# \[Archive\] How to retrieve the wallet of a user authenticated via AWS Cognito?

**URL:** <https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356>\
**Category:** Embedded Wallets (Web3Auth)\
**Created:** [May 22, 2024, 10:11am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356 "2024-05-22T10:11:51Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![luca](https://avatars.discourse-cdn.com/v4/letter/l/51bf81/32.png) [@luca](https://builder.metamask.io/u/luca)\
**Post date:** [May 22, 2024, 10:11am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356/1 "2024-05-22T10:11:51Z")

</div>

> **🏛 Archived Content from Web3Auth Community**
> 
> This topic was originally posted by **luca** on 5/22/2024.  
> This content has been migrated from our previous community forum to preserve valuable discussions.

* * *

Hello, I’ve setup web3auth + aws cognito by using the “Web3Auth & ReactJS Example using AWS Cognito” example code on my NextJS app. Everything works fine and I’m able to login/authenticate a user.

On the frontend code, I’m able to retrieve the user wallet.

Now, I want to retrieve the user wallet on my backend code, which probably means I need to use the “@web3auth/node-sdk”. I’m not able to retrieve the user wallet on my backend, I get error 403 Unauthorized. Can you please help?

- SDK Version:  
“@web3auth/base”: “^8.4.0”,  
“@web3auth/ethereum-provider”: “^8.4.0”,  
“@web3auth/no-modal”: “^8.4.0”,  
“@web3auth/openlogin-adapter”: “^8.4.0”,  
“@web3auth/node-sdk”: “^3.3.0”,

- Platform: NextJS/NodeJS

Code:

```auto
import { Web3Auth } from "@web3auth/node-sdk";
import { CHAIN_NAMESPACES } from "@web3auth/base";
import jwt, { JwtHeader, SigningKeyCallback } from "jsonwebtoken";
import jwksClient, { SigningKey } from "jwks-rsa";
import { EthereumPrivateKeyProvider } from "@web3auth/ethereum-provider";
const web3authClientId = “<web3auth_client_id>”;
const awsCognitoClientId = “<aws_cognito_client_id>”;
const w3aVerifier = “<w3a_verifier>”;
const cognitoDomain = “<cognito_domain_url>”;
const web3auth = new Web3Auth({
clientId: web3authClientId,
web3AuthNetwork: “mainnet”,
usePnPKey: false, // Setting this to true returns the same key as PnP Web SDK.
// By default, this SDK returns CoreKitKey.
});
const chainConfig = {
chainNamespace: CHAIN_NAMESPACES.EIP155,
displayName: “ETH Mainnet”,
blockExplorer: “https://etherscan.io”,
ticker: “ETH”,
tickerName: “Ethereum”,
chainId: “0x1”,
rpcTarget: “https://rpc.ankr.com/eth”, // needed for non-other chains
};
const provider = new EthereumPrivateKeyProvider({ config: { chainConfig } });
web3auth.init({ provider });
const client = jwksClient({
jwksUri:
“https://cognito-idp.eu-central-1.amazonaws.com/eu-central-1_gkn7r52OP/.well-known/jwks.json”,
});
function getKey(header: JwtHeader, callback: SigningKeyCallback): void {
client.getSigningKey(
header.kid as string,
(err: Error | null, key: SigningKey | undefined) => {
const signingKey = key?.getPublicKey();
callback(null, signingKey);
}
);
}
const verifyJWT = (token: string): Promise<any> => {
return new Promise((resolve, reject) => {
jwt.verify(token, getKey, { algorithms: [“RS256”] }, (err, decoded) => {
if (err) {
return reject(“Invalid token”);
}
resolve(decoded);
});
});
};
const getToken = async (idToken: string): Promise<void> => {
try {
// Fetch wallet address using Web3Auth
const walletProvider = await web3auth.connect({
verifier: w3aVerifier,
verifierId: “1314b8b2-20a1-7034-68fc-dab6ee931e03”,
idToken,
});
	// Proceed with the logic to create a checkout session using the wallet address
	console.log("Wallet Address:");
	// ...
} catch (error) {
	console.error("Error getting token:", error);
}

};
// Example usage
const exampleUsage = async () => {
const idToken =
“eyJraWQiOiJTckp3cWtWT1R1Y29qQzlZWG9rRmY4NG5mN3BGbnp0V1NieGpIWHF2SGlvPSIsImFsZyI6IlJTMjU2In0.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.GHCWGZ1U88W5h7ztPzUUIgYa19_v8SeSAxQ8BYFRt7MtxrIfei9pqgHZZKmpZH8p_JJWTMbsqBANsB7IRBKOqW4FIJ7VOH5iOyQ4dQC1lcjvx8zoP0EGMP26GZXWW1mWgN9p5OJPTrzrilD90aCTw4pBKAsvTFS9oZ6l1DFtsyKn9_xE1wS8lPjUDRXUfynVt5yfmhx3-qkTT4poixDWyJA1gs1Pyki5l7mFiC93Z1BL1DZREs4SurhVSghuzKPwwbHWQ-2utRmnYMZFyq_pADY7De7l60HcqCkqdtMk1iZPhmbXlLgnDChALH9ei9Kx3PEXN9Z2XmKXhcGai8iUcw”;
try {
const decodedToken = await verifyJWT(idToken);
console.log(“Decoded Token:”, decodedToken);
await getToken(idToken);
} catch (error) {
console.error(“Error:”, error);
}
};

