diff --git a/lualib-src/sproto/lsproto.c b/lualib-src/sproto/lsproto.c
index c7708fed..3eb32163 100644
--- a/lualib-src/sproto/lsproto.c
+++ b/lualib-src/sproto/lsproto.c
@@ -166,10 +166,16 @@ encode(const struct sproto_arg *args) {
 		lua_Integer v;
 		lua_Integer vh;
 		int isnum;
-		v = lua_tointegerx(L, -1, &isnum);
-		if(!isnum) {
-			return luaL_error(L, ".%s[%d] is not an integer (Is a %s)", 
-				args->tagname, args->index, lua_typename(L, lua_type(L, -1)));
+		if (args->extra) {
+			// It's decimal.
+			lua_Number vn = lua_tonumber(L, -1);
+			v = (lua_Integer)(vn * args->extra + 0.5);
+		} else {
+			v = lua_tointegerx(L, -1, &isnum);
+			if(!isnum) {
+				return luaL_error(L, ".%s[%d] is not an integer (Is a %s)", 
+					args->tagname, args->index, lua_typename(L, lua_type(L, -1)));
+			}
 		}
 		lua_pop(L,1);
 		// notice: in lua 5.2, lua_Integer maybe 52bit
@@ -332,8 +338,15 @@ decode(const struct sproto_arg *args) {
 	switch (args->type) {
 	case SPROTO_TINTEGER: {
 		// notice: in lua 5.2, 52bit integer support (not 64)
-		lua_Integer v = *(uint64_t*)args->value;
-		lua_pushinteger(L, v);
+		if (args->extra) {
+			lua_Integer v = *(uint64_t*)args->value;
+			lua_Number vn = (lua_Number)v;
+			vn /= args->extra;
+			lua_pushnumber(L, vn);
+		} else {
+			lua_Integer v = *(uint64_t*)args->value;
+			lua_pushinteger(L, v);
+		}
 		break;
 	}
 	case SPROTO_TBOOLEAN: {
@@ -660,7 +673,7 @@ ldefault(lua_State *L) {
 	return 1;
 }
 
-int
+LUAMOD_API int
 luaopen_sproto_core(lua_State *L) {
 #ifdef luaL_checkversion
 	luaL_checkversion(L);
diff --git a/lualib-src/sproto/sproto.c b/lualib-src/sproto/sproto.c
index 9b23af49..416f1006 100644
--- a/lualib-src/sproto/sproto.c
+++ b/lualib-src/sproto/sproto.c
@@ -18,6 +18,7 @@ struct field {
 	const char * name;
 	struct sproto_type * st;
 	int key;
+	int extra;
 };
 
 struct sproto_type {
@@ -177,6 +178,18 @@ import_string(struct sproto *s, const uint8_t * stream) {
 	return buffer;
 }
 
+static int
+calc_pow(int base, int n) {
+	int r;
+	if (n == 0)
+		return 1;
+	r = calc_pow(base * base , n / 2);
+	if (n&1) {
+		r *= base;
+	}
+	return r;
+}
+
 static const uint8_t *
 import_field(struct sproto *s, struct field *f, const uint8_t * stream) {
 	uint32_t sz;
@@ -190,6 +203,7 @@ import_field(struct sproto *s, struct field *f, const uint8_t * stream) {
 	f->name = NULL;
 	f->st = NULL;
 	f->key = -1;
+	f->extra = 0;
 
