diff --git a/core/src/main/java/com/mapzen/android/core/ApiKeyChangeListener.java b/core/src/main/java/com/mapzen/android/core/ApiKeyChangeListener.java
index c39d20d2..12a478b6 100644
--- a/core/src/main/java/com/mapzen/android/core/ApiKeyChangeListener.java
+++ b/core/src/main/java/com/mapzen/android/core/ApiKeyChangeListener.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.core;
 
+import android.support.annotation.NonNull;
+
 /**
  * Listener for handling changes to API key.
  */
@@ -8,5 +10,5 @@ public interface ApiKeyChangeListener {
    * Called when the {@link MapzenManager}'s API key is changed.
    * @param apiKey the current API key
    */
-  void onApiKeyChanged(String apiKey);
+  void onApiKeyChanged(@NonNull String apiKey);
 }
diff --git a/core/src/main/java/com/mapzen/android/core/GenericHttpHandler.java b/core/src/main/java/com/mapzen/android/core/GenericHttpHandler.java
index 60eb12f8..58f1f600 100644
--- a/core/src/main/java/com/mapzen/android/core/GenericHttpHandler.java
+++ b/core/src/main/java/com/mapzen/android/core/GenericHttpHandler.java
@@ -1,6 +1,7 @@
 package com.mapzen.android.core;
 
 import android.os.Build;
+import android.support.annotation.Nullable;
 
 import java.util.Map;
 
@@ -75,11 +76,11 @@ enum LogLevel {
    * Return query parameters to be appended to every request.
    * @return
    */
-  Map<String, String> queryParamsForRequest();
+  @Nullable Map<String, String> queryParamsForRequest();
 
   /**
    * Return headers to be added to every request.
    * @return
    */
-  Map<String, String> headersForRequest();
+  @Nullable Map<String, String> headersForRequest();
 }
diff --git a/core/src/main/java/com/mapzen/android/core/MapzenManager.java b/core/src/main/java/com/mapzen/android/core/MapzenManager.java
index edbb8ecb..e01d5864 100644
--- a/core/src/main/java/com/mapzen/android/core/MapzenManager.java
+++ b/core/src/main/java/com/mapzen/android/core/MapzenManager.java
@@ -4,6 +4,7 @@
 
 import android.content.Context;
 import android.content.res.Resources;
+import android.support.annotation.NonNull;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -42,7 +43,7 @@ public class MapzenManager {
   /**
    * Get singleton instance.
    */
-  public static MapzenManager instance(Context context) {
+  public static @NonNull MapzenManager instance(@NonNull Context context) {
     if (instance == null) {
       instance = new MapzenManager(context.getApplicationContext());
     }
@@ -55,7 +56,7 @@ public static MapzenManager instance(Context context) {
   /**
    * Creates a new instance of the manager.
    */
-  private MapzenManager(Context context) {
+  private MapzenManager(@NonNull Context context) {
     final Resources resources = context.getResources();
     if (resources != null) {
       int id = resources.getIdentifier(API_KEY_RES_NAME, API_KEY_RES_TYPE,
@@ -72,7 +73,7 @@ private MapzenManager(Context context) {
    * @throws IllegalStateException if a valid API key has not been set in code or as a string
    * resource.
    */
-  public String getApiKey() {
+  public @NonNull String getApiKey() {
     if (apiKey == null || API_KEY_DEFAULT_VALUE.equals(apiKey)) {
       throw new IllegalStateException("A valid Mapzen API key has not been provided. Please visit "
           + "https://mapzen.com/documentation/android/getting-started/ to learn how.");
@@ -84,7 +85,7 @@ public String getApiKey() {
   /**
    * Sets a new API key value. This will override any previous key including those declared in xml.
    */
-  public void setApiKey(String apiKey) {
+  public void setApiKey(@NonNull String apiKey) {
     this.apiKey = apiKey;
     notifyListeners();
   }
@@ -93,7 +94,7 @@ public void setApiKey(String apiKey) {
    * Returns the maven artifact version.
    * @return
    */
-  public static String getSdkVersion() {
+  public static @NonNull String getSdkVersion() {
     return BuildConfig.SDK_VERSION;
   }
 
@@ -102,7 +103,7 @@ public static String getSdkVersion() {
    * occur.
    * @param listener
    */
-  public void addApiKeyChangeListener(ApiKeyChangeListener listener) {
+  public void addApiKeyChangeListener(@NonNull ApiKeyChangeListener listener) {
     Collections.synchronizedList(listeners).add(listener);
   }
 
@@ -110,7 +111,7 @@ public void addApiKeyChangeListener(ApiKeyChangeListener listener) {
    * Removes listener from list of managed callbacks.
    * @param listener
    */
-  public void removeApiKeyChangeListener(ApiKeyChangeListener listener) {
+  public void removeApiKeyChangeListener(@NonNull ApiKeyChangeListener listener) {
     Collections.synchronizedList(listeners).remove(listener);
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/DataLayerType.java b/core/src/main/java/com/mapzen/android/graphics/DataLayerType.java
index 12e8eab4..64fcba6c 100644
--- a/core/src/main/java/com/mapzen/android/graphics/DataLayerType.java
+++ b/core/src/main/java/com/mapzen/android/graphics/DataLayerType.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics;
 
+import android.support.annotation.NonNull;
+
 /**
  * Default data layers for bundled Mapzen stylesheets including Bubble Wrap, Cinnabar, and Refill.
  * Used to add client data layers to the map and optionally persist them on configuration change.
@@ -32,7 +34,7 @@ public enum DataLayerType {
    * Returns the enum's name.
    * @return
    */
-  public String toString() {
+  @NonNull public String toString() {
     return name;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/FeaturePickListener.java b/core/src/main/java/com/mapzen/android/graphics/FeaturePickListener.java
index ba8bc686..89465a00 100644
--- a/core/src/main/java/com/mapzen/android/graphics/FeaturePickListener.java
+++ b/core/src/main/java/com/mapzen/android/graphics/FeaturePickListener.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics;
 
+import android.support.annotation.NonNull;
+
 import java.util.Map;
 
 /**
@@ -22,5 +24,5 @@ public interface FeaturePickListener {
    * @param positionX The horizontal screen coordinate of the center of the feature
    * @param positionY The vertical screen coordinate of the center of the feature
    */
-  void onFeaturePick(Map<String, String> properties, float positionX, float positionY);
+  void onFeaturePick(@NonNull Map<String, String> properties, float positionX, float positionY);
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/LabelPickListener.java b/core/src/main/java/com/mapzen/android/graphics/LabelPickListener.java
index 20c6cb01..c65d3bd0 100644
--- a/core/src/main/java/com/mapzen/android/graphics/LabelPickListener.java
+++ b/core/src/main/java/com/mapzen/android/graphics/LabelPickListener.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.tangram.LabelPickResult;
 
+import android.support.annotation.NonNull;
+
 /**
  * Listener invoked when a label on the map is selected.
  */
@@ -27,5 +29,5 @@ public interface LabelPickListener {
    * @param positionY The vertical screen coordinate of the center of the feature. Will be 0 if
    * {@link LabelPickResult} is null.
    */
-  void onLabelPicked(LabelPickResult result, float positionX, float positionY);
+  void onLabelPicked(@NonNull LabelPickResult result, float positionX, float positionY);
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/MapView.java b/core/src/main/java/com/mapzen/android/graphics/MapView.java
index 8fbb4e6e..34e61c4e 100644
--- a/core/src/main/java/com/mapzen/android/graphics/MapView.java
+++ b/core/src/main/java/com/mapzen/android/graphics/MapView.java
@@ -106,7 +106,7 @@ private void initViews(Context context) {
   /**
    * Get the underlying Tangram map object.
    */
-  public TangramMapView getTangramMapView() {
+  @NonNull public TangramMapView getTangramMapView() {
     return tangramMapView;
   }
 
@@ -127,7 +127,7 @@ public void getMapAsync(@NonNull OnMapReadyCallback callback) {
    * @param mapStyle mapStyle that should be set.
    * @param callback listener to be invoked when map is initialized and ready to use.
    */
-  public void getMapAsync(MapStyle mapStyle, @NonNull OnMapReadyCallback callback) {
+  public void getMapAsync(@NonNull MapStyle mapStyle, @NonNull OnMapReadyCallback callback) {
     mapInitializer.init(this, mapStyle, callback);
   }
 
@@ -139,21 +139,22 @@ public void getMapAsync(MapStyle mapStyle, @NonNull OnMapReadyCallback callback)
    * @param locale used to determine language that should be used for map labels.
    * @param callback listener to be invoked when map is initialized and ready to use.
    */
-  public void getMapAsync(MapStyle mapStyle, Locale locale, @NonNull OnMapReadyCallback callback) {
+  public void getMapAsync(@NonNull MapStyle mapStyle, @NonNull Locale locale,
+      @NonNull OnMapReadyCallback callback) {
     mapInitializer.init(this, mapStyle, locale, callback);
   }
 
   /**
    * Get the compass button.
    */
-  public CompassView getCompass() {
+  @NonNull public CompassView getCompass() {
     return compass;
   }
 
   /**
    * Show compass button.
    */
-  public CompassView showCompass() {
+  @NonNull public CompassView showCompass() {
     compass.setVisibility(View.VISIBLE);
     return compass;
   }
@@ -168,14 +169,14 @@ public void hideCompass() {
   /**
    * Get the find me button.
    */
-  public ImageButton getFindMe() {
+  @NonNull public ImageButton getFindMe() {
     return findMe;
   }
 
   /**
    * Show button for finding user's location on map.
    */
-  public ImageButton showFindMe() {
+  @NonNull public ImageButton showFindMe() {
     findMe.setVisibility(View.VISIBLE);
     return findMe;
   }
@@ -190,14 +191,14 @@ public void hideFindMe() {
   /**
    * Get the zoom in button.
    */
-  public ImageButton getZoomIn() {
+  @NonNull public ImageButton getZoomIn() {
     return zoomIn;
   }
 
   /**
    * Show button for zooming in.
    */
-  public ImageButton showZoomIn() {
+  @NonNull public ImageButton showZoomIn() {
     zoomIn.setVisibility(View.VISIBLE);
     return zoomIn;
   }
@@ -212,14 +213,14 @@ public void hideZoomIn() {
   /**
    * Get the zoom out button.
    */
-  public ImageButton getZoomOut() {
+  @NonNull public ImageButton getZoomOut() {
     return zoomOut;
   }
 
   /**
    * Show button for zooming out.
    */
-  public ImageButton showZoomOut() {
+  @NonNull public ImageButton showZoomOut() {
     zoomOut.setVisibility(View.VISIBLE);
     return zoomOut;
   }
@@ -234,7 +235,7 @@ public void hideZoomOut() {
   /**
    * Return the attribution text view.
    */
-  public TextView getAttribution() {
+  @NonNull public TextView getAttribution() {
     return attribution;
   }
 
@@ -250,7 +251,7 @@ public void onDestroy() {
     getTangramMapView().onDestroy();
   }
 
-  void setMapzenMap(MapzenMap mapzenMap) {
+  void setMapzenMap(@NonNull MapzenMap mapzenMap) {
     this.mapzenMap = mapzenMap;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/MapzenMap.java b/core/src/main/java/com/mapzen/android/graphics/MapzenMap.java
index 96410862..59faeb5f 100644
--- a/core/src/main/java/com/mapzen/android/graphics/MapzenMap.java
+++ b/core/src/main/java/com/mapzen/android/graphics/MapzenMap.java
@@ -199,21 +199,21 @@ public boolean onRotate(float x, float y, float rotation) {
   /**
    * Provides access to the underlying Tangram {@link MapController}.
    */
-  public MapController getMapController() {
+  @NonNull public MapController getMapController() {
     return mapController;
   }
 
   /**
    * Provides access to the underlying {@link OverlayManager}.
    */
-  public OverlayManager getOverlayManager() {
+  @NonNull public OverlayManager getOverlayManager() {
     return overlayManager;
   }
 
