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. It supports both EIP-1271, the standard for signature validation in smart accounts, and EIP-6492, which enables signature validation for smart accounts (contracts) that are not yet deployed, allowing messages to be signed without requiring prior deployment.

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.

NextAuth

NextAuth is a complete open-source authentication solution for Next.js applications. It is designed from the ground up to support Next.js and Serverless. We can use NextAuth with SIWE to handle users authentication and sessions.

Installation

npm install @reown/appkit-siwe next-auth

npm install @reown/appkit-siwe next-auth

For a better UX we recommend using One-Click Auth.

Install the AppKit SIWE package, additionally we also recommend installing siwe which will abstract a lot of the required logic.

npm install @reown/appkit-siwe siwe next-auth viem

Configure your SIWE Client

Next.js SIWE Example

Check the Next.js example using NextAuth

import { getCsrfToken, signIn, signOut, getSession } from "next-auth/react";
import type {
  SIWEVerifyMessageArgs,
  SIWECreateMessageArgs,
  SIWESession,
} from "@reown/appkit-siwe";
import { createSIWEConfig, formatMessage } from "@reown/appkit-siwe";
import { mainnet, sepolia } from "@reown/appkit/networks";

export const siweConfig = createSIWEConfig({
  getMessageParams: async () => ({
    domain: typeof window !== "undefined" ? window.location.host : "",
    uri: typeof window !== "undefined" ? window.location.origin : "",
    chains: [mainnet.id, sepolia.id],
    statement: "Please sign with your account",
  }),
  createMessage: ({ address, ...args }: SIWECreateMessageArgs) =>
    formatMessage(args, address),
  getNonce: async () => {
    const nonce = await getCsrfToken();
    if (!nonce) {
      throw new Error("Failed to get nonce!");
    }

    return nonce;
  },
  getSession: async () => {
    const session = await getSession();
    if (!session) {
      return null;
    }

    // Validate address and chainId types
    if (
      typeof session.address !== "string" ||
      typeof session.chainId !== "number"
    ) {
      return null;
    }

    return {
      address: session.address,
      chainId: session.chainId,
    } satisfies SIWESession;
  },
  verifyMessage: async ({ message, signature }: SIWEVerifyMessageArgs) => {
    try {
      const success = await signIn("credentials", {
        message,
        redirect: false,
        signature,
        callbackUrl: "/protected",
      });

      return Boolean(success?.ok);
    } catch (error) {
      return false;
    }
  },
  signOut: async () => {
    try {
      await signOut({
        redirect: false,
      });

      return true;
    } catch (error) {
      return false;
    }
  },
});

`verifySignature`

Verify a SIWE signature.

import { createPublicClient, http } from "viem";

const publicClient = createPublicClient({
  transport: http(
    `https://rpc.walletconnect.org/v1/?chainId=${chainId}&projectId=${projectId}`
  ),
});
const isValid = await publicClient.verifyMessage({
  message,
  address: address as `0x${string}`,
  signature: signature as `0x${string}`,
});

// The verifySignature is not working with social logins and emails with non deployed smart accounts
// for this reason we recommend using the viem to verify the signature
// import { verifySignature } from '@reown/appkit-siwe'
// const isValid = await verifySignature({ address, message, signature, chainId, projectId })

`getChainIdFromMessage`

Get the chain ID from the SIWE message.

import { getChainIdFromMessage } from "@reown/appkit-siwe";

const chainId = getChainIdFromMessage(message);

`getAddressFromMessage`

Get the address from the SIWE message.

