diff --git a/weed/iam/storage.go b/weed/iam/storage.go
new file mode 100644
index 000000000..82349c0f6
--- /dev/null
+++ b/weed/iam/storage.go
@@ -0,0 +1,23 @@
+package iam
+
+import (
+	"context"
+
+	"github.com/seaweedfs/seaweedfs/weed/iam/policy"
+	"github.com/seaweedfs/seaweedfs/weed/pb/iam_pb"
+)
+
+type IamStorage interface {
+	// Identity Management
+	CreateIdentity(ctx context.Context, identity *iam_pb.Identity) error
+	GetIdentity(ctx context.Context, name string) (*iam_pb.Identity, error)
+	UpdateIdentity(ctx context.Context, identity *iam_pb.Identity) error
+	DeleteIdentity(ctx context.Context, name string) error
+	ListIdentities(ctx context.Context, limit int, offset string) ([]*iam_pb.Identity, error)
+
+	// Policy Management
+	CreatePolicy(ctx context.Context, policy *policy.PolicyDocument) error
+	GetPolicy(ctx context.Context, name string) (*policy.PolicyDocument, error)
+	DeletePolicy(ctx context.Context, name string) error
+	ListPolicies(ctx context.Context, limit int, offset string) ([]string, error)
+}