diff --git a/libnativebridge/Android.bp b/libnativebridge/Android.bp
index 377b7dd..1cea4cd 100644
--- a/libnativebridge/Android.bp
+++ b/libnativebridge/Android.bp
@@ -1,4 +1,11 @@
 
+cc_library_headers {
+    name: "libnativebridge-dummy-headers",
+
+    host_supported: true,
+    export_include_dirs=["include"],
+}
+
 cc_library {
     name: "libnativebridge",
 
@@ -7,6 +14,8 @@
     shared_libs: ["liblog"],
     clang: true,
 
+    export_include_dirs=["include"],
+
     cflags: [
         "-Werror",
         "-Wall",
@@ -23,4 +32,4 @@
     },
 }
 
-subdirs = ["tests"]
\ No newline at end of file
+subdirs = ["tests"]
diff --git a/libnativebridge/include/nativebridge/native_bridge.h b/libnativebridge/include/nativebridge/native_bridge.h
new file mode 100644
index 0000000..9bfc935
--- /dev/null
+++ b/libnativebridge/include/nativebridge/native_bridge.h
@@ -0,0 +1,401 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef NATIVE_BRIDGE_H_
+#define NATIVE_BRIDGE_H_
+
+#include "jni.h"
+#include <signal.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+namespace android {
+
+struct NativeBridgeRuntimeCallbacks;
+struct NativeBridgeRuntimeValues;
+
+// Function pointer type for sigaction. This is mostly the signature of a signal handler, except
+// for the return type. The runtime needs to know whether the signal was handled or should be given
+// to the chain.
+typedef bool (*NativeBridgeSignalHandlerFn)(int, siginfo_t*, void*);
+
+
+// Open the native bridge, if any. Should be called by Runtime::Init(). A null library filename
+// signals that we do not want to load a native bridge.
+bool LoadNativeBridge(const char* native_bridge_library_filename,
+                      const NativeBridgeRuntimeCallbacks* runtime_callbacks);
+
+// Quick check whether a native bridge will be needed. This is based off of the instruction set
+// of the process.
+bool NeedsNativeBridge(const char* instruction_set);
+
+// Do the early initialization part of the native bridge, if necessary. This should be done under
+// high privileges.
+bool PreInitializeNativeBridge(const char* app_data_dir, const char* instruction_set);
+
+// Initialize the native bridge, if any. Should be called by Runtime::DidForkFromZygote. The JNIEnv*
+// will be used to modify the app environment for the bridge.
+bool InitializeNativeBridge(JNIEnv* env, const char* instruction_set);
+
+// Unload the native bridge, if any. Should be called by Runtime::DidForkFromZygote.
+void UnloadNativeBridge();
+
+// Check whether a native bridge is available (opened or initialized). Requires a prior call to
+// LoadNativeBridge.
+bool NativeBridgeAvailable();
+
+// Check whether a native bridge is available (initialized). Requires a prior call to
+// LoadNativeBridge & InitializeNativeBridge.
+bool NativeBridgeInitialized();
+
+// Load a shared library that is supported by the native bridge.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Use NativeBridgeLoadLibraryExt() instead in namespace scenario.
+void* NativeBridgeLoadLibrary(const char* libpath, int flag);
+
+// Get a native bridge trampoline for specified native method.
+void* NativeBridgeGetTrampoline(void* handle, const char* name, const char* shorty, uint32_t len);
+
+// True if native library paths are valid and is for an ABI that is supported by native bridge.
+// The *libpath* must point to a library.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Use NativeBridgeIsPathSupported() instead in namespace scenario.
+bool NativeBridgeIsSupported(const char* libpath);
+
+// Returns the version number of the native bridge. This information is available after a
+// successful LoadNativeBridge() and before closing it, that is, as long as NativeBridgeAvailable()
+// returns true. Returns 0 otherwise.
+uint32_t NativeBridgeGetVersion();
+
+// Returns a signal handler that the bridge would like to be managed. Only valid for a native
+// bridge supporting the version 2 interface. Will return null if the bridge does not support
+// version 2, or if it doesn't have a signal handler it wants to be known.
+NativeBridgeSignalHandlerFn NativeBridgeGetSignalHandler(int signal);
+
+// Returns whether we have seen a native bridge error. This could happen because the library
+// was not found, rejected, could not be initialized and so on.
+//
+// This functionality is mainly for testing.
