diff --git a/upsilon_creole.h b/upsilon_creole.h
new file mode 100644
index 0000000..cf32c47
--- /dev/null
+++ b/upsilon_creole.h
@@ -0,0 +1,26 @@
+/* Copyright (c) 2023 Peter McGoron <code@mcgoron.com>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+#pragma once
+
+creole_word upsilon_get_adc(creole_word adc);
+creole_word upsilon_get_dac(creole_word adc);
+creole_word upsilon_write_dac(creole_word dac, creole_word val);
+creole_word upsilon_sleep(creole_word usec);
+creole_word upsilon_control_loop_read(creole_word reg);
+creole_word upsilon_control_loop_write(creole_word reg, creole_word val);
+creole_word upsilon_load_waveform(struct creole_env *env, creole_word slot,
+                                  creole_word db);
+creole_word upsilon_exec_waveform(creole_word slot, creole_word dac);
+creole_word upsilon_sendval(creole_word num);
+creole_word upsilon_senddat(struct creole_env *env, creole_word db);