diff --git a/include/android/choreographer.h b/include/android/choreographer.h
index 43346fe..11f8f6b 100644
--- a/include/android/choreographer.h
+++ b/include/android/choreographer.h
@@ -30,8 +30,6 @@
 
 __BEGIN_DECLS
 
-#if __ANDROID_API__ >= 24
-
 struct AChoreographer;
 typedef struct AChoreographer AChoreographer;
 
@@ -49,23 +47,23 @@
  * Get the AChoreographer instance for the current thread. This must be called
  * on an ALooper thread.
  */
-AChoreographer* AChoreographer_getInstance();
+AChoreographer* AChoreographer_getInstance() __INTRODUCED_IN(24);
 
 /**
  * Post a callback to be run on the next frame. The data pointer provided will
  * be passed to the callback function when it's called.
  */
 void AChoreographer_postFrameCallback(AChoreographer* choreographer,
-                AChoreographer_frameCallback callback, void* data);
+                AChoreographer_frameCallback callback, void* data) __INTRODUCED_IN(24);
+
 /**
  * Post a callback to be run on the frame following the specified delay. The
  * data pointer provided will be passed to the callback function when it's
  * called.
  */
 void AChoreographer_postFrameCallbackDelayed(AChoreographer* choreographer,
-                AChoreographer_frameCallback callback, void* data, long delayMillis);
-
-#endif /* __ANDROID_API__ >= 24 */
+                AChoreographer_frameCallback callback, void* data,
+                long delayMillis) __INTRODUCED_IN(24);
 
 __END_DECLS
 
diff --git a/include/android/configuration.h b/include/android/configuration.h
index 6287332..81aedca 100644
--- a/include/android/configuration.h
+++ b/include/android/configuration.h
@@ -30,6 +30,10 @@
 
 #include <android/asset_manager.h>
 
+#if !defined(__INTRODUCED_IN)
+#define __INTRODUCED_IN(__api_level) /* nothing */
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -671,53 +675,49 @@
  */
 void AConfiguration_setUiModeNight(AConfiguration* config, int32_t uiModeNight);
 
-#if __ANDROID_API__ >= 13
 /**
  * Return the current configuration screen width in dp units, or
  * ACONFIGURATION_SCREEN_WIDTH_DP_ANY if not set.
  */
-int32_t AConfiguration_getScreenWidthDp(AConfiguration* config);
+int32_t AConfiguration_getScreenWidthDp(AConfiguration* config) __INTRODUCED_IN(13);
 
 /**
  * Set the configuration's current screen width in dp units.
  */
-void AConfiguration_setScreenWidthDp(AConfiguration* config, int32_t value);
+void AConfiguration_setScreenWidthDp(AConfiguration* config, int32_t value) __INTRODUCED_IN(13);
 
 /**
  * Return the current configuration screen height in dp units, or
  * ACONFIGURATION_SCREEN_HEIGHT_DP_ANY if not set.
  */
-int32_t AConfiguration_getScreenHeightDp(AConfiguration* config);
+int32_t AConfiguration_getScreenHeightDp(AConfiguration* config) __INTRODUCED_IN(13);
 
 /**
  * Set the configuration's current screen width in dp units.
  */
-void AConfiguration_setScreenHeightDp(AConfiguration* config, int32_t value);
+void AConfiguration_setScreenHeightDp(AConfiguration* config, int32_t value) __INTRODUCED_IN(13);
 
 /**
  * Return the configuration's smallest screen width in dp units, or
  * ACONFIGURATION_SMALLEST_SCREEN_WIDTH_DP_ANY if not set.
  */
-int32_t AConfiguration_getSmallestScreenWidthDp(AConfiguration* config);
+int32_t AConfiguration_getSmallestScreenWidthDp(AConfiguration* config) __INTRODUCED_IN(13);
 
 /**
  * Set the configuration's smallest screen width in dp units.
  */
-void AConfiguration_setSmallestScreenWidthDp(AConfiguration* config, int32_t value);
-#endif /* __ANDROID_API__ >= 13 */
+void AConfiguration_setSmallestScreenWidthDp(AConfiguration* config, int32_t value) __INTRODUCED_IN(13);
 
