeMap,
+                eventTagMap);
+
+        List<Decision> expectedDecisions = new ArrayList<Decision>();
+
+        for (Experiment experiment : experimentsForEventKey) {
+            if (experiment.isRunning()) {
+                Decision layerState = new Decision(experiment.getLayerId(), experiment.getId(),
+                        experiment.getVariations().get(0).getId(), false);
+                expectedDecisions.add(layerState);
+            }
+        }
+
+        // verify that the request endpoint is correct
+        assertThat(conversionEvent.getEndpointUrl(), is(EventBuilder.EVENT_ENDPOINT));
+
+        EventBatch conversion = gson.fromJson(conversionEvent.getBody(), EventBatch.class);
+
+        // verify payload information
+        assertThat(conversion.getVisitors().get(0).getVisitorId(), is(userId));
+        assertThat(conversion.getProjectId(), is(validProjectConfig.getProjectId()));
+        assertThat(conversion.getAccountId(), is(validProjectConfig.getAccountId()));
+
+        com.optimizely.ab.event.internal.payload.Attribute feature = new com.optimizely.ab.event.internal.payload.Attribute(
+                attribute.getId(), attribute.getKey(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                AUDIENCE_GRYFFINDOR_VALUE);
+        com.optimizely.ab.event.internal.payload.Attribute userAgentFeature = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.USER_AGENT_ATTRIBUTE.toString(),
+                ControlAttribute.USER_AGENT_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                "Chrome");
+        com.optimizely.ab.event.internal.payload.Attribute botFilteringFeature = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
+
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(userAgentFeature, feature, botFilteringFeature);
+        else
+            expectedUserFeatures = Arrays.asList(userAgentFeature, feature);
 
         assertEquals(conversion.getVisitors().get(0).getAttributes(), expectedUserFeatures);
         assertThat(conversion.getVisitors().get(0).getSnapshots().get(0).getDecisions(), containsInAnyOrder(expectedDecisions.toArray()));
@@ -542,7 +737,7 @@ public void createConversionEventReturnsNullWhenExperimentVariationMapIsEmpty()
     @Test
     public void createImpressionEventWithBucketingId() throws Exception {
         // use the "valid" project config and its associated experiment, variation, and attributes
-        ProjectConfig projectConfig = validProjectConfigV2();
+        ProjectConfig projectConfig = validProjectConfig;
         Experiment activatedExperiment = projectConfig.getExperiments().get(0);
         Variation bucketedVariation = activatedExperiment.getVariations().get(0);
         Attribute attribute = projectConfig.getAttributes().get(0);
@@ -550,19 +745,30 @@ public void createImpressionEventWithBucketingId() throws Exception {
         Map<String, String> attributeMap = new HashMap<String, String>();
         attributeMap.put(attribute.getKey(), "value");
 
-        attributeMap.put(com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE, "variation");
+        attributeMap.put(ControlAttribute.BUCKETING_ATTRIBUTE.toString(), "variation");
 
         Decision expectedDecision = new Decision(activatedExperiment.getLayerId(), activatedExperiment.getId(), bucketedVariation.getId(), false);
 
         com.optimizely.ab.event.internal.payload.Attribute feature = new com.optimizely.ab.event.internal.payload.Attribute(attribute.getId(), attribute.getKey(),
                 com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 "value");
-        com.optimizely.ab.event.internal.payload.Attribute feature1 = new com.optimizely.ab.event.internal.payload.Attribute(com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE,
-                EventBuilder.ATTRIBUTE_KEY_FOR_BUCKETING_ATTRIBUTE,
+        com.optimizely.ab.event.internal.payload.Attribute feature1 = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BUCKETING_ATTRIBUTE.toString(),
+                ControlAttribute.BUCKETING_ATTRIBUTE.toString(),
                 com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 "variation");
+        com.optimizely.ab.event.internal.payload.Attribute feature2 = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
 
-        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures = Arrays.asList(feature, feature1);
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(feature, feature1, feature2);
+        else
+            expectedUserFeatures = Arrays.asList(feature, feature1);
 
         LogEvent impressionEvent = builder.createImpressionEvent(projectConfig, activatedExperiment, bucketedVariation,
                 userId, attributeMap);
@@ -619,7 +825,7 @@ public void createConversionEventWithBucketingId() throws Exception {
 
         Map<String, String> attributeMap = new java.util.HashMap<String, String>();
         attributeMap.put(attribute.getKey(), AUDIENCE_GRYFFINDOR_VALUE);
-        attributeMap.put(com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE, bucketingId);
+        attributeMap.put(ControlAttribute.BUCKETING_ATTRIBUTE.toString(), bucketingId);
 
         Map<String, Object> eventTagMap = new HashMap<String, Object>();
         eventTagMap.put("boolean_param", false);
@@ -663,11 +869,22 @@ public void createConversionEventWithBucketingId() throws Exception {
         com.optimizely.ab.event.internal.payload.Attribute attribute1 = new com.optimizely.ab.event.internal.payload.Attribute(attribute.getId(), attribute.getKey(),
                 com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 AUDIENCE_GRYFFINDOR_VALUE);
-        com.optimizely.ab.event.internal.payload.Attribute attribute2 = new com.optimizely.ab.event.internal.payload.Attribute(com.optimizely.ab.bucketing.DecisionService.BUCKETING_ATTRIBUTE,
-                EventBuilder.ATTRIBUTE_KEY_FOR_BUCKETING_ATTRIBUTE,
+        com.optimizely.ab.event.internal.payload.Attribute attribute2 = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BUCKETING_ATTRIBUTE.toString(),
+                ControlAttribute.BUCKETING_ATTRIBUTE.toString(),
                 com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
                 bucketingId);
-        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures = Arrays.asList(attribute1, attribute2);
+        com.optimizely.ab.event.internal.payload.Attribute attribute3 = new com.optimizely.ab.event.internal.payload.Attribute(
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                ControlAttribute.BOT_FILTERING_ATTRIBUTE.toString(),
+                com.optimizely.ab.event.internal.payload.Attribute.CUSTOM_ATTRIBUTE_TYPE,
+                validProjectConfig.getBotFiltering());
+        List<com.optimizely.ab.event.internal.payload.Attribute> expectedUserFeatures;
+
+        if(datafileVersion >= Integer.parseInt(ProjectConfig.Version.V4.toString()))
+            expectedUserFeatures = Arrays.asList(attribute1, attribute2, attribute3);
+        else
+            expectedUserFeatures = Arrays.asList(attribute1, attribute2);
 
         assertEquals(conversion.getVisitors().get(0).getAttributes(), expectedUserFeatures);
         assertThat(conversion.getVisitors().get(0).getSnapshots().get(0).getDecisions(), containsInAnyOrder(expectedDecisions.toArray()));
diff --git a/core-api/src/test/resources/config/valid-project-config-v4.json b/core-api/src/test/resources/config/valid-project-config-v4.json
index bfd683888..db961012e 100644
--- a/core-api/src/test/resources/config/valid-project-config-v4.json
+++ b/core-api/src/test/resources/config/valid-project-config-v4.json
@@ -1,6 +1,7 @@
 {
   "accountId": "2360254204",
   "anonymizeIP": true,
+  "botFiltering": true,
   "projectId": "3918735994",
   "revision": "1480511547",
   "version": "4",
@@ -34,6 +35,10 @@
     {
       "id": "58339410",
       "key": "nationality"
+    },
+    {
+      "id": "583394100",
+      "key": "$opt_test"
     }
   ],
   "events": [