diff --git a/generator/fastgo/codewriter.go b/generator/fastgo/codewriter.go
index b307e07..7fdb733 100644
--- a/generator/fastgo/codewriter.go
+++ b/generator/fastgo/codewriter.go
@@ -19,24 +19,29 @@ package fastgo
 import (
 	"bytes"
 	"fmt"
+	"path"
 	"strings"
 )
 
 type codewriter struct {
 	*bytes.Buffer
 
-	pkgs map[string]struct{}
+	pkgs map[string]string // import -> alias
 }
 
 func newCodewriter() *codewriter {
 	return &codewriter{
 		Buffer: &bytes.Buffer{},
-		pkgs:   make(map[string]struct{}),
+		pkgs:   make(map[string]string),
 	}
 }
 
-func (w *codewriter) usePkg(s string) {
-	w.pkgs[s] = struct{}{}
+func (w *codewriter) UsePkg(s, a string) {
+	if path.Base(s) == a {
+		w.pkgs[s] = ""
+	} else {
+		w.pkgs[s] = a
+	}
 }
 
 func (w *codewriter) Imports() string {
@@ -63,7 +68,7 @@ func (w *codewriter) Imports() string {
 
 	// only imports one pkg?
 	if len(pp0) == 1 {
-		return fmt.Sprintf("import %q", pp0[0])
+		return fmt.Sprintf("import %s %q", w.pkgs[pp0[0]], pp0[0])
 	}
 
 	// more than one imports
@@ -73,7 +78,7 @@ func (w *codewriter) Imports() string {
 		if p == "" {
 			fmt.Fprintln(s, "")
 		} else {
-			fmt.Fprintf(s, "  %q\n", p)
+			fmt.Fprintf(s, "%s %q\n", w.pkgs[p], p)
 		}
 	}
 	fmt.Fprintln(s, ")")
diff --git a/generator/fastgo/fastgo.go b/generator/fastgo/fastgo.go
index 5aa17e7..bd04ff9 100644
--- a/generator/fastgo/fastgo.go
+++ b/generator/fastgo/fastgo.go
@@ -55,7 +55,7 @@ func (g *FastGoBackend) Generate(req *plugin.Request, log backend.LogFunc) *plug
 	}
 	g.req = req
 	g.log = log
-	g.utils = golang.NewCodeUtils(log)
+	g.utils = g.GoBackend.GetCoreUtils()
 	var trees chan *parser.Thrift
 	if req.Recursive {
 		trees = req.AST.DepthFirstSearch()
@@ -105,10 +105,20 @@ func (g *FastGoBackend) GenerateOne(ast *parser.Thrift) (*plugin.Generated, erro
 		g.generateStruct(w, scope, s)
 	}
 	for _, s := range scope.Unions() {
-		_ = s
+		g.generateStruct(w, scope, s)
 	}
 	for _, s := range scope.Exceptions() {
-		_ = s
+		g.generateStruct(w, scope, s)
+	}
+	for _, ss := range scope.Services() {
+		for _, f := range ss.Functions() {
+			if s := f.ArgType(); s != nil {
+				g.generateStruct(w, scope, s)
+			}
+			if s := f.ResType(); s != nil {
+				g.generateStruct(w, scope, s)
+			}
+		}
 	}
 
 	ret := &plugin.Generated{}
@@ -123,11 +133,31 @@ func (g *FastGoBackend) GenerateOne(ast *parser.Thrift) (*plugin.Generated, erro
 	fmt.Fprintf(c, "%s\npackage %s\n\n", fixedFileHeader, packageName)
 
 	// Imports
+	unusedProtect := false
+	for _, incl := range scope.Includes() {
+		if incl == nil { // TODO(liyun.339): fix this
+			continue
+		}
+		unusedProtect = true
+		w.UsePkg(incl.ImportPath, incl.PackageName)
+	}
 	if len(w.pkgs) > 0 {
 		c.WriteString(w.Imports())
 	}
 	c.WriteByte('\n')
 
+	// Unused protects
+	if unusedProtect {
+		fmt.Fprintln(c, "var (")
+		for _, incl := range scope.Includes() {
+			if incl == nil { // TODO(liyun.339): fix this
+				continue
+			}
+			fmt.Fprintf(c, "_ = %s.KitexUnusedProtection\n", incl.PackageName)
+		}
+		fmt.Fprintln(c, ")")
+	}
+
 	// Methods
 	c.Write(w.Bytes())
 
diff --git a/generator/fastgo/gen_blength.go b/generator/fastgo/gen_blength.go
index d7dab46..19b9c3e 100644
--- a/generator/fastgo/gen_blength.go
+++ b/generator/fastgo/gen_blength.go
@@ -31,7 +31,7 @@ func (g *FastGoBackend) genBLength(w *codewriter, scope *golang.Scope, s *golang
 	// - off is the counter of BLength
 
