diff --git a/third_party/libuweave/src/macaroon_caveat.h b/third_party/libuweave/src/macaroon_caveat.h
new file mode 100644
index 0000000..5f2c384
--- /dev/null
+++ b/third_party/libuweave/src/macaroon_caveat.h
@@ -0,0 +1,51 @@
+// 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_CAVEAT_H_
+#define LIBUWEAVE_SRC_MACAROON_CAVEAT_H_
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct {
+  size_t num_bytes;
+  const uint8_t* bytes;
+} UwMacaroonCaveat;
+
+typedef enum {
+  kUwMacaroonCaveatTypeStop = 0,
+  kUwMacaroonCaveatTypeScope = 1,
+  kUwMacaroonCaveatTypeIdentifier = 2,
+  kUwMacaroonCaveatTypeIssued = 3,
+  kUwMacaroonCaveatTypeTTL = 4,
+  kUwMacaroonCaveatTypeExpiration = 5,
+  kUwMacaroonCaveatTypeSessionIdentifier = 16
+} UwMacaroonCaveatType;
+
+bool uw_macaroon_caveat_create_without_value_(UwMacaroonCaveatType type,
+                                              uint8_t* buffer,
+                                              size_t buffer_size,
+                                              UwMacaroonCaveat* new_caveat);
+bool uw_macaroon_caveat_create_with_uint_(UwMacaroonCaveatType type,
+                                          uint32_t value, uint8_t* buffer,
+                                          size_t buffer_size,
+                                          UwMacaroonCaveat* new_caveat);
+bool uw_macaroon_caveat_create_with_str_(UwMacaroonCaveatType type,
+                                         const uint8_t* str, size_t str_len,
+                                         uint8_t* buffer, size_t buffer_size,
+                                         UwMacaroonCaveat* new_caveat);
+
+bool uw_macaroon_caveat_get_type_(const UwMacaroonCaveat* caveat,
+                                  UwMacaroonCaveatType* type);
+bool uw_macaroon_caveat_get_value_uint_(const UwMacaroonCaveat* caveat,
+                                        uint32_t* unsigned_int);
+bool uw_macaroon_caveat_get_value_str_(const UwMacaroonCaveat* caveat,
+                                       const uint8_t** str, size_t* str_len);
+
+bool uw_macaroon_caveat_sign_(const uint8_t* key, size_t key_len,
+                              const UwMacaroonCaveat* caveat, uint8_t* mac_tag,
+                              size_t mac_tag_size);
+
+#endif  // LIBUWEAVE_SRC_MACAROON_CAVEAT_H_