import { getAddressFromMessage } from "@reown/appkit-siwe";

const address = getAddressFromMessage(message);

import { getCsrfToken, signIn, signOut, getSession } from "next-auth/react";
import type {
  SIWEVerifyMessageArgs,
  SIWECreateMessageArgs,
  SIWESession,
} from "@reown/appkit-siwe";
import { createSIWEConfig, formatMessage } from "@reown/appkit-siwe";
import { mainnet, sepolia } from "@reown/appkit/networks";

export const siweConfig = createSIWEConfig({
  getMessageParams: async () => ({
    domain: typeof window !== "undefined" ? window.location.host : "",
    uri: typeof window !== "undefined" ? window.location.origin : "",
    chains: [mainnet.id, sepolia.id],
    statement: "Please sign with your account",
  }),
  createMessage: ({ address, ...args }: SIWECreateMessageArgs) =>
    formatMessage(args, address),
  getNonce: async () => {
    const nonce = await getCsrfToken();
    if (!nonce) {
      throw new Error("Failed to get nonce!");
    }

    return nonce;
  },
  getSession: async () => {
    const session = await getSession();
    if (!session) {
      return null;
    }

    // Validate address and chainId types
    if (
      typeof session.address !== "string" ||
      typeof session.chainId !== "number"
    ) {
      return null;
    }

    return {
      address: session.address,
      chainId: session.chainId,
    } satisfies SIWESession;
  },
  verifyMessage: async ({ message, signature }: SIWEVerifyMessageArgs) => {
    try {
      const success = await signIn("credentials", {
        message,
        redirect: false,
        signature,
        callbackUrl: "/protected",
      });

      return Boolean(success?.ok);
    } catch (error) {
      return false;
    }
  },
  signOut: async () => {
    try {
      await signOut({
        redirect: false,
      });

      return true;
    } catch (error) {
      return false;
    }
  },
});

`verifySignature`

Verify a SIWE signature.

import { createPublicClient, http } from "viem";

const publicClient = createPublicClient({
  transport: http(
    `https://rpc.walletconnect.org/v1/?chainId=${chainId}&projectId=${projectId}`
  ),
});
const isValid = await publicClient.verifyMessage({
  message,
  address: address as `0x${string}`,
  signature: signature as `0x${string}`,
});

// The verifySignature is not working with social logins and emails with non deployed smart accounts
// for this reason we recommend using the viem to verify the signature
// import { verifySignature } from '@reown/appkit-siwe'
// const isValid = await verifySignature({ address, message, signature, chainId, projectId })

`getChainIdFromMessage`

Get the chain ID from the SIWE message.

import { getChainIdFromMessage } from "@reown/appkit-siwe";

const chainId = getChainIdFromMessage(message);

`getAddressFromMessage`

Get the address from the SIWE message.

import { getAddressFromMessage } from "@reown/appkit-siwe";

const address = getAddressFromMessage(message);

With help of the siwe package we will create the required configuration for AppKit.

The nonce and verification process will be implemented in your backend. Read more.

Let’s create a file to instantiate our SIWE configuration. For this example we will use config/siwe.ts

import { getCsrfToken, signIn, signOut, getSession } from "next-auth/react";

import { SiweMessage } from "siwe";

import type {
  SIWEVerifyMessageArgs,
  SIWECreateMessageArgs,
} from "@reown/appkit-siwe";
import { createSIWEConfig, formatMessage } from "@reown/appkit-siwe";

export const siweConfig = createSIWEConfig({
  createMessage: ({ nonce, address, chainId }: SIWECreateMessageArgs) =>
    new SiweMessage({
      version: "1",
      domain: window.location.host,
      uri: window.location.origin,
      address,
      chainId,
      nonce,
      // Human-readable ASCII assertion that the user will sign, and it must not contain `\n`.
      statement: "Sign in With Ethereum.",
    }).prepareMessage(),
  getNonce: async () => {
    const nonce = await getCsrfToken();
    if (!nonce) {
      throw new Error("Failed to get nonce!");
    }

    return nonce;
  },
  getSession,
  verifyMessage: async ({ message, signature }: SIWEVerifyMessageArgs) => {
    try {
      const success = await signIn("credentials", {
        message,
        redirect: false,
        signature,
        callbackUrl: "/protected",
      });

      return Boolean(success?.ok);
    } catch (error) {
      return false;
    }
  },
  signOut: async () => {
    try {
      await signOut({
        redirect: false,
      });

      return true;
    } catch (error) {
      return false;
    }
  },
});

Set up your API route

Add NEXTAUTH_SECRET as an environment variable, it will be used to encrypt and decrypt user sessions. Learn more.

