diff --git a/.gx/lastpubver b/.gx/lastpubver
index 5f31091..b793b14 100644
--- a/.gx/lastpubver
+++ b/.gx/lastpubver
@@ -1 +1 @@
-0.1.0: QmfSc2xehWmWLnwwYR91Y8QF4xdASypTFVknutoKQS3GHp
+0.3.0: QmfAjb1QYA9SS9TLVJBRZXEVriGaGrRZ3vJSajhLa52aYg
diff --git a/cid.go b/cid.go
index 745cf26..bc450ea 100644
--- a/cid.go
+++ b/cid.go
@@ -164,3 +164,7 @@ func (c *Cid) UnmarshalJSON(b []byte) error {
 func (c *Cid) MarshalJSON() ([]byte, error) {
 	return []byte(fmt.Sprintf("\"%s\"", c.String())), nil
 }
+
+func (c *Cid) KeyString() string {
+	return string(c.Bytes())
+}
diff --git a/package.json b/package.json
index 8c48ff2..ecf70f1 100644
--- a/package.json
+++ b/package.json
@@ -24,5 +24,7 @@
   "language": "go",
   "license": "",
   "name": "go-cid",
-  "version": "0.1.0"
+  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
+  "version": "0.3.0"
 }
+