diff --git a/api/src/main/java/io/github/libxposed/XposedContextWrapper.java b/api/src/main/java/io/github/libxposed/XposedContextWrapper.java
index 8e5dd5c..d228ad3 100644
--- a/api/src/main/java/io/github/libxposed/XposedContextWrapper.java
+++ b/api/src/main/java/io/github/libxposed/XposedContextWrapper.java
@@ -80,73 +80,73 @@ public class XposedContextWrapper extends ContextWrapper implements XposedInterf
         return getBaseContext().featuredMethod(name, args);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<BeforeHooker<Method>, Method> hookBefore(@NonNull Method origin, @NonNull BeforeHooker<Method> hooker) {
         return getBaseContext().hookBefore(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<AfterHooker<Method>, Method> hookAfter(@NonNull Method origin, @NonNull AfterHooker<Method> hooker) {
         return getBaseContext().hookAfter(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<Hooker<Method>, Method> hook(@NonNull Method origin, @NonNull Hooker<Method> hooker) {
         return getBaseContext().hook(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<BeforeHooker<Method>, Method> hookBefore(@NonNull Method origin, int priority, @NonNull BeforeHooker<Method> hooker) {
         return getBaseContext().hookBefore(origin, priority, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<AfterHooker<Method>, Method> hookAfter(@NonNull Method origin, int priority, @NonNull AfterHooker<Method> hooker) {
         return getBaseContext().hookAfter(origin, priority, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public MethodUnhooker<Hooker<Method>, Method> hook(@NonNull Method origin, int priority, @NonNull Hooker<Method> hooker) {
         return getBaseContext().hook(origin, priority, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<BeforeHooker<Constructor<T>>, Constructor<T>> hookBefore(@NonNull Constructor<T> origin, @NonNull BeforeHooker<Constructor<T>> hooker) {
         return getBaseContext().hookBefore(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<AfterHooker<Constructor<T>>, Constructor<T>> hookAfter(@NonNull Constructor<T> origin, @NonNull AfterHooker<Constructor<T>> hooker) {
         return getBaseContext().hookAfter(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<Hooker<Constructor<T>>, Constructor<T>> hook(@NonNull Constructor<T> origin, @NonNull Hooker<Constructor<T>> hooker) {
         return getBaseContext().hook(origin, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<BeforeHooker<Constructor<T>>, Constructor<T>> hookBefore(@NonNull Constructor<T> origin, int priority, @NonNull BeforeHooker<Constructor<T>> hooker) {
         return getBaseContext().hookBefore(origin, priority, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<AfterHooker<Constructor<T>>, Constructor<T>> hookAfter(@NonNull Constructor<T> origin, int priority, @NonNull AfterHooker<Constructor<T>> hooker) {
         return getBaseContext().hookAfter(origin, priority, hooker);
     }
 
-    @Nullable
+    @NonNull
     @Override
     final public <T> MethodUnhooker<Hooker<Constructor<T>>, Constructor<T>> hook(@NonNull Constructor<T> origin, int priority, @NonNull Hooker<Constructor<T>> hooker) {
         return getBaseContext().hook(origin, priority, hooker);
diff --git a/api/src/main/java/io/github/libxposed/XposedInterface.java b/api/src/main/java/io/github/libxposed/XposedInterface.java
index 6ca2e9c..541afc3 100644
--- a/api/src/main/java/io/github/libxposed/XposedInterface.java
+++ b/api/src/main/java/io/github/libxposed/XposedInterface.java
@@ -45,6 +45,19 @@ public interface XposedInterface {
      */
     int FRAMEWORK_PRIVILEGE_EMBEDDED = 3;
 
+    /**
+     * The default hook priority.
+     */
+    int PRIORITY_DEFAULT = 50;
+    /**
+     * Execute the hook callback late.
+     */
+    int PRIORITY_LOWEST = -10000;
+    /**
+     * Execute the hook callback early.
+     */
+    int PRIORITY_HIGHEST = 10000;
+
     /**
      * The interface Before hook callback.
      *
@@ -306,6 +319,24 @@ public interface XposedInterface {
         void unhook();
     }
 
+    /**
+     * The exception thrown when a hook fails
+     */
+    class HookFailedException extends RuntimeException {
+
+        public HookFailedException(String message) {
+            super(message);
+        }
+
+        public HookFailedException(Throwable cause) {
+            super(cause);
+        }
+
+        public HookFailedException(String message, Throwable cause) {
+            super(message, cause);
+        }
+    }
+
     /**
      * Gets framework name.
      *
@@ -343,6 +374,7 @@ public interface XposedInterface {
      * @param args the args
      * @return the object
      */
+    @Nullable
     Object featuredMethod(String name, Object... args);
 
     /**
@@ -351,8 +383,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<BeforeHooker<Method>, Method> hookBefore(@NonNull Method origin, @NonNull BeforeHooker<Method> hooker);
 
     /**
@@ -361,8 +394,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<AfterHooker<Method>, Method> hookAfter(@NonNull Method origin, @NonNull AfterHooker<Method> hooker);
 
     /**
@@ -371,8 +405,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<Hooker<Method>, Method> hook(@NonNull Method origin, @NonNull Hooker<Method> hooker);
 
     /**
@@ -382,8 +417,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<BeforeHooker<Method>, Method> hookBefore(@NonNull Method origin, int priority, @NonNull BeforeHooker<Method> hooker);
 
     /**
@@ -393,8 +429,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<AfterHooker<Method>, Method> hookAfter(@NonNull Method origin, int priority, @NonNull AfterHooker<Method> hooker);
 
     /**
@@ -404,8 +441,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     MethodUnhooker<Hooker<Method>, Method> hook(@NonNull Method origin, int priority, @NonNull Hooker<Method> hooker);
 
     /**
@@ -415,8 +453,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<BeforeHooker<Constructor<T>>, Constructor<T>> hookBefore(@NonNull Constructor<T> origin, @NonNull BeforeHooker<Constructor<T>> hooker);
 
     /**
@@ -426,8 +465,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<AfterHooker<Constructor<T>>, Constructor<T>> hookAfter(@NonNull Constructor<T> origin, @NonNull AfterHooker<Constructor<T>> hooker);
 
     /**
@@ -437,8 +477,9 @@ public interface XposedInterface {
      * @param origin the origin
      * @param hooker the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<Hooker<Constructor<T>>, Constructor<T>> hook(@NonNull Constructor<T> origin, @NonNull Hooker<Constructor<T>> hooker);
 
     /**
@@ -449,8 +490,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<BeforeHooker<Constructor<T>>, Constructor<T>> hookBefore(@NonNull Constructor<T> origin, int priority, @NonNull BeforeHooker<Constructor<T>> hooker);
 
     /**
@@ -461,8 +503,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<AfterHooker<Constructor<T>>, Constructor<T>> hookAfter(@NonNull Constructor<T> origin, int priority, @NonNull AfterHooker<Constructor<T>> hooker);
 
     /**
@@ -473,8 +516,9 @@ public interface XposedInterface {
      * @param priority the priority
      * @param hooker   the hooker
      * @return the method unhooker
+     * @throws HookFailedException if hook fails
      */
-    @Nullable
+    @NonNull
     <T> MethodUnhooker<Hooker<Constructor<T>>, Constructor<T>> hook(@NonNull Constructor<T> origin, int priority, @NonNull Hooker<Constructor<T>> hooker);
 
     /**