Create your API route at app/api/auth/[...nextauth]/route.ts.

import NextAuth from "next-auth";
import credentialsProvider from "next-auth/providers/credentials";
import {
  type SIWESession,
  verifySignature,
  getChainIdFromMessage,
  getAddressFromMessage,
} from "@reown/appkit-siwe";

declare module "next-auth" {
  interface Session extends SIWESession {
    address: string;
    chainId: number;
  }
}

const nextAuthSecret = process.env.NEXTAUTH_SECRET;
if (!nextAuthSecret) {
  throw new Error("NEXTAUTH_SECRET is not set");
}

const projectId = process.env.NEXT_PUBLIC_PROJECT_ID;
if (!projectId) {
  throw new Error("NEXT_PUBLIC_PROJECT_ID is not set");
}

const providers = [
  credentialsProvider({
    name: "Ethereum",
    credentials: {
      message: {
        label: "Message",
        type: "text",
        placeholder: "0x0",
      },
      signature: {
        label: "Signature",
        type: "text",
        placeholder: "0x0",
      },
    },
    async authorize(credentials) {
      try {
        if (!credentials?.message) {
          throw new Error("SiweMessage is undefined");
        }
        const { message, signature } = credentials;
        const address = getAddressFromMessage(message);
        const chainId = getChainIdFromMessage(message);

        const isValid = await verifySignature({
          address,
          message,
          signature,
          chainId,
          projectId,
        });

        if (isValid) {
          return {
            id: `${chainId}:${address}`,
          };
        }

        return null;
      } catch (e) {
        return null;
      }
    },
  }),
];

const handler = NextAuth({
  // https://next-auth.js.org/configuration/providers/oauth
  secret: nextAuthSecret,
  providers,
  session: {
    strategy: "jwt",
  },
  callbacks: {
    session({ session, token }) {
      if (!token.sub) {
        return session;
      }

      const [, chainId, address] = token.sub.split(":");
      if (chainId && address) {
        session.address = address;
        session.chainId = parseInt(chainId, 10);
      }

      return session;
    },
  },
});

export { handler as GET, handler as POST };

import NextAuth from "next-auth";
import credentialsProvider from "next-auth/providers/credentials";
import {
  type SIWESession,
  verifySignature,
  getChainIdFromMessage,
  getAddressFromMessage,
} from "@reown/appkit-siwe";

declare module "next-auth" {
  interface Session extends SIWESession {
    address: string;
    chainId: number;
  }
}

const nextAuthSecret = process.env.NEXTAUTH_SECRET;
if (!nextAuthSecret) {
  throw new Error("NEXTAUTH_SECRET is not set");
}

const projectId = process.env.NEXT_PUBLIC_PROJECT_ID;
if (!projectId) {
  throw new Error("NEXT_PUBLIC_PROJECT_ID is not set");
}

const providers = [
  credentialsProvider({
    name: "Ethereum",
    credentials: {
      message: {
        label: "Message",
        type: "text",
        placeholder: "0x0",
      },
      signature: {
        label: "Signature",
        type: "text",
        placeholder: "0x0",
      },
    },
    async authorize(credentials) {
      try {
        if (!credentials?.message) {
          throw new Error("SiweMessage is undefined");
        }
        const { message, signature } = credentials;
        const address = getAddressFromMessage(message);
        const chainId = getChainIdFromMessage(message);

        const isValid = await verifySignature({
          address,
          message,
          signature,
          chainId,
          projectId,
        });

        if (isValid) {
          return {
            id: `${chainId}:${address}`,
          };
        }

        return null;
      } catch (e) {
        return null;
      }
    },
  }),
];

const handler = NextAuth({
  // https://next-auth.js.org/configuration/providers/oauth
  secret: nextAuthSecret,
  providers,
  session: {
    strategy: "jwt",
  },
  callbacks: {
    session({ session, token }) {
      if (!token.sub) {
        return session;
      }

