The digital identity landscape is evolving rapidly, and one of the most exciting developments in recent years is Sign In With Ethereum (SIWE)—a secure, decentralized authentication method now seamlessly integrated into Auth0 through a powerful partnership with Spruce. This integration marks a pivotal step toward bridging Web2 and Web3 identity systems, empowering developers to offer users a more autonomous, secure, and user-centric login experience.
Thanks to Spruce’s innovative work and their official announcement on March 8th, developers can now add SIWE to any Auth0 tenant via the Auth0 Marketplace. While debates continue around the long-term value of cryptocurrencies, NFTs, and DAOs, there's no denying that Web3 technologies are reshaping digital identity and authentication. The Auth0 Lab team has been closely monitoring these shifts, and we’re thrilled to support this forward-looking capability.
The Rise of Web3 Authentication
Growing Adoption of Crypto Wallets
As of late 2021, an estimated 300 million people worldwide owned some form of cryptocurrency—a number that has likely grown significantly since. Each of these users relies on a digital wallet to securely manage private keys, which are essential for accessing funds and interacting with decentralized applications (DApps).
Among these, 71 million wallets hold Ethereum, making it one of the most widely adopted blockchains for both financial and identity use cases. This widespread adoption has spurred the development of tools that allow users to leverage their private keys beyond simple transactions—extending into authentication, access control, and identity verification.
👉 Discover how decentralized login methods are transforming user security and experience.
Popular Wallet Options
Users today have a variety of wallet choices, broadly categorized as custodial or non-custodial:
- Metamask: A leading non-custodial software wallet that serves as a gateway to Web3 DApps.
- Portis and Torus: Emerging non-custodial alternatives focused on ease of use.
- Coinbase Wallet: A custodial solution trusted by over 89 million verified users, offering simplified crypto management.
- Fortmatic (now Web3Auth): Provides custodial wallet functionality specifically for authentication, using familiar email/password flows.
Additionally, WalletConnect has emerged as a universal standard and SDK suite enabling any app to connect with virtually any Web3 wallet. With over 160 integrated apps, it's becoming the go-to solution for cross-platform interoperability.
Enhancing Usability: Ethereum Name Service (ENS)
One major barrier to mainstream Web3 adoption has been the complexity of long, alphanumeric wallet addresses. The Ethereum Name Service (ENS) solves this by assigning human-readable names (e.g., alice.eth) to machine-readable addresses—similar to how DNS works on the traditional web.
With over 300,000 registered ENS domains, this system is streamlining user interactions across decentralized platforms, making it easier than ever for everyday users to manage identities and conduct transactions.
Understanding Sign In With Ethereum (SIWE)
At its core, SIWE allows users to authenticate using their Ethereum wallet by signing a message with their private key. This proves ownership without revealing sensitive information—offering a privacy-preserving alternative to traditional login methods.
Ethereum’s support for smart contracts enables rich data storage on-chain, including JWT claims, verifiable credentials, and access rights. When combined with SIWE, this opens up powerful new possibilities:
- Granting access to exclusive communities via NFT ownership
- Authenticating users at physical venues like restaurants or events
- Enabling permissioned access to gated digital content
Back in December 2021, the Auth0 Lab team released a proof-of-concept demo showcasing SIWE integration with Auth0. The response was immediate and enthusiastic—drawing attention from major players like Metamask and driving increased engagement within the Auth0 Lab Discord community.
Today, thanks to Spruce’s official SIWE integration on the Auth0 Marketplace, any developer can implement this cutting-edge authentication method in minutes.
How SIWE Works with Auth0
The integration leverages an OpenID Connect (OIDC)-compatible identity provider (oidc.login.xyz) to facilitate seamless authentication between Ethereum wallets and Auth0-powered applications.
Here’s how it works:
- A user selects “Sign In With Ethereum” on your Auth0-enabled site.
- They sign a challenge message using their wallet (e.g., Metamask).
