diff --git a/.github/workflows/test.js.yml b/.github/workflows/test.js.yml
index d98fbd1..19e71bf 100644
--- a/.github/workflows/test.js.yml
+++ b/.github/workflows/test.js.yml
@@ -15,7 +15,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [16.x, 18.x]
+        node-version: [18.x, 19.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:
diff --git a/app_template.yaml b/app_template.yaml
index 2ed6ff7..c5ce7d2 100644
--- a/app_template.yaml
+++ b/app_template.yaml
@@ -1,4 +1,4 @@
-runtime: nodejs16 # or another supported version
+runtime: nodejs18 # or another supported version
 
 instance_class: F2
 
diff --git a/package.json b/package.json
index 2846839..bd8ed72 100644
--- a/package.json
+++ b/package.json
@@ -9,8 +9,8 @@
   },
   "dependencies": {
     "@adraffy/ens-normalize": "^1.9.0",
-    "@ensdomains/ens-avatar": "^0.2.5",
-    "@ensdomains/ensjs": "^3.0.0-alpha.61",
+    "@ensdomains/ens-avatar": "^0.3.2",
+    "@ensdomains/ensjs": "^3.0.0-alpha.67",
     "@types/lodash": "^4.14.170",
     "btoa": "^1.2.1",
     "canvas": "^2.11.2",
@@ -80,6 +80,6 @@
     ]
   },
   "volta": {
-    "node": "16.15.0"
+    "node": "18.15.0"
   }
 }
diff --git a/src/assets/DejaVuSans-Bold.ttf b/src/assets/DejaVuSans-Bold.ttf
deleted file mode 100644
index 6d65fa7..0000000
Binary files a/src/assets/DejaVuSans-Bold.ttf and /dev/null differ
diff --git a/src/config.ts b/src/config.ts
index 7c9c9df..bac8d16 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -13,6 +13,7 @@ const INAMEWRAPPER = process.env.INAMEWRAPPER || '0xd82c42d8';
 
 const IPFS_GATEWAY = process.env.IPFS_GATEWAY || 'https://ipfs.io';
 const INFURA_API_KEY = process.env.INFURA_API_KEY || '';
+const OPENSEA_API_KEY = process.env.OPENSEA_API_KEY || '';
 const NODE_PROVIDER = process.env.NODE_PROVIDER || 'geth';
 const NODE_PROVIDER_URL = process.env.NODE_PROVIDER_URL || 'http://localhost:8545';
 
@@ -32,7 +33,7 @@ const ETH_REGISTRY_ABI = [
 ];
 
 // response timeout: 1 min
-const RESPONSE_TIMEOUT = 10 * 1000;
+const RESPONSE_TIMEOUT = 15 * 1000;
 
 export {
   ADDRESS_ETH_REGISTRAR,
@@ -44,6 +45,7 @@ export {
   INAMEWRAPPER,
   IPFS_GATEWAY,
   INFURA_API_KEY,
+  OPENSEA_API_KEY,
   REDIS_URL,
   NODE_PROVIDER,
   NODE_PROVIDER_URL,
diff --git a/src/controller/ensImage.ts b/src/controller/ensImage.ts
index 738e0e6..8de06b9 100644
--- a/src/controller/ensImage.ts
+++ b/src/controller/ensImage.ts
@@ -81,10 +81,12 @@ export async function ensImage(req: Request, res: Response) {
       error instanceof NamehashMismatchError ||
       error instanceof UnsupportedNetwork
     ) {
-      res.status(errCode).json({
-        message: error.message,
-      });
-      return;
+      if (!res.headersSent) {
+        res.status(errCode).json({
+          message: error.message,
+        });
+        return;
+      }
     }
 
     /* #swagger.responses[404] = { 
diff --git a/src/controller/ensMetadata.ts b/src/controller/ensMetadata.ts
index bbcb823..a7d6c88 100644
--- a/src/controller/ensMetadata.ts
+++ b/src/controller/ensMetadata.ts
@@ -73,10 +73,12 @@ export async function ensMetadata(req: Request, res: Response) {
       error instanceof NamehashMismatchError ||
       error instanceof UnsupportedNetwork
     ) {
-      res.status(errCode).json({
-        message: error.message,
-      });
-      return;
+      if (!res.headersSent) {
+        res.status(errCode).json({
+          message: error.message,
+        });
+        return;
+      }
     }
 