   /**
    * Sets the map's underlying stylesheet asynchronously.
    */
-  public void setStyleAsync(MapStyle mapStyle, OnStyleLoadedListener listener) {
+  public void setStyleAsync(@NonNull MapStyle mapStyle, @NonNull OnStyleLoadedListener listener) {
     styleLoadedListener = listener;
     currSceneId = internalSetStyle(mapStyle, true);
   }
@@ -221,7 +221,7 @@ public void setStyleAsync(MapStyle mapStyle, OnStyleLoadedListener listener) {
   /**
    * Sets the map's underlying stylesheet.
    */
-  public void setStyle(MapStyle mapStyle) {
+  public void setStyle(@NonNull MapStyle mapStyle) {
     internalSetStyle(mapStyle, false);
   }
 
@@ -232,8 +232,8 @@ public void setStyle(MapStyle mapStyle) {
    * @param themedMapStyle
    * @param labelLevel
    */
-  public void setStyleAndLabelLevelAsync(ThemedMapStyle themedMapStyle, int labelLevel,
-      OnStyleLoadedListener listener) {
+  public void setStyleAndLabelLevelAsync(@NonNull ThemedMapStyle themedMapStyle, int labelLevel,
+      @NonNull OnStyleLoadedListener listener) {
     setStyleLabelLevelLodThemeColorAsync(themedMapStyle, labelLevel,
         themedMapStyle.getDefaultLod(), themedMapStyle.getDefaultColor(), listener);
   }
@@ -245,7 +245,7 @@ public void setStyleAndLabelLevelAsync(ThemedMapStyle themedMapStyle, int labelL
    * @param themedMapStyle
    * @param labelLevel
    */
-  public void setStyleAndLabelLevel(ThemedMapStyle themedMapStyle, int labelLevel) {
+  public void setStyleAndLabelLevel(@NonNull ThemedMapStyle themedMapStyle, int labelLevel) {
     setStyleLabelLevelLodThemeColor(themedMapStyle, labelLevel,
         themedMapStyle.getDefaultLod(), themedMapStyle.getDefaultColor());
   }
@@ -257,8 +257,8 @@ public void setStyleAndLabelLevel(ThemedMapStyle themedMapStyle, int labelLevel)
    * @param themedMapStyle
    * @param detailLevel
    */
-  public void setStyleAndLodAsync(ThemedMapStyle themedMapStyle, int detailLevel,
-      OnStyleLoadedListener listener) {
+  public void setStyleAndLodAsync(@NonNull ThemedMapStyle themedMapStyle, int detailLevel,
+      @NonNull OnStyleLoadedListener listener) {
     setStyleLabelLevelLodThemeColorAsync(themedMapStyle, themedMapStyle.getDefaultLabelLevel(),
         detailLevel, themedMapStyle.getDefaultColor(), listener);
   }
@@ -270,7 +270,7 @@ public void setStyleAndLodAsync(ThemedMapStyle themedMapStyle, int detailLevel,
    * @param themedMapStyle
    * @param detailLevel
    */
-  public void setStyleAndLod(ThemedMapStyle themedMapStyle, int detailLevel) {
+  public void setStyleAndLod(@NonNull ThemedMapStyle themedMapStyle, int detailLevel) {
     setStyleLabelLevelLodThemeColor(themedMapStyle, themedMapStyle.getDefaultLabelLevel(),
         detailLevel, themedMapStyle.getDefaultColor());
   }
@@ -280,8 +280,8 @@ public void setStyleAndLod(ThemedMapStyle themedMapStyle, int detailLevel) {
    * @param themedMapStyle
    * @param color
    */
-  public void setStyleAndThemeColorAsync(ThemedMapStyle themedMapStyle, ThemeColor color,
-      OnStyleLoadedListener listener) {
+  public void setStyleAndThemeColorAsync(@NonNull ThemedMapStyle themedMapStyle,
+      @NonNull ThemeColor color, @NonNull OnStyleLoadedListener listener) {
     setStyleLabelLevelLodThemeColorAsync(themedMapStyle, themedMapStyle.getDefaultLabelLevel(),
         themedMapStyle.getDefaultLod(), color, listener);
   }
@@ -291,7 +291,8 @@ public void setStyleAndThemeColorAsync(ThemedMapStyle themedMapStyle, ThemeColor
    * @param themedMapStyle
    * @param color
    */
-  public void setStyleAndThemeColor(ThemedMapStyle themedMapStyle, ThemeColor color) {
+  public void setStyleAndThemeColor(@NonNull ThemedMapStyle themedMapStyle,
+      @NonNull ThemeColor color) {
     setStyleLabelLevelLodThemeColor(themedMapStyle, themedMapStyle.getDefaultLabelLevel(),
         themedMapStyle.getDefaultLod(), color);
   }
@@ -304,8 +305,9 @@ public void setStyleAndThemeColor(ThemedMapStyle themedMapStyle, ThemeColor colo
    * @param detailLevel
    * @param color
    */
-  public void setStyleLabelLevelLodThemeColorAsync(ThemedMapStyle themedMapStyle, int labelLevel,
-      int detailLevel, ThemeColor color, OnStyleLoadedListener listener) {
+  public void setStyleLabelLevelLodThemeColorAsync(@NonNull ThemedMapStyle themedMapStyle,
+      int labelLevel, int detailLevel, @NonNull ThemeColor color,
+      @NonNull OnStyleLoadedListener listener) {
     styleLoadedListener = listener;
     mapStateManager.setMapStyle(themedMapStyle);
     currSceneId = setLabelLevelLodThemeColor(labelLevel, detailLevel, color, true);
@@ -319,8 +321,8 @@ public void setStyleLabelLevelLodThemeColorAsync(ThemedMapStyle themedMapStyle,
    * @param detailLevel
    * @param color
    */
-  public void setStyleLabelLevelLodThemeColor(ThemedMapStyle themedMapStyle, int labelLevel,
-      int detailLevel, ThemeColor color) {
+  public void setStyleLabelLevelLodThemeColor(@NonNull ThemedMapStyle themedMapStyle,
+      int labelLevel, int detailLevel, @NonNull ThemeColor color) {
     mapStateManager.setMapStyle(themedMapStyle);
     setLabelLevelLodThemeColor(labelLevel, detailLevel, color, false);
   }
@@ -350,7 +352,7 @@ public void setZoom(float zoom, int duration) {
    * @param duration animation duration in millis
    * @param easeType map ease type
    */
-  public void setZoom(float zoom, int duration, EaseType easeType) {
+  public void setZoom(float zoom, int duration, @NonNull EaseType easeType) {
     mapStateManager.setZoom(zoom);
     mapController.setZoomEased(zoom, duration, EASE_TYPE_TO_MAP_CONTROLLER_EASE_TYPE.get(easeType));
   }
@@ -365,7 +367,7 @@ public float getZoom() {
   /**
    * Set map position without animation.
    */
-  public void setPosition(LngLat lngLat) {
+  public void setPosition(@NonNull LngLat lngLat) {
     mapStateManager.setPosition(lngLat);
     mapController.setPosition(lngLat);
   }
@@ -376,7 +378,7 @@ public void setPosition(LngLat lngLat) {
    * @param lngLat position to center map on
    * @param duration animation duration in millis
    */
-  public void setPosition(LngLat lngLat, int duration) {
+  public void setPosition(@NonNull LngLat lngLat, int duration) {
     setPosition(lngLat, duration, EaseType.CUBIC);
   }
 
@@ -387,7 +389,7 @@ public void setPosition(LngLat lngLat, int duration) {
    * @param duration animation duration in millis
    * @param easeType map ease type
    */
-  public void setPosition(LngLat lngLat, int duration, EaseType easeType) {
+  public void setPosition(@NonNull LngLat lngLat, int duration, @NonNull EaseType easeType) {
     mapStateManager.setPosition(lngLat);
     mapController.setPositionEased(lngLat, duration,
         EASE_TYPE_TO_MAP_CONTROLLER_EASE_TYPE.get(easeType));
@@ -396,7 +398,7 @@ public void setPosition(LngLat lngLat, int duration, EaseType easeType) {
   /**
    * Returns map position.
    */
-  public LngLat getPosition() {
+  @NonNull public LngLat getPosition() {
     return mapController.getPosition();
   }
 
@@ -428,7 +430,7 @@ public void setRotation(float radians, int duration) {
    * @param duration animation duration in millis
    * @param easeType map ease type
    */
-  public void setRotation(float radians, int duration, EaseType easeType) {
+  public void setRotation(float radians, int duration, @NonNull EaseType easeType) {
     mapStateManager.setRotation(radians);
     mapController.setRotationEased(radians, duration,
         EASE_TYPE_TO_MAP_CONTROLLER_EASE_TYPE.get(easeType));
@@ -476,7 +478,7 @@ public void setTilt(float radians, int duration) {
    * @param duration duration in millis
    * @param easeType map ease type
    */
-  public void setTilt(float radians, int duration, EaseType easeType) {
+  public void setTilt(float radians, int duration, @NonNull EaseType easeType) {
     mapStateManager.setTilt(radians);
     mapController.setTiltEased(radians, duration,
         EASE_TYPE_TO_MAP_CONTROLLER_EASE_TYPE.get(easeType));
@@ -493,7 +495,7 @@ public float getTilt() {
    * Set the camera type for the map view.
    * @param type A {@code CameraType}
    */
-  public void setCameraType(CameraType type) {
+  public void setCameraType(@NonNull CameraType type) {
     mapStateManager.setCameraType(type);
     mapController.setCameraType(CAMERA_TYPE_TO_MAP_CONTROLLER_CAMERA_TYPE.get(type));
   }
@@ -502,7 +504,7 @@ public void setCameraType(CameraType type) {
    * Get the camera type currently in use for the map view.
    * @return A {@code CameraType}
    */
-  public CameraType getCameraType() {
+  @NonNull public CameraType getCameraType() {
     return MAP_CONTROLLER_CAMERA_TYPE_TO_CAMERA_TYPE.get(mapController.getCameraType());
   }
 
@@ -529,35 +531,35 @@ public boolean isMyLocationEnabled() {
   /**
    * Set an external click listener to be invoked after the internal listener.
    */
-  public void setCompassOnClickListener(View.OnClickListener listener) {
+  public void setCompassOnClickListener(@Nullable View.OnClickListener listener) {
     overlayManager.setCompassOnClickListener(listener);
   }
 
   /**
    * Set an external click listener to be invoked after the internal listener.
    */
-  public void setFindMeOnClickListener(View.OnClickListener listener) {
+  public void setFindMeOnClickListener(@Nullable View.OnClickListener listener) {
     overlayManager.setFindMeOnClickListener(listener);
   }
 
   /**
    * Set an external click listener to be invoked after the internal listener.
    */
-  public void setZoomInOnClickListener(View.OnClickListener listener) {
+  public void setZoomInOnClickListener(@Nullable View.OnClickListener listener) {
     overlayManager.setZoomInOnClickListener(listener);
   }
 
   /**
    * Set an external click listener to be invoked after the internal listener.
    */
-  public void setZoomOutOnClickListener(View.OnClickListener listener) {
+  public void setZoomOutOnClickListener(@Nullable View.OnClickListener listener) {
     overlayManager.setZoomOutOnClickListener(listener);
   }
 
   /**
    * Adds marker overlay to map. Returned {@link MapData} should be removed from map
    */
-  public MapData addMarker(Marker marker) {
+  @NonNull public MapData addMarker(@NonNull Marker marker) {
     return overlayManager.addMarker(marker);
   }
 
@@ -571,7 +573,7 @@ public void removeMarker() {
   /**
    * Adds polyline overlay to map.
    */
-  public MapData addPolyline(Polyline polyline) {
+  @NonNull public MapData addPolyline(@NonNull Polyline polyline) {
     return overlayManager.addPolyline(polyline);
   }
 
@@ -585,7 +587,7 @@ public void removePolyline() {
   /**
    * Adds polygon overlay to map.
    */
-  public MapData addPolygon(Polygon polygon) {
+  @NonNull public MapData addPolygon(@NonNull Polygon polygon) {
     return overlayManager.addPolygon(polygon);
   }
 
@@ -602,7 +604,7 @@ public void removePolygon() {
    * @param position Pixels from the top-left edge of the screen
    * @return LngLat corresponding to the given point
    */
-  public LngLat screenPositionToLngLat(PointF position) {
+  @NonNull public LngLat screenPositionToLngLat(@NonNull PointF position) {
     return mapController.screenPositionToLngLat(position);
   }
 
