diff --git a/Cognito/decode-verify-jwt/decode-verify-jwt.ts b/Cognito/decode-verify-jwt/decode-verify-jwt.ts
index 00da2c1..88dc4f9 100644
--- a/Cognito/decode-verify-jwt/decode-verify-jwt.ts
+++ b/Cognito/decode-verify-jwt/decode-verify-jwt.ts
@@ -1,110 +1,49 @@
-import {promisify} from 'util';
-import * as Axios from 'axios';
-import * as jsonwebtoken from 'jsonwebtoken';
-const jwkToPem = require('jwk-to-pem');
+import { CognitoJwtVerifier } from "aws-jwt-verify";
 
-export interface ClaimVerifyRequest {
-  readonly token?: string;
-}
-
-export interface ClaimVerifyResult {
-  readonly userName: string;
-  readonly clientId: string;
-  readonly isValid: boolean;
-  readonly error?: any;
-}
-
-interface TokenHeader {
-  kid: string;
-  alg: string;
-}
-interface PublicKey {
-  alg: string;
-  e: string;
-  kid: string;
-  kty: string;
-  n: string;
-  use: string;
-}
-interface PublicKeyMeta {
-  instance: PublicKey;
-  pem: string;
-}
-
-interface PublicKeys {
-  keys: PublicKey[];
-}
-
-interface MapOfKidToPublicKey {
-  [key: string]: PublicKeyMeta;
+const userPoolId = process.env.USER_POOL_ID as string;
+if (!userPoolId) {
+  throw new Error("env var required: USER_POOL_ID");
 }
-
-interface Claim {
-  token_use: string;
-  auth_time: number;
-  iss: string;
-  exp: number;
-  username: string;
-  client_id: string;
-}
-
-const cognitoPoolId = process.env.COGNITO_POOL_ID || '';
-if (!cognitoPoolId) {
-  throw new Error('env var required for cognito pool');
+const clientId = process.env.CLIENT_ID as string;
+if (!clientId) {
+  throw new Error("env var required: CLIENT_ID");
 }
-const cognitoIssuer = `https://cognito-idp.us-east-1.amazonaws.com/${cognitoPoolId}`;
 
-let cacheKeys: MapOfKidToPublicKey | undefined;
-const getPublicKeys = async (): Promise<MapOfKidToPublicKey> => {
-  if (!cacheKeys) {
-    const url = `${cognitoIssuer}/.well-known/jwks.json`;
-    const publicKeys = await Axios.default.get<PublicKeys>(url);
-    cacheKeys = publicKeys.data.keys.reduce((agg, current) => {
-      const pem = jwkToPem(current);
-      agg[current.kid] = {instance: current, pem};
-      return agg;
-    }, {} as MapOfKidToPublicKey);
-    return cacheKeys;
-  } else {
-    return cacheKeys;
-  }
-};
+const verifier = CognitoJwtVerifier.create({
+  userPoolId,
+  clientId,
+  tokenUse: "access", // or set to "id" if you want to verify ID tokens
+});
 
-const verifyPromised = promisify(jsonwebtoken.verify.bind(jsonwebtoken));
-
-const handler = async (request: ClaimVerifyRequest): Promise<ClaimVerifyResult> => {
+const handler = async (
+  request: ClaimVerifyRequest
+): Promise<ClaimVerifyResult> => {
   let result: ClaimVerifyResult;
   try {
     console.log(`user claim verify invoked for ${JSON.stringify(request)}`);
-    const token = request.token;
-    const tokenSections = (token || '').split('.');
-    if (tokenSections.length < 2) {
-      throw new Error('requested token is invalid');
-    }
-    const headerJSON = Buffer.from(tokenSections[0], 'base64').toString('utf8');
-    const header = JSON.parse(headerJSON) as TokenHeader;
-    const keys = await getPublicKeys();
-    const key = keys[header.kid];
-    if (key === undefined) {
-      throw new Error('claim made for unknown kid');
-    }
-    const claim = await verifyPromised(token, key.pem) as Claim;
-    const currentSeconds = Math.floor( (new Date()).valueOf() / 1000);
-    if (currentSeconds > claim.exp || currentSeconds < claim.auth_time) {
-      throw new Error('claim is expired or invalid');
-    }
-    if (claim.iss !== cognitoIssuer) {
-      throw new Error('claim issuer is invalid');
-    }
-    if (claim.token_use !== 'access') {
-      throw new Error('claim use is not access');
-    }
-    console.log(`claim confirmed for ${claim.username}`);
-    result = {userName: claim.username, clientId: claim.client_id, isValid: true};
+    const payload = await verifier.verify(request.token as string);
+    console.log(`payload confirmed for ${payload.username}`);
+    result = {
+      userName: payload.username,
+      clientId: payload.client_id,
+      isValid: true,
+    };
   } catch (error) {
-    result = {userName: '', clientId: '', error, isValid: false};
+    result = { userName: "", clientId: "", error, isValid: false };
   }
   return result;
 };
 
-export {handler};
+export { handler };
+
+// Helper types:
+export interface ClaimVerifyRequest {
+  readonly token?: string;
+}
+
+export interface ClaimVerifyResult {
+  readonly userName: string;
+  readonly clientId: string;
+  readonly isValid: boolean;
+  readonly error?: any;
+}