     try {
diff --git a/src/index.ts b/src/index.ts
index 06d268d..f710719 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -37,14 +37,14 @@ app.use(
         'https://unpkg.com/redoc@latest/bundles/redoc.standalone.js'
       ],
       imgSrc: ['*', 'data:'],
-      styleSrc: ["'self'", "'unsafe-inline'"],
-      fontSrc: ["'self'", 'data:'],
+      styleSrc: ["'self'", "'unsafe-inline'", 'https://fonts.googleapis.com'],
+      fontSrc: ["'self'", 'data:', 'https://fonts.gstatic.com'],
       connectSrc: ['*', 'data:'],
       objectSrc: ["'none'"],
       frameAncestors: ["'none'"],
       frameSrc: ["'none'"],
       childSrc: ["'none'"],
-      workerSrc: ["'none'"],
+      workerSrc: ['blob:'],
       baseUri: ["'none'"],
       formAction: ["'none'"],
       upgradeInsecureRequests: [],
diff --git a/src/service/avatar.ts b/src/service/avatar.ts
index 1e667fa..f1bbe39 100644
--- a/src/service/avatar.ts
+++ b/src/service/avatar.ts
@@ -8,7 +8,10 @@ import {
   RetrieveURIFailed,
   TextRecordNotFound,
 }                           from '../base';
-import { IPFS_GATEWAY }     from '../config';
+import { 
+  IPFS_GATEWAY, 
+  OPENSEA_API_KEY 
+}                           from '../config';
 import { abortableFetch }   from '../utils/abortableFetch';
 
 const window = new JSDOM('').window;
@@ -46,7 +49,13 @@ export class AvatarMetadata {
   avtResolver: AvatarResolver;
   constructor(provider: ethers.providers.BaseProvider, uri: string) {
     this.defaultProvider = provider;
-    this.avtResolver = new AvatarResolver(provider, { ipfs: IPFS_GATEWAY });
+    this.avtResolver = new AvatarResolver(provider, 
+      { 
+        ipfs: IPFS_GATEWAY, 
+        apiKey: { opensea: OPENSEA_API_KEY },
+        urlDenyList: [ 'metadata.ens.domains' ]
+      }
+    );
     this.uri = uri;
   }
 
diff --git a/src/service/metadata.test.ts b/src/service/metadata.test.ts
new file mode 100644
index 0000000..e1d7731
--- /dev/null
+++ b/src/service/metadata.test.ts
@@ -0,0 +1,28 @@
+import avaTest, { ExecutionContext, TestFn } from 'ava';
+import { TestContext } from '../../mock/interface';
+import { Metadata } from './metadata';
+import { Version } from '../base';
+
+const test = avaTest as TestFn<TestContext>;
+
+test('should compute metadata correctly', async (t: ExecutionContext<TestContext>) => {
+    const nickMetadataObj = {
+        name: 'nick.eth',
+        description: 'nick.eth, an ENS name.',
+        created_date: 1571924851000,
+        tokenId: '0x5d5727cb0fb76e4944eafb88ec9a3cf0b3c9025a4b2f947729137c5d7f84f68f',
+        version: Version.v1,
+        last_request_date: Date.now()
+    };
+    const testMetadata = new Metadata(nickMetadataObj);
+
+    t.is(testMetadata.name, nickMetadataObj.name);
+    t.is(testMetadata.description, nickMetadataObj.description);
+    t.is(testMetadata.attributes[0].value, nickMetadataObj.created_date * 1000);
+    t.is(testMetadata.version, Version.v1);
+  });
+
+test('should return correct font size', async (t: ExecutionContext<TestContext>) => {
+  const textSize = Metadata._getFontSize('nick.eth');
+  t.is(textSize, 32);
+});
diff --git a/src/service/metadata.ts b/src/service/metadata.ts
index 741e993..1d6bd2d 100644
--- a/src/service/metadata.ts
+++ b/src/service/metadata.ts
@@ -1,4 +1,9 @@
 import {ens_normalize}                          from '@adraffy/ens-normalize';
+import { 
+  CanvasRenderingContext2D, 
+  createCanvas, 
+  registerFont 
+}                                               from 'canvas';
 import { Version }                              from '../base';
 import {
   CANVAS_FONT_PATH,
@@ -9,19 +14,13 @@ import base64EncodeUnicode                      from '../utils/base64encode';
 import { isASCII, findCharacterSet }            from '../utils/characterSet';
 import { getCodePointLength, getSegmentLength } from '../utils/charLength';
 