- The signed message is sent to the OIDC server for verification.
- Auth0 receives verified identity data and issues a standard JWT token.
- Your application gains access to enriched user claims while maintaining full compatibility with existing systems.
This approach allows organizations to tap into the growing Web3 user base without overhauling their current authentication infrastructure.
Supported wallets include:
- Metamask
- WalletConnect
- Fortmatic
- Torus
- Coinbase
Step-by-Step: Enable SIWE in Your Auth0 Tenant
Adding Sign In With Ethereum to your application takes just a few minutes.
Step 1: Add the Integration
Visit the SIWE integration page and click “Add Integration”. Select your target Auth0 tenant to begin setup.
Step 2: Generate Client Credentials
Use a simple cURL command to register your app and obtain a Client ID and Secret:
curl -X POST https://oidc.login.xyz/register \
-d '{"redirect_uris":["https://YOUR_AUTH0_DOMAIN/login/callback"]}'Replace YOUR_AUTH0_DOMAIN with your actual Auth0 domain.
Step 3: Create a Social Connection
Log in to your Auth0 dashboard, navigate to Connections > Social, and locate the new Sign-In with Ethereum option.
Step 4: Configure the Connection
Click “Continue” to authorize access, then enter the Client ID from Step 2. If your app is a Confidential Application, also provide the Client Secret.
Step 5: Enable for Your Application
Go to your application settings and toggle the SIWE connection to ON.
That’s it—you’ve enabled decentralized authentication! For troubleshooting or advanced configurations, refer to the integration documentation or join the Spruce Discord server.
👉 See how next-gen login systems improve security and user trust.
SIWE: An Open Standard for the Future
Sign In With Ethereum is not a proprietary technology—it’s an open standard defined under EIP-4361, developed publicly by Spruce with input from security experts, Ethereum Foundation contributors, and ENS developers. Its transparency and community-driven design ensure long-term viability and trust.
Spruce continues to maintain open-source libraries for direct integration (docs.login.xyz) and hosts an open-source OpenID Connect Identity Provider (GitHub repo), reinforcing its commitment to decentralization and developer freedom.
Frequently Asked Questions (FAQ)
Q: What is Sign In With Ethereum (SIWE)?
A: SIWE is a decentralized authentication method that lets users log in using their Ethereum wallet by signing a cryptographic message. It enhances security and user control compared to traditional username/password logins.
Q: Do users need cryptocurrency to use SIWE?
A: No. While SIWE uses Ethereum wallets, users don’t need to hold ETH or make transactions. The wallet simply provides a secure way to prove identity.
Q: Is SIWE secure?
A: Yes. SIWE leverages public-key cryptography and adheres to rigorous security standards. Since private keys never leave the user’s device, it reduces risks like phishing and password breaches.
Q: Can I combine SIWE with other login methods in Auth0?
A: Absolutely. Auth0 supports multiple social and enterprise connections simultaneously. You can offer SIWE alongside Google, GitHub, or enterprise SSO.
Q: Which wallets are supported?
A: The current integration supports Metamask, WalletConnect, Fortmatic, Torus, and Coinbase Wallet.
Q: Is this suitable for enterprise applications?
A: Yes. Organizations can use SIWE for secure employee access, customer identity verification, or membership gating—especially useful in hybrid Web2/Web3 environments.
What’s Next for Web3 Identity?
The Auth0 Lab team remains deeply committed to exploring the potential of Web3 identity solutions. We’re actively building demos and experimental apps that showcase how decentralized identities can benefit both traditional businesses and emerging blockchain-native organizations.
Follow our progress on Twitter (@Auth0Lab) or engage directly in our Discord community. We welcome collaboration, feedback, and co-creation as we shape the future of digital identity together.
Additionally, the Auth0 Marketplace is always open to new partners building innovative extensions. Learn more at auth0.com/integrate.
👉 Explore how modern authentication platforms are integrating blockchain-based identity solutions.