diff --git a/codecov.yml b/.codecov.yml
similarity index 100%
rename from codecov.yml
rename to .codecov.yml
diff --git a/.gitignore b/.gitignore
index 783cd5b..175b291 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.swp
 
+multibase-conv/multibase-conv
diff --git a/.travis.yml b/.travis.yml
index 6a741bc..b95a291 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@ install:
 
 script:
     - gx-go rewrite
-    - go test -race -coverprofile=unittest.coverprofile -covermode=atomic ./...
+    - go test -race -coverprofile=unittest.coverprofile -covermode=atomic .
 
 
 after_success:
diff --git a/multibase-conv/main.go b/multibase-conv/main.go
new file mode 100644
index 0000000..cec445b
--- /dev/null
+++ b/multibase-conv/main.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	multibase "github.com/multiformats/go-multibase"
+)
+
+func main() {
+	if len(os.Args) < 3 {
+		fmt.Printf("usage: %s <new-base> <multibase-str>...\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	var newBase multibase.Encoding
+	if baseParm := os.Args[1]; len(baseParm) != 0 {
+		newBase = multibase.Encoding(baseParm[0])
+	} else {
+		fmt.Fprintln(os.Stderr, "<new-base> is empty")
+		os.Exit(1)
+	}
+
+	input := os.Args[2:]
+
+	for _, strmbase := range input {
+		_, data, err := multibase.Decode(strmbase)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error while decoding: %s\n", err)
+			os.Exit(1)
+		}
+
+		newCid, err := multibase.Encode(newBase, data)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error while encoding: %s\n", err)
+			os.Exit(1)
+		}
+		fmt.Println(newCid)
+	}
+
+}