diff --git a/api.go b/api.go
index 1dc79664b..f8d197798 100644
--- a/api.go
+++ b/api.go
@@ -23,6 +23,9 @@ import (
     `github.com/bytedance/sonic/internal/rt`
 )
 
+// APIKind is the kind of API, 0 is std json, 1 is sonic.
+const APIKind = apiKind
+
 // Config is a combination of sonic/encoder.Options and sonic/decoder.Options
 type Config struct {
     // EscapeHTML indicates encoder to escape all HTML characters 
diff --git a/compat.go b/compat.go
index 5fea281e5..f6dc5dd58 100644
--- a/compat.go
+++ b/compat.go
@@ -27,6 +27,8 @@ import (
     `github.com/bytedance/sonic/option`
 )
 
+const apiKind = 0
+
 type frozenConfig struct {
     Config
 }
diff --git a/sonic.go b/sonic.go
index 96b5cb1c4..2c987906d 100644
--- a/sonic.go
+++ b/sonic.go
@@ -30,6 +30,8 @@ import (
     `github.com/bytedance/sonic/internal/rt`
 )
 
+const apiKind = 1
+
 type frozenConfig struct {
     Config
     encoderOpts encoder.Options