diff --git a/metadata/sandbox.go b/metadata/sandbox.go
index b125358ce..cb9dc548b 100644
--- a/metadata/sandbox.go
+++ b/metadata/sandbox.go
@@ -369,9 +369,5 @@ func (s *sandboxStore) validate(new *api.Sandbox) error {
 		return fmt.Errorf("updated date must not be zero: %w", errdefs.ErrInvalidArgument)
 	}
 
-	if new.Runtime.Name == "" {
-		return fmt.Errorf("sandbox.Runtime.Name must be set: %w", errdefs.ErrInvalidArgument)
-	}
-
 	return nil
 }
diff --git a/sandbox/store.go b/sandbox/store.go
index d81a17e77..5db1b65c9 100644
--- a/sandbox/store.go
+++ b/sandbox/store.go
@@ -18,8 +18,10 @@ package sandbox
 
 import (
 	"context"
+	"fmt"
 	"time"
 
+	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/typeurl"
 )
 
@@ -64,3 +66,51 @@ type Store interface {
 	// Delete a sandbox from metadata store using the id
 	Delete(ctx context.Context, id string) error
 }
+
+// AddExtension is a helper function to add sandbox metadata extension.
+func (s *Sandbox) AddExtension(name string, obj interface{}) error {
+	if s.Extensions == nil {
+		s.Extensions = map[string]typeurl.Any{}
+	}
+
+	out, err := typeurl.MarshalAny(obj)
+	if err != nil {
+		return fmt.Errorf("failed to marshal sandbox extension %q: %w", name, err)
+	}
+
+	s.Extensions[name] = out
+	return nil
+}
+
+// AddLabel adds a label to sandbox's labels.
+func (s *Sandbox) AddLabel(name string, value string) {
+	if s.Labels == nil {
+		s.Labels = map[string]string{}
+	}
+
+	s.Labels[name] = value
+}
+
+// GetExtension retrieves a sandbox extension by name.
+func (s *Sandbox) GetExtension(name string, obj interface{}) error {
+	out, ok := s.Extensions[name]
+	if !ok {
+		return errdefs.ErrNotFound
+	}
+
+	if err := typeurl.UnmarshalTo(out, obj); err != nil {
+		return fmt.Errorf("failed to unmarshal sandbox extension %q: %w", name, err)
+	}
+
+	return nil
+}
+
+// GetLabel retrieves a sandbox label by name.
+func (s *Sandbox) GetLabel(name string) (string, error) {
+	out, ok := s.Labels[name]
+	if !ok {
+		return "", fmt.Errorf("unable to find label %q in sandbox metadata: %w", name, errdefs.ErrNotFound)
+	}
+
+	return out, nil
+}
diff --git a/sandbox/store_test.go b/sandbox/store_test.go
new file mode 100644
index 000000000..46783eec0
--- /dev/null
+++ b/sandbox/store_test.go
@@ -0,0 +1,40 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sandbox
+
+import (
+	"testing"
+
+	"github.com/containerd/typeurl"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAddExtension(t *testing.T) {
+	sb := Sandbox{ID: "1"}
+
+	type test struct{ Name string }
+
+	typeurl.Register(&test{})
+
+	var in = test{Name: "test"}
+	assert.NoError(t, sb.AddExtension("test", &in))
+
+	var out test
+	err := sb.GetExtension("test", &out)
+	assert.NoError(t, err)
+	assert.Equal(t, "test", out.Name)
+}