diff --git a/third_party/libuweave/src/macaroon.h b/third_party/libuweave/src/macaroon.h
new file mode 100644
index 0000000..98ada11
--- /dev/null
+++ b/third_party/libuweave/src/macaroon.h
@@ -0,0 +1,47 @@
+// Copyright 2015 The Weave 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 LIBUWEAVE_SRC_MACAROON_H_
+#define LIBUWEAVE_SRC_MACAROON_H_
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "macaroon_caveat.h"
+
+#define UW_MACAROON_MAC_LEN 16
+
+// Note: If we are looking to make memory savings on MCUs,
+// at the cost of a little extra processing, we can make
+// the macaroon encoding the actual in-memory representation.
+// This can save much copying of macaroon data if need be.
+typedef struct {
+  uint8_t mac_tag[UW_MACAROON_MAC_LEN];
+  size_t num_caveats;
+  const UwMacaroonCaveat* caveats;
+} UwMacaroon;
+
+bool uw_macaroon_new_from_mac_tag_(UwMacaroon* new_macaroon,
+                                   const uint8_t mac_tag[UW_MACAROON_MAC_LEN],
+                                   const UwMacaroonCaveat* caveats,
+                                   size_t num_caveats);
+
+bool uw_macaroon_new_from_root_key_(UwMacaroon* new_macaroon,
+                                    const uint8_t* root_key,
+                                    size_t root_key_len,
+                                    const UwMacaroonCaveat* caveats,
+                                    size_t num_caveats);
+
+bool uw_macaroon_verify_(const UwMacaroon* macaroon,
+                         const uint8_t* root_key,
+                         size_t root_key_len);
+
+// Create a new macaroon with a new caveat
+bool uw_macaroon_extend_(const UwMacaroon* old_macaroon,
+                         UwMacaroon* new_macaroon,
+                         const UwMacaroonCaveat* additional_caveat,
+                         uint8_t* buffer, size_t buffer_size);
+
+#endif  // LIBUWEAVE_SRC_MACAROON_H_