diff --git a/libc/include/android/api-level.h b/libc/include/android/api-level.h
index 6ed6c0a..ebce900 100644
--- a/libc/include/android/api-level.h
+++ b/libc/include/android/api-level.h
@@ -26,39 +26,80 @@
  * SUCH DAMAGE.
  */
 
-#ifndef ANDROID_API_LEVEL_H
-#define ANDROID_API_LEVEL_H
+#pragma once
+
+/**
+ * @file android/api-level.h
+ * @brief Functions and constants for dealing with multiple API levels.
+ */
 
 #include <sys/cdefs.h>
 
-/*
- * Magic version number for a current development build, which has
- * not yet turned into an official release.
- */
 #ifndef __ANDROID_API_FUTURE__
+/**
+ * Magic version number for an Android OS build which has
+ * not yet turned into an official release,
+ * for comparisons against __ANDROID_API__.
+ */
 #define __ANDROID_API_FUTURE__ 10000
 #endif
 
 #ifndef __ANDROID_API__
+/**
+ * `__ANDROID_API__` is the API level being targeted. For the OS,
+ * this is `__ANDROID_API_FUTURE__`. For the NDK, this is set by the
+ * compiler/build system based on the API level you claimed to target.
+ */
 #define __ANDROID_API__ __ANDROID_API_FUTURE__
 #else
+/**
+ * `__ANDROID_NDK__` is defined for code that's built by the NDK
+ * rather than as part of the OS.
+ */
 #define __ANDROID_NDK__ 1
 #endif
 
+/** Names the Gingerbread API level (9), for comparisons against __ANDROID_API__. */
 #define __ANDROID_API_G__ 9
-#define __ANDROID_API_I__ 14
-#define __ANDROID_API_J__ 16
-#define __ANDROID_API_J_MR1__ 17
-#define __ANDROID_API_J_MR2__ 18
-#define __ANDROID_API_K__ 19
-#define __ANDROID_API_L__ 21
-#define __ANDROID_API_L_MR1__ 22
-#define __ANDROID_API_M__ 23
-#define __ANDROID_API_N__ 24
-#define __ANDROID_API_N_MR1__ 25
-#define __ANDROID_API_O__ 26
-#define __ANDROID_API_O_MR1__ 27
-#define __ANDROID_API_P__ 28
-#define __ANDROID_API_Q__ 29
 
-#endif
+/** Names the Ice-Cream Sandwich API level (14), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_I__ 14
+
+/** Names the Jellybean API level (16), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_J__ 16
+
+/** Names the Jellybean MR1 API level (17), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_J_MR1__ 17
+
+/** Names the Jellybean MR2 API level (18), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_J_MR2__ 18
+
+/** Names the KitKat API level (19), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_K__ 19
+
+/** Names the Lollipop API level (21), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_L__ 21
+
+/** Names the Lollipop MR1 API level (22), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_L_MR1__ 22
+
+/** Names the Marshmallow API level (23), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_M__ 23
+
+/** Names the Nougat API level (24), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_N__ 24
+
+/** Names the Nougat MR1 API level (25), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_N_MR1__ 25
+
+/** Names the Oreo API level (26), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_O__ 26
+
+/** Names the Oreo MR1 API level (27), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_O_MR1__ 27
+
+/** Names the Pie API level (28), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_P__ 28
+
+/** Names the "Q" API level (29), for comparisons against __ANDROID_API__. */
+#define __ANDROID_API_Q__ 29
diff --git a/libc/include/android/get_device_api_level.h b/libc/include/android/get_device_api_level.h
new file mode 100644
index 0000000..39609da
--- /dev/null
+++ b/libc/include/android/get_device_api_level.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file android/get_device_api_level.h
+ * @brief Check the API level of the device we're actually running on.
+ */
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#if __ANDROID_API__ >= __ANDROID_API_Q__
+// This file is implemented as static inlines before API level 29.
+
+/**
+ * Returns the API level of the device we're actually running on, or -1 on failure.
+ * The returned values correspond to the named constants in <android/api-level.h>,
+ * and is equivalent to the Java `Build.VERSION.SDK_INT` API.
+ */
+int android_get_device_api_level() __INTRODUCED_IN(29);
+
+#endif
+
+__END_DECLS
+
+#include <android/legacy_get_device_api_level_inlines.h>
diff --git a/libc/include/android/legacy_get_device_api_level_inlines.h b/libc/include/android/legacy_get_device_api_level_inlines.h
new file mode 100644
index 0000000..b60123c
--- /dev/null
+++ b/libc/include/android/legacy_get_device_api_level_inlines.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <sys/cdefs.h>
+
+#if __ANDROID_API__ < __ANDROID_API_Q__
+
+#define __BIONIC_GET_DEVICE_API_LEVEL_INLINE static __inline
+#include <bits/get_device_api_level_inlines.h>
+
+#endif
diff --git a/libc/include/bits/get_device_api_level_inlines.h b/libc/include/bits/get_device_api_level_inlines.h
new file mode 100644
index 0000000..8e17814
--- /dev/null
+++ b/libc/include/bits/get_device_api_level_inlines.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <stdlib.h>
+#include <sys/cdefs.h>
+#include <sys/system_properties.h>
+
+#if !defined(__BIONIC_GET_DEVICE_API_LEVEL_INLINE)
+#define __BIONIC_GET_DEVICE_API_LEVEL_INLINE static __inline
+#endif
+
+__BEGIN_DECLS
+
+__BIONIC_GET_DEVICE_API_LEVEL_INLINE int android_get_device_api_level() {
+  char value[PROP_VALUE_MAX] = { 0 };
+  if (__system_property_get("ro.build.version.sdk", value) < 1) return -1;
+  int api_level = atoi(value);
+  return (api_level > 0) ? api_level : -1;
+}
+
+__END_DECLS