@@ -612,14 +614,14 @@ public LngLat screenPositionToLngLat(PointF position) {
    * @return Position in pixels from the top-left corner of the map area (the point
    * may not lie within the viewable screen area)
    */
-  public PointF lngLatToScreenPosition(LngLat lngLat) {
+  @NonNull public PointF lngLatToScreenPosition(@NonNull LngLat lngLat) {
     return mapController.lngLatToScreenPosition(lngLat);
   }
 
   /**
    * Set tap responder for tap gestures on map.
    */
-  public void setTapResponder(final TouchInput.TapResponder tapResponder) {
+  public void setTapResponder(@Nullable TouchInput.TapResponder tapResponder) {
     this.tapResponder = tapResponder;
     mapController.setTapResponder(internalTapResponder);
   }
@@ -627,14 +629,14 @@ public void setTapResponder(final TouchInput.TapResponder tapResponder) {
   /**
    * Get the map's tap responder.
    */
-  public TouchInput.TapResponder getTapResponder() {
+  @Nullable public TouchInput.TapResponder getTapResponder() {
     return tapResponder;
   }
 
   /**
    * Set double tap responder for tap gestures on map.
    */
-  public void setDoubleTapResponder(TouchInput.DoubleTapResponder doubleTapResponder) {
+  public void setDoubleTapResponder(@Nullable TouchInput.DoubleTapResponder doubleTapResponder) {
     this.doubleTapResponder = doubleTapResponder;
     mapController.setDoubleTapResponder(this.doubleTapResponder);
   }
@@ -642,14 +644,14 @@ public void setDoubleTapResponder(TouchInput.DoubleTapResponder doubleTapRespond
   /**
    * Get the map's double tap responder.
    */
-  public TouchInput.DoubleTapResponder getDoubleTapResponder() {
+  @Nullable public TouchInput.DoubleTapResponder getDoubleTapResponder() {
     return doubleTapResponder;
   }
 
   /**
    * Set long press responder for tap gestures on map.
    */
-  public void setLongPressResponder(TouchInput.LongPressResponder longPressResponder) {
+  public void setLongPressResponder(@Nullable TouchInput.LongPressResponder longPressResponder) {
     this.longPressResponder = longPressResponder;
     mapController.setLongPressResponder(this.longPressResponder);
   }
@@ -657,42 +659,42 @@ public void setLongPressResponder(TouchInput.LongPressResponder longPressRespond
   /**
    * Get the map's long press responder.
    */
-  public TouchInput.LongPressResponder getLongPressResponder() {
+  @Nullable public TouchInput.LongPressResponder getLongPressResponder() {
     return longPressResponder;
   }
 
   /**
    * Set pan responder for tap gestures on map.
    */
-  public void setPanResponder(TouchInput.PanResponder panResponder) {
+  public void setPanResponder(@Nullable TouchInput.PanResponder panResponder) {
     this.panResponder = panResponder;
   }
 
   /**
    * Get the map's pan responder.
    */
-  public TouchInput.PanResponder getPanResponder() {
+  @Nullable public TouchInput.PanResponder getPanResponder() {
     return panResponder;
   }
 
   /**
    * Set rotate responder for tap gestures on map.
    */
-  public void setRotateResponder(TouchInput.RotateResponder rotateResponder) {
+  public void setRotateResponder(@Nullable TouchInput.RotateResponder rotateResponder) {
     this.rotateResponder = rotateResponder;
   }
 
   /**
    * Get the map's rotate responder.
    */
-  public TouchInput.RotateResponder getRotateResponder() {
+  @Nullable public TouchInput.RotateResponder getRotateResponder() {
     return rotateResponder;
   }
 
   /**
    * Set scale responder for tap gestures on map.
    */
-  public void setScaleResponder(TouchInput.ScaleResponder scaleResponder) {
+  public void setScaleResponder(@Nullable TouchInput.ScaleResponder scaleResponder) {
     this.scaleResponder = scaleResponder;
     mapController.setScaleResponder(scaleResponder);
   }
@@ -700,14 +702,14 @@ public void setScaleResponder(TouchInput.ScaleResponder scaleResponder) {
   /**
    * Get the map's scale responder.
    */
-  public TouchInput.ScaleResponder getScaleResponder() {
+  @Nullable public TouchInput.ScaleResponder getScaleResponder() {
     return scaleResponder;
   }
 
   /**
    * Set shove responder for tap gestures on map.
    */
-  public void setShoveResponder(TouchInput.ShoveResponder shoveResponder) {
+  public void setShoveResponder(@Nullable TouchInput.ShoveResponder shoveResponder) {
     this.shoveResponder = shoveResponder;
     mapController.setShoveResponder(this.shoveResponder);
   }
@@ -715,7 +717,7 @@ public void setShoveResponder(TouchInput.ShoveResponder shoveResponder) {
   /**
    * Get the map's shove responder.
    */
-  public TouchInput.ShoveResponder getShoveResponder() {
+  @Nullable public TouchInput.ShoveResponder getShoveResponder() {
     return shoveResponder;
   }
 
@@ -726,8 +728,8 @@ public TouchInput.ShoveResponder getShoveResponder() {
    * @param second Subsequent gesture type
    * @param allowed True if {@code second} should be recognized, else false
    */
-  public void setSimultaneousGestureAllowed(TouchInput.Gestures first, TouchInput.Gestures second,
-      boolean allowed) {
+  public void setSimultaneousGestureAllowed(@NonNull TouchInput.Gestures first,
+      @NonNull TouchInput.Gestures second, boolean allowed) {
     mapController.setSimultaneousGestureAllowed(first, second, allowed);
   }
 
@@ -738,8 +740,8 @@ public void setSimultaneousGestureAllowed(TouchInput.Gestures first, TouchInput.
    * @param second Subsequent gesture type
    * @return True if {@code second} will be recognized, else false
    */
-  public boolean isSimultaneousGestureAllowed(TouchInput.Gestures first,
-      TouchInput.Gestures second) {
+  public boolean isSimultaneousGestureAllowed(@NonNull TouchInput.Gestures first,
+      @NonNull TouchInput.Gestures second) {
     return mapController.isSimultaneousGestureAllowed(first, second);
   }
 
@@ -748,7 +750,7 @@ public boolean isSimultaneousGestureAllowed(TouchInput.Gestures first,
    *
    * @param listener Listener to call when {@link Marker}s are selected.
    */
-  public void setFeaturePickListener(final FeaturePickListener listener) {
+  public void setFeaturePickListener(@Nullable final FeaturePickListener listener) {
     mapController.setFeaturePickListener(new MapController.FeaturePickListener() {
       @Override public void onFeaturePick(final Map<String, String> properties,
           final float positionX, final float positionY) {
@@ -764,7 +766,7 @@ public void setFeaturePickListener(final FeaturePickListener listener) {
    *
    * @param listener Listener to receive callback when labels are selected.
    */
-  public void setLabelPickListener(final LabelPickListener listener) {
+  public void setLabelPickListener(@Nullable final LabelPickListener listener) {
     labelPickHandler.setListener(listener);
     mapController.setLabelPickListener(labelPickHandler);
     pickLabelOnSingleTapConfirmed = (listener != null);
@@ -776,7 +778,7 @@ public void setLabelPickListener(final LabelPickListener listener) {
    *
    * @param listener Listener to receive callback when {@link BitmapMarker}s are selected.
    */
-  public void setMarkerPickListener(final MarkerPickListener listener) {
+  public void setMarkerPickListener(@Nullable final MarkerPickListener listener) {
     mapController.setMarkerPickListener(new MapController.MarkerPickListener() {
       @Override
       public void onMarkerPick(final MarkerPickResult markerPickResult, final float positionX,
@@ -798,7 +800,7 @@ public void onMarkerPick(final MarkerPickResult markerPickResult, final float po
   /**
    * Set a listener for when view is fully loaded and no ease or label animations running.
    */
-  public void setViewCompleteListener(final ViewCompleteListener listener) {
+  public void setViewCompleteListener(@Nullable final ViewCompleteListener listener) {
     mapController.setViewCompleteListener(new MapController.ViewCompleteListener() {
       @Override public void onViewComplete() {
         new Handler(Looper.getMainLooper()).post(new Runnable() {
@@ -815,7 +817,7 @@ public void setViewCompleteListener(final ViewCompleteListener listener) {
    *
    * @param r Runnable to run
    */
-  public void queueEvent(Runnable r) {
+  public void queueEvent(@NonNull Runnable r) {
     mapController.queueEvent(r);
   }
 
@@ -826,7 +828,7 @@ public void queueEvent(Runnable r) {
    * @param value A YAML valid string (example "{ property: true }" or "true")
    */
   @Deprecated
-  public void queueSceneUpdate(String componentPath, String value) {
+  public void queueSceneUpdate(@NonNull String componentPath, @NonNull String value) {
     queuedSceneUpdates.add(new SceneUpdate(componentPath, value));
   }
 
@@ -861,7 +863,7 @@ public void setCompassButtonEnabled(boolean enabled) {
   /**
    * Draws two pins on the map. The start pin is active and the end pin is inactive.
    */
-  public void drawRoutePins(LngLat start, LngLat end) {
+  public void drawRoutePins(@NonNull LngLat start, @NonNull LngLat end) {
     overlayManager.drawRoutePins(start, end);
   }
 
@@ -875,7 +877,7 @@ public void clearRoutePins() {
   /**
    * Draws a dropped pin on the map at the point supplied.
    */
-  public void drawDroppedPin(LngLat point) {
+  public void drawDroppedPin(@NonNull LngLat point) {
     overlayManager.drawDroppedPin(point);
   }
 
@@ -889,21 +891,21 @@ public void clearDroppedPins() {
   /**
    * Draws a search result on the map at the point supplied. The pin will be active.
    */
-  public void drawSearchResult(LngLat point) {
+  public void drawSearchResult(@NonNull LngLat point) {
     drawSearchResult(point, true);
   }
 
   /**
    * Draws a search result on the map at the point supplied.
    */
-  public void drawSearchResult(LngLat point, boolean active) {
+  public void drawSearchResult(@NonNull LngLat point, boolean active) {
     overlayManager.drawSearchResult(point, active);
   }
 
   /**
    * Draws search results on the map. All pins are displayed as active.
    */
-  public void drawSearchResults(List<LngLat> points) {
+  public void drawSearchResults(@NonNull List<LngLat> points) {
     int index = 0;
     for (LngLat point : points) {
       overlayManager.drawSearchResult(point, true, index);
@@ -915,7 +917,7 @@ public void drawSearchResults(List<LngLat> points) {
    * Draws search results on the map. All pins will be inactive except for the one at the active
    * index supplied.
    */
-  public void drawSearchResults(List<LngLat> points, int... activeIndexes) {
+  public void drawSearchResults(@NonNull List<LngLat> points, int... activeIndexes) {
     int index = 0;
     for (LngLat point : points) {
       boolean status = false;
@@ -940,7 +942,7 @@ public void clearSearchResults() {
   /**
    * Draws route pin at the point supplied.
    */
-  public void drawRouteLocationMarker(LngLat point) {
+  public void drawRouteLocationMarker(@NonNull LngLat point) {
     overlayManager.drawRouteLocationMarker(point);
   }
 
@@ -954,7 +956,7 @@ public void clearRouteLocationMarker() {
   /**
    * Draws route line on the map for the points supplied.
    */
-  public void drawRouteLine(List<LngLat> points) {
+  public void drawRouteLine(@NonNull List<LngLat> points) {
     overlayManager.drawRouteLine(points);
   }
 
@@ -1054,7 +1056,7 @@ public void setOverlaysEnabled(boolean transitOverlayEnabled, boolean bikeOverla
    * Sets the object used to add query parameters and headers to each request.
    * @param handler
    */
-  public void setHttpHandler(MapzenMapHttpHandler handler) {
+  public void setHttpHandler(@NonNull MapzenMapHttpHandler handler) {
     mapController.setHttpHandler(handler.httpHandler());
   }
 
