diff --git a/README.md b/README.md
index ed51fc4..22186b4 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,13 @@
 
 Electrum Protocol Client for Node.js
 
+## what is this
+
+https://electrum.org/
+
+electrum is bitcoin wallet service.  
+This is a library of Node.js that can communicate with the electrum(x) server.  
+
 ## install
 
 ```
@@ -14,6 +21,8 @@ npm i electrum-client
 * TCP / TLS
 * JSON-RPC
 * Subscribe Message
+* High Performance Message
+* no dependency for other library
 
 ## usage
 
@@ -34,3 +43,4 @@ const main = async () => {
 main()
 ```
 
+
diff --git a/example/riaa_client_transaction_send.js b/example/riaa_client_transaction_send.js
new file mode 100644
index 0000000..1abaace
--- /dev/null
+++ b/example/riaa_client_transaction_send.js
@@ -0,0 +1,38 @@
+'use strict';
+const ElectrumClient = require('electrum-client');
+
+const createRiaaClient = (port, host, protocol, options) => {
+    return (params, promise) => {
+        const name = params.join(':')
+        const client = new ElectrumClient(port, host, protocol, options)
+        console.time(name)
+        return client.connect().then( () => {
+            return promise(client)
+        }).catch( e => {
+            client.close()
+            console.timeEnd(name)
+            throw e
+        }).then( res => {
+            client.close()
+            console.timeEnd(name)
+            return res
+        })
+    }
+
+}
+
+const main = async(hex) => {
+    const connect = createRiaaClient(50001, 'electrumx.tamami-foundation.org', 'tcp')
+    await connect(['blockchainTransaction_broadcast', hex], async(client) => {
+        const ver = await client.server_version('2.7.11', '1.0')
+        console.log(ver)
+        const result = await client.blockchainTransaction_broadcast(hex)
+        console.log(result)
+    })
+}
+
+const getopt = () => {
+    return process.argv.slice(2)[0]
+}
+
+main(getopt())
diff --git a/package.json b/package.json
index d885459..ccfca26 100644
--- a/package.json
+++ b/package.json
@@ -1,13 +1,12 @@
 {
   "name": "electrum-client",
-  "version": "0.0.4",
+  "version": "0.0.5",
   "description": "Electrum protocol client for node.js",
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },
-  "dependencies": {
-  },
+  "dependencies": {},
   "repository": {
     "type": "git",
     "url": "git://github.com/you21979/node-electrum-client.git"
@@ -20,6 +19,9 @@
     "electrum",
     "bitcoin"
   ],
+  "engines": {
+    "node": ">=6"
+  },
   "author": "Yuki Akiyama",
   "license": "MIT"
 }