-// no ts declaration files
-const { createCanvas, registerFont } = require('canvas');
 
-
-try {
-  registerFont(CANVAS_FONT_PATH, { family: 'Satoshi' });
-  registerFont(CANVAS_EMOJI_FONT_PATH, { family: 'Noto Color Emoji' });
-} catch(error) {
-  console.warn("Font registeration is failed.");
-  console.warn(error);
+interface Attribute {
+  trait_type: string,
+  display_type: string,
+  value: any
 }
 
-
 export interface MetadataInit {
   name               : string;
   description?       : string;
@@ -36,7 +35,7 @@ export interface MetadataInit {
 export interface Metadata {
   name               : string;
   description        : string;
-  attributes         : object[];
+  attributes         : Attribute[];
   name_length?       : number;
   segment_length?    : number;
   image              : string;
@@ -51,20 +50,24 @@ export interface Metadata {
 
 export class Metadata {
   static MAX_CHAR = 60;
+  static ctx: CanvasRenderingContext2D;
+
   constructor({
     name,
     description,
     created_date,
     tokenId,
     version,
-    last_request_date
+    last_request_date,
   }: MetadataInit) {
     const label = this.getLabel(name);
     this.is_normalized = this._checkNormalized(name);
     this.name = this.formatName(name, tokenId);
     this.description = this.formatDescription(name, description);
     this.attributes = this.initializeAttributes(created_date, label);
-    this.url = this.is_normalized ? `https://app.ens.domains/name/${name}` : null;
+    this.url = this.is_normalized
+      ? `https://app.ens.domains/name/${name}`
+      : null;
     this.last_request_date = last_request_date;
     this.version = version;
   }
@@ -84,19 +87,23 @@ export class Metadata {
 
   formatDescription(name: string, description?: string) {
     const baseDescription = description || `${this.name}, an ENS name.`;
-    const normalizedNote = !this.is_normalized ? ` (${name} is not in normalized form)` : '';
+    const normalizedNote = !this.is_normalized
+      ? ` (${name} is not in normalized form)`
+      : '';
     const asciiWarning = this.generateAsciiWarning(this.getLabel(name));
     return `${baseDescription}${normalizedNote}${asciiWarning}`;
   }
 
   generateAsciiWarning(label: string) {
     if (!isASCII(label)) {
-      return ' ⚠️ ATTENTION: This name contains non-ASCII characters as shown above. ' +
+      return (
+        ' ⚠️ ATTENTION: This name contains non-ASCII characters as shown above. ' +
         'Please be aware that there are characters that look identical or very ' +
         'similar to English letters, especially characters from Cyrillic and Greek. ' +
         'Also, traditional Chinese characters can look identical or very similar to ' +
         'simplified variants. For more information: ' +
-        'https://en.wikipedia.org/wiki/IDN_homograph_attack';
+        'https://en.wikipedia.org/wiki/IDN_homograph_attack'
+      );
     }
     return '';
   }
@@ -129,7 +136,7 @@ export class Metadata {
     ];
   }
 
-  addAttribute(attribute: object) {
+  addAttribute(attribute: Attribute) {
     this.attributes.push(attribute);
   }
 
@@ -152,7 +159,12 @@ export class Metadata {
 
     const { domain, subdomainText } = this.processSubdomain(name, isSubdomain);
     const { processedDomain, domainFontSize } = this.processDomain(domain);
-    const svg = this._generateByVersion(domainFontSize, subdomainText, isSubdomain, processedDomain);
+    const svg = this._generateByVersion(
+      domainFontSize,
+      subdomainText,
+      isSubdomain,
+      processedDomain
+    );
 
     try {
       this.setImage('data:image/svg+xml;base64,' + base64EncodeUnicode(svg));
@@ -165,7 +177,7 @@ export class Metadata {
   processSubdomain(name: string, isSubdomain: boolean) {
     let subdomainText;
     let domain = name;
-    
+
     if (isSubdomain && !name.includes('...')) {
       const labels = name.split('.');
       let subdomain = labels.slice(0, labels.length - 2).join('.') + '.';
@@ -241,11 +253,20 @@ export class Metadata {
   }
 
