added to get token balance feature

Author: gloryan

README.md

@@ -1 +1,25 @@
 # amb-query-nodejs
+
+### 1. Authenticated AWS on your local machine
+
+```
+export AWS_ACCESS_KEY_ID="{input here}"
+export AWS_SECRET_ACCESS_KEY="{input here}"
+```
+
+### 2. use node 14 version (using nvm dependency)
+```
+nvm use 14
+```
+
+### 3. install dependencies
+```
+npm install
+```
+
+## AMB Query
+
+### 1. Token Balance
+```
+node tokenBalance.js
+```

package.json

@@ -0,0 +1,11 @@
+{
+  "name": "amb-query-nodejs",
+  "version": "1.0.0",
+  "dependencies": {
+    "@aws-crypto/sha256-js": "^4.0.0",
+    "@aws-sdk/credential-provider-node": "^3.360.0",
+    "@aws-sdk/protocol-http": "^3.357.0",
+    "@aws-sdk/signature-v4": "^3.357.0",
+    "axios": "^1.4.0"
+  }
+}

tokenBalance.js

@@ -0,0 +1,70 @@
+const axios = require('axios').default;
+const SHA256 = require('@aws-crypto/sha256-js').Sha256
+const defaultProvider = require('@aws-sdk/credential-provider-node').defaultProvider
+const HttpRequest = require('@aws-sdk/protocol-http').HttpRequest
+const SignatureV4 = require('@aws-sdk/signature-v4').SignatureV4
+
+// define a signer object with AWS service name, credentials, and region
+const signer = new SignatureV4({
+    credentials: defaultProvider(),
+    service: 'managedblockchain-query',
+    region: 'us-east-1',
+    sha256: SHA256,
+});
+
+const queryRequest = async (path, data) => {
+    //query endpoint
+    let queryEndpoint = `https://managedblockchain-query.us-east-1.amazonaws.com/${path}`;
+
+    // parse the URL into its component parts (e.g. host, path)
+    const url = new URL(queryEndpoint);
+
+    // create an HTTP Request object
+    const req = new HttpRequest({
+        hostname: url.hostname.toString(),
+        path: url.pathname.toString(),
+        body: JSON.stringify(data),
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/json',
+            'Accept-Encoding': 'gzip',
+            host: url.hostname,
+        }
+    });
+
+
+    // use AWS SignatureV4 utility to sign the request, extract headers and body
+    const signedRequest = await signer.sign(req, { signingDate: new Date() });
+
+    try {
+        //make the request using axios
+        const response = await axios({...signedRequest, url: queryEndpoint, data: data})
+
+        console.log(response.data)
+    } catch (error) {
+        console.error('Something went wrong: ', error)
+        throw error
+    }
+
+
+}
+
+
+let methodArg = 'get-token-balance';
+
+let dataArg = {
+    // " atBlockchainInstant": {
+    //     "time": 1688071493
+    // }, // (Optional)
+    "ownerIdentifier": {
+        "address": "0x02E6C1d540d17BcD8A47596390E9f1d3d25041d1" // 지갑 혹은 컨트랙트 주소
+    },
+    "tokenIdentifier": {
+        // "contractAddress":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE********", //USDC contract address (Optional)
+        "network":"ETHEREUM_MAINNET",
+        "tokenId": "eth"
+    }
+}
+
+//Run the query request.
+queryRequest(methodArg, dataArg);