Multichain Authentication (SIWX): How and why to enable it in your app
Building multichain applications often involves significant friction, requiring developers to manage fragmented authentication flows for different ecosystems. Multichain Authentication (SIWX) solves this by providing a unified, secure way for users to sign in across various networks. As the flagship authentication method powered by Reown, SIWX serves as a powerful upgrade to Sign-In with Ethereum (SIWE), extending secure, message-based authentication to a multichain environment.
Why add Multichain Authentication (SIWX) to your app
Support multiple networks
SIWX enables seamless support across Ethereum, Solana, Bitcoin, and more. This allows developers to unlock access to hundreds of trusted wallets and millions of users across the financial internet without fragmentation.
Remove the need for multiple authentication methods
By integrating SIWX, teams can consolidate their authentication infrastructure into one flexible flow that supports various login preferences. This eliminates the complexity of maintaining separate implementations for different chains or login types, allowing builders to ship faster.
Enable Travel Rule compliance by default
Reown infrastructure includes built-in verification APIs that ensure global compliance without breaking the user experience. Using SIWX allows apps to meet Travel Rule requirements and track regions seamlessly as part of the standard authentication process.
Learn more about SIWX and the travel rule →
Who should add Multichain Authentication (SIWX) to their apps?
Multichain blockchain games
Games operating across different ecosystems can use SIWX to provide players with a consistent cross-chain UX. This allows players to move assets or progress across chains like Ethereum and Solana using a single, frictionless login.
Multichain Decentralized Exchanges
DEXs can leverage SIWX to offer users a streamlined onboarding experience where they can pay, swap, or deposit directly in-app across multiple chains. This reduces friction and ensures every transaction is secured by the underlying WalletConnect protocol.
Multichain Marketplaces
Marketplaces can benefit from built-in analytics that reveal user sessions and wallet behavior across different networks. This helps product teams optimize the onboarding and retention of users who interact with assets on various ecosystems.
Multichain prediction markets
For prediction markets requiring high security and control, SIWX provides a trusted infrastructure powering billions in monthly volume. It allows institutional-grade teams to launch embedded onchain offerings with cross-ecosystem freedom for their users.
How does Multichain Authentication (SIWX) work?
Multichain Authentication (SIWX) functions as a message-based authentication standard that allows users to prove ownership of their wallet across different blockchain ecosystems using a single interface. When integrated via the Reown SDK, SIWX streamlines the process of creating, signing, and verifying authentication messages.
The Reown SDK handles the complexities of different chain signatures (such as EVM, Solana, or Bitcoin), providing a unified "Sign-In" experience. It generates a standardized message that the user signs with their wallet; the app then verifies this signature to establish a secure, authenticated session. This replaces manual, chain-specific implementations with a single, secure product that combines login and insights.
What to consider when you add Multichain Authentication (SIWX) to your app
Compliance
When choosing an authentication solution, it is vital to consider how it handles global regulations. SIWX via Reown offers Travel Rule compliance by default, using verification APIs to ensure teams meet requirements without sacrificing the user experience.
Proving Wallet Ownership
Developers should ensure their chosen method provides a secure, cryptographically sound way for users to verify wallet ownership. SIWX provides this secure infrastructure, allowing builders to integrate login and more with fewer steps while maintaining institutional-grade control.
User Experience
A primary consideration is the end-user friction; SIWX provides a better experience than SIWE by offering a consistent UX across all supported chains. Users can connect with hundreds of wallets without switching apps or moving assets, resulting in faster, frictionless onboarding.
How to integrate Multichain Authentication (SIWX) into your app: a step by step guide
Follow these steps to implement Multichain Authentication using the Reown SDK to provide a seamless login experience for your users.
Step 1: Initialize the SDK
Configure the Reown SDK within your application environment. This involves setting up your Project ID from the Reown Cloud and defining the metadata for your app to ensure a secure connection between the app and the user's wallet.
Step 2: Configure SIWX Provider
Set up the SIWX provider within your app's configuration. This step defines the authentication parameters, such as the statement the user will sign and the domain they are authenticating to, which is essential for preventing phishing attacks.
Step 3: Implement the Login Logic
Integrate the authentication flow into your UI. When a user clicks "Connect" or "Login," the SDK will trigger the SIWX message request, allowing the user to select their preferred wallet and sign the authentication message across any supported network.
Step 4: Verify the Signature
Once the user signs the message, the signature is sent to your backend for verification. The Reown SDK simplifies this by providing utility functions to validate the signature against the provided message and address, ensuring the session is authentic and secure.
Learn more in the Reown docs →
SIWX vs SIWE: What’s the difference?
While SIWE (Sign-In with Ethereum) revolutionized message-based authentication for the Ethereum ecosystem, SIWX is the evolution designed for the modern multichain landscape. The primary difference lies in SIWX's native multichain functionality, which supports Ethereum, Solana, Bitcoin, and others within a single flow. Additionally, SIWX includes in-built Travel Rule compliance and verification features that are not standard in SIWE, making it a more robust solution for growth-driven teams building compliant onchain finance. However, if you want to enable SIWE (One-click auth) with Reown, it’s still supported.
Learn more about enabling SIWE in the docs here.
Authenticate any user, crosschain, seamlessly with Reown
Congratulations on implementing Multichain Authentication (SIWX)! By choosing Reown’s infrastructure, you’ve significantly reduced friction for your users and built a more scalable, compliant application.
