Sign-In with Algorand (SIWA)

@avmkit/siwa is a package that lets you easily allow users to authenticate themselves with your off-chain services by signing in with their Algorand accounts.

Problem & Motivation

When building our on-chain applications for users to connect with Algorand and other virtual machines, we needed a way for users to prove that they own an Algorand address before they can request resources relevant to that address. There was no solution that offered a good user experience, where users could easily understand what they are signing with their Algorand wallet. Inspired by Sign-In with Ethereum, we decided to build the right tool for the Algorand ecosystem.

Features

• Construct human-readable sign-in messages
• Create messages in stringified JSON format
• Decode and parse string messages of both formats into JavaScript objects
• Basic validations (e.g., expiration)
• Utility functions to handle Algorand addresses
• Full TypeScript support

Installation

npm install @avmkit/siwa

Usage

Frontend

// 1. Import necessary modules
import { SiwaMessage } from '@avmkit/siwa';

// 2. Handle sign-in after `account` is selected
const handleSignIn = async () => {
  const siwa = new SiwaMessage({
    domain: 'localhost',
    uri: 'http://localhost:3000/sign-in',
    address: account.address,
    nonce, // a challenge generated from the backend
    statement: 'Welcome to my dApp!',
  });

  // Sign the message using the Algorand wallet
  const signedMessage = await siwa.sign(account);

  // API call to sign in with the backend
  await signIn(signedMessage);
};

Backend

// 1. Import SIWA utilities
import { SiwaMessage } from '@avmkit/siwa';

// 2. Backend handler to handle sign-in request
const verifyData: any = {
  signature: credentials.signature,
  domain: nextAuthUrl.host,
  algoAddress: credentials.algoAddress,
  algoSignature: credentials.algoSignature || '',
  nonce: await getCsrfToken({ req }),
};

if (credentials.nfd) {
  verifyData.nfd = credentials.nfd;
}

// VerifyParams
const result: any = await siwa.verify({
  ...verifyData,
});

Documentation

Check out our full guide on how to implement SIWA into your dapp!

Support

• Siwa
• Algorand Foundation
• xGov Badge

Recognition

This project is supported by the Algorand Foundation. This work has been performed with support from the Algorand Foundation xGov Grants Program