diff --git a/contracts/utils/hookapi.h b/contracts/utils/hookapi.h
index a607ab7..0d31f29 100644
--- a/contracts/utils/hookapi.h
+++ b/contracts/utils/hookapi.h
@@ -53,5 +53,6 @@
 #include "extern.h"
 #include "macro.h"
 #include "sfcodes.h"
+#include "tts.h"
 
 #endif
diff --git a/contracts/utils/tts.h b/contracts/utils/tts.h
new file mode 100644
index 0000000..d49cc25
--- /dev/null
+++ b/contracts/utils/tts.h
@@ -0,0 +1,43 @@
+// For documentation please see: https://xrpl-hooks.readme.io/reference/
+#define ttPAYMENT 0
+#define ttESCROW_CREATE 1
+#define ttESCROW_FINISH 2
+#define ttACCOUNT_SET 3
+#define ttESCROW_CANCEL 4
+#define ttREGULAR_KEY_SET 5
+// #define ttNICKNAME_SET 6 // deprecated
+#define ttOFFER_CREATE 7
+#define ttOFFER_CANCEL 8
+#define ttTICKET_CREATE 10
+// #define ttSPINAL_TAP 11 // deprecated
+#define ttSIGNER_LIST_SET 12
+#define ttPAYCHAN_CREATE 13
+#define ttPAYCHAN_FUND 14
+#define ttPAYCHAN_CLAIM 15
+#define ttCHECK_CREATE 16
+#define ttCHECK_CASH 17
+#define ttCHECK_CANCEL 18
+#define ttDEPOSIT_PREAUTH 19
+#define ttTRUST_SET 20
+#define ttACCOUNT_DELETE 21
+#define ttHOOK_SET 22
+#define ttNFTOKEN_MINT 25
+#define ttNFTOKEN_BURN 26
+#define ttNFTOKEN_CREATE_OFFER 27
+#define ttNFTOKEN_CANCEL_OFFER 28
+#define ttNFTOKEN_ACCEPT_OFFER 29
+#define ttURITOKEN_MINT 45
+#define ttURITOKEN_BURN 46
+#define ttURITOKEN_BUY 47
+#define ttURITOKEN_CREATE_SELL_OFFER 48
+#define ttURITOKEN_CANCEL_SELL_OFFER 49
+#define ttREMIT 95
+#define ttGENESIS_MINT 96
+#define ttIMPORT 97
+#define ttCLAIM_REWARD 98
+#define ttINVOKE 99
+#define ttAMENDMENT 100
+#define ttFEE 101
+#define ttUNL_MODIFY 102
+#define ttEMIT_FAILURE 103
+#define ttUNL_REPORT 104