@@ -1074,7 +1076,7 @@ public BitmapMarker addBitmapMarker(MarkerOptions markerOptions) {
    * @param markerOptions options used to define marker appearance.
    * @return a new bitmap marker instance.
    */
-  public BitmapMarker addBitmapMarker(BitmapMarkerOptions markerOptions) {
+  @NonNull public BitmapMarker addBitmapMarker(@NonNull BitmapMarkerOptions markerOptions) {
     return bitmapMarkerManager.addMarker(markerOptions);
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/MapzenMapPeliasLocationProvider.java b/core/src/main/java/com/mapzen/android/graphics/MapzenMapPeliasLocationProvider.java
index 379b2073..b1427133 100644
--- a/core/src/main/java/com/mapzen/android/graphics/MapzenMapPeliasLocationProvider.java
+++ b/core/src/main/java/com/mapzen/android/graphics/MapzenMapPeliasLocationProvider.java
@@ -6,6 +6,8 @@
 
 import android.content.Context;
 import android.graphics.PointF;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.Display;
 import android.view.WindowManager;
 
@@ -24,7 +26,7 @@ public class MapzenMapPeliasLocationProvider implements PeliasLocationProvider {
    * Public constructor.
    * @param context
    */
-  public MapzenMapPeliasLocationProvider(Context context) {
+  public MapzenMapPeliasLocationProvider(@NonNull Context context) {
     this.context = context;
   }
 
@@ -32,7 +34,7 @@ public MapzenMapPeliasLocationProvider(Context context) {
    * Set the map to use for retrieving lat/lon/bounding box.
    * @param map
    */
-  public void setMapzenMap(MapzenMap map) {
+  public void setMapzenMap(@Nullable MapzenMap map) {
     this.mapzenMap = map;
   }
 
@@ -58,7 +60,7 @@ public void setMapzenMap(MapzenMap map) {
     return midLatLon.longitude;
   }
 
-  @Override public BoundingBox getBoundingBox() {
+  @Override @Nullable public BoundingBox getBoundingBox() {
     if (mapzenMap == null) {
       return null;
     }
diff --git a/core/src/main/java/com/mapzen/android/graphics/MarkerPickListener.java b/core/src/main/java/com/mapzen/android/graphics/MarkerPickListener.java
index c3b89a3e..10db866b 100644
--- a/core/src/main/java/com/mapzen/android/graphics/MarkerPickListener.java
+++ b/core/src/main/java/com/mapzen/android/graphics/MarkerPickListener.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.android.graphics.model.BitmapMarker;
 
+import android.support.annotation.NonNull;
+
 /**
  * Listener invoked when a marker on the map is selected. Note that all
  * {@link com.mapzen.android.graphics.model.Polygon}s,
@@ -14,5 +16,5 @@ public interface MarkerPickListener {
    * Receives information about markers found in a call to {@link
    * com.mapzen.tangram.MapController#pickMarker(float, float)} (float, float)}.
    */
-  void onMarkerPick(BitmapMarker marker);
+  void onMarkerPick(@NonNull BitmapMarker marker);
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/OnMapReadyCallback.java b/core/src/main/java/com/mapzen/android/graphics/OnMapReadyCallback.java
index 900bfdfd..2b2fc105 100644
--- a/core/src/main/java/com/mapzen/android/graphics/OnMapReadyCallback.java
+++ b/core/src/main/java/com/mapzen/android/graphics/OnMapReadyCallback.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics;
 
+import android.support.annotation.NonNull;
+
 /**
  * Interface for receiving a {@code MapController} once it is ready to be used.
  */
@@ -9,5 +11,5 @@ public interface OnMapReadyCallback {
    *
    * @param mapzenMap A non-null {@link MapzenMap} instance for this {@code MapView}.
    */
-  void onMapReady(MapzenMap mapzenMap);
+  void onMapReady(@NonNull MapzenMap mapzenMap);
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/ViewCompleteListener.java b/core/src/main/java/com/mapzen/android/graphics/ViewCompleteListener.java
index 110289a7..ca0c64c0 100644
--- a/core/src/main/java/com/mapzen/android/graphics/ViewCompleteListener.java
+++ b/core/src/main/java/com/mapzen/android/graphics/ViewCompleteListener.java
@@ -8,5 +8,5 @@ public interface ViewCompleteListener {
    * Called on the render-thread at the end of whenever the view is fully loaded and
    * no ease- or label-animation is running.
    */
-  public void onViewComplete();
+  void onViewComplete();
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarker.java b/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarker.java
index 953a3065..cbe0e024 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarker.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarker.java
@@ -6,6 +6,8 @@
 import com.mapzen.tangram.Marker;
 
 import android.graphics.drawable.Drawable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 /**
  * Dynamic marker overlay constructed using a local bitmap.
@@ -50,7 +52,7 @@ public void remove() {
    * Sets the marker's coordinate position.
    * @param position
    */
-  public void setPosition(LngLat position) {
+  public void setPosition(@NonNull LngLat position) {
     this.position = position;
     this.tangramMarker.setPoint(position);
   }
@@ -61,7 +63,7 @@ public void setPosition(LngLat position) {
    * @param duration
    * @param easeType
    */
-  public void setPosition(LngLat position, int duration, EaseType easeType) {
+  public void setPosition(@NonNull LngLat position, int duration, EaseType easeType) {
     this.position = position;
     this.tangramMarker.setPointEased(position, duration,
         EaseTypeConverter.EASE_TYPE_TO_MAP_CONTROLLER_EASE_TYPE.get(easeType));
@@ -71,7 +73,7 @@ public void setPosition(LngLat position, int duration, EaseType easeType) {
    * Returns the marker's coordinate position.
    * @return
    */
-  public LngLat getPosition() {
+  public @NonNull LngLat getPosition() {
     return this.position;
   }
 
@@ -99,7 +101,7 @@ public int getIcon() {
    * icon resource id values set via {@link BitmapMarker#setIcon(int)}.
    * @param drawable
    */
-  public void setIcon(Drawable drawable) {
+  public void setIcon(@Nullable Drawable drawable) {
     this.resourceId = Integer.MIN_VALUE;
     this.drawable = drawable;
     this.tangramMarker.setDrawable(drawable);
@@ -109,7 +111,7 @@ public void setIcon(Drawable drawable) {
    * Returns the marker's icon drawable.
    * @return
    */
-  public Drawable getIconDrawable() {
+  public @Nullable Drawable getIconDrawable() {
     return this.drawable;
   }
 
@@ -178,7 +180,7 @@ public int getDrawOrder() {
    * Sets extra data to be associated with this marker.
    * @param userData
    */
-  public void setUserData(Object userData) {
+  public void setUserData(@Nullable Object userData) {
     this.tangramMarker.setUserData(userData);
   }
 
@@ -186,7 +188,7 @@ public void setUserData(Object userData) {
    * Gets extra data associated with this marker.
    * @return
    */
-  public Object getUserData() {
+  public @Nullable Object getUserData() {
     return this.tangramMarker.getUserData();
   }
 
@@ -214,7 +216,7 @@ public int getColor() {
    * color int values set via {@link BitmapMarker#setColor(int)}.
    * @param hex
    */
-  public void setColor(String hex) {
+  public void setColor(@NonNull String hex) {
     this.colorHex = hex;
     this.colorInt = Integer.MIN_VALUE;
     updateStyleString();
@@ -224,7 +226,7 @@ public void setColor(String hex) {
    * Returns the marker's color hex.
    * @return
    */
-  public String getColorHex() {
+  public @NonNull String getColorHex() {
     return this.colorHex;
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarkerOptions.java b/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarkerOptions.java
index e9afb8a4..af2a1f3c 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarkerOptions.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/BitmapMarkerOptions.java
@@ -4,6 +4,8 @@
 import com.mapzen.tangram.LngLat;
 
 import android.graphics.drawable.Drawable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 /**
  * Defines options for a {@link BitmapMarker}.
@@ -35,7 +37,7 @@ public class BitmapMarkerOptions {
    * @param position coordinate to display the marker.
    * @return this marker options instance.
    */
-  public BitmapMarkerOptions position(LngLat position) {
+  public @NonNull BitmapMarkerOptions position(@NonNull LngLat position) {
     this.position = position;
     return this;
   }
@@ -47,7 +49,7 @@ public BitmapMarkerOptions position(LngLat position) {
    * @param resId drawable resource ID for the marker to display.
    * @return this marker options instance.
    */
-  public BitmapMarkerOptions icon(int resId) {
+  public @NonNull BitmapMarkerOptions icon(int resId) {
     this.resId = resId;
     this.res = null;
     return this;
@@ -60,7 +62,7 @@ public BitmapMarkerOptions icon(int resId) {
    * @param res drawable resource for the marker to display.
    * @return this marker options instance.
    */
-  public BitmapMarkerOptions icon(Drawable res) {
+  public @NonNull BitmapMarkerOptions icon(@NonNull Drawable res) {
     this.res = res;
     this.resId = RES_NONE;
     return this;
@@ -73,7 +75,7 @@ public BitmapMarkerOptions icon(Drawable res) {
    * @param height in pixels
    * @return this marker options instance.
    */
-  public BitmapMarkerOptions size(int width, int height) {
+  public @NonNull BitmapMarkerOptions size(int width, int height) {
     this.width = width;
     this.height = height;
     return this;
@@ -84,7 +86,7 @@ public BitmapMarkerOptions size(int width, int height) {
    * @param isVisible
    * @return
    */
-  public BitmapMarkerOptions visible(boolean isVisible) {
+  public @NonNull BitmapMarkerOptions visible(boolean isVisible) {
     this.isVisible = isVisible;
     return this;
   }
@@ -92,7 +94,7 @@ public BitmapMarkerOptions visible(boolean isVisible) {
   /**
    * Sets marker z-axis draw order.
    */
-  public BitmapMarkerOptions drawOrder(int drawOrder) {
+  public @NonNull BitmapMarkerOptions drawOrder(int drawOrder) {
     this.drawOrder = drawOrder;
     return this;
   }
@@ -102,7 +104,7 @@ public BitmapMarkerOptions drawOrder(int drawOrder) {
    * @param userData
    * @return
    */
-  public BitmapMarkerOptions userData(Object userData) {
+  public @NonNull BitmapMarkerOptions userData(@NonNull Object userData) {
     this.userData = userData;
     return this;
   }
@@ -113,7 +115,7 @@ public BitmapMarkerOptions userData(Object userData) {
    * @param colorInt
    * @return
    */
-  public BitmapMarkerOptions colorInt(int colorInt) {
+  public @NonNull BitmapMarkerOptions colorInt(int colorInt) {
     this.colorInt = colorInt;
     this.colorHex = null;
     return this;
@@ -125,7 +127,7 @@ public BitmapMarkerOptions colorInt(int colorInt) {
    * @param colorHex
    * @return
    */
-  public BitmapMarkerOptions colorHex(String colorHex) {
+  public @NonNull BitmapMarkerOptions colorHex(@NonNull String colorHex) {
     this.colorHex = colorHex;
     this.colorInt = Integer.MIN_VALUE;
     return this;
@@ -136,14 +138,14 @@ public BitmapMarkerOptions colorHex(String colorHex) {
    * @param isInteractive
    * @return
    */
-  public BitmapMarkerOptions interactive(boolean isInteractive) {
+  public @NonNull BitmapMarkerOptions interactive(boolean isInteractive) {
     this.isInteractive = isInteractive;
     return this;
   }
 
   // Getters
 
-  public LngLat getPosition() {
+  public @NonNull LngLat getPosition() {
     return position;
   }
 
@@ -151,7 +153,7 @@ public int getIcon() {
     return resId;
   }
 
-  public Drawable getIconDrawable() {
+  public @Nullable Drawable getIconDrawable() {
     return res;
   }
 
@@ -171,7 +173,7 @@ public int getDrawOrder() {
     return drawOrder;
   }
 
-  public Object getUserData() {
+  public @Nullable Object getUserData() {
     return userData;
   }
 
@@ -179,7 +181,7 @@ public int getColorInt() {
     return colorInt;
   }
 
-  public String getColorHex() {
+  public @NonNull String getColorHex() {
     return colorHex;
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/BubbleWrapStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/BubbleWrapStyle.java
index b4c0e4ef..bba6dd40 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/BubbleWrapStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/BubbleWrapStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.Set;
 