 	sz = todword(stream);
 	stream += SIZEOF_LENGTH;
@@ -222,12 +236,18 @@ import_field(struct sproto *s, struct field *f, const uint8_t * stream) {
 			f->type = value;
 			break;
 		case 2: // type index
-			if (value >= s->type_n)
-				return NULL;	// invalid type index
-			if (f->type >= 0)
-				return NULL;
-			f->type = SPROTO_TSTRUCT;
-			f->st = &s->type[value];
+			if (f->type == SPROTO_TINTEGER) {
+				f->extra = calc_pow(10, value);
+			} else if (f->type == SPROTO_TSTRING) {
+				f->extra = value;	// string if 0 ; binary is 1
+			} else {
+				if (value >= s->type_n)
+					return NULL;	// invalid type index
+				if (f->type >= 0)
+					return NULL;
+				f->type = SPROTO_TSTRUCT;
+				f->st = &s->type[value];
+			}
 			break;
 		case 3: // tag
 			f->tag = value;
@@ -463,11 +483,6 @@ sproto_release(struct sproto * s) {
 void
 sproto_dump(struct sproto *s) {
 	int i,j;
-	static const char * buildin[] = {
-		"integer",
-		"boolean",
-		"string",
-	};
 	printf("=== %d types ===\n", s->type_n);
 	for (i=0;i<s->type_n;i++) {
 		struct sproto_type *t = &s->type[i];
@@ -476,25 +491,45 @@ sproto_dump(struct sproto *s) {
 			char array[2] = { 0, 0 };
 			const char * type_name = NULL;
 			struct field *f = &t->f[j];
+			int type = f->type & ~SPROTO_TARRAY;
 			if (f->type & SPROTO_TARRAY) {
 				array[0] = '*';
 			} else {
 				array[0] = 0;
 			}
-			{
-				int t = f->type & ~SPROTO_TARRAY;
-				if (t == SPROTO_TSTRUCT) {
-					type_name = f->st->name;
-				} else {
-					assert(t<SPROTO_TSTRUCT);
-					type_name = buildin[t];
+			if (type == SPROTO_TSTRUCT) {
+				type_name = f->st->name;
+			} else {
+				switch(type) {
+				case SPROTO_TINTEGER:
+					if (f->extra) {
+						type_name = "decimal";
+					} else {
+						type_name = "integer";
+					}
+					break;
+				case SPROTO_TBOOLEAN:
+					type_name = "boolean";
+					break;
+				case SPROTO_TSTRING:
+					if (f->extra == SPROTO_TSTRING_BINARY)
+						type_name = "binary";
+					else
+						type_name = "string";
+					break;
+				default:
+					type_name = "invalid";
+					break;
 				}
 			}
-			if (f->key >= 0) {
-				printf("\t%s (%d) %s%s(%d)\n", f->name, f->tag, array, type_name, f->key);
-			} else {
-				printf("\t%s (%d) %s%s\n", f->name, f->tag, array, type_name);
+			printf("\t%s (%d) %s%s", f->name, f->tag, array, type_name);
+			if (type == SPROTO_TINTEGER && f->extra > 0) {
+				printf("(%d)", f->extra);
 			}
+			if (f->key >= 0) {
+				printf("[%d]", f->key);
+			}
+			printf("\n");
 		}
 	}
 	printf("=== %d protocol ===\n", s->protocol_n);
@@ -884,6 +919,7 @@ sproto_encode(const struct sproto_type *st, void * buffer, int size, sproto_call
 		args.tagid = f->tag;
 		args.subtype = f->st;
 		args.mainindex = f->key;
+		args.extra = f->extra;
 		if (type & SPROTO_TARRAY) {
 			args.type = type & ~SPROTO_TARRAY;
 			sz = encode_array(cb, &args, data, size);
@@ -1116,6 +1152,7 @@ sproto_decode(const struct sproto_type *st, const void * data, int size, sproto_
 		args.subtype = f->st;
 		args.index = 0;
 		args.mainindex = f->key;
+		args.extra = f->extra;
 		if (value < 0) {
 			if (f->type & SPROTO_TARRAY) {
 				if (decode_array(cb, &args, currentdata)) {
diff --git a/lualib-src/sproto/sproto.h b/lualib-src/sproto/sproto.h
index c38a12c0..cf40497b 100644
--- a/lualib-src/sproto/sproto.h
+++ b/lualib-src/sproto/sproto.h
@@ -9,11 +9,16 @@ struct sproto_type;
 #define SPROTO_REQUEST 0
 #define SPROTO_RESPONSE 1
 