+bool NativeBridgeError();
+
+// Returns whether a given string is acceptable as a native bridge library filename.
+//
+// This functionality is exposed mainly for testing.
+bool NativeBridgeNameAcceptable(const char* native_bridge_library_filename);
+
+// Decrements the reference count on the dynamic library handler. If the reference count drops
+// to zero then the dynamic library is unloaded.
+int NativeBridgeUnloadLibrary(void* handle);
+
+// Get last error message of native bridge when fail to load library or search symbol.
+// This is reflection of dlerror() for native bridge.
+const char* NativeBridgeGetError();
+
+struct native_bridge_namespace_t;
+
+// True if native library paths are valid and is for an ABI that is supported by native bridge.
+// Different from NativeBridgeIsSupported(), the *path* here must be a directory containing
+// libraries of an ABI.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Use NativeBridgeIsSupported() instead in non-namespace scenario.
+bool NativeBridgeIsPathSupported(const char* path);
+
+// Initializes anonymous namespace.
+// NativeBridge's peer of android_init_anonymous_namespace() of dynamic linker.
+//
+// The anonymous namespace is used in the case when a NativeBridge implementation
+// cannot identify the caller of dlopen/dlsym which happens for the code not loaded
+// by dynamic linker; for example calls from the mono-compiled code.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Should not use in non-namespace scenario.
+bool NativeBridgeInitAnonymousNamespace(const char* public_ns_sonames,
+                                        const char* anon_ns_library_path);
+
+// Create new namespace in which native libraries will be loaded.
+// NativeBridge's peer of android_create_namespace() of dynamic linker.
+//
+// The libraries in the namespace are searched by folowing order:
+// 1. ld_library_path (Think of this as namespace-local LD_LIBRARY_PATH)
+// 2. In directories specified by DT_RUNPATH of the "needed by" binary.
+// 3. deault_library_path (This of this as namespace-local default library path)
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Should not use in non-namespace scenario.
+native_bridge_namespace_t* NativeBridgeCreateNamespace(const char* name,
+                                                       const char* ld_library_path,
+                                                       const char* default_library_path,
+                                                       uint64_t type,
+                                                       const char* permitted_when_isolated_path,
+                                                       native_bridge_namespace_t* parent_ns);
+
+// Creates a link which shares some libraries from one namespace to another.
+// NativeBridge's peer of android_link_namespaces() of dynamic linker.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Should not use in non-namespace scenario.
+bool NativeBridgeLinkNamespaces(native_bridge_namespace_t* from, native_bridge_namespace_t* to,
+                                const char* shared_libs_sonames);
+
+// Load a shared library with namespace key that is supported by the native bridge.
+// NativeBridge's peer of android_dlopen_ext() of dynamic linker, only supports namespace
+// extension.
+//
+// Starting with v3, NativeBridge has two scenarios: with/without namespace.
+// Use NativeBridgeLoadLibrary() instead in non-namespace scenario.
+void* NativeBridgeLoadLibraryExt(const char* libpath, int flag, native_bridge_namespace_t* ns);
+
+// Returns vendor namespace if it is enabled for the device and null otherwise
+native_bridge_namespace_t* NativeBridgeGetVendorNamespace();
+
+// Native bridge interfaces to runtime.
+struct NativeBridgeCallbacks {
+  // Version number of the interface.
+  uint32_t version;
+
+  // Initialize native bridge. Native bridge's internal implementation must ensure MT safety and
+  // that the native bridge is initialized only once. Thus it is OK to call this interface for an
+  // already initialized native bridge.
+  //
+  // Parameters:
+  //   runtime_cbs [IN] the pointer to NativeBridgeRuntimeCallbacks.
+  // Returns:
+  //   true if initialization was successful.
+  bool (*initialize)(const NativeBridgeRuntimeCallbacks* runtime_cbs, const char* private_dir,
+                     const char* instruction_set);
+
+  // Load a shared library that is supported by the native bridge.
+  //
+  // Parameters:
+  //   libpath [IN] path to the shared library
+  //   flag [IN] the stardard RTLD_XXX defined in bionic dlfcn.h
+  // Returns:
+  //   The opaque handle of the shared library if sucessful, otherwise NULL
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Use loadLibraryExt instead in namespace scenario.
+  void* (*loadLibrary)(const char* libpath, int flag);
+
+  // Get a native bridge trampoline for specified native method. The trampoline has same
+  // sigature as the native method.
