diff --git a/libguac/include/protocol.h b/libguac/include/protocol.h
index 087971a6..ba3a04ec 100644
--- a/libguac/include/protocol.h
+++ b/libguac/include/protocol.h
@@ -349,6 +349,80 @@ int guac_protocol_send_audio_data(guac_socket* socket, void* data, int count);
  */
 int guac_protocol_send_audio_end(guac_socket* socket);
 
+/**
+ * Sends a file instruction over the given guac_socket connection.
+ *
+ * If an error occurs sending the instruction, a non-zero value is
+ * returned, and guac_error is set appropriately.
+ *
+ * @param socket The guac_socket connection to use.
+ * @param name A name describing the file being sent.
+ * @param mimetype The mimetype of the data being sent.
+ * @param data The file data to be sent.
+ * @param size The number of bytes of file data to send.
+ * @return Zero on success, non-zero on error.
+ */
+int guac_protocol_send_file(guac_socket* socket, const char* name,
+        const char* mimetype, void* data, int size);
+
+/**
+ * Begins a file instruction over the given guac_socket connection. Only the
+ * initial non-data part of the instruction and the length of the data part
+ * of the instruction are sent. The actual contents of the data must be
+ * sent with guac_protocol_send_file_data(), and the instruction must be
+ * completed with guac_protocol_send_file_end().
+ *
+ * Note that the size of the file to be sent MUST be known ahead of time,
+ * even though the data of the file may be sent in chunks.
+ *
+ * No further instruction data may be sent along the givven guac_socket
+ * except via guac_protocol_send_file_data() until the file instruction
+ * is completed with guac_protocol_send_file_end().
+ *
+ * If an error occurs sending the instruction, a non-zero value is
+ * returned, and guac_error is set appropriately.
+ *
+ * @param socket The guac_socket connection to use.
+ * @param name A name describing the file being sent.
+ * @param mimetype The mimetype of the data being sent.
+ * @param size The number of bytes of file data to send.
+ * @return Zero on success, non-zero on error.
+ */
+int guac_protocol_send_file_header(guac_socket* socket, const char* name,
+        const char* mimetype, int size);
+
+/**
+ * Writes a block of file data to the currently in-progress file instruction
+ * which was started with guac_protocol_send_file_header(). Exactly the
+ * number of requested bytes are written unless an error occurs. This function
+ * may be called multiple times per file instruction for each chunk of file
+ * data being written, allowing the potentially huge file instruction to be
+ * split across multiple writes.
+ *
+ * If an error occurs sending the instruction, a non-zero value is
+ * returned, and guac_error is set appropriately.
+ *
+ * @param socket The guac_socket connection to use.
+ * @param data The file data to write.
+ * @param count The number of bytes within the given buffer of file data
+ *              that must be written.
+ * @return Zero on success, non-zero on error.
+ */
+int guac_protocol_send_file_data(guac_socket* socket, void* data, int count);
+
+/**
+ * Completes the file instruction which was started with
+ * guac_protocol_send_file_header(), and whose data has been written with
+ * guac_protocol_send_file_data().
+ *
+ * If an error occurs sending the instruction, a non-zero value is
+ * returned, and guac_error is set appropriately.
+ *
+ * @param socket The guac_socket connection to use.
+ * @return Zero on success, non-zero on error.
+ */
+int guac_protocol_send_file_end(guac_socket* socket);
+
 /**
  * Sends a video instruction over the given guac_socket connection.
  *
diff --git a/libguac/src/protocol.c b/libguac/src/protocol.c
index ab28f3b5..4d4fd19a 100644
--- a/libguac/src/protocol.c
+++ b/libguac/src/protocol.c
@@ -665,6 +665,48 @@ int guac_protocol_send_error(guac_socket* socket, const char* error) {
 }
 
 
+int guac_protocol_send_file(guac_socket* socket, const char* name,
+        const char* mimetype, void* data, int size) {
+
+    return
+           guac_protocol_send_file_header(socket, name,
+                mimetype, size)
+        || guac_protocol_send_file_data(socket, data, size)
+        || guac_protocol_send_file_end(socket);
+
+}
+
+int guac_protocol_send_file_header(guac_socket* socket, const char* name,
+        const char* mimetype, int size) {
+
+    int base64_length = (size + 2) / 3 * 4;
+
+    return
+           guac_socket_write_string(socket, "4.file,")
+        || __guac_socket_write_length_string(socket, name)
+        || guac_socket_write_string(socket, ",")
+        || __guac_socket_write_length_string(socket, mimetype)
+        || guac_socket_write_string(socket, ",")
+        || guac_socket_write_int(socket, base64_length)
+        || guac_socket_write_string(socket, ".");
+
+}
+
+int guac_protocol_send_file_data(guac_socket* socket, void* data, int count) {
+
+    return guac_socket_write_base64(socket, data, count);
+
+}
+
+int guac_protocol_send_file_end(guac_socket* socket) {
+
+    return
+           guac_socket_flush_base64(socket)
+        || guac_socket_write_string(socket, ";");
+
+}
+
+
 int guac_protocol_send_identity(guac_socket* socket, const guac_layer* layer) {
 
     return