-#if __ANDROID_API__ >= 17
 /**
  * Return the configuration's layout direction, or
  * ACONFIGURATION_LAYOUTDIR_ANY if not set.
  */
-int32_t AConfiguration_getLayoutDirection(AConfiguration* config);
+int32_t AConfiguration_getLayoutDirection(AConfiguration* config) __INTRODUCED_IN(17);
 
 /**
  * Set the configuration's layout direction.
  */
-void AConfiguration_setLayoutDirection(AConfiguration* config, int32_t value);
-#endif /* __ANDROID_API__ >= 17 */
+void AConfiguration_setLayoutDirection(AConfiguration* config, int32_t value) __INTRODUCED_IN(17);
 
 /**
  * Perform a diff between two configurations.  Returns a bit mask of
diff --git a/include/android/input.h b/include/android/input.h
index f3f5312..3b36d2e 100644
--- a/include/android/input.h
+++ b/include/android/input.h
@@ -56,6 +56,10 @@
 #include <android/keycodes.h>
 #include <android/looper.h>
 
+#if !defined(__INTRODUCED_IN)
+#define __INTRODUCED_IN(__api_level) /* nothing */
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -982,10 +986,8 @@
  */
 int32_t AMotionEvent_getMetaState(const AInputEvent* motion_event);
 
-#if __ANDROID_API__ >= 14
 /** Get the button state of all buttons that are pressed. */
-int32_t AMotionEvent_getButtonState(const AInputEvent* motion_event);
-#endif
+int32_t AMotionEvent_getButtonState(const AInputEvent* motion_event) __INTRODUCED_IN(14);
 
 /**
  * Get a bitfield indicating which edges, if any, were touched by this motion event.
@@ -1050,14 +1052,12 @@
  */
 int32_t AMotionEvent_getPointerId(const AInputEvent* motion_event, size_t pointer_index);
 
-#if __ANDROID_API__ >= 14
 /**
  * Get the tool type of a pointer for the given pointer index.
  * The tool type indicates the type of tool used to make contact such as a
  * finger or stylus, if known.
  */
-int32_t AMotionEvent_getToolType(const AInputEvent* motion_event, size_t pointer_index);
-#endif
+int32_t AMotionEvent_getToolType(const AInputEvent* motion_event, size_t pointer_index) __INTRODUCED_IN(14);
 
 /**
  * Get the original raw X coordinate of this event.
@@ -1147,11 +1147,9 @@
  */
 float AMotionEvent_getOrientation(const AInputEvent* motion_event, size_t pointer_index);
 
-#if __ANDROID_API__ >= 13
 /** Get the value of the request axis for the given pointer index. */
 float AMotionEvent_getAxisValue(const AInputEvent* motion_event,
-        int32_t axis, size_t pointer_index);
-#endif
+        int32_t axis, size_t pointer_index) __INTRODUCED_IN(13);
 
 /**
  * Get the number of historical points in this event.  These are movements that
@@ -1282,14 +1280,12 @@
 float AMotionEvent_getHistoricalOrientation(const AInputEvent* motion_event, size_t pointer_index,
         size_t history_index);
 
-#if __ANDROID_API__ >= 13
 /**
  * Get the historical value of the request axis for the given pointer index
  * that occurred between this event and the previous motion event.
  */
 float AMotionEvent_getHistoricalAxisValue(const AInputEvent* motion_event,
-        int32_t axis, size_t pointer_index, size_t history_index);
-#endif
+        int32_t axis, size_t pointer_index, size_t history_index) __INTRODUCED_IN(13);
 
 
 struct AInputQueue;
diff --git a/include/android/multinetwork.h b/include/android/multinetwork.h
index 5f2a57f..55df9f8 100644
--- a/include/android/multinetwork.h
+++ b/include/android/multinetwork.h
@@ -60,8 +60,6 @@
  * on failure with an appropriate errno value set.
  */
 