+  //
+  // Parameters:
+  //   handle [IN] the handle returned from loadLibrary
+  //   shorty [IN] short descriptor of native method
+  //   len [IN] length of shorty
+  // Returns:
+  //   address of trampoline if successful, otherwise NULL
+  void* (*getTrampoline)(void* handle, const char* name, const char* shorty, uint32_t len);
+
+  // Check whether native library is valid and is for an ABI that is supported by native bridge.
+  //
+  // Parameters:
+  //   libpath [IN] path to the shared library
+  // Returns:
+  //   TRUE if library is supported by native bridge, FALSE otherwise
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Use isPathSupported instead in namespace scenario.
+  bool (*isSupported)(const char* libpath);
+
+  // Provide environment values required by the app running with native bridge according to the
+  // instruction set.
+  //
+  // Parameters:
+  //   instruction_set [IN] the instruction set of the app
+  // Returns:
+  //   NULL if not supported by native bridge.
+  //   Otherwise, return all environment values to be set after fork.
+  const struct NativeBridgeRuntimeValues* (*getAppEnv)(const char* instruction_set);
+
+  // Added callbacks in version 2.
+
+  // Check whether the bridge is compatible with the given version. A bridge may decide not to be
+  // forwards- or backwards-compatible, and libnativebridge will then stop using it.
+  //
+  // Parameters:
+  //   bridge_version [IN] the version of libnativebridge.
+  // Returns:
+  //   true if the native bridge supports the given version of libnativebridge.
+  bool (*isCompatibleWith)(uint32_t bridge_version);
+
+  // A callback to retrieve a native bridge's signal handler for the specified signal. The runtime
+  // will ensure that the signal handler is being called after the runtime's own handler, but before
+  // all chained handlers. The native bridge should not try to install the handler by itself, as
+  // that will potentially lead to cycles.
+  //
+  // Parameters:
+  //   signal [IN] the signal for which the handler is asked for. Currently, only SIGSEGV is
+  //                 supported by the runtime.
+  // Returns:
+  //   NULL if the native bridge doesn't use a handler or doesn't want it to be managed by the
+  //   runtime.
+  //   Otherwise, a pointer to the signal handler.
+  NativeBridgeSignalHandlerFn (*getSignalHandler)(int signal);
+
+  // Added callbacks in version 3.
+
+  // Decrements the reference count on the dynamic library handler. If the reference count drops
+  // to zero then the dynamic library is unloaded.
+  //
+  // Parameters:
+  //   handle [IN] the handler of a dynamic library.
+  //
+  // Returns:
+  //   0 on success, and nonzero on error.
+  int (*unloadLibrary)(void* handle);
+
+  // Dump the last failure message of native bridge when fail to load library or search symbol.
+  //
+  // Parameters:
+  //
+  // Returns:
+  //   A string describing the most recent error that occurred when load library
+  //   or lookup symbol via native bridge.
+  const char* (*getError)();
+
+  // Check whether library paths are supported by native bridge.
+  //
+  // Parameters:
+  //   library_path [IN] search paths for native libraries (directories separated by ':')
+  // Returns:
+  //   TRUE if libraries within search paths are supported by native bridge, FALSE otherwise
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Use isSupported instead in non-namespace scenario.
+  bool (*isPathSupported)(const char* library_path);
+
+  // Initializes anonymous namespace at native bridge side.
+  // NativeBridge's peer of android_init_anonymous_namespace() of dynamic linker.
+  //
+  // The anonymous namespace is used in the case when a NativeBridge implementation
+  // cannot identify the caller of dlopen/dlsym which happens for the code not loaded
+  // by dynamic linker; for example calls from the mono-compiled code.
+  //
+  // Parameters:
+  //   public_ns_sonames [IN] the name of "public" libraries.
+  //   anon_ns_library_path [IN] the library search path of (anonymous) namespace.
+  // Returns:
+  //   true if the pass is ok.
+  //   Otherwise, false.
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Should not use in non-namespace scenario.
+  bool (*initAnonymousNamespace)(const char* public_ns_sonames, const char* anon_ns_library_path);
+
+  // Create new namespace in which native libraries will be loaded.
+  // NativeBridge's peer of android_create_namespace() of dynamic linker.
+  //
+  // Parameters:
+  //   name [IN] the name of the namespace.
+  //   ld_library_path [IN] the first set of library search paths of the namespace.
+  //   default_library_path [IN] the second set of library search path of the namespace.