      const [, chainId, address] = token.sub.split(":");
      if (chainId && address) {
        session.address = address;
        session.chainId = parseInt(chainId, 10);
      }

      return session;
    },
  },
});

export { handler as GET, handler as POST };

import { NextAuthOptions } from "next-auth";
import credentialsProvider from "next-auth/providers/credentials";
import { getCsrfToken } from "next-auth/react";
import NextAuth from "next-auth/next";

import type { SIWESession } from "@reown/appkit-siwe";
import { SiweMessage } from "siwe";

declare module "next-auth" {
  interface Session extends SIWESession {
    address: string;
    chainId: number;
  }
}

const nextAuthSecret = process.env.NEXTAUTH_SECRET;
if (!nextAuthSecret) {
  throw new Error("NEXTAUTH_SECRET is not set");
}
// Get your projectId on https://cloud.reown.com
const projectId = process.env.NEXT_PUBLIC_PROJECT_ID;
if (!projectId) {
  throw new Error("NEXT_PUBLIC_PROJECT_ID is not set");
}

const authOptions: NextAuthOptions = {
  // https://next-auth.js.org/configuration/providers/oauth
  secret: nextAuthSecret,
  providers: [
    credentialsProvider({
      name: "Ethereum",
      credentials: {
        message: {
          label: "Message",
          type: "text",
          placeholder: "0x0",
        },
        signature: {
          label: "Signature",
          type: "text",
          placeholder: "0x0",
        },
      },
      async authorize(credentials, req) {
        try {
          if (!credentials?.message) {
            throw new Error("SiweMessage is undefined");
          }
          const siwe = new SiweMessage(credentials.message);
          const nonce = await getCsrfToken({ req: { headers: req.headers } });
          const result = await siwe.verify({
            signature: credentials?.signature || "",
            nonce,
          });
          if (result.success) {
            return {
              id: `eip155:${siwe.chainId}:${siwe.address}`,
            };
          }

          return null;
        } catch (e) {
          return null;
        }
      },
    }),
  ],
  session: {
    strategy: "jwt",
  },
  callbacks: {
    session({ session, token }) {
      if (!token.sub) {
        return session;
      }

      const [, chainId, address] = token.sub.split(":");
      if (chainId && address) {
        session.address = address;
        session.chainId = parseInt(chainId, 10);
      }

      return session;
    },
  },
};

const handler = NextAuth(authOptions);
export { handler as GET, handler as POST };

Learn More

Initialize AppKit with your `siweConfig`.

// Pass your siweConfig inside the createAppKit() function
const modal = createAppKit({
  adapters: [wagmiAdapter], //or your Ethers adapter
  projectId,
  networks: [mainnet, arbitrum],
  defaultNetwork: mainnet,
  features: {
    analytics: true, // Optional - defaults to your Cloud configuration
  },
  siweConfig: siweConfig, // pass your siweConfig
});

SIWE Config reference

interface SIWEConfig {
  // Required
  getNonce: () => Promise<string>;
  createMessage: (args: SIWECreateMessageArgs) => string;
  verifyMessage: (args: SIWEVerifyMessageArgs) => Promise<boolean>;
  getSession: () => Promise<SIWESession | null>;
  signOut: () => Promise<boolean>;

  // Optional
  onSignIn?: (session?: SIWESession) => void;
  onSignOut?: () => void;
  // Defaults to true
  enabled?: boolean;
  // In milliseconds, defaults to 5 minutes
  nonceRefetchIntervalMs?: number;
  // In milliseconds, defaults to 5 minutes
  sessionRefetchIntervalMs?: number;
  // Defaults to true
  signOutOnDisconnect?: boolean;
  // Defaults to true
  signOutOnAccountChange?: boolean;
  // Defaults to true
  signOutOnNetworkChange?: boolean;
}

Required

getNonce

The getNonce method functions as a safeguard against spoofing, akin to a CSRF token. The siwe package provides a generateNonce() helper, or you can utilize an existing CSRF token from your backend if available.

createMessage

The official siwe package offers a straightforward method for generating an EIP-4361-compatible message, which can subsequently be authenticated using the same package. The nonce parameter is derived from your getNonce endpoint, while the address and chainId variables are sourced from the presently connected wallet.

verifyMessage

The verifyMessage method should lean on the siwe package’s new

SiweMessage(message).validate(signature);

to ensure the message is valid, has not been tampered with, and has been appropriately signed by the wallet address.

getSession

The backend session should store the associated address and chainId and return it via the getSession method.

signOut

The users session can be destroyed calling signOut.

