diff --git a/clang/ffi/api.c b/clang/ffi/api.c
index b9a36d7..6d71552 100644
--- a/clang/ffi/api.c
+++ b/clang/ffi/api.c
@@ -13,19 +13,34 @@ fn Term term_new_app(Term f, Term x);
 fn Term term_new_lam_at(u64 loc, Term body);
 fn Term term_new_lam(Term body);
 fn Term term_new_var(u64 loc);
+fn Term term_new_era(void);
+fn Term term_new_ref(u32 nam);
+fn Term term_new_mat(u32 nam, Term val, Term nxt);
 
-fn u8  term_tag(Term t);
-fn u32 term_ext(Term t);
-fn u64 term_val(Term t);
+fn u8   term_tag(Term t);
+fn u32  term_ext(Term t);
+fn u64  term_val(Term t);
+fn u32  term_arity(Term t);
+fn u8   term_sub_get(Term t);
+fn Term term_sub_set(Term t, u8 sub);
 
 fn Term heap_read(u64 loc);
 fn void heap_set(u64 loc, Term t);
 fn u64 heap_alloc(u64 words);
 
-fn u32 table_find(const char *name, u32 len);
+fn u32   table_find(const char *name, u32 len);
+fn char *table_get(u32 id);
 
 fn void sys_runtime_error(const char *msg);
 
+fn u64 ffi_book_get(u32 id) {
+  return BOOK[id];
+}
+
+fn void ffi_book_set(u32 id, u64 loc) {
+  BOOK[id] = loc;
+}
+
 static const HvmApi HVM_API = {
   .abi_version   = ABI_VERSION,
 
@@ -40,10 +55,16 @@ static const HvmApi HVM_API = {
   .term_new_lam_at = term_new_lam_at,
   .term_new_lam    = term_new_lam,
   .term_new_var    = term_new_var,
+  .term_new_era    = term_new_era,
+  .term_new_ref    = term_new_ref,
+  .term_new_mat    = term_new_mat,
 
   .term_tag        = term_tag,
   .term_ext        = term_ext,
   .term_val        = term_val,
+  .term_arity      = term_arity,
+  .term_sub_get    = term_sub_get,
+  .term_sub_set    = term_sub_set,
 
   .heap_read       = heap_read,
   .heap_set        = heap_set,
@@ -51,6 +72,9 @@ static const HvmApi HVM_API = {
 
   .table_find      = table_find,
   .name_from_str   = table_find,
+  .table_get       = table_get,
+  .book_get        = ffi_book_get,
+  .book_set        = ffi_book_set,
 
   .runtime_error   = sys_runtime_error
 };
diff --git a/clang/hvm_ffi.h b/clang/hvm_ffi.h
index 5bc9d0b..719c05f 100644
--- a/clang/hvm_ffi.h
+++ b/clang/hvm_ffi.h
@@ -7,7 +7,7 @@
 extern "C" {
 #endif
 
-#define ABI_VERSION 1
+#define ABI_VERSION 2
 
 #ifndef HVM_RUNTIME
 typedef uint8_t  u8;
@@ -38,20 +38,29 @@ typedef struct {
   Term (*term_new_lam_at)(u64 loc, Term body);
   Term (*term_new_lam)(Term body);
   Term (*term_new_var)(u64 loc);
+  Term (*term_new_era)(void);
+  Term (*term_new_ref)(u32 name);
+  Term (*term_new_mat)(u32 name, Term hit, Term miss);
 
   // accessors
   u8   (*term_tag)(Term t);
   u32  (*term_ext)(Term t);
   u64  (*term_val)(Term t);
+  u32  (*term_arity)(Term t);
+  u8   (*term_sub_get)(Term t);
+  Term (*term_sub_set)(Term t, u8 sub);
 
   // heap
   Term (*heap_read)(u64 loc);
   void (*heap_set)(u64 loc, Term t);
   u64  (*heap_alloc)(u64 words);
 
-  // names
-  u32  (*table_find)(const char *name, u32 len);
-  u32  (*name_from_str)(const char *name, u32 len);
+  // book / names
+  u32    (*table_find)(const char *name, u32 len);
+  u32    (*name_from_str)(const char *name, u32 len);
+  char  *(*table_get)(u32 id);
+  u64    (*book_get)(u32 id);
+  void   (*book_set)(u32 id, u64 loc);
 
   // errors
   void (*runtime_error)(const char *msg);