+  //   type [IN] the attribute of the namespace.
+  //   permitted_when_isolated_path [IN] the permitted path for isolated namespace(if it is).
+  //   parent_ns [IN] the pointer of the parent namespace to be inherited from.
+  // Returns:
+  //   native_bridge_namespace_t* for created namespace or nullptr in the case of error.
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Should not use in non-namespace scenario.
+  native_bridge_namespace_t* (*createNamespace)(const char* name,
+                                                const char* ld_library_path,
+                                                const char* default_library_path,
+                                                uint64_t type,
+                                                const char* permitted_when_isolated_path,
+                                                native_bridge_namespace_t* parent_ns);
+
+  // Creates a link which shares some libraries from one namespace to another.
+  // NativeBridge's peer of android_link_namespaces() of dynamic linker.
+  //
+  // Parameters:
+  //   from [IN] the namespace where libraries are accessed.
+  //   to [IN] the namespace where libraries are loaded.
+  //   shared_libs_sonames [IN] the libraries to be shared.
+  //
+  // Returns:
+  //   Whether successed or not.
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Should not use in non-namespace scenario.
+  bool (*linkNamespaces)(native_bridge_namespace_t* from, native_bridge_namespace_t* to,
+                         const char* shared_libs_sonames);
+
+  // Load a shared library within a namespace.
+  // NativeBridge's peer of android_dlopen_ext() of dynamic linker, only supports namespace
+  // extension.
+  //
+  // Parameters:
+  //   libpath [IN] path to the shared library
+  //   flag [IN] the stardard RTLD_XXX defined in bionic dlfcn.h
+  //   ns [IN] the pointer of the namespace in which the library should be loaded.
+  // Returns:
+  //   The opaque handle of the shared library if sucessful, otherwise NULL
+  //
+  // Starting with v3, NativeBridge has two scenarios: with/without namespace.
+  // Use loadLibrary instead in non-namespace scenario.
+  void* (*loadLibraryExt)(const char* libpath, int flag, native_bridge_namespace_t* ns);
+
+  // Get native bridge version of vendor namespace.
+  // The vendor namespace is the namespace used to load vendor public libraries.
+  // With O release this namespace can be different from the default namespace.
+  // For the devices without enable vendor namespaces this function should return null
+  //
+  // Returns:
+  //   vendor namespace or null if it was not set up for the device
+  native_bridge_namespace_t* (*getVendorNamespace)();
+};
+
+// Runtime interfaces to native bridge.
+struct NativeBridgeRuntimeCallbacks {
+  // Get shorty of a Java method. The shorty is supposed to be persistent in memory.
+  //
+  // Parameters:
+  //   env [IN] pointer to JNIenv.
+  //   mid [IN] Java methodID.
+  // Returns:
+  //   short descriptor for method.
+  const char* (*getMethodShorty)(JNIEnv* env, jmethodID mid);
+
+  // Get number of native methods for specified class.
+  //
+  // Parameters:
+  //   env [IN] pointer to JNIenv.
+  //   clazz [IN] Java class object.
+  // Returns:
+  //   number of native methods.
+  uint32_t (*getNativeMethodCount)(JNIEnv* env, jclass clazz);
+
+  // Get at most 'method_count' native methods for specified class 'clazz'. Results are outputed
+  // via 'methods' [OUT]. The signature pointer in JNINativeMethod is reused as the method shorty.
+  //
+  // Parameters:
+  //   env [IN] pointer to JNIenv.
+  //   clazz [IN] Java class object.
+  //   methods [OUT] array of method with the name, shorty, and fnPtr.
+  //   method_count [IN] max number of elements in methods.
+  // Returns:
+  //   number of method it actually wrote to methods.
+  uint32_t (*getNativeMethods)(JNIEnv* env, jclass clazz, JNINativeMethod* methods,
+                               uint32_t method_count);
+};
+
+};  // namespace android
+
+#endif  // NATIVE_BRIDGE_H_
diff --git a/libnativebridge/tests/Android.bp b/libnativebridge/tests/Android.bp
index efd3978..e31dae0 100644
--- a/libnativebridge/tests/Android.bp
+++ b/libnativebridge/tests/Android.bp
@@ -23,6 +23,7 @@
         "-Wextra",
         "-Werror",
     ],
+    header_libs: ["libnativebridge-dummy-headers"],
     cppflags: ["-fvisibility=protected"],
     target: {
         android: {