 /**
@@ -14,15 +17,15 @@ public BubbleWrapStyle() {
     super("bubble-wrap/bubble-wrap-style.yaml");
   }
 
-  @Override public String getBaseStyleFilename() {
+  @NonNull @Override public String getBaseStyleFilename() {
     return "bubble-wrap-style.yaml";
   }
 
-  @Override public String getStyleRootPath() {
+  @NonNull @Override public String getStyleRootPath() {
     return "bubble-wrap/";
   }
 
-  @Override public String getThemesPath() {
+  @NonNull @Override public String getThemesPath() {
     return "themes/";
   }
 
@@ -42,11 +45,11 @@ public BubbleWrapStyle() {
     return 12;
   }
 
-  @Override public ThemeColor getDefaultColor() {
+  @NonNull @Override public ThemeColor getDefaultColor() {
     return ThemeColor.NONE;
   }
 
-  @Override public Set<ThemeColor> getColors() {
+  @Nullable @Override public Set<ThemeColor> getColors() {
     return null;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/CinnabarStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/CinnabarStyle.java
index 6fd1d51c..bfdfdad2 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/CinnabarStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/CinnabarStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.HashSet;
 import java.util.Set;
 
@@ -21,15 +24,15 @@ public CinnabarStyle() {
     super("cinnabar-style/cinnabar-style.yaml");
   }
 
-  @Override public String getBaseStyleFilename() {
+  @NonNull @Override public String getBaseStyleFilename() {
     return "cinnabar-style.yaml";
   }
 
-  @Override public String getStyleRootPath() {
+  @NonNull @Override public String getStyleRootPath() {
     return "cinnabar-style/";
   }
 
-  @Override public String getThemesPath() {
+  @NonNull @Override public String getThemesPath() {
     return "themes/";
   }
 
@@ -49,11 +52,11 @@ public CinnabarStyle() {
     return 12;
   }
 
-  @Override public ThemeColor getDefaultColor() {
+  @NonNull @Override public ThemeColor getDefaultColor() {
     return CINNABAR;
   }
 
-  @Override public Set<ThemeColor> getColors() {
+  @Nullable @Override public Set<ThemeColor> getColors() {
     return supportedColors;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/MapStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/MapStyle.java
index 2d06b3f5..a660a8b0 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/MapStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/MapStyle.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+
 /**
  * Map style given a scene file.
  */
@@ -10,14 +12,14 @@ public class MapStyle {
   /**
    * Creates a new instance.
    */
-  public MapStyle(String sceneFile) {
+  public MapStyle(@NonNull String sceneFile) {
     this.sceneFile = sceneFile;
   }
 
   /**
    * Get the underlying scene filename.
    */
-  public String getSceneFile() {
+  @NonNull public String getSceneFile() {
     return sceneFile;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/Marker.java b/core/src/main/java/com/mapzen/android/graphics/model/Marker.java
index 6e828fba..ca2cfcce 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/Marker.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/Marker.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.tangram.LngLat;
 
+import android.support.annotation.NonNull;
+
 /**
  * Represents a pin marker on a map backed by {@link com.mapzen.tangram.MapData} objects.
  */
@@ -19,7 +21,7 @@ public Marker(double longitude, double latitude) {
   /**
    * Return the marker's coordinate location.
    */
-  public LngLat getLocation() {
+  public @NonNull LngLat getLocation() {
     return latLng;
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/Polygon.java b/core/src/main/java/com/mapzen/android/graphics/model/Polygon.java
index 3bbbfd18..549d9d0e 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/Polygon.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/Polygon.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.tangram.LngLat;
 
+import android.support.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -32,7 +34,7 @@ public Builder() {
     /**
      * Add a new coordinate pair to the {@link Polygon}.
      */
-    public Builder add(LngLat c) {
+    @NonNull public Builder add(@NonNull LngLat c) {
       coordinates.add(c);
       return this;
     }
@@ -42,7 +44,7 @@ public Builder add(LngLat c) {
      *
      * @return the configured {@link Polygon}
      */
-    public Polygon build() {
+    @NonNull public Polygon build() {
       return new Polygon(coordinates);
     }
   }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/Polyline.java b/core/src/main/java/com/mapzen/android/graphics/model/Polyline.java
index d3352694..a7a18c71 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/Polyline.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/Polyline.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.tangram.LngLat;
 
+import android.support.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -15,7 +17,7 @@ public class Polyline {
   /**
    * Constructs a new {@link Polyline} object.
    */
-  public Polyline(List<LngLat> coordinates) {
+  public Polyline(@NonNull List<LngLat> coordinates) {
     this.coordinates = coordinates;
   }
 
@@ -34,7 +36,7 @@ public Builder() {
     /**
      * Add a coordinate pair to the {@link Polyline}.
      */
-    public Builder add(LngLat c) {
+    @NonNull public Builder add(@NonNull LngLat c) {
       coordinates.add(c);
       return this;
     }
@@ -44,7 +46,7 @@ public Builder add(LngLat c) {
      *
      * @return the newly created {@link Polyline}
      */
-    public Polyline build() {
+    @NonNull public Polyline build() {
       return new Polyline(coordinates);
     }
   }
@@ -52,7 +54,7 @@ public Polyline build() {
   /**
    * The {@link Polyline}'s coordinates.
    */
-  public List<LngLat> getCoordinates() {
+  @NonNull public List<LngLat> getCoordinates() {
     return coordinates;
   }
 
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/RefillStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/RefillStyle.java
index 32031d72..4ce67d2c 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/RefillStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/RefillStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.HashSet;
 import java.util.Set;
 
@@ -47,15 +50,15 @@ public RefillStyle() {
     super("refill-style/refill-style.yaml");
   }
 
-  @Override public String getBaseStyleFilename() {
+  @NonNull @Override public String getBaseStyleFilename() {
     return "refill-style.yaml";
   }
 
-  @Override public String getStyleRootPath() {
+  @NonNull @Override public String getStyleRootPath() {
     return "refill-style/";
   }
 
-  @Override public String getThemesPath() {
+  @NonNull @Override public String getThemesPath() {
     return "themes/";
   }
 
@@ -75,11 +78,11 @@ public RefillStyle() {
     return 12;
   }
 
-  @Override public ThemeColor getDefaultColor() {
+  @NonNull @Override public ThemeColor getDefaultColor() {
     return BLACK;
   }
 
-  @Override public Set<ThemeColor> getColors() {
+  @Nullable @Override public Set<ThemeColor> getColors() {
     return supportedColors;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/ThemeColor.java b/core/src/main/java/com/mapzen/android/graphics/model/ThemeColor.java
index 204c0b65..c128491d 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/ThemeColor.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/ThemeColor.java
@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+
 /**
  * Available color themes for {@link RefillStyle}.
  */
@@ -35,7 +37,7 @@ public enum ThemeColor {
    * Returns string value of theme color.
    * @return
    */
-  public String toString() {
+  @NonNull public String toString() {
     return color;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/ThemedMapStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/ThemedMapStyle.java
index efc9ffba..7a8be9a9 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/ThemedMapStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/ThemedMapStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.Set;
 
 /**
@@ -22,21 +25,21 @@ public ThemedMapStyle(String baseSceneFile) {
    * ie. "styles/refill-style/"
    * @return
    */
-  public abstract String getStyleRootPath();
+  @NonNull public abstract String getStyleRootPath();
 
   /**
    * Returns the style's base file.
    * ie. "refill-style.yaml"
    * @return
    */
-  public abstract String getBaseStyleFilename();
+  @NonNull public abstract String getBaseStyleFilename();
 
   /**
    * Returns the themes directory path.
    * ie "themes/"
    * @return
    */
-  public abstract String getThemesPath();
+  @NonNull public abstract String getThemesPath();
 
   /**
    * Returns the default detail level for the style.
@@ -70,7 +73,7 @@ public ThemedMapStyle(String baseSceneFile) {
    * Returns the default color for the style.
    * @return
    */
-  public abstract ThemeColor getDefaultColor();
+  @NonNull public abstract ThemeColor getDefaultColor();
 
   /**
    * Returns colors the theme supports. Color theme filenames should follow the format
@@ -78,5 +81,5 @@ public ThemedMapStyle(String baseSceneFile) {
    * ie. "color-pink.yaml"
    * @return
    */
-  public abstract Set<ThemeColor> getColors();
+  @Nullable public abstract Set<ThemeColor> getColors();
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/TronStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/TronStyle.java
index 175627c0..dd405f41 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/TronStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/TronStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.Set;
 
 /**
@@ -14,15 +17,15 @@ public TronStyle() {
     super("tron-style/tron-style.yaml");
   }
 
-  @Override public String getBaseStyleFilename() {
+  @NonNull @Override public String getBaseStyleFilename() {
     return "tron-style.yaml";
   }
 
-  @Override public String getStyleRootPath() {
+  @NonNull @Override public String getStyleRootPath() {
     return "tron-style/";
   }
 
-  @Override public String getThemesPath() {
+  @NonNull @Override public String getThemesPath() {
     return "themes/";
   }
 
@@ -42,11 +45,11 @@ public TronStyle() {
     return 12;
   }
 
-  @Override public ThemeColor getDefaultColor() {
+  @NonNull @Override public ThemeColor getDefaultColor() {
     return ThemeColor.NONE;
   }
 
-  @Override public Set<ThemeColor> getColors() {
+  @Nullable @Override public Set<ThemeColor> getColors() {
     return null;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/graphics/model/WalkaboutStyle.java b/core/src/main/java/com/mapzen/android/graphics/model/WalkaboutStyle.java
index 56a22e1f..dcd166b7 100644
--- a/core/src/main/java/com/mapzen/android/graphics/model/WalkaboutStyle.java
+++ b/core/src/main/java/com/mapzen/android/graphics/model/WalkaboutStyle.java
@@ -1,5 +1,8 @@
 package com.mapzen.android.graphics.model;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.Set;
 
 /**
@@ -14,15 +17,15 @@ public WalkaboutStyle() {
     super("walkabout-style/walkabout-style.yaml");
   }
 
-  @Override public String getBaseStyleFilename() {
+  @NonNull @Override public String getBaseStyleFilename() {
     return "walkabout-style.yaml";
   }
 
-  @Override public String getStyleRootPath() {
+  @NonNull @Override public String getStyleRootPath() {
     return "walkabout-style/";
   }
 
-  @Override public String getThemesPath() {
+  @NonNull @Override public String getThemesPath() {
     return "themes/";
   }
 
@@ -42,11 +45,11 @@ public WalkaboutStyle() {
     return 12;
   }
 
-  @Override public ThemeColor getDefaultColor() {
+  @NonNull @Override public ThemeColor getDefaultColor() {
     return ThemeColor.NONE;
   }
 
-  @Override public Set<ThemeColor> getColors() {
+  @Nullable @Override public Set<ThemeColor> getColors() {
     return null;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/search/MapzenSearch.java b/core/src/main/java/com/mapzen/android/search/MapzenSearch.java
index 66893c47..f254321e 100644
--- a/core/src/main/java/com/mapzen/android/search/MapzenSearch.java
+++ b/core/src/main/java/com/mapzen/android/search/MapzenSearch.java
@@ -9,6 +9,8 @@
 import com.mapzen.pelias.gson.Result;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import javax.inject.Inject;
 
@@ -26,7 +28,7 @@ public class MapzenSearch {
   /**
    * Creates a new {@link MapzenSearch} with api key set from mapzen.xml.
    */
-  public MapzenSearch(Context context) {
+  public MapzenSearch(@NonNull Context context) {
     initDI(context);
     internalSearch = new Pelias();
     searchInitializer.initSearch(this);
@@ -36,7 +38,7 @@ public MapzenSearch(Context context) {
    * Creates a new {@link MapzenSearch} with the {@link Pelias} object used for underlying
    * search/autocomplete queries.
    */
-  public MapzenSearch(Context context, Pelias pelias) {
+  public MapzenSearch(@NonNull Context context, @NonNull Pelias pelias) {
     initDI(context);
     internalSearch = pelias;
     searchInitializer.initSearch(this);
@@ -54,7 +56,7 @@ private void initDI(Context context) {
    * @param query
    * @param callback
    */
-  public Request suggest(String query, Callback<Result> callback) {
+  public Request suggest(@NonNull String query, @Nullable Callback<Result> callback) {
     return new CallRequest(internalSearch.suggest(query, callback));
   }
 
