diff --git a/interface.go b/interface.go
new file mode 100644
index 0000000..fec2b99
--- /dev/null
+++ b/interface.go
@@ -0,0 +1,46 @@
+package nostr
+
+import (
+	"context"
+	"errors"
+	"slices"
+)
+
+type RelayStore interface {
+	Publish(ctx context.Context, event Event) error
+	QuerySync(ctx context.Context, filter Filter, opts ...SubscriptionOption) ([]*Event, error)
+}
+
+var (
+	_ RelayStore = (*Relay)(nil)
+	_ RelayStore = (*MultiStore)(nil)
+)
+
+type MultiStore []RelayStore
+
+func (multi MultiStore) Publish(ctx context.Context, event Event) error {
+	errs := make([]error, len(multi))
+	for i, s := range multi {
+		errs[i] = s.Publish(ctx, event)
+	}
+	return errors.Join(errs...)
+}
+
+func (multi MultiStore) QuerySync(ctx context.Context, filter Filter, opts ...SubscriptionOption) ([]*Event, error) {
+	errs := make([]error, len(multi))
+	events := make([]*Event, 0, max(filter.Limit, 10))
+	for i, s := range multi {
+		res, err := s.QuerySync(ctx, filter, opts...)
+		errs[i] = err
+		events = append(events, res...)
+	}
+	slices.SortFunc(events, func(a, b *Event) int {
+		if b.CreatedAt > a.CreatedAt {
+			return 1
+		} else if b.CreatedAt < a.CreatedAt {
+			return -1
+		}
+		return 0
+	})
+	return events, errors.Join(errs...)
+}