diff --git a/config/default.go b/config/default.go
index b28269f4..179fc9ba 100644
--- a/config/default.go
+++ b/config/default.go
@@ -7,7 +7,9 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/imdario/mergo"
+	mid "go.unistack.org/micro/v3/util/id"
 	rutil "go.unistack.org/micro/v3/util/reflect"
 	mtime "go.unistack.org/micro/v3/util/time"
 )
@@ -124,6 +126,20 @@ func fillValue(value reflect.Value, val string) error {
 		}
 		value.Set(reflect.ValueOf(v))
 	case reflect.String:
+		switch val {
+		case "micro:generate uuid":
+			uid, err := uuid.NewRandom()
+			if err != nil {
+				return err
+			}
+			val = uid.String()
+		case "micro:generate id":
+			uid, err := mid.New()
+			if err != nil {
+				return err
+			}
+			val = uid
+		}
 		value.Set(reflect.ValueOf(val))
 	case reflect.Float32:
 		v, err := strconv.ParseFloat(val, 32)
diff --git a/config/default_test.go b/config/default_test.go
index 180d687e..40ee6924 100644
--- a/config/default_test.go
+++ b/config/default_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"go.unistack.org/micro/v3/config"
+	mid "go.unistack.org/micro/v3/util/id"
 	mtime "go.unistack.org/micro/v3/util/time"
 )
 
@@ -14,9 +15,12 @@ type cfg struct {
 	StringValue    string `default:"string_value"`
 	IgnoreValue    string `json:"-"`
 	StructValue    *cfgStructValue
-	IntValue       int            `default:"99"`
-	DurationValue  time.Duration  `default:"10s"`
-	MDurationValue mtime.Duration `default:"10s"`
+	IntValue       int             `default:"99"`
+	DurationValue  time.Duration   `default:"10s"`
+	MDurationValue mtime.Duration  `default:"10s"`
+	MapValue       map[string]bool `default:"key1=true,key2=false"`
+	UUIDValue      string          `default:"micro:generate uuid"`
+	IDValue        string          `default:"micro:generate id"`
 }
 
 type cfgStructValue struct {
@@ -67,6 +71,21 @@ func TestDefault(t *testing.T) {
 	if conf.StringValue != "after_load" {
 		t.Fatal("AfterLoad option not working")
 	}
+	if len(conf.MapValue) != 2 {
+		t.Fatalf("map value invalid: %#+v\n", conf.MapValue)
+	}
+
+	if conf.UUIDValue == "" {
+		t.Fatalf("uuid value empty")
+	} else if len(conf.UUIDValue) != 36 {
+		t.Fatalf("uuid value invalid: %s", conf.UUIDValue)
+	}
+
+	if conf.IDValue == "" {
+		t.Fatalf("id value empty")
+	} else if len(conf.IDValue) != mid.DefaultSize {
+		t.Fatalf("id value invalid: %s", conf.IDValue)
+	}
 	_ = conf
 	// t.Logf("%#+v\n", conf)
 }
diff --git a/go.mod b/go.mod
index 55853a55..890d2b81 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,8 @@ module go.unistack.org/micro/v3
 go 1.19
 
 require (
-	github.com/imdario/mergo v0.3.14
+	github.com/google/uuid v1.3.0
+	github.com/imdario/mergo v0.3.15
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35
 )
diff --git a/go.sum b/go.sum
index 40151841..22b410b6 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,7 @@
-github.com/imdario/mergo v0.3.14 h1:fOqeC1+nCuuk6PKQdg9YmosXX7Y7mHX6R/0ZldI9iHo=
-github.com/imdario/mergo v0.3.14/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/imdario/mergo v0.3.15 h1:M8XP7IuFNsqUx6VPK2P9OSmsYsI/YFaGil0uD21V3dM=
+github.com/imdario/mergo v0.3.15/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35 h1:4mohWoM/UGg1BvFFiqSPRl5uwJY3rVV0HQX0ETqauqQ=