   static _getFontSize(name: string): number {
-    const canvas = createCanvas(270, 270, 'svg');
-    const ctx = canvas.getContext('2d');
-    ctx.font =
-      '20px Satoshi, Noto Color Emoji, Apple Color Emoji, sans-serif';
-    const fontMetrics = ctx.measureText(name);
+    if (!this.ctx) {
+      try {
+        registerFont(CANVAS_FONT_PATH, { family: 'Satoshi' });
+        registerFont(CANVAS_EMOJI_FONT_PATH, { family: 'Noto Color Emoji' });
+      } catch (error) {
+        console.warn('Font registration is failed.');
+        console.warn(error);
+      }
+      const canvas = createCanvas(270, 270, 'svg');
+      this.ctx = canvas.getContext('2d');
+      this.ctx.font =
+        '20px Satoshi, Noto Color Emoji, Apple Color Emoji, sans-serif';
+    }
+    const fontMetrics = this.ctx.measureText(name);
     const fontSize = Math.floor(20 * (200 / fontMetrics.width));
     return fontSize < 34 ? fontSize : 32;
   }
diff --git a/src/utils/blockRecursiveCalls.ts b/src/utils/blockRecursiveCalls.ts
index 2fd65d7..370fb22 100644
--- a/src/utils/blockRecursiveCalls.ts
+++ b/src/utils/blockRecursiveCalls.ts
@@ -8,14 +8,19 @@ export function blockRecursiveCalls(
   const requestOrigin = req.get('origin') || req.get('referer');
 
   if (requestOrigin) {
-    const parsedRequestOrigin = new URL(requestOrigin);
+    try {
+      const parsedRequestOrigin = new URL(requestOrigin);
 
-    if (
-      parsedRequestOrigin.hostname === req.hostname &&
-      parsedRequestOrigin.protocol.includes('http')
-    ) {
-      console.warn(`Recursive call detected`);
-      res.status(403).json({ message: 'Recursive calls are not allowed.' });
+      if (
+        parsedRequestOrigin.hostname === req.hostname &&
+        parsedRequestOrigin.protocol.includes('http')
+      ) {
+        console.warn(`Recursive call detected`);
+        res.status(403).json({ message: 'Recursive calls are not allowed.' });
+        return;
+      }
+    } catch (error) {
+      console.warn('Error parsing URL', error);
     }
   }
   next();
diff --git a/src/utils/rateLimiter.ts b/src/utils/rateLimiter.ts
index 9d0ffe3..c6b4b86 100644
--- a/src/utils/rateLimiter.ts
+++ b/src/utils/rateLimiter.ts
@@ -18,8 +18,8 @@ if (REDIS_URL) {
 
   const opts = {
     storeClient: redisClient,
-    points: 100,  // Number of total points
-    duration: 5,  // Per second(s)
+    points: 10,  // Number of total points
+    duration: 2,  // Per second(s)
     execEvenly: false,  // Do not delay actions evenly
     blockDuration: 0,   // Do not block the caller if consumed more than points
     keyPrefix: 'ensrl', // Assign unique keys for each limiters with different purposes
diff --git a/yarn.lock b/yarn.lock
index faecedf..64dc6a1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -454,10 +454,10 @@
     dns-packet "^5.2.1"
     ethers "^5.0.30"
 
-"@ensdomains/ens-avatar@^0.2.5":
-  version "0.2.5"
-  resolved "https://registry.yarnpkg.com/@ensdomains/ens-avatar/-/ens-avatar-0.2.5.tgz#f89e53c4e1fb706b27c504f5bbeb7851f3af13af"
-  integrity sha512-2Tko+KgXQvsYyX8BZ8zapLpzxMZ9oLEzUsyUFgWfM0O83SvURSEqHXW+GyEGkgNRg2ZPte5qnq0+FnthxXZQRA==
+"@ensdomains/ens-avatar@^0.3.2":
+  version "0.3.2"
+  resolved "https://registry.yarnpkg.com/@ensdomains/ens-avatar/-/ens-avatar-0.3.2.tgz#f182085a8d865b6048ca3819b4be3c14e79a5c97"
+  integrity sha512-4PkDxfj4KUC0BoX9lEqonrgq3KJDz1mcznh8u4hapeLnEWgLqlPrHrA84ZxWhH61iE8E7qZSEUN+NHJp1W6QrA==
   dependencies:
     "@ethersproject/contracts" "^5.7.0"
     "@ethersproject/providers" "^5.7.0"
@@ -470,10 +470,10 @@
     multiformats "^9.6.2"
     url-join "^4.0.1"
 