-#if __ANDROID_API__ >= 24
-
 /**
  * Set the network to be used by the given socket file descriptor.
  *
@@ -70,7 +68,7 @@
  * This is the equivalent of: [android.net.Network#bindSocket()](https://developer.android.com/reference/android/net/Network.html#bindSocket(java.net.Socket))
  *
  */
-int android_setsocknetwork(net_handle_t network, int fd);
+int android_setsocknetwork(net_handle_t network, int fd) __INTRODUCED_IN(23);
 
 
 /**
@@ -87,7 +85,7 @@
  * This is the equivalent of: [android.net.ConnectivityManager#setProcessDefaultNetwork()](https://developer.android.com/reference/android/net/ConnectivityManager.html#setProcessDefaultNetwork(android.net.Network))
  *
  */
-int android_setprocnetwork(net_handle_t network);
+int android_setprocnetwork(net_handle_t network) __INTRODUCED_IN(23);
 
 
 /**
@@ -106,9 +104,7 @@
  */
 int android_getaddrinfofornetwork(net_handle_t network,
         const char *node, const char *service,
-        const struct addrinfo *hints, struct addrinfo **res);
-
-#endif /* __ANDROID_API__ >= 24 */
+        const struct addrinfo *hints, struct addrinfo **res) __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/include/android/native_window_jni.h b/include/android/native_window_jni.h
index 082fab2..74e43c7 100644
--- a/include/android/native_window_jni.h
+++ b/include/android/native_window_jni.h
@@ -44,7 +44,6 @@
  */
 ANativeWindow* ANativeWindow_fromSurface(JNIEnv* env, jobject surface);
 
-#if __ANDROID_API__ >= 26
 /**
  * Return a Java Surface object derived from the ANativeWindow, for interacting
  * with it through Java code. The returned Java object acquires a reference on
@@ -52,8 +51,7 @@
  * and will automatically release the reference when the Java object gets garbage
  * collected.
  */
-jobject ANativeWindow_toSurface(JNIEnv* env, ANativeWindow* window);
-#endif
+jobject ANativeWindow_toSurface(JNIEnv* env, ANativeWindow* window) __INTRODUCED_IN(26);
 
 #ifdef __cplusplus
 };
diff --git a/include/android/sensor.h b/include/android/sensor.h
index 191777c..59229c1 100644
--- a/include/android/sensor.h
+++ b/include/android/sensor.h
@@ -478,7 +478,6 @@
 ASensorManager* ASensorManager_getInstance();
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
 /**
  * Get a reference to the sensor manager. ASensorManager is a singleton
  * per package as different packages may have access to different sensors.
@@ -488,8 +487,7 @@
  *     ASensorManager* sensorManager = ASensorManager_getInstanceForPackage("foo.bar.baz");
  *
  */
-ASensorManager* ASensorManager_getInstanceForPackage(const char* packageName);
-#endif
+ASensorManager* ASensorManager_getInstanceForPackage(const char* packageName) __INTRODUCED_IN(26);
 
 /**
  * Returns the list of available sensors.
@@ -502,13 +500,11 @@
  */
 ASensor const* ASensorManager_getDefaultSensor(ASensorManager* manager, int type);
 
-#if __ANDROID_API__ >= 21
 /**
  * Returns the default sensor with the given type and wakeUp properties or NULL if no sensor
  * of this type and wakeUp properties exists.
  */
-ASensor const* ASensorManager_getDefaultSensorEx(ASensorManager* manager, int type, bool wakeUp);
-#endif
+ASensor const* ASensorManager_getDefaultSensorEx(ASensorManager* manager, int type, bool wakeUp) __INTRODUCED_IN(21);
 