@@ -64,7 +66,8 @@ public Request suggest(String query, Callback<Result> callback) {
    * @param query
    * @param callback
    */
-  public Request suggest(String query, double lat, double lon, Callback<Result> callback) {
+  public Request suggest(@NonNull String query, double lat, double lon,
+      @Nullable Callback<Result> callback) {
     return new CallRequest(internalSearch.suggest(query, lat, lon, callback));
   }
 
@@ -75,8 +78,8 @@ public Request suggest(String query, double lat, double lon, Callback<Result> ca
    * @param query
    * @param callback
    */
-  public Request search(String query, Callback<Result> callback) {
-    return new CallRequest(internalSearch.search(query, callback));
+  public Request search(@NonNull String query, @Nullable Callback<Result> callback) {
+      return new CallRequest(internalSearch.search(query, callback));
   }
 
   /**
@@ -86,7 +89,8 @@ public Request search(String query, Callback<Result> callback) {
    * @param query
    * @param callback
    */
-  public Request search(String query, BoundingBox box, Callback<Result> callback) {
+  public Request search(@NonNull String query, @NonNull BoundingBox box,
+      @Nullable Callback<Result> callback) {
     return new CallRequest(internalSearch.search(query, box, callback));
   }
 
@@ -97,8 +101,9 @@ public Request search(String query, BoundingBox box, Callback<Result> callback)
    * @param query
    * @param callback
    */
-  public Request search(String query, double lat, double lon, Callback<Result> callback) {
-    return new CallRequest(internalSearch.search(query, lat, lon, callback));
+  public Request search(@NonNull String query, double lat, double lon,
+      @Nullable Callback<Result> callback) {
+      return new CallRequest(internalSearch.search(query, lat, lon, callback));
   }
 
   /**
@@ -108,7 +113,7 @@ public Request search(String query, double lat, double lon, Callback<Result> cal
    * @param lon
    * @param callback
    */
-  public Request reverse(double lat, double lon, Callback<Result> callback) {
+  public Request reverse(double lat, double lon, @Nullable Callback<Result> callback) {
     return new CallRequest(internalSearch.reverse(lat, lon, callback));
   }
 
@@ -118,7 +123,7 @@ public Request reverse(double lat, double lon, Callback<Result> callback) {
    * @param gid
    * @param callback
    */
-  public Request place(String gid, Callback<Result> callback) {
+  public Request place(@NonNull String gid, @Nullable Callback<Result> callback) {
     return new CallRequest(internalSearch.place(gid, callback));
   }
 
@@ -127,7 +132,7 @@ public Request place(String gid, Callback<Result> callback) {
    * more relevant results for given positions and areas
    * @param locationProvider
    */
-  public void setLocationProvider(PeliasLocationProvider locationProvider) {
+  public void setLocationProvider(@NonNull PeliasLocationProvider locationProvider) {
     internalSearch.setLocationProvider(locationProvider);
   }
 
@@ -136,7 +141,7 @@ public void setLocationProvider(PeliasLocationProvider locationProvider) {
    * requests.
    * @param handler
    */
-  public void setHttpHandler(MapzenSearchHttpHandler handler) {
+  public void setHttpHandler(@Nullable MapzenSearchHttpHandler handler) {
     internalSearch.setRequestHandler(handler.searchHandler());
   }
 
@@ -144,7 +149,7 @@ public void setHttpHandler(MapzenSearchHttpHandler handler) {
    * Return the underlying {@link Pelias} object.
    * @return
    */
-  public Pelias getPelias() {
+  @NonNull public Pelias getPelias() {
     return internalSearch;
   }
 }
diff --git a/core/src/main/java/com/mapzen/android/search/MapzenSearchHttpHandler.java b/core/src/main/java/com/mapzen/android/search/MapzenSearchHttpHandler.java
index f7646f8a..5bf969b0 100644
--- a/core/src/main/java/com/mapzen/android/search/MapzenSearchHttpHandler.java
+++ b/core/src/main/java/com/mapzen/android/search/MapzenSearchHttpHandler.java
@@ -6,6 +6,7 @@
 import com.mapzen.pelias.PeliasRequestHandler;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -25,7 +26,7 @@ public abstract class MapzenSearchHttpHandler implements GenericHttpHandler {
   /**
    * Public constructor.
    */
-  public MapzenSearchHttpHandler(Context context) {
+  public MapzenSearchHttpHandler(@NonNull Context context) {
     searchHandler = new SearchRequestHandler();
     MapzenManager mapzenManager = MapzenManager.instance(context);
     mapzenManager.addApiKeyChangeListener(apiKeyChangeListener);
@@ -36,7 +37,7 @@ public MapzenSearchHttpHandler(Context context) {
    * Returns the internal handler.
    * @return
    */
-  SearchRequestHandler searchHandler() {
+  @NonNull SearchRequestHandler searchHandler() {
     return searchHandler;
   }
 
diff --git a/core/src/main/java/com/mapzen/android/search/SearchInitializer.java b/core/src/main/java/com/mapzen/android/search/SearchInitializer.java
index 2d601484..549757cc 100644
--- a/core/src/main/java/com/mapzen/android/search/SearchInitializer.java
+++ b/core/src/main/java/com/mapzen/android/search/SearchInitializer.java
@@ -1,6 +1,7 @@
 package com.mapzen.android.search;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 
 import java.util.Map;
 
@@ -14,7 +15,7 @@ public class SearchInitializer {
    * Constructor.
    * @param context
    */
-  public SearchInitializer(Context context) {
+  public SearchInitializer(@NonNull Context context) {
     requestHandler = new MapzenSearchHttpHandler(context) {
       @Override public Map<String, String> queryParamsForRequest() {
         return null;
@@ -30,7 +31,7 @@ public SearchInitializer(Context context) {
    * Set the {@link MapzenSearch}'s {@link MapzenSearchHttpHandler}.
    * @param search
    */
-  public void initSearch(MapzenSearch search) {
+  public void initSearch(@NonNull MapzenSearch search) {
     search.getPelias().setRequestHandler(requestHandler.searchHandler());
   }
 
@@ -39,7 +40,7 @@ public void initSearch(MapzenSearch search) {
    * Returns the request handler.
    * @return
    */
-  public MapzenSearchHttpHandler getRequestHandler() {
+  @NonNull public MapzenSearchHttpHandler getRequestHandler() {
     return requestHandler;
   }
 }
diff --git a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/Converter.java b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/Converter.java
index c867fab9..96f3c55e 100644
--- a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/Converter.java
+++ b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/Converter.java
@@ -2,6 +2,8 @@
 
 import com.mapzen.valhalla.Router;
 
+import android.support.annotation.NonNull;
+
 import java.util.HashMap;
 
 /**
@@ -10,7 +12,7 @@
  */
 public class Converter {
 
-  public static final HashMap<MapzenRouter.DistanceUnits,
+  @NonNull public static final HashMap<MapzenRouter.DistanceUnits,
       Router.DistanceUnits> UNITS_TO_ROUTER_UNITS = new HashMap<>();
   static {
     UNITS_TO_ROUTER_UNITS.put(MapzenRouter.DistanceUnits.MILES, Router.DistanceUnits.MILES);
diff --git a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenDistanceFormatter.java b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenDistanceFormatter.java
index 108c4377..07cbd089 100644
--- a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenDistanceFormatter.java
+++ b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenDistanceFormatter.java
@@ -3,6 +3,8 @@
 import com.mapzen.helpers.DistanceFormatter;
 import com.mapzen.valhalla.Router;
 
+import android.support.annotation.NonNull;
+
 /**
  * Formatter for dealing with {@link MapzenRouter.DistanceUnits}.
  */
@@ -16,7 +18,7 @@ public class MapzenDistanceFormatter {
    * @param units miles or kilometers.
    * @return distance string formatted according to the rules of the formatter.
    */
-  public static String format(int distanceInMeters, boolean realTime,
+  @NonNull public static String format(int distanceInMeters, boolean realTime,
       MapzenRouter.DistanceUnits units) {
     Router.DistanceUnits routerUnits = Converter.UNITS_TO_ROUTER_UNITS.get(units);
     return DistanceFormatter.format(distanceInMeters, realTime, routerUnits);
diff --git a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouter.java b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouter.java
index 972d9bde..6e52a2ae 100644
--- a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouter.java
+++ b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouter.java
@@ -8,6 +8,8 @@
 import com.mapzen.valhalla.ValhallaRouter;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.VisibleForTesting;
 
 import javax.inject.Inject;
@@ -26,7 +28,7 @@ public class MapzenRouter {
   /**
    * Creates a new {@link MapzenRouter} with api key set from mapzen.xml.
    */
-  public MapzenRouter(Context context) {
+  public MapzenRouter(@NonNull Context context) {
     initDI(context);
     routerInitializer.initRouter(this);
   }
@@ -48,7 +50,7 @@ public Request fetch() {
    * @param callback
    * @return
    */
-  public MapzenRouter setCallback(RouteCallback callback) {
+  @NonNull public MapzenRouter setCallback(@Nullable RouteCallback callback) {
     internalRouter.setCallback(callback);
     return this;
   }
@@ -58,7 +60,7 @@ public MapzenRouter setCallback(RouteCallback callback) {
    * @param units
    * @return
    */
-  public MapzenRouter setDistanceUnits(DistanceUnits units) {
+  @NonNull public MapzenRouter setDistanceUnits(@NonNull DistanceUnits units) {
     internalRouter.setDistanceUnits(UNITS_TO_ROUTER_UNITS.get(units));
     return this;
   }
@@ -71,7 +73,7 @@ public MapzenRouter setDistanceUnits(DistanceUnits units) {
    * <p />
    * https://github.com/valhalla/valhalla-docs/blob/master/api-reference.md#directions-options.
    */
-  public MapzenRouter setLanguage(Router.Language language) {
+  @NonNull public MapzenRouter setLanguage(Router.Language language) {
     internalRouter.setLanguage(language);
     return this;
   }
@@ -80,7 +82,7 @@ public MapzenRouter setLanguage(Router.Language language) {
    * The router can fetch different types of directions. Set the type to be biking.
    * @return
    */
-  public MapzenRouter setBiking() {
+  @NonNull public MapzenRouter setBiking() {
     internalRouter.setBiking();
     return this;
   }
@@ -89,7 +91,7 @@ public MapzenRouter setBiking() {
    * The router can fetch different types of directions. Set the type to be driving.
    * @return
    */
-  public MapzenRouter setDriving() {
+  @NonNull public MapzenRouter setDriving() {
     internalRouter.setDriving();
     return this;
   }
@@ -98,7 +100,7 @@ public MapzenRouter setDriving() {
    * The router can fetch different types of directions. Set the type to be walking.
    * @return
    */
-  public MapzenRouter setWalking() {
+  @NonNull public MapzenRouter setWalking() {
     internalRouter.setWalking();
     return this;
   }
@@ -107,7 +109,7 @@ public MapzenRouter setWalking() {
    * The router can fetch different types of directions. Set the type to be multimodal.
    * @return
    */
-  public MapzenRouter setMultimodal() {
+  @NonNull public MapzenRouter setMultimodal() {
     internalRouter.setMultimodal();
     return this;
   }
@@ -117,7 +119,7 @@ public MapzenRouter setMultimodal() {
    * @param point
    * @return
    */
-  public MapzenRouter setLocation(double[] point) {
+  @NonNull public MapzenRouter setLocation(double[] point) {
     internalRouter.setLocation(point);
     return this;
   }
@@ -127,7 +129,7 @@ public MapzenRouter setLocation(double[] point) {
    * @param point
    * @return
    */
-  public MapzenRouter setLocation(double[] point, int heading) {
+  @NonNull public MapzenRouter setLocation(double[] point, int heading) {
     internalRouter.setLocation(point, heading);
     return this;
   }
@@ -137,8 +139,8 @@ public MapzenRouter setLocation(double[] point, int heading) {
    * @param point
    * @return
    */
-  public MapzenRouter setLocation(double[] point, String name, String street, String city,
-      String state) {
+  @NonNull public MapzenRouter setLocation(double[] point, @Nullable String name,
+      @Nullable String street, @Nullable String city, @Nullable String state) {
     internalRouter.setLocation(point, name, street, city, state);
     return this;
   }
@@ -147,7 +149,7 @@ public MapzenRouter setLocation(double[] point, String name, String street, Stri
    * Remove all locations from the route.
    * @return
    */
-  public MapzenRouter clearLocations() {
+  @NonNull public MapzenRouter clearLocations() {
     internalRouter.clearLocations();
     return this;
   }
@@ -157,11 +159,11 @@ public MapzenRouter clearLocations() {
    * requests.
    * @param handler
    */
-  public void setHttpHandler(MapzenRouterHttpHandler handler) {
+  public void setHttpHandler(@Nullable MapzenRouterHttpHandler handler) {
     internalRouter.setHttpHandler(handler.turnByTurnHandler());
   }
 
