Sign-In With Ethereum

AppKit provides a simple solution for integrating with "Sign-In With Ethereum" (SIWE), a new form of authentication that enables users to control their digital identity with their Ethereum account. SIWE is a standard also known as EIP-4361.

One-Click Auth#

One-Click Auth represents a key advancement within WalletConnect v2, streamlining the user authentication process in AppKit by enabling them to seamlessly connect with a wallet and sign a SIWE message with just one click.

Connecting a wallet, proving control of an address with an off-chain signature, authorizing specific actions. These are the kinds of authorizations that can be encoded as "ReCaps". ReCaps are permissions for a specific website or dapp that can be compactly encoded as a long string in the message you sign and translated by any wallet into a straight-forward one-sentence summary. WalletConnect uses permissions expressed as ReCaps to enable a One-Click Authentication.

Note

One-Click Auth and Sign-In With Ethereum are currently not supported on WebGL.

Local Address Verification#

When connecting wallets to applications using the WalletConnect protocol, the wallet supplies a list of accounts. However, there is a potential risk that the wallet could provide an address the user does not control. To mitigate this account spoofing risk, the standard practice is to require the user to sign a message with the provided address and then verify the signature.

The Sign-In With Ethereum (SIWE) feature in AppKit can facilitate this verification process, enabling the application to confirm the user's Ethereum address even the app doesn't have a backend.

0. Create basic SIWE configuration#

// Create SIWE configurationvar siweConfig = new SiweConfig{    // The properties from `SiweMessageParams` be used to generate SIWE message.    // There're no strict rules on what Domain and Uri parameters have to be on native platforms.    // In this example we use website domain and app URL scheme.    GetMessageParams = () => new SiweMessageParams    {        Domain = "mywebsite.com",        Uri = "my-app://"    },    // By setting this to false, we disable a requirement to sign a new SIWE message    // every time the active chain changes in AppKit or wallet.    SignOutOnChainChange = false};// Subscribe to SIWE eventssiweConfig.SignInSuccess += _ => Debug.Log("Address verified successfully!");siweConfig.SignOutSuccess += () => Debug.Log("Address verification canceled or wallet disconnected.");

1. Initialize AppKit with your `SiweConfig`#

Add the SIWE configuration to AppKitConfig

var appKitConfig = new AppKitConfig{    // Project ID from https://dashboard.reown.com/    projectId = "MY_PROJECT_ID",    metadata = new Metadata(        "App Name",        "App Description",        "https://reown.com",        "https://raw.githubusercontent.com/reown-com/reown-dotnet/main/media/appkit-icon.png",        new RedirectData        {            // Used by native wallets to redirect back to the app after approving requests            Native = "my-app://"        }    ),    // Assign the SIWE configuration created above. Can be null if SIWE is not used.    siweConfig = siweConfig};

With this configuration, AppKit will enforce address verification and invoke the SignInSuccess delegate when the user successfully verifies the address.

To use 1-CA + SIWE at full extend, a backend for communication is required. This backend will be used to generate a nonce, verify messages and handle sessions. You can read more about SIWE backend implementation at here.

0. Create SIWE configuration#

var siweConfig = new SiweConfig{    GetNonce = async () =>    {        // The getNonce method functions as a safeguard against spoofing,        // akin to a CSRF token.        return await yourApi.getNonce();    },    // The properties from `SiweMessageParams` be used to generate SIWE message.    // There's no strict rules on what Domain and Uri parameters have to be    // on native platforms.    // In this example we use website domain and app URL scheme.    GetMessageParams = () =>    {        // Returns parameters that are used to create the SIWE message internally.        return new SiweMessageParams        {            Domain = "mywebsite.com",            Uri = "my-app://",            // The custom statement that will be prepended to the SIWE message.            // Optional.            Statement = "My custom statement."        };    },    CreateMessage = (createMessageArgs) =>    {        // Generates an EIP-4361-compatible message.        // You can use our provided SiweUtils.FormatMessage        // method (default behaviour if delegate is null) or implement your own.        return SiweUtils.FormatMessage(createMessageArgs);    },    VerifyMessage = async (verifyMessageArgs) =>    {        // Ensures the message is valid, has not been tampered with,        // and has been appropriately signed by the wallet address.        try {            var json = JsonConvert.SerializeObject(verifyMessageArgs);            var isValidMessage = await yourApi.verifyMessage(json);            return isValidMessage;        } catch (Exception) {            return false;        }    },    GetSession = async (getSessionArgs) =>    {        // Called after VerifyMessage() succeeds        // The backend session should store the associated address and chainId        // and return it via the `getSession` method.        var session = await yourApi.getSession();        return new SiweSession        {            EthAddress = session.address,            EthChainIds = session.ChainIdArray,        };    },    SignOut = async () =>    {        // Called when the wallet disconnects if SignOutOnWalletDisconnect is true,        // and/or when the account changes if SignOutOnAccountChange is true,        // and/or when the network changes if SignOutOnChainChange is true.        await yourApi.signOut();    },    SignOutOnAccountChange = true,    SignOutOnChainChange = true,    SignOutOnWalletDisconnect = true,};// Called after SiweConfig.GetSession() succeedssiweConfig.SignInSuccess += _ => Debug.Log("[Dapp] SIWE Sign In Success!");// Called after SiweConfig.SignOut() succeedssiweConfig.SignOutSuccess += () => Debug.Log("[Dapp] SIWE Sign Out Success!");