 /**
  * Creates a new sensor event queue and associate it with a looper.
@@ -525,7 +521,6 @@
  */
 int ASensorManager_destroyEventQueue(ASensorManager* manager, ASensorEventQueue* queue);
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
 /**
  * Create direct channel based on shared memory
  *
@@ -542,7 +537,7 @@
  *         {@link ASensorManager_destroyDirectChannel} and
  *         {@link ASensorManager_configureDirectReport}, or value less or equal to 0 for failures.
  */
-int ASensorManager_createSharedMemoryDirectChannel(ASensorManager* manager, int fd, size_t size);
+int ASensorManager_createSharedMemoryDirectChannel(ASensorManager* manager, int fd, size_t size) __INTRODUCED_IN(26);
 
 /**
  * Create direct channel based on AHardwareBuffer
@@ -560,7 +555,7 @@
  *         {@link ASensorManager_configureDirectReport}, or value less or equal to 0 for failures.
  */
 int ASensorManager_createHardwareBufferDirectChannel(
-        ASensorManager* manager, AHardwareBuffer const * buffer, size_t size);
+        ASensorManager* manager, AHardwareBuffer const * buffer, size_t size) __INTRODUCED_IN(26);
 
 /**
  * Destroy a direct channel
@@ -575,7 +570,7 @@
  *                  {@link ASensorManager_createSharedMemoryDirectChannel} or
  *                  {@link ASensorManager_createHardwareBufferDirectChannel}.
  */
-void ASensorManager_destroyDirectChannel(ASensorManager* manager, int channelId);
+void ASensorManager_destroyDirectChannel(ASensorManager* manager, int channelId) __INTRODUCED_IN(26);
 
 /**
  * Configure direct report on channel
@@ -612,9 +607,8 @@
  *
  * \return positive token for success or negative error code.
  */
-int ASensorManager_configureDirectReport(
-        ASensorManager* manager, ASensor const* sensor, int channelId, int rate);
-#endif
+int ASensorManager_configureDirectReport(ASensorManager* manager,
+        ASensor const* sensor, int channelId, int rate) __INTRODUCED_IN(26);
 
 /*****************************************************************************/
 
@@ -733,35 +727,32 @@
  */
 int ASensor_getMinDelay(ASensor const* sensor);
 
-#if __ANDROID_API__ >= 21
 /**
  * Returns the maximum size of batches for this sensor. Batches will often be
  * smaller, as the hardware fifo might be used for other sensors.
  */
-int ASensor_getFifoMaxEventCount(ASensor const* sensor);
+int ASensor_getFifoMaxEventCount(ASensor const* sensor) __INTRODUCED_IN(21);
 
 /**
  * Returns the hardware batch fifo size reserved to this sensor.
  */
-int ASensor_getFifoReservedEventCount(ASensor const* sensor);
+int ASensor_getFifoReservedEventCount(ASensor const* sensor) __INTRODUCED_IN(21);
 
 /**
  * Returns this sensor's string type.
  */
-const char* ASensor_getStringType(ASensor const* sensor);
+const char* ASensor_getStringType(ASensor const* sensor) __INTRODUCED_IN(21);
 
 /**
  * Returns the reporting mode for this sensor. One of AREPORTING_MODE_* constants.
  */
-int ASensor_getReportingMode(ASensor const* sensor);
+int ASensor_getReportingMode(ASensor const* sensor) __INTRODUCED_IN(21);
 
 /**
  * Returns true if this is a wake up sensor, false otherwise.
  */
-bool ASensor_isWakeUpSensor(ASensor const* sensor);
-#endif /* __ANDROID_API__ >= 21 */
+bool ASensor_isWakeUpSensor(ASensor const* sensor) __INTRODUCED_IN(21);
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
 /**
  * Test if sensor supports a certain type of direct channel.
  *
@@ -771,7 +762,8 @@
  *                     or {@link ASENSOR_DIRECT_CHANNEL_TYPE_HARDWARE_BUFFER}.
  * \returns true if sensor supports the specified direct channel type.
  */
-bool ASensor_isDirectChannelTypeSupported(ASensor const* sensor, int channelType);
+bool ASensor_isDirectChannelTypeSupported(ASensor const* sensor, int channelType) __INTRODUCED_IN(26);
+
 /**
  * Get the highest direct rate level that a sensor support.
  *
@@ -781,8 +773,7 @@
  *         If return value is {@link ASENSOR_DIRECT_RATE_STOP}, it means the sensor
  *         does not support direct report.
  */
-int ASensor_getHighestDirectReportRateLevel(ASensor const* sensor);
-#endif
+int ASensor_getHighestDirectReportRateLevel(ASensor const* sensor) __INTRODUCED_IN(26);
 