-  public Router getRouter() {
+  @NonNull public Router getRouter() {
     return internalRouter;
   }
 
@@ -184,7 +186,7 @@ public enum DistanceUnits {
     /**
      * Returns string value.
      */
-    public String toString() {
+    @NonNull public String toString() {
       return name;
     }
   }
diff --git a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouterHttpHandler.java b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouterHttpHandler.java
index f61b1b78..d7b82edb 100644
--- a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouterHttpHandler.java
+++ b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/MapzenRouterHttpHandler.java
@@ -7,6 +7,7 @@
 import com.mapzen.valhalla.HttpHandler;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 
 import java.io.IOException;
 import java.lang.ref.WeakReference;
@@ -41,14 +42,15 @@ public abstract class MapzenRouterHttpHandler implements GenericHttpHandler {
   /**
    * Construct handler with default url and log levels.
    */
-  public MapzenRouterHttpHandler(Context context) {
+  public MapzenRouterHttpHandler(@NonNull Context context) {
     this(context, DEFAULT_URL, DEFAULT_LOG_LEVEL);
   }
 
   /**
    * Construct handler with custom url and log levels.
    */
-  public MapzenRouterHttpHandler(Context context, String url, LogLevel logLevel) {
+  public MapzenRouterHttpHandler(@NonNull Context context, @NonNull String url,
+      @NonNull LogLevel logLevel) {
     handler = new TurnByTurnHttpHandler(url, logLevel);
     MapzenManager mapzenManager = MapzenManager.instance(context);
     mapzenManager.addApiKeyChangeListener(apiKeyChangeListener);
@@ -59,11 +61,11 @@ public MapzenRouterHttpHandler(Context context, String url, LogLevel logLevel) {
    * Returns the internal handler.
    * @return
    */
-  TurnByTurnHttpHandler turnByTurnHandler() {
+  @NonNull TurnByTurnHttpHandler turnByTurnHandler() {
     return handler;
   }
 
-  private static LogLevel getDefaultLogLevel() {
+  @NonNull private static LogLevel getDefaultLogLevel() {
     return BASIC;
   }
 
diff --git a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/RouterInitializer.java b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/RouterInitializer.java
index e7019629..0d216b88 100644
--- a/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/RouterInitializer.java
+++ b/mapzen-android-sdk/src/main/java/com/mapzen/android/routing/RouterInitializer.java
@@ -1,6 +1,7 @@
 package com.mapzen.android.routing;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 
 import java.util.Map;
 
@@ -15,7 +16,7 @@ public class RouterInitializer {
    * Constructor.
    * @param context
    */
-  public RouterInitializer(Context context) {
+  public RouterInitializer(@NonNull Context context) {
     requestHandler = new MapzenRouterHttpHandler(context) {
       @Override public Map<String, String> queryParamsForRequest() {
         return null;
@@ -31,7 +32,7 @@ public RouterInitializer(Context context) {
    * Set the {@link MapzenRouter}'s {@link MapzenRouterHttpHandler}.
    * @param router
    */
-  public void initRouter(MapzenRouter router) {
+  public void initRouter(@NonNull MapzenRouter router) {
     router.getRouter().setHttpHandler(requestHandler.turnByTurnHandler());
   }
 
@@ -39,7 +40,7 @@ public void initRouter(MapzenRouter router) {
    * Returns the request handler.
    * @return
    */
-  public MapzenRouterHttpHandler getRequestHandler() {
+  @NonNull public MapzenRouterHttpHandler getRequestHandler() {
     return requestHandler;
   }
 }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompleteFilter.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompleteFilter.java
index 172346f2..163bcd0e 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompleteFilter.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompleteFilter.java
@@ -2,6 +2,8 @@
 
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 /**
  * Filter for customizing autocomplete results from {@link GeoDataApi}.
@@ -39,7 +41,7 @@ public class AutocompleteFilter implements Parcelable {
   /**
    * Constructs a new object.
    */
-  AutocompleteFilter(String country, int typeFilter) {
+  AutocompleteFilter(@Nullable String country, int typeFilter) {
     this.country = country;
     this.typeFilter = typeFilter;
   }
@@ -49,7 +51,7 @@ public class AutocompleteFilter implements Parcelable {
    * code or null.
    * @return
    */
-  public String getCountry() {
+  @Nullable public String getCountry() {
     return country;
   }
 
@@ -85,7 +87,7 @@ public static class Builder {
      * @param country
      * @return
      */
-    public Builder setCountry(String country) {
+    @NonNull public Builder setCountry(@Nullable String country) {
       this.country = country;
       return this;
     }
@@ -106,7 +108,7 @@ public Builder setCountry(String country) {
      * @param typeFilter
      * @return
      */
-    public Builder setTypeFilter(int typeFilter) {
+    @NonNull public Builder setTypeFilter(int typeFilter) {
       this.typeFilter = typeFilter;
       return this;
     }
@@ -117,7 +119,7 @@ public Builder setTypeFilter(int typeFilter) {
      * String, LatLngBounds, AutocompleteFilter}.
      * @return
      */
-    public AutocompleteFilter build() {
+    @NonNull public AutocompleteFilter build() {
       return new AutocompleteFilter(country, typeFilter);
     }
   }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePrediction.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePrediction.java
index 8f26edbc..2b535f35 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePrediction.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePrediction.java
@@ -19,7 +19,7 @@ public class AutocompletePrediction {
    * @param id
    * @param text
    */
-  public AutocompletePrediction(String id, String text) {
+  public AutocompletePrediction(@Nullable String id, @Nullable String text) {
     placeId = id;
     primaryText = text;
   }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePredictionBuffer.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePredictionBuffer.java
index cda1c32f..d1ff4059 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePredictionBuffer.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/AutocompletePredictionBuffer.java
@@ -3,6 +3,9 @@
 import com.mapzen.android.lost.api.Result;
 import com.mapzen.android.lost.api.Status;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.List;
 
 /**
@@ -18,12 +21,13 @@ public class AutocompletePredictionBuffer implements Result, DataBuffer<Autocomp
    * @param status
    * @param predictions
    */
-  public AutocompletePredictionBuffer(Status status, List<AutocompletePrediction> predictions) {
+  public AutocompletePredictionBuffer(@NonNull Status status,
+      @Nullable List<AutocompletePrediction> predictions) {
     this.status = status;
     this.predictions = predictions;
   }
 
-  @Override public Status getStatus() {
+  @NonNull @Override public Status getStatus() {
     return status;
   }
 
@@ -34,7 +38,7 @@ public AutocompletePredictionBuffer(Status status, List<AutocompletePrediction>
     return predictions.size();
   }
 
-  @Override public AutocompletePrediction get(int index) {
+  @Nullable @Override public AutocompletePrediction get(int index) {
     if (predictions == null || index < 0 || index > predictions.size() - 1) {
       return null;
     }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/GeoDataApi.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/GeoDataApi.java
index 1639ecf8..a4a68cc4 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/GeoDataApi.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/GeoDataApi.java
@@ -3,6 +3,8 @@
 import com.mapzen.android.lost.api.LostApiClient;
 import com.mapzen.android.lost.api.PendingResult;
 
+import android.support.annotation.NonNull;
+
 /**
  * Main entry point for the Mapzen Places Geo Data API.
  */
@@ -15,6 +17,7 @@ public interface GeoDataApi {
    * @param filter
    * @return
    */
-  PendingResult<AutocompletePredictionBuffer> getAutocompletePredictions(LostApiClient client,
-      String query, LatLngBounds bounds, AutocompleteFilter filter);
+  @NonNull PendingResult<AutocompletePredictionBuffer> getAutocompletePredictions(
+      @NonNull LostApiClient client, @NonNull String query, @NonNull LatLngBounds bounds,
+      @NonNull AutocompleteFilter filter);
 }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/LatLngBounds.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/LatLngBounds.java
index 5499d7e4..6c3d4da5 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/LatLngBounds.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/LatLngBounds.java
@@ -2,6 +2,7 @@
 
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.support.annotation.NonNull;
 
 /**
  * Represents a rectangular area.
@@ -16,16 +17,16 @@ public class LatLngBounds implements Parcelable {
    * @param southwest
    * @param northeast
    */
-  public LatLngBounds(LatLng southwest, LatLng northeast) {
+  public LatLngBounds(@NonNull LatLng southwest, @NonNull LatLng northeast) {
     this.southwest = southwest;
     this.northeast = northeast;
   }
 
-  public LatLng getSouthwest() {
+  @NonNull public LatLng getSouthwest() {
     return southwest;
   }
 
-  public LatLng getNortheast() {
+  @NonNull public LatLng getNortheast() {
     return northeast;
   }
 
@@ -43,7 +44,7 @@ public boolean contains(LatLng point) {
    * @param point
    * @return
    */
-  public LatLngBounds including(LatLng point) {
+  @NonNull public LatLngBounds including(@NonNull LatLng point) {
     double swLat = Math.min(this.southwest.getLatitude(), point.getLatitude());
     double neLat = Math.max(this.northeast.getLatitude(), point.getLatitude());
     double neLng = this.northeast.getLongitude();
@@ -64,7 +65,7 @@ public LatLngBounds including(LatLng point) {
    * Returns the center of the lat/lng bounds.
    * @return
    */
-  public LatLng getCenter() {
+  @NonNull public LatLng getCenter() {
     double midLat = (this.southwest.getLatitude() + this.northeast.getLatitude()) / 2.0D;
     double neLng = this.northeast.getLongitude();
     double swLng = this.southwest.getLongitude();
@@ -137,7 +138,7 @@ public static class Builder {
      * @param point
      * @return builder object
      */
-    public Builder include(LatLng point) {
+    @NonNull public Builder include(@NonNull LatLng point) {
       if (northeastLat == 0) {
         northeastLat = point.getLatitude();
         northeastLng = point.getLongitude();
@@ -161,7 +162,7 @@ public Builder include(LatLng point) {
      * Constructs a new {@link LatLngBounds} from current boundaries.
      * @return
      */
-    public LatLngBounds build() {
+    @NonNull public LatLngBounds build() {
       LatLng sw = new LatLng(southwestLat, southwestLng);
       LatLng ne = new LatLng(northeastLat, northeastLng);
       return new LatLngBounds(sw, ne);
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/Place.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/Place.java
index b1d23569..51daec66 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/Place.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/Place.java
@@ -2,6 +2,8 @@
 
 import android.net.Uri;
 import android.os.Parcelable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import java.util.List;
 import java.util.Locale;
@@ -28,7 +30,7 @@ public interface Place extends Parcelable {
    * Returns human readable address for this place.
    * @return
    */
-  abstract CharSequence getAddress();
+  @NonNull CharSequence getAddress();
 
   /**
    * Returns the attributions to be shown to the user if data from the Place is used.
@@ -37,31 +39,31 @@ public interface Place extends Parcelable {
    * {@link UnsupportedOperationException} if accessed
    * @return
    */
-  abstract CharSequence getAttributions();
+  @Nullable CharSequence getAttributions();
 
   /**
    * Returns the unique id of this Place.
    * @return
    */
-  abstract String getId();
+  @NonNull String getId();
 