 	// func definition
-	w.usePkg("github.com/cloudwego/gopkg/protocol/thrift")
+	w.UsePkg("github.com/cloudwego/gopkg/protocol/thrift", "")
 	w.f("func (p *%s) BLength() int {", s.GoName())
 
 	// case nil, STOP
@@ -40,7 +40,8 @@ func (g *FastGoBackend) genBLength(w *codewriter, scope *golang.Scope, s *golang
 	w.f("off := 0")
 
 	// fields
-	for _, f := range s.Fields() {
+	ff := getSortedFields(s)
+	for _, f := range ff {
 		rwctx, err := g.utils.MkRWCtx(scope, f)
 		if err != nil {
 			// never goes here, should fail early in generator/golang pkg
@@ -167,7 +168,7 @@ func genBLengthMap(w *codewriter, rwctx *golang.ReadWriteContext, varname string
 		genBLengthAny(w, rwctx.ValCtx, tmpv, depth+1)
 		w.f("}")
 	} else if vsz > 0 {
-		w.f("off += %s * %d", varname, vsz)
+		w.f("off += len(%s) * %d", varname, vsz)
 		w.f("for %s, _ := range %s {", tmpk, varname)
 		genBLengthAny(w, rwctx.KeyCtx, tmpk, depth+1)
 		w.f("}")
diff --git a/generator/fastgo/gen_fastread.go b/generator/fastgo/gen_fastread.go
index 5bf3fda..7da4e1a 100644
--- a/generator/fastgo/gen_fastread.go
+++ b/generator/fastgo/gen_fastread.go
@@ -38,15 +38,15 @@ func (g *FastGoBackend) genFastRead(w *codewriter, scope *golang.Scope, s *golan
 	// Instead of using consts for vars above, would like to use the names directly making code clear
 
 	// func definition
-	w.usePkg("github.com/cloudwego/gopkg/protocol/thrift")
+	w.UsePkg("github.com/cloudwego/gopkg/protocol/thrift", "")
 	w.f("func (p *%s) FastRead(b []byte) (off int, err error) {", s.GoName())
 	w.f("var ftyp thrift.TType")
 	w.f("var fid int16")
 	w.f("var l int")
 
 	isset := newBitsetCodeGen("isset", "uint8")
-	ff := getSortedFields(s)
 	hasEnum := false
+	ff := getSortedFields(s)
 	for _, f := range ff {
 		if f.Type.Category == parser.Category_Enum {
 			hasEnum = true
@@ -100,12 +100,14 @@ func (g *FastGoBackend) genFastRead(w *codewriter, scope *golang.Scope, s *golan
 
 	w.f("return") // no error
 
-	w.usePkg("fmt")
+	w.UsePkg("fmt", "")
 	w.f("ReadFieldBeginError:")
 	w.f(`return off, thrift.PrependError(fmt.Sprintf("%%T read field begin error: ", p), err)`)
 
-	w.f("ReadFieldError:")
-	w.f(`return off, thrift.PrependError(fmt.Sprintf("%%T read field %%d '%%s' error: ", p, fid, fieldIDToName_%s[fid]), err)`, s.GoName())
+	if len(ff) > 0 { // fix `label ReadFieldError defined and not used`
+		w.f("ReadFieldError:")
+		w.f(`return off, thrift.PrependError(fmt.Sprintf("%%T read field %%d '%%s' error: ", p, fid, fieldIDToName_%s[fid]), err)`, s.GoName())
+	}
 
 	w.f("SkipFieldError:")
 	w.f(`return off, thrift.PrependError(fmt.Sprintf("%%T skip field %%d type %%d error: ", p, fid, ftyp), err)`)
@@ -311,7 +313,13 @@ func genFastReadMap(w *codewriter, rwctx *golang.ReadWriteContext, varname strin
 
 	w.f("%s = make(%s, %s)", varname, rwctx.TypeName, tmpsize)
 	w.f("for %s := 0; %s < %s; %s++ {", tmpi, tmpi, tmpsize, tmpi)
-	w.f("var %s %s", tmpk, rwctx.KeyCtx.TypeName)
+	if rwctx.KeyCtx.TypeID == "Struct" && !rwctx.KeyCtx.IsPointer {
+		// hotfix for struct, it's always pointer for keys
+		// remove this check after generator/gopkg fix it
+		w.f("var %s *%s", tmpk, rwctx.KeyCtx.TypeName)
+	} else {
+		w.f("var %s %s", tmpk, rwctx.KeyCtx.TypeName)
+	}
 	w.f("var %s %s", tmpv, rwctx.ValCtx.TypeName)
 	genFastReadAny(w, rwctx.KeyCtx, tmpk, depth+1)
 	genFastReadAny(w, rwctx.ValCtx, tmpv, depth+1)
diff --git a/generator/fastgo/gen_fastwrite.go b/generator/fastgo/gen_fastwrite.go
index 25911a6..246d49f 100644
--- a/generator/fastgo/gen_fastwrite.go
+++ b/generator/fastgo/gen_fastwrite.go
@@ -31,7 +31,7 @@ func (g *FastGoBackend) genFastWrite(w *codewriter, scope *golang.Scope, s *gola
 	// - off is the offset of b
 