+// type (sproto_arg.type)
 #define SPROTO_TINTEGER 0
 #define SPROTO_TBOOLEAN 1
 #define SPROTO_TSTRING 2
 #define SPROTO_TSTRUCT 3
 
+// sub type of string (sproto_arg.extra)
+#define SPROTO_TSTRING_STRING 0
+#define SPROTO_TSTRING_BINARY 1
+
 #define SPROTO_CB_ERROR -1
 #define SPROTO_CB_NIL -2
 #define SPROTO_CB_NOARRAY -3
@@ -41,6 +46,7 @@ struct sproto_arg {
 	int length;
 	int index;	// array base 1
 	int mainindex;	// for map
+	int extra; // SPROTO_TINTEGER: decimal ; SPROTO_TSTRING 0:utf8 string 1:binary
 };
 
 typedef int (*sproto_callback)(const struct sproto_arg *args);
diff --git a/lualib/sprotoparser.lua b/lualib/sprotoparser.lua
index 03524ac0..898a1cbc 100644
--- a/lualib/sprotoparser.lua
+++ b/lualib/sprotoparser.lua
@@ -70,6 +70,7 @@ local name = C(word)
 local typename = C(word * ("." * word) ^ 0)
 local tag = R"09" ^ 1 / tonumber
 local mainkey = "(" * blank0 * name * blank0 * ")"
+local decimal = "(" * blank0 * C(tag) * blank0 * ")"
 
 local function multipat(pat)
 	return Ct(blank0 * (pat * blanks) ^ 0 * pat^0 * blank0)
@@ -81,7 +82,7 @@ end
 
 local typedef = P {
 	"ALL",
-	FIELD = namedpat("field", (name * blanks * tag * blank0 * ":" * blank0 * (C"*")^-1 * typename * mainkey^0)),
+	FIELD = namedpat("field", (name * blanks * tag * blank0 * ":" * blank0 * (C"*")^-1 * typename * (mainkey +  decimal)^0)),
 	STRUCT = P"{" * multipat(V"FIELD" + V"TYPE") * P"}",
 	TYPE = namedpat("type", P"." * name * blank0 * V"STRUCT" ),
 	SUBPROTO = Ct((C"request" + C"response") * blanks * (typename + V"STRUCT")),
@@ -134,8 +135,12 @@ function convert.type(all, obj)
 			end
 			local mainkey = f[5]
 			if mainkey then
-				assert(field.array)
-				field.key = mainkey
+				if fieldtype == "integer" then
+					field.decimal = mainkey
+				else
+					assert(field.array)
+					field.key = mainkey
+				end
 			end
 			field.typename = fieldtype
 		else
@@ -167,6 +172,7 @@ local buildin_types = {
 	integer = 0,
 	boolean = 1,
 	string = 2,
+	binary = 2,	-- binary is a sub type of string
 }
 
 local function checktype(types, ptype, t)
@@ -275,7 +281,11 @@ local function packfield(f)
 	table.insert(strtbl, "\0\0")	-- name	(tag = 0, ref an object)
 	if f.buildin then
 		table.insert(strtbl, packvalue(f.buildin))	-- buildin (tag = 1)
-		table.insert(strtbl, "\1\0")	-- skip (tag = 2)
+		if f.extra then
+			table.insert(strtbl, packvalue(f.extra))	-- f.buildin can be integer or string
+		else
+			table.insert(strtbl, "\1\0")	-- skip (tag = 2)
+		end
 		table.insert(strtbl, packvalue(f.tag))		-- tag (tag = 3)
 	else
 		table.insert(strtbl, "\1\0")	-- skip (tag = 1)
@@ -299,8 +309,12 @@ local function packtype(name, t, alltypes)
 		tmp.array = f.array
 		tmp.name = f.name
 		tmp.tag = f.tag
+		tmp.extra = f.decimal
 
 		tmp.buildin = buildin_types[f.typename]
+		if f.typename == "binary" then
+			tmp.extra = 1	-- binary is sub type of string
+		end
 		local subtype
 		if not tmp.buildin then
 			subtype = assert(alltypes[f.typename])