   /**
    * Returns the location of this Place.
    * @return
    */
-  abstract LatLng getLatLng();
+  @NonNull LatLng getLatLng();
 
   /**
    * Returns the locale in which the names and addresses were localized.
    * @return
    */
-  abstract Locale getLocale();
+  @Nullable Locale getLocale();
 
   /**
    * Returns the name of this Place.
    * @return
    */
-  abstract CharSequence getName();
+  @Nullable CharSequence getName();
 
   /**
    * Returns the place's phone number in international format.
@@ -70,13 +72,13 @@ public interface Place extends Parcelable {
    * {@link UnsupportedOperationException} if accessed
    * @return
    */
-  abstract CharSequence getPhoneNumber();
+  @Nullable CharSequence getPhoneNumber();
 
   /**
    * Returns a list of place types for this Place.
    * @return
    */
-  abstract List<Integer> getPlaceTypes();
+  @Nullable List<Integer> getPlaceTypes();
 
   /**
    * Returns the price level for this place on a scale from 0 (cheapest) to 4.
@@ -85,7 +87,7 @@ public interface Place extends Parcelable {
    * {@link UnsupportedOperationException} if accessed
    * @return
    */
-  abstract int getPriceLevel();
+  int getPriceLevel();
 
   /**
    * Returns the place's rating, from 1.0 to 5.0, based on aggregated user reviews.
@@ -94,13 +96,13 @@ public interface Place extends Parcelable {
    * {@link UnsupportedOperationException} if accessed
    * @return
    */
-  abstract float getRating();
+  float getRating();
 
   /**
    * Returns a viewport for displaying this Place.
    * @return
    */
-  abstract LatLngBounds getViewport();
+  @Nullable LatLngBounds getViewport();
 
   /**
    * Returns website uri for this place.
@@ -109,5 +111,5 @@ public interface Place extends Parcelable {
    * {@link UnsupportedOperationException} if accessed
    * @return
    */
-  abstract Uri getWebsiteUri();
+  @Nullable Uri getWebsiteUri();
 }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/Places.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/Places.java
index 41cb2fed..c8dfc727 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/Places.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/Places.java
@@ -2,9 +2,11 @@
 
 import com.mapzen.places.api.internal.GeoDataApiImpl;
 
+import android.support.annotation.NonNull;
+
 /**
  * Main entry point for Mapzen Places API.
  */
 public class Places {
-  public static final GeoDataApi GeoDataApi = new GeoDataApiImpl();
+  @NonNull public static final GeoDataApi GeoDataApi = new GeoDataApiImpl();
 }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocomplete.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocomplete.java
index 4c7280a0..81614fdd 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocomplete.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocomplete.java
@@ -9,6 +9,8 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import static com.mapzen.places.api.internal.PlaceIntentConsts.EXTRA_BOUNDS;
 import static com.mapzen.places.api.internal.PlaceIntentConsts.EXTRA_FILTER;
@@ -31,7 +33,7 @@ public class PlaceAutocomplete {
    * @param intent
    * @return
    */
-  public static Place getPlace(Context context, Intent intent) {
+  @Nullable public static Place getPlace(@Nullable Context context, @Nullable Intent intent) {
     if (intent == null) {
       return null;
     }
@@ -44,7 +46,7 @@ public static Place getPlace(Context context, Intent intent) {
    * @param intent
    * @return
    */
-  public static Status getStatus(Context context, Intent intent) {
+  @Nullable public static Status getStatus(@Nullable Context context, @Nullable Intent intent) {
     if (intent == null) {
       return null;
     }
@@ -74,7 +76,7 @@ public IntentBuilder(int mode) {
      * @param activity
      * @return
      */
-    public Intent build(Activity activity) {
+    @NonNull public Intent build(@NonNull Activity activity) {
       Intent intent = new Intent(activity, PlaceAutocompleteActivity.class);
       intent.putExtra(EXTRA_BOUNDS, bounds);
       intent.putExtra(EXTRA_FILTER, filter);
@@ -90,7 +92,7 @@ public Intent build(Activity activity) {
      * @param latLngBounds
      * @return
      */
-    public IntentBuilder setBoundsBias(LatLngBounds latLngBounds) {
+    @NonNull public IntentBuilder setBoundsBias(@Nullable LatLngBounds latLngBounds) {
       this.bounds = latLngBounds;
       return this;
     }
@@ -100,7 +102,7 @@ public IntentBuilder setBoundsBias(LatLngBounds latLngBounds) {
      * @param filter
      * @return
      */
-    public IntentBuilder setFilter(AutocompleteFilter filter) {
+    @NonNull public IntentBuilder setFilter(@Nullable AutocompleteFilter filter) {
       this.filter = filter;
       return this;
     }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocompleteFragment.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocompleteFragment.java
index 824d9590..0f54cb12 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocompleteFragment.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceAutocompleteFragment.java
@@ -9,6 +9,7 @@
 import android.app.Fragment;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -24,15 +25,15 @@ public class PlaceAutocompleteFragment extends Fragment {
   private PlaceAutocompleteView autocompleteView;
   private PlaceSelectionListener listener;
 
-  @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,
-      Bundle savedInstanceState) {
+  @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater,
+      @NonNull ViewGroup container, Bundle savedInstanceState) {
     autocompleteView = (PlaceAutocompleteView) inflater.inflate(
         R.layout.place_autocomplete_fragment, container, false);
     autocompleteView.setFragment(this);
     return autocompleteView;
   }
 
-  @Override public void onActivityResult(int requestCode, int resultCode, Intent data) {
+  @Override public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
     if (resultCode == RESULT_OK) {
       Place place = PlaceAutocomplete.getPlace(this.getActivity(), data);
       String address = null;
@@ -46,7 +47,7 @@ public class PlaceAutocompleteFragment extends Fragment {
     }
   }
 
-  public void setPlaceSelectionListener(PlaceSelectionListener listener) {
+  public void setPlaceSelectionListener(@Nullable PlaceSelectionListener listener) {
     this.listener = listener;
   }
 
@@ -57,7 +58,7 @@ public void setPlaceSelectionListener(PlaceSelectionListener listener) {
    * be limited by any bounds.
    * @param boundsBias
    */
-  public void setBoundsBias(LatLngBounds boundsBias) {
+  public void setBoundsBias(@Nullable LatLngBounds boundsBias) {
     autocompleteView.setBoundsBias(boundsBias);
   }
 
@@ -65,7 +66,7 @@ public void setBoundsBias(LatLngBounds boundsBias) {
    * Set the {@link PlaceAutocompleteView}'s filter.
    * @param filter
    */
-  public void setFilter(AutocompleteFilter filter) {
+  public void setFilter(@Nullable AutocompleteFilter filter) {
     autocompleteView.setFilter(filter);
   }
 
@@ -73,7 +74,7 @@ public void setFilter(AutocompleteFilter filter) {
    * Set the {@link PlaceAutocompleteView}'s hint.
    * @param hint
    */
-  public void setHint(CharSequence hint) {
+  public void setHint(@Nullable CharSequence hint) {
     autocompleteView.setHint(hint);
   }
 
@@ -81,7 +82,7 @@ public void setHint(CharSequence hint) {
    * Set the {@link PlaceAutocompleteView}'s text.
    * @param text
    */
-  public void setText(CharSequence text) {
+  public void setText(@Nullable CharSequence text) {
     autocompleteView.setText(text);
   }
 }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlacePicker.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlacePicker.java
index 5be2c60b..c4b1f00a 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlacePicker.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlacePicker.java
@@ -7,6 +7,8 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import static com.mapzen.places.api.internal.PlaceIntentConsts.EXTRA_BOUNDS;
 import static com.mapzen.places.api.internal.PlaceIntentConsts.EXTRA_PLACE;
@@ -25,7 +27,7 @@ public class PlacePicker {
    * @param intent intent returned in {@link Activity#onActivityResult(int, int, Intent)}
    * @return
    */
-  public static String getAttributions(Intent intent) {
+  @Nullable public static String getAttributions(@Nullable Intent intent) {
     if (intent == null) {
       return null;
     }
@@ -41,7 +43,7 @@ public static String getAttributions(Intent intent) {
    * @param intent intent returned in {@link Activity#onActivityResult(int, int, Intent)}
    * @return
    */
-  public static LatLngBounds getLatLngBounds(Intent intent) {
+  @Nullable public static LatLngBounds getLatLngBounds(@Nullable Intent intent) {
     if (intent == null) {
       return null;
     }
@@ -55,7 +57,7 @@ public static LatLngBounds getLatLngBounds(Intent intent) {
    * @param intent intent returned in {@link Activity#onActivityResult(int, int, Intent)}
    * @return
    */
-  public static Place getPlace(Context context, Intent intent) {
+  @Nullable public static Place getPlace(@Nullable Context context, @Nullable Intent intent) {
     if (intent == null) {
       return null;
     }
@@ -74,7 +76,7 @@ public static class IntentBuilder {
      * @param activity
      * @return
      */
-    public Intent build(Activity activity) {
+    @Nullable public Intent build(@NonNull Activity activity) {
       Intent intent = new Intent(activity, PlacePickerActivity.class);
       intent.putExtra(EXTRA_BOUNDS, bounds);
       return intent;
@@ -86,7 +88,7 @@ public Intent build(Activity activity) {
      * @param latLngBounds
      * @return
      */
-    public PlacePicker.IntentBuilder setLatLngBounds(LatLngBounds latLngBounds) {
+    @NonNull public PlacePicker.IntentBuilder setLatLngBounds(@Nullable LatLngBounds latLngBounds) {
       this.bounds = latLngBounds;
       return this;
     }
diff --git a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceSelectionListener.java b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceSelectionListener.java
index f80b3fdd..b5319afd 100644
--- a/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceSelectionListener.java
+++ b/mapzen-places-api/src/main/java/com/mapzen/places/api/ui/PlaceSelectionListener.java
@@ -3,6 +3,8 @@
 import com.mapzen.android.lost.api.Status;
 import com.mapzen.places.api.Place;
 
+import android.support.annotation.NonNull;
+
 /**
  * Interface for receiving information about a {@link Place} after it is selected from a
  * {@link PlaceAutocompleteFragment}.
@@ -13,11 +15,11 @@ public interface PlaceSelectionListener {
    * Called when the user selects a {@link Place}.
    * @param place
    */
-  void onPlaceSelected(Place place);
+  void onPlaceSelected(@NonNull Place place);
 
   /**
    * Called when an error occurs while trying to select a {@link Place}.
    * @param status
    */
-  void onError(Status status);
+  void onError(@NonNull Status status);
 }
diff --git a/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/fragments/RoutePinsFragment.kt b/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/fragments/RoutePinsFragment.kt
index 9c6bbfd6..af90da63 100644
--- a/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/fragments/RoutePinsFragment.kt
+++ b/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/fragments/RoutePinsFragment.kt
@@ -41,6 +41,6 @@ class RoutePinsFragment : BaseFragment() {
   private fun addPin(x: Float, y: Float) {
     val lngLat = map?.screenPositionToLngLat(PointF(x, y))
     val marker = lngLat?.let { Marker(it.longitude, it.latitude) }
-    map?.addMarker(marker)
+    marker?.let { map?.addMarker(it) }
   }
 }
diff --git a/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/presenters/RoutingPresenterImpl.kt b/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/presenters/RoutingPresenterImpl.kt
index 05d0e38a..32fcb555 100644
--- a/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/presenters/RoutingPresenterImpl.kt
+++ b/samples/mapzen-sample/src/main/java/mapzen/com/sdksampleapp/presenters/RoutingPresenterImpl.kt
@@ -69,7 +69,7 @@ class RoutingPresenterImpl(val router: MapzenRouter) : RoutingPresenter, RouteCa
     count++
     val lngLat = controller?.getMapzenMap()?.screenPositionToLngLat(PointF(x, y))
     val marker = lngLat?.let { Marker(it.longitude, it.latitude) }
-    controller?.getMapzenMap()?.addMarker(marker)
+    marker?.let { controller?.getMapzenMap()?.addMarker(it) }
     lngLat?.let { addToRouter(doubleArrayOf(it.latitude, it.longitude)) }
     getRoute()
   }