Optional

onSignIn `(session?: SIWESession) => void`

Callback when user signs in.

onSignOut `() => void`

Callback when user signs out.

enabled `boolean` - defaults to `true`

Whether or not to enable SIWE. Defaults to true.

nonceRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

How often to refetch the nonce, in milliseconds.

sessionRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

How often to refetch the session, in milliseconds.

signOutOnDisconnect `boolean` - defaults to true

Whether or not to sign out when the user disconnects their wallet.

signOutOnAccountChange `boolean` - defaults to true

Users will be signed out and redirected to the SIWE view to sign a new message in order to keep the SIWE session in sync with the connected account.

signOutOnNetworkChange `boolean` - defaults to true

Users will be signed out and redirected to the SIWE view to sign a new message in order to keep the SIWE session in sync with the connected account/network.

Fundamentals

Authentication

Early Access

Payments

Transactions

Notifications

Cloud

Sign In With Ethereum

One-Click Auth

NextAuth

Installation

Configure your SIWE Client

Next.js SIWE Example

`verifySignature`

`getChainIdFromMessage`

`getAddressFromMessage`

`verifySignature`

`getChainIdFromMessage`

`getAddressFromMessage`

Set up your API route

Learn More

Initialize AppKit with your `siweConfig`.

SIWE Config reference

Required

getNonce

createMessage

verifyMessage

getSession

signOut

Optional

onSignIn `(session?: SIWESession) => void`

onSignOut `() => void`

enabled `boolean` - defaults to `true`

nonceRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

sessionRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

signOutOnDisconnect `boolean` - defaults to true

signOutOnAccountChange `boolean` - defaults to true

signOutOnNetworkChange `boolean` - defaults to true

Fundamentals

Authentication

Early Access

Payments

Transactions

Notifications

Cloud

​One-Click Auth

​NextAuth

​Installation

​Configure your SIWE Client

Next.js SIWE Example

​verifySignature

​getChainIdFromMessage

​getAddressFromMessage

​verifySignature

​getChainIdFromMessage

​getAddressFromMessage

​Set up your API route

Learn More

​Initialize AppKit with your siweConfig.

​SIWE Config reference

​Required

​getNonce

​createMessage

​verifyMessage

​getSession

​signOut

​Optional

​onSignIn (session?: SIWESession) => void

​onSignOut () => void

​enabled boolean - defaults to true

​nonceRefetchIntervalMs number - defaults to 300000ms (5 minutes)

​sessionRefetchIntervalMs number - defaults to 300000ms (5 minutes)

​signOutOnDisconnect boolean - defaults to true

​signOutOnAccountChange boolean - defaults to true

​signOutOnNetworkChange boolean - defaults to true

One-Click Auth

NextAuth

Installation

Configure your SIWE Client

`verifySignature`

`getChainIdFromMessage`

`getAddressFromMessage`

`verifySignature`

`getChainIdFromMessage`

`getAddressFromMessage`

Set up your API route

Initialize AppKit with your `siweConfig`.

SIWE Config reference

Required

getNonce

createMessage

verifyMessage

getSession

signOut

Optional

onSignIn `(session?: SIWESession) => void`

onSignOut `() => void`

enabled `boolean` - defaults to `true`

nonceRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

sessionRefetchIntervalMs `number` - defaults to `300000`ms (5 minutes)

signOutOnDisconnect `boolean` - defaults to true

signOutOnAccountChange `boolean` - defaults to true

signOutOnNetworkChange `boolean` - defaults to true