diff --git a/objectivec/GPBCodedInputStream.h b/objectivec/GPBCodedInputStream.h
new file mode 100644
index 0000000..42a0494
--- /dev/null
+++ b/objectivec/GPBCodedInputStream.h
@@ -0,0 +1,87 @@
+// 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>
+
+@class GPBMessage;
+@class GPBExtensionRegistry;
+
+NS_ASSUME_NONNULL_BEGIN
+
+// Reads and decodes protocol message fields.
+// Subclassing of GPBCodedInputStream is NOT supported.
+@interface GPBCodedInputStream : NSObject
+
++ (instancetype)streamWithData:(NSData *)data;
+- (instancetype)initWithData:(NSData *)data;
+
+// Attempt to read a field tag, returning zero if we have reached EOF.
+// Protocol message parsers use this to read tags, since a protocol message
+// may legally end wherever a tag occurs, and zero is not a valid tag number.
+- (int32_t)readTag;
+
+- (double)readDouble;
+- (float)readFloat;
+- (uint64_t)readUInt64;
+- (uint32_t)readUInt32;
+- (int64_t)readInt64;
+- (int32_t)readInt32;
+- (uint64_t)readFixed64;
+- (uint32_t)readFixed32;
+- (int32_t)readEnum;
+- (int32_t)readSFixed32;
+- (int64_t)readSFixed64;
+- (int32_t)readSInt32;
+- (int64_t)readSInt64;
+- (BOOL)readBool;
+- (NSString *)readString;
+- (NSData *)readBytes;
+
+// Read an embedded message field value from the stream.
+- (void)readMessage:(GPBMessage *)message
+    extensionRegistry:(nullable GPBExtensionRegistry *)extensionRegistry;
+
+// Reads and discards a single field, given its tag value. Returns NO if the
+// tag is an endgroup tag, in which case nothing is skipped.  Otherwise,
+// returns YES.
+- (BOOL)skipField:(int32_t)tag;
+
+// Reads and discards an entire message.  This will read either until EOF
+// or until an endgroup tag, whichever comes first.
+- (void)skipMessage;
+
+// Verifies that the last call to readTag() returned the given tag value.
+// This is used to verify that a nested group ended with the correct end tag.
+// Throws NSParseErrorException if value does not match the last tag.
+- (void)checkLastTagWas:(int32_t)value;
+
+@end
+
+NS_ASSUME_NONNULL_END