diff --git a/objectivec/GPBMessage.h b/objectivec/GPBMessage.h
new file mode 100644
index 0000000..332393e
--- /dev/null
+++ b/objectivec/GPBMessage.h
@@ -0,0 +1,177 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// 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.
+
+#import <Foundation/Foundation.h>
+
+#import "GPBBootstrap.h"
+
+@class GPBDescriptor;
+@class GPBCodedInputStream;
+@class GPBCodedOutputStream;
+@class GPBExtensionDescriptor;
+@class GPBExtensionRegistry;
+@class GPBFieldDescriptor;
+@class GPBUnknownFieldSet;
+
+NS_ASSUME_NONNULL_BEGIN
+
+CF_EXTERN_C_BEGIN
+
+// NSError domain used for errors.
+extern NSString *const GPBMessageErrorDomain;
+
+typedef NS_ENUM(NSInteger, GPBMessageErrorCode) {
+  GPBMessageErrorCodeMalformedData = -100,
+  GPBMessageErrorCodeMissingRequiredField = -101,
+};
+
+// In DEBUG ONLY, an NSException is thrown when a parsed message doesn't
+// contain required fields. This key allows you to retrieve the parsed message
+// from the exception's |userInfo| dictionary.
+#ifdef DEBUG
+extern NSString *const GPBExceptionMessageKey;
+#endif  // DEBUG
+
+CF_EXTERN_C_END
+
+@interface GPBMessage : NSObject<NSSecureCoding, NSCopying>
+
+// NOTE: If you add a instance method/property to this class that may conflict
+// with methods declared in protos, you need to update objective_helpers.cc.
+// The main cases are methods that take no arguments, or setFoo:/hasFoo: type
+// methods.
+
+@property(nonatomic, copy, nullable) GPBUnknownFieldSet *unknownFields;
+
+// Are all required fields in the message and all embedded messages set.
+@property(nonatomic, readonly, getter=isInitialized) BOOL initialized;
+
+// Returns an autoreleased instance.
++ (instancetype)message;
+
+// Create a message based on a variety of inputs.  If there is a data parse
+// error, nil is returned and if not NULL, errorPtr is filled in.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, the parse will fail (returning nil, filling in errorPtr).
++ (instancetype)parseFromData:(NSData *)data error:(NSError **)errorPtr;
++ (instancetype)parseFromData:(NSData *)data
+            extensionRegistry:(nullable GPBExtensionRegistry *)extensionRegistry
+                        error:(NSError **)errorPtr;
++ (instancetype)parseFromCodedInputStream:(GPBCodedInputStream *)input
+                        extensionRegistry:
+                            (nullable GPBExtensionRegistry *)extensionRegistry
+                                    error:(NSError **)errorPtr;
+
+// Create a message based on delimited input.  If there is a data parse
+// error, nil is returned and if not NULL, errorPtr is filled in.
++ (instancetype)parseDelimitedFromCodedInputStream:(GPBCodedInputStream *)input
+                                 extensionRegistry:
+                                     (nullable GPBExtensionRegistry *)extensionRegistry
+                                             error:(NSError **)errorPtr;
+
+// If there is a data parse error, nil is returned and if not NULL, errorPtr is
+// filled in.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, the parse will fail (returning nil, filling in errorPtr).
+- (instancetype)initWithData:(NSData *)data error:(NSError **)errorPtr;
+- (instancetype)initWithData:(NSData *)data
+           extensionRegistry:(nullable GPBExtensionRegistry *)extensionRegistry
+                       error:(NSError **)errorPtr;
+- (instancetype)initWithCodedInputStream:(GPBCodedInputStream *)input
+                       extensionRegistry:
+                           (nullable GPBExtensionRegistry *)extensionRegistry
+                                   error:(NSError **)errorPtr;
+
+// Serializes the message and writes it to output.
+- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)output;
+- (void)writeToOutputStream:(NSOutputStream *)output;
+
+// Serializes the message and writes it to output, but writes the size of the
+// message as a variant before writing the message.
+- (void)writeDelimitedToCodedOutputStream:(GPBCodedOutputStream *)output;
+- (void)writeDelimitedToOutputStream:(NSOutputStream *)output;
+
+// Serializes the message to an NSData. Note that this value is not cached, so
+// if you are using it repeatedly, cache it yourself. If there is an error
+// while generating the data, nil is returned.
+// NOTE: In DEBUG ONLY, the message is also checked for all required field,
+// if one is missing, nil will be returned.
+- (nullable NSData *)data;
+
+// Same as -[data], except a delimiter is added to the start of the data
+// indicating the size of the message data that follows.
+- (NSData *)delimitedData;
+
+// Returns the size of the object if it were serialized.
+// This is not a cached value. If you are following a pattern like this:
+//   size_t size = [aMsg serializedSize];
+//   NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
+//   [foo writeSize:size];
+//   [foo appendData:[aMsg data]];
+// you would be better doing:
+//   NSData *data = [aMsg data];
+//   NSUInteger size = [aMsg length];
+//   NSMutableData *foo = [NSMutableData dataWithCapacity:size + sizeof(size)];
+//   [foo writeSize:size];
+//   [foo appendData:data];
+- (size_t)serializedSize;
+
+// Return the descriptor for the message
++ (GPBDescriptor *)descriptor;
+- (GPBDescriptor *)descriptor;
+
+// Extensions use boxed values (NSNumbers) for PODs, NSMutableArrays for
+// repeated. If the extension is a Message one will be auto created for you
+// and returned similar to fields.
+- (BOOL)hasExtension:(GPBExtensionDescriptor *)extension;
+- (nullable id)getExtension:(GPBExtensionDescriptor *)extension;
+- (void)setExtension:(GPBExtensionDescriptor *)extension value:(nullable id)value;
+- (void)addExtension:(GPBExtensionDescriptor *)extension value:(id)value;
+- (void)setExtension:(GPBExtensionDescriptor *)extension
+               index:(NSUInteger)index
+               value:(id)value;
+- (void)clearExtension:(GPBExtensionDescriptor *)extension;
+
+// Resets all fields to their default values.
+- (void)clear;
+
+// Parses a message of this type from the input and merges it with this
+// message.
+// NOTE: This will throw if there is an error parsing the data.
+- (void)mergeFromData:(NSData *)data
+    extensionRegistry:(nullable GPBExtensionRegistry *)extensionRegistry;
+
+// Merges the fields from another message (of the same type) into this
+// message.
+- (void)mergeFrom:(GPBMessage *)other;
+
+@end
+
+NS_ASSUME_NONNULL_END