-"@ensdomains/ensjs@^3.0.0-alpha.61":
-  version "3.0.0-alpha.61"
-  resolved "https://registry.yarnpkg.com/@ensdomains/ensjs/-/ensjs-3.0.0-alpha.61.tgz#a9b7386633625acce996e528627b396e1b93349e"
-  integrity sha512-ThHj9c2wCsl4At6arwEwxmQwTJLCgeW1f9MHBrcM8OH/8BpZXfUuO1UTxHeZqy6gGPb58eWQpGMDW8uI7iGoNg==
+"@ensdomains/ensjs@^3.0.0-alpha.67":
+  version "3.0.0-alpha.67"
+  resolved "https://registry.yarnpkg.com/@ensdomains/ensjs/-/ensjs-3.0.0-alpha.67.tgz#fa69ba63d39e7bdbb2291dd1e9329b6f3e3d8197"
+  integrity sha512-fV5KPIfxcWjkKnQ1iicndJRl8ADQDgoPVvEw02q6on6HTx5QNvUqc/+vccv3dPqIas7yTRShXpT87hweDxPE+g==
   dependencies:
     "@adraffy/ens-normalize" "1.9.0"
     "@ensdomains/address-encoder" "^0.2.18"
@@ -1895,13 +1895,13 @@ caniuse-lite@^1.0.30001449:
   resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001472.tgz#3f484885f2a2986c019dc416e65d9d62798cdd64"
   integrity sha512-xWC/0+hHHQgj3/vrKYY0AAzeIUgr7L9wlELIcAvZdDUHlhL/kNxMdnQLOSOQfP8R51ZzPhmHdyMkI0MMpmxCfg==
 
-canvas@^2.8.0:
-  version "2.8.0"
-  resolved "https://registry.yarnpkg.com/canvas/-/canvas-2.8.0.tgz#f99ca7f25e6e26686661ffa4fec1239bbef74461"
-  integrity sha512-gLTi17X8WY9Cf5GZ2Yns8T5lfBOcGgFehDFb+JQwDqdOoBOcECS9ZWMEAqMSVcMYwXD659J8NyzjRY/2aE+C2Q==
+canvas@^2.11.2:
+  version "2.11.2"
+  resolved "https://registry.yarnpkg.com/canvas/-/canvas-2.11.2.tgz#553d87b1e0228c7ac0fc72887c3adbac4abbd860"
+  integrity sha512-ItanGBMrmRV7Py2Z+Xhs7cT+FNt5K0vPL4p9EZ/UX/Mu7hFbkxSjKF2KVtPwX7UYWp7dRKnrTvReflgrItJbdw==
   dependencies:
     "@mapbox/node-pre-gyp" "^1.0.0"
-    nan "^2.14.0"
+    nan "^2.17.0"
     simple-get "^3.0.3"
 
 cbor@^8.1.0:
@@ -4639,11 +4639,16 @@ multihashes@^4.0.1:
     uint8arrays "^3.0.0"
     varint "^5.0.2"
 
-nan@^2.12.1, nan@^2.14.0:
+nan@^2.12.1:
   version "2.15.0"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.15.0.tgz#3f34a473ff18e15c1b5626b62903b5ad6e665fee"
   integrity sha512-8ZtvEnA2c5aYCZYd1cvgdnU6cqwixRoYg70xPLWUws5ORTa/lnw+u4amixRS/Ac5U5mQVgp9pnlSUnbNWFaWZQ==
 
+nan@^2.17.0:
+  version "2.17.0"
+  resolved "https://registry.yarnpkg.com/nan/-/nan-2.17.0.tgz#c0150a2368a182f033e9aa5195ec76ea41a199cb"
+  integrity sha512-2ZTgtl0nJsO0KQCjEpxcIr5D+Yv90plTitZt9JBfQvVJDS5seMl3FOvsh3+9CoYWXf/1l5OaZzzF6nDm4cagaQ==
+
 nano-base32@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/nano-base32/-/nano-base32-1.0.1.tgz#ba548c879efcfb90da1c4d9e097db4a46c9255ef"