 #ifdef __cplusplus
 };
diff --git a/include/android/sharedmem.h b/include/android/sharedmem.h
index 46d2f4b..0354f17 100644
--- a/include/android/sharedmem.h
+++ b/include/android/sharedmem.h
@@ -52,8 +52,6 @@
 extern "C" {
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
-
 /**
  * Create a shared memory region.
  *
@@ -67,7 +65,7 @@
  * \param size size of the shared memory region
  * \return file descriptor that denotes the shared memory; error code on failure.
  */
-int ASharedMemory_create(const char *name, size_t size);
+int ASharedMemory_create(const char *name, size_t size) __INTRODUCED_IN(26);
 
 /**
  * Get the size of the shared memory region.
@@ -75,7 +73,7 @@
  * \param fd file descriptor of the shared memory region
  * \return size in bytes; 0 if fd is not a valid shared memory file descriptor.
  */
-size_t ASharedMemory_getSize(int fd);
+size_t ASharedMemory_getSize(int fd) __INTRODUCED_IN(26);
 
 /**
  * Restrict access of shared memory region.
@@ -106,9 +104,7 @@
  *             updated access. Note access can only be removed, but not added back.
  * \return 0 for success, error code on failure.
  */
-int ASharedMemory_setProt(int fd, int prot);
-
-#endif
+int ASharedMemory_setProt(int fd, int prot) __INTRODUCED_IN(26);
 
 #ifdef __cplusplus
 };
diff --git a/include/android/sharedmem_jni.h b/include/android/sharedmem_jni.h
index 85ac78f..d8b514f 100644
--- a/include/android/sharedmem_jni.h
+++ b/include/android/sharedmem_jni.h
@@ -54,8 +54,6 @@
 extern "C" {
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_O_MR1__
-
 /**
  * Returns a dup'd FD from the given Java android.os.SharedMemory object. The returned file
  * descriptor has all the same properties & capabilities as the FD returned from
@@ -70,9 +68,7 @@
  *      already closed, if the JNIEnv or jobject is NULL, or if there are too many open file
  *      descriptors (errno=EMFILE)
  */
-int ASharedMemory_dupFromJava(JNIEnv* env, jobject sharedMemory);
-
-#endif
+int ASharedMemory_dupFromJava(JNIEnv* env, jobject sharedMemory) __INTRODUCED_IN(27);
 
 #ifdef __cplusplus
 };
diff --git a/include/android/surface_texture.h b/include/android/surface_texture.h
index 56b3342..db10a16 100644
--- a/include/android/surface_texture.h
+++ b/include/android/surface_texture.h
@@ -64,7 +64,7 @@
  * Failing to do so will result in leaked memory and graphic resources.
  * \param st A ASurfaceTexture reference acquired with ASurfaceTexture_fromSurfaceTexture()
  */
-void ASurfaceTexture_release(ASurfaceTexture* st);
+void ASurfaceTexture_release(ASurfaceTexture* st) __INTRODUCED_IN(28);
 
 /**
  * Returns a reference to an ANativeWindow (i.e. the Producer) for this SurfaceTexture.
@@ -75,7 +75,7 @@
  * using ANativeWindow_release(). Failing to do so will result in leaked resources. nullptr is
  * returned if \st is null or if it's not an instance of android.graphics.SurfaceTexture
  */
-ANativeWindow* ASurfaceTexture_acquireANativeWindow(ASurfaceTexture* st);
+ANativeWindow* ASurfaceTexture_acquireANativeWindow(ASurfaceTexture* st) __INTRODUCED_IN(28);
 