 	// func definition
-	w.usePkg("github.com/cloudwego/gopkg/protocol/thrift")
+	w.UsePkg("github.com/cloudwego/gopkg/protocol/thrift", "")
 	w.f("func (p *%s) FastWrite(b []byte) int { return p.FastWriteNocopy(b, nil) }\n\n", s.GoName())
 	w.f("func (p *%s) FastWriteNocopy(b []byte, w thrift.NocopyWriter) int {", s.GoName())
 
@@ -42,7 +42,8 @@ func (g *FastGoBackend) genFastWrite(w *codewriter, scope *golang.Scope, s *gola
 	w.f("off := 0")
 
 	// fields
-	for _, f := range s.Fields() {
+	ff := getSortedFields(s)
+	for _, f := range ff {
 		rwctx, err := g.utils.MkRWCtx(scope, f)
 		if err != nil {
 			// never goes here, should fail early in generator/golang pkg
@@ -82,7 +83,7 @@ func genFastWriteField(w *codewriter, rwctx *golang.ReadWriteContext, f *golang.
 	}
 
 	// field header
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	w.f("b[off] = %d", category2ThriftWireType[f.Type.Category])
 	w.f("binary.BigEndian.PutUint16(b[off+1:], %d) ", f.ID)
 	w.f("off += 3")
@@ -125,7 +126,7 @@ func genFastWriteAny(w *codewriter, rwctx *golang.ReadWriteContext, varname stri
 func genFastWriteBool(w *codewriter, pointer bool, varname string) {
 	// for bool, the underlying byte of true is always 1, and 0 for false
 	// which is same as thrift binary protocol
-	w.usePkg("unsafe")
+	w.UsePkg("unsafe", "")
 	w.f("b[off] = *((*byte)(unsafe.Pointer(%s)))", varnamePtr(pointer, varname))
 	w.f("off++")
 }
@@ -136,25 +137,25 @@ func genFastWriteByte(w *codewriter, pointer bool, varname string) {
 }
 
 func genFastWriteDouble(w *codewriter, pointer bool, varname string) {
-	w.usePkg("unsafe")
+	w.UsePkg("unsafe", "")
 	w.f("binary.BigEndian.PutUint64(b[off:], *(*uint64)(unsafe.Pointer(%s)))", varnamePtr(pointer, varname))
 	w.f("off += 8")
 }
 
 func genFastWriteInt16(w *codewriter, pointer bool, varname string) {
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	w.f("binary.BigEndian.PutUint16(b[off:], uint16(%s))", varnameVal(pointer, varname))
 	w.f("off += 2")
 }
 
 func genFastWriteInt32(w *codewriter, pointer bool, varname string) {
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	w.f("binary.BigEndian.PutUint32(b[off:], uint32(%s))", varnameVal(pointer, varname))
 	w.f("off += 4")
 }
 
 func genFastWriteInt64(w *codewriter, pointer bool, varname string) {
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	w.f("binary.BigEndian.PutUint64(b[off:], uint64(%s))", varnameVal(pointer, varname))
 	w.f("off += 8")
 }
@@ -176,7 +177,7 @@ func genFastWriteStruct(w *codewriter, rwctx *golang.ReadWriteContext, varname s
 func genFastWriteList(w *codewriter, rwctx *golang.ReadWriteContext, varname string, depth int) {
 	rwctx = rwctx.ValCtx
 	t := rwctx.Type
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	// list header
 	w.f("b[off] = %d", category2ThriftWireType[t.Category])
 	w.f("binary.BigEndian.PutUint32(b[off+1:], uint32(len(%s)))", varname)
@@ -197,7 +198,7 @@ func genFastWriteMap(w *codewriter, rwctx *golang.ReadWriteContext, varname stri
 	kt := t.KeyType
 	vt := t.ValueType
 	// map header
-	w.usePkg("encoding/binary")
+	w.UsePkg("encoding/binary", "")
 	w.f("b[off] = %d", category2ThriftWireType[kt.Category])
 	w.f("b[off+1] = %d", category2ThriftWireType[vt.Category])
 	w.f("binary.BigEndian.PutUint32(b[off+2:], uint32(len(%s)))", varname)
diff --git a/generator/golang/backend.go b/generator/golang/backend.go
index caa29d2..b949f30 100644
--- a/generator/golang/backend.go
+++ b/generator/golang/backend.go
@@ -107,6 +107,10 @@ func (g *GoBackend) Generate(req *plugin.Request, log backend.LogFunc) *plugin.R
 	return g.buildResponse()
 }
 
+func (g *GoBackend) GetCoreUtils() *CodeUtils {
+	return g.utils
+}
+
 func (g *GoBackend) prepareUtilities() {
 	if g.err != nil {
 		return