diff --git a/mie/id.c b/mie/id.c
index 18e3e32..29a50f7 100644
--- a/mie/id.c
+++ b/mie/id.c
@@ -99,19 +99,10 @@ void mie_id_init_random(mie_id *out)
 
 void mie_id_init_ns(mie_id *out, const mie_id *ns, const b_rope *name)
 {
-	b_hash_ctx hash;
-	b_hash_ctx_init(&hash, B_HASH_SHA1);
-
-	b_hash_ctx_update(&hash, ns->id_bytes, sizeof ns->id_bytes);
-	b_hash_ctx_update_rope(&hash, name);
-
-	b_hash_ctx_finish(&hash, out->id_bytes, sizeof out->id_bytes);
-
-	out->id_bytes[6] &= 0x0F;
-	out->id_bytes[6] |= 0x50;
-
-	out->id_bytes[8] &= 0x3F;
-	out->id_bytes[8] |= 0x80;
+	struct mie_id_builder ctx;
+	mie_id_builder_begin(&ctx, ns);
+	mie_id_builder_add_rope(&ctx, name);
+	mie_id_builder_end(&ctx, out);
 }
 
 void mie_id_to_string(const mie_id *id, char *out, size_t max)
@@ -145,7 +136,48 @@ void mie_id_map_put(struct mie_id_map *map, mie_id *id, const b_rope *name)
 	put_id(&map->map_entries, id);
 }
 
+void mie_id_map_put_id(struct mie_id_map *map, mie_id *node)
+{
+	put_id(&map->map_entries, node);
+}
+
 mie_id *mie_id_map_get(const struct mie_id_map *map, mie_id *id)
 {
 	return get_id(&map->map_entries, id);
 }
+
+void mie_id_builder_begin(struct mie_id_builder *builder, const mie_id *ns)
+{
+	memset(builder, 0x0, sizeof *builder);
+	b_hash_ctx_init(&builder->b_hash, B_HASH_SHA1);
+	b_hash_ctx_update(&builder->b_hash, ns->id_bytes, sizeof ns->id_bytes);
+}
+
+void mie_id_builder_add(struct mie_id_builder *builder, const void *p, size_t len)
+{
+	b_hash_ctx_update(&builder->b_hash, p, len);
+}
+
+void mie_id_builder_add_rope(struct mie_id_builder *builder, const b_rope *rope)
+{
+	b_hash_ctx_update_rope(&builder->b_hash, rope);
+}
+
+void mie_id_builder_add_marker(
+	struct mie_id_builder *builder, enum mie_id_builder_marker marker)
+{
+	unsigned char c = marker;
+	b_hash_ctx_update(&builder->b_hash, &c, sizeof c);
+}
+
+void mie_id_builder_end(struct mie_id_builder *builder, mie_id *out)
+{
+	memset(out, 0x0, sizeof *out);
+	b_hash_ctx_finish(&builder->b_hash, out->id_bytes, sizeof out->id_bytes);
+
+	out->id_bytes[6] &= 0x0F;
+	out->id_bytes[6] |= 0x50;
+
+	out->id_bytes[8] &= 0x3F;
+	out->id_bytes[8] |= 0x80;
+}
diff --git a/mie/include/mie/id.h b/mie/include/mie/id.h
index 68353d6..c556cfa 100644
--- a/mie/include/mie/id.h
+++ b/mie/include/mie/id.h
@@ -22,6 +22,15 @@
 #define MIE_ID_NR_WORDS_32 (MIE_ID_NR_BYTES / sizeof(uint32_t))
 #define MIE_ID_NR_WORDS_64 (MIE_ID_NR_BYTES / sizeof(uint64_t))
 
+enum mie_id_builder_marker {
+	MIE_ID_BUILDER_STORAGE_START = 0x32,
+	MIE_ID_BUILDER_STORAGE_END = 0x8a,
+	MIE_ID_BUILDER_FUNCTION_IN_START = 0x78,
+	MIE_ID_BUILDER_FUNCTION_IN_END = 0x55,
+	MIE_ID_BUILDER_FUNCTION_OUT_START = 0xa2,
+	MIE_ID_BUILDER_FUNCTION_OUT_END = 0xbc,
+};
+
 typedef struct mie_id {
 	union {
 		uint8_t id_bytes[MIE_ID_NR_BYTES];
@@ -31,9 +40,16 @@ typedef struct mie_id {
 		uint64_t id_words_64[MIE_ID_NR_WORDS_64];
 	};
 
-	b_btree_node e_node;
+	union {
+		b_btree_node e_node;
+		b_queue_entry e_entry;
+	};
 } mie_id;
 
+struct mie_id_builder {
+	b_hash_ctx b_hash;
+};
+
 struct mie_id_map {
 	mie_id map_ns_id;
 	b_btree map_entries;
@@ -54,7 +70,27 @@ MIE_API void mie_id_to_string(const mie_id *id, char *out, size_t max);
 
 MIE_API void mie_id_map_init(struct mie_id_map *map, const mie_id *ns);
 MIE_API const mie_id *mie_id_map_get_ns(const struct mie_id_map *map);
-MIE_API void mie_id_map_put(struct mie_id_map *map, mie_id *id, const b_rope *name);
+MIE_API void mie_id_map_put(
+	struct mie_id_map *map, mie_id *node, const b_rope *name);
+MIE_API void mie_id_map_put_id(struct mie_id_map *map, mie_id *node);
 MIE_API mie_id *mie_id_map_get(const struct mie_id_map *map, mie_id *id);
 
+MIE_API void mie_id_builder_begin(struct mie_id_builder *builder, const mie_id *ns);
+MIE_API void mie_id_builder_add(
+	struct mie_id_builder *builder, const void *p, size_t len);
+static inline void mie_id_builder_add_char(struct mie_id_builder *builder, char c)
+{
+	mie_id_builder_add(builder, &c, 1);
+}
+static inline void mie_id_builder_add_cstr(
+	struct mie_id_builder *builder, const char *s)
+{
+	mie_id_builder_add(builder, s, strlen(s));
+}
+MIE_API void mie_id_builder_add_rope(
+	struct mie_id_builder *builder, const b_rope *rope);
+MIE_API void mie_id_builder_add_marker(
+	struct mie_id_builder *builder, enum mie_id_builder_marker marker);
+MIE_API void mie_id_builder_end(struct mie_id_builder *builder, mie_id *out);
+
 #endif