Add ssm api server

include/ssmapi.go

@@ -0,0 +1,5 @@
+//go:build with_ssm_api
+
+package include
+
+import _ "github.com/sagernet/sing-box/experimental/ssmapi"

include/ssmapi_stub.go

@@ -0,0 +1,17 @@
+//go:build !with_ssm_api
+
+package include
+
+import (
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/experimental"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func init() {
+	experimental.RegisterSSMServerConstructor(func(router adapter.Router, logger log.Logger, options option.SSMAPIOptions) (adapter.SSMServer, error) {
+		return nil, E.New(`SSM api is not included in this build, rebuild with -tags with_ssm_api`)
+	})
+}