diff --git a/src/components/courgette/courgette.h b/src/components/courgette/courgette.h
new file mode 100644
index 0000000..b80c3ca
--- /dev/null
+++ b/src/components/courgette/courgette.h
@@ -0,0 +1,118 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_COURGETTE_COURGETTE_H_
+#define COMPONENTS_COURGETTE_COURGETTE_H_
+
+#include <stddef.h>  // Required to define size_t on GCC
+
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+
+namespace courgette {
+
+// Status codes for Courgette APIs.
+//
+// Client code should only rely on the distintion between C_OK and the other
+// status codes.
+//
+enum Status {
+  C_OK = 1,  // Successful operation.
+
+  C_GENERAL_ERROR = 2,  // Error other than listed below.
+
+  C_READ_OPEN_ERROR = 3,  // Could not open input file for reading.
+  C_READ_ERROR = 4,       // Could not read from opened input file.
+
+  C_WRITE_OPEN_ERROR = 3,  // Could not open output file for writing.
+  C_WRITE_ERROR = 4,       // Could not write to opened output file.
+
+  C_BAD_ENSEMBLE_MAGIC = 5,    // Ensemble patch has bad magic.
+  C_BAD_ENSEMBLE_VERSION = 6,  // Ensemble patch has wrong version.
+  C_BAD_ENSEMBLE_HEADER = 7,   // Ensemble patch has corrupt header.
+  C_BAD_ENSEMBLE_CRC = 8,      // Ensemble patch has corrupt data.
+
+  C_BAD_TRANSFORM = 12,  // Transform mis-specified.
+  C_BAD_BASE = 13,       // Base for transform malformed.
+
+  C_BINARY_DIFF_CRC_ERROR = 14,  // Internal diff input doesn't have expected
+                                 // CRC.
+
+  // Internal errors.
+  C_STREAM_ERROR = 20,            // Unexpected error from streams.h.
+  C_STREAM_NOT_CONSUMED = 21,     // Stream has extra data, is expected to be
+                                  // used up.
+  C_SERIALIZATION_FAILED = 22,    //
+  C_DESERIALIZATION_FAILED = 23,  //
+  C_INPUT_NOT_RECOGNIZED = 24,    // Unrecognized input (not an executable).
+  C_DISASSEMBLY_FAILED = 25,      //
+  C_ASSEMBLY_FAILED = 26,         //
+  C_ADJUSTMENT_FAILED = 27,       //
+};
+
+// What type of executable is something
+// This is part of the patch format. Never reuse an id number.
+enum ExecutableType {
+  EXE_UNKNOWN = 0,
+  EXE_WIN_32_X86 = 1,
+  EXE_ELF_32_X86 = 2,
+  EXE_ELF_32_ARM = 3,
+  EXE_WIN_32_X64 = 4,
+};
+
+class SinkStream;
+class SinkStreamSet;
+class SourceStream;
+
+class AssemblyProgram;
+class EncodedProgram;
+
+// Applies the patch to the bytes in |old| and writes the transformed ensemble
+// to |output|.
+// Returns C_OK unless something went wrong.
+Status ApplyEnsemblePatch(SourceStream* old,
+                          SourceStream* patch,
+                          SinkStream* output);
+
+// Applies the patch in |patch_file| to the bytes in |old_file| and writes the
+// transformed ensemble to |new_file|.
+// Returns C_OK unless something went wrong.
+// This function first validates that the patch file has a proper header, so the
+// function can be used to 'try' a patch.
+Status ApplyEnsemblePatch(base::File old_file,
+                          base::File patch_file,
+                          base::File new_file);
+
+// Applies the patch in |patch_file_name| to the bytes in |old_file_name| and
+// writes the transformed ensemble to |new_file_name|.
+// Returns C_OK unless something went wrong.
+// This function first validates that the patch file has a proper header, so the
+// function can be used to 'try' a patch.
+Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name,
+                          const base::FilePath::CharType* patch_file_name,
+                          const base::FilePath::CharType* new_file_name);
+
+// Generates a patch that will transform the bytes in |old| into the bytes in
+// |target|.
+// Returns C_OK unless something when wrong (unexpected).
+Status GenerateEnsemblePatch(SourceStream* old,
+                             SourceStream* target,
+                             SinkStream* patch);
+
+// Serializes |encoded| into the stream set.
+// Returns C_OK if succeeded, otherwise returns an error status.
+Status WriteEncodedProgram(EncodedProgram* encoded, SinkStreamSet* sink);
+
+// Assembles |encoded|, emitting the bytes into |buffer|.
+// Returns C_OK if succeeded, otherwise returns an error status and leaves
+// |buffer| in an undefined state.
+Status Assemble(EncodedProgram* encoded, SinkStream* buffer);
+
+// Adjusts |program| to look more like |model|.
+//
+Status Adjust(const AssemblyProgram& model, AssemblyProgram* program);
+
+}  // namespace courgette
+
+#endif  // COMPONENTS_COURGETTE_COURGETTE_H_