 /**
  * Attach the SurfaceTexture to the OpenGL ES context that is current on the calling thread.  A
@@ -92,7 +92,7 @@
  * must be unusued in the OpenGL ES context that is current on the calling thread.
  * \return 0 on success, negative posix error code otherwise (see <errno.h>)
  */
-int ASurfaceTexture_attachToGLContext(ASurfaceTexture* st, uint32_t texName);
+int ASurfaceTexture_attachToGLContext(ASurfaceTexture* st, uint32_t texName) __INTRODUCED_IN(28);
 
 /**
  * Detach the SurfaceTexture from the OpenGL ES context that owns the OpenGL ES texture object.
@@ -108,7 +108,7 @@
  * \param st A ASurfaceTexture reference acquired with ASurfaceTexture_fromSurfaceTexture()
  * \return 0 on success, negative posix error code otherwise (see <errno.h>)
  */
-int ASurfaceTexture_detachFromGLContext(ASurfaceTexture* st);
+int ASurfaceTexture_detachFromGLContext(ASurfaceTexture* st) __INTRODUCED_IN(28);
 
 /**
  * Update the texture image to the most recent frame from the image stream.  This may only be
@@ -118,7 +118,7 @@
  * \param st A ASurfaceTexture reference acquired with ASurfaceTexture_fromSurfaceTexture()
  * \return 0 on success, negative posix error code otherwise (see <errno.h>)
  */
-int ASurfaceTexture_updateTexImage(ASurfaceTexture* st);
+int ASurfaceTexture_updateTexImage(ASurfaceTexture* st) __INTRODUCED_IN(28);
 
 /**
  * Retrieve the 4x4 texture coordinate transform matrix associated with the texture image set by
@@ -136,7 +136,7 @@
  * \param mtx the array into which the 4x4 matrix will be stored.  The array must have exactly
  *     16 elements.
  */
-void ASurfaceTexture_getTransformMatrix(ASurfaceTexture* st, float mtx[16]);
+void ASurfaceTexture_getTransformMatrix(ASurfaceTexture* st, float mtx[16]) __INTRODUCED_IN(28);
 
 /**
  * Retrieve the timestamp associated with the texture image set by the most recent call to
@@ -155,7 +155,7 @@
  *
  * \param st A ASurfaceTexture reference acquired with ASurfaceTexture_fromSurfaceTexture()
  */
-int64_t ASurfaceTexture_getTimestamp(ASurfaceTexture* st);
+int64_t ASurfaceTexture_getTimestamp(ASurfaceTexture* st) __INTRODUCED_IN(28);
 
 __END_DECLS
 
diff --git a/include/android/trace.h b/include/android/trace.h
index d9e5d88..9f59acf 100644
--- a/include/android/trace.h
+++ b/include/android/trace.h
@@ -37,13 +37,11 @@
 extern "C" {
 #endif
 
-#if __ANDROID_API__ >= 23
-
 /**
  * Returns true if tracing is enabled. Use this signal to avoid expensive computation only necessary
  * when tracing is enabled.
  */
-bool ATrace_isEnabled();
+bool ATrace_isEnabled() __INTRODUCED_IN(23);
 
 /**
  * Writes a tracing message to indicate that the given section of code has begun. This call must be
@@ -53,7 +51,7 @@
  * by the tracing mechanism. If sectionName contains these characters they will be replaced with a
  * space character in the trace.
  */
-void ATrace_beginSection(const char* sectionName);
+void ATrace_beginSection(const char* sectionName) __INTRODUCED_IN(23);
 
 /**
  * Writes a tracing message to indicate that a given section of code has ended. This call must be
@@ -61,9 +59,7 @@
  * will mark the end of the most recently begun section of code, so care must be taken to ensure
  * that beginSection / endSection pairs are properly nested and called from the same thread.
  */
-void ATrace_endSection();
-
-#endif /* __ANDROID_API__ >= 23 */
+void ATrace_endSection() __INTRODUCED_IN(23);
 
 #ifdef __cplusplus
 };