```

---

<div class="post-metadata">

**Author:** ![TomTom](https://avatars.discourse-cdn.com/v4/letter/t/a9a28c/32.png) [@TomTom](https://builder.metamask.io/u/TomTom)\
**Post date:** [May 23, 2024, 10:23am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356/2 "2024-05-23T10:23:58Z")

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hi @luca,

Please check this example: [web3auth-core-kit-examples/single-factor-auth-node/sfa-node-quick-start/index.js at 4f5756aefaf6765a9c8db9cb984f3d29d9ad9a27 · Web3Auth/web3auth-core-kit-examples · GitHub](https://github.com/Web3Auth/web3auth-core-kit-examples/blob/4f5756aefaf6765a9c8db9cb984f3d29d9ad9a27/single-factor-auth-node/sfa-node-quick-start/index.js#L4)

```auto
const provider = await web3auth.connect({
    verifier: "w3a-node-demo", // replace with your verifier name
    verifierId: sub, // replace with your verifier id's value, for example, sub value of JWT Token, or email address.
    idToken: token, 
  });
  const eth_private_key = await provider.request({ method: "eth_private_key" });

```

---

<div class="post-metadata">

**Author:** ![luca](https://avatars.discourse-cdn.com/v4/letter/l/51bf81/32.png) [@luca](https://builder.metamask.io/u/luca)\
**Post date:** [May 24, 2024, 7:49am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356/3 "2024-05-24T07:49:47Z")

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Hi @TomTom when I run this code, I get the error “Duplicate token found”.  
I’ve used a fresh new user to test this, so I’m sure there is not more than 1 token for that user.  
Any suggestion on how to fix this error?

Also, in the example code you provided, do I need to modify it to include information about AWS cognito?

---

<div class="post-metadata">

**Author:** ![TomTom](https://avatars.discourse-cdn.com/v4/letter/t/a9a28c/32.png) [@TomTom](https://builder.metamask.io/u/TomTom)\
**Post date:** [May 28, 2024, 9:25am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356/4 "2024-05-28T09:25:42Z")

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Hi Luca,

I’ve shared this problem with the team so they can assist us in solving it.

thanks for your patience

---

<div class="post-metadata">

**Author:** ![maharshi](https://yyz1.discourse-cdn.com/flex011/user_avatar/builder.metamask.io/maharshi/32/1525_2.png) [@maharshi](https://builder.metamask.io/u/maharshi)\
**Post date:** [May 28, 2024, 11:02am UTC](https://builder.metamask.io/t/archive-how-to-retrieve-the-wallet-of-a-user-authenticated-via-aws-cognito/1356/5 "2024-05-28T11:02:42Z")

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Hey @luca,

I noticed that you are hardcoding the idToken. Could you try obtaining a fresh one using Cognito and testing it again? Sometimes, when we hardcode tokens, we might forget to use a new one, which often leads to errors.