diff --git a/gateway/config.go b/gateway/config.go
index a26d14471f47..a547d2aef5c6 100644
--- a/gateway/config.go
+++ b/gateway/config.go
@@ -11,12 +11,12 @@ type (
 	// GatewayConf is the configuration for gateway.
 	GatewayConf struct {
 		rest.RestConf
-		Upstreams []upstream
+		Upstreams []Upstream
 		Timeout   time.Duration `json:",default=5s"`
 	}
 
-	// mapping is a mapping between a gateway route and a upstream rpc method.
-	mapping struct {
+	// RouteMapping is a mapping between a gateway route and an upstream rpc method.
+	RouteMapping struct {
 		// Method is the HTTP method, like GET, POST, PUT, DELETE.
 		Method string
 		// Path is the HTTP path.
@@ -25,14 +25,14 @@ type (
 		RpcPath string
 	}
 
-	// upstream is the configuration for upstream.
-	upstream struct {
-		// Grpc is the target of upstream.
+	// Upstream is the configuration for an upstream.
+	Upstream struct {
+		// Grpc is the target of the upstream.
 		Grpc zrpc.RpcClientConf
 		// ProtoSet is the file of proto set, like hello.pb
 		ProtoSet string `json:",optional"`
-		// Mapping is the mapping between gateway routes and upstream rpc methods.
+		// Mapping is the mapping between gateway routes and Upstream rpc methods.
 		// Keep it blank if annotations are added in rpc methods.
-		Mapping []mapping `json:",optional"`
+		Mapping []RouteMapping `json:",optional"`
 	}
 )
diff --git a/gateway/server.go b/gateway/server.go
index 8529ee698c73..a15b17da3576 100644
--- a/gateway/server.go
+++ b/gateway/server.go
@@ -23,7 +23,7 @@ type (
 	// Server is a gateway server.
 	Server struct {
 		*rest.Server
-		upstreams     []upstream
+		upstreams     []Upstream
 		timeout       time.Duration
 		processHeader func(http.Header) []string
 	}
@@ -63,7 +63,7 @@ func (s *Server) build() error {
 			source <- up
 		}
 	}, func(item interface{}, writer mr.Writer, cancel func(error)) {
-		up := item.(upstream)
+		up := item.(Upstream)
 		cli := zrpc.MustNewClient(up.Grpc)
 		source, err := s.createDescriptorSource(cli, up)
 		if err != nil {
@@ -138,7 +138,7 @@ func (s *Server) buildHandler(source grpcurl.DescriptorSource, resolver jsonpb.A
 	}
 }
 
-func (s *Server) createDescriptorSource(cli zrpc.Client, up upstream) (grpcurl.DescriptorSource, error) {
+func (s *Server) createDescriptorSource(cli zrpc.Client, up Upstream) (grpcurl.DescriptorSource, error) {
 	var source grpcurl.DescriptorSource
 	var err error