BA
Better Auth•2d ago
Phil

How to link Generic OAuth to existing user

I have a question about Generic OAuth account linking. Say I have a user [email protected]. I set up a Generic OAuth plugin to authenticate to Nylas, which in turn sends the user through an OAuth authentication with their Google account. But say the user's Google account email is [email protected]. Currently when user completes the Nylas authentication, better-auth is creating a new user [email protected], then creating a Nylas account record linked to that new user. But I want the Nylas account record to be linked to the currently-logged-in user [email protected] and not create a new user when the emails are different. I tried this in my auth.ts config but it didn't help: 
    account: {
        accountLinking: {
            allowDifferentEmails: true,
        },
    },
    account: {
        accountLinking: {
            allowDifferentEmails: true,
        },
    },
1 Reply
Phil
PhilOP•2d ago
Here is my Generic OAuth config if it helps: 
                    providerId: "nylas", 
                    clientId: process.env.NEXT_PUBLIC_NYLAS_CLIENT_ID!,
                    clientSecret: process.env.NEXT_PUBLIC_NYLAS_CLIENT_SECRET!,
                    authorizationUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/connect/auth`,
                    tokenUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/connect/token`,
                       userInfoUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/grants/me`,
                    scopes: ['https://www.googleapis.com/auth/userinfo.email', 'https://www.googleapis.com/auth/gmail.modify', 'https://www.googleapis.com/auth/calendar', 'https://www.googleapis.com/auth/gmail.labels',             'https://www.googleapis.com/auth/contacts'],
                    getUserInfo: async ({ accessToken }) => {
                      const response = await fetch(
                        `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/grants/me`,
                        { headers: { Authorization: `Bearer ${accessToken}` } }
                      );
                      const userData = await response.json();
                      return {
                        id: userData.data.id,
                            provider: userData.data.provider,                        
                            email: userData.data.email,
                            emailVerified: true,
                            name: userData.data.name,
                      };
                    },
                    providerId: "nylas", 
                    clientId: process.env.NEXT_PUBLIC_NYLAS_CLIENT_ID!,
                    clientSecret: process.env.NEXT_PUBLIC_NYLAS_CLIENT_SECRET!,
                    authorizationUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/connect/auth`,
                    tokenUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/connect/token`,
                       userInfoUrl: `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/grants/me`,
                    scopes: ['https://www.googleapis.com/auth/userinfo.email', 'https://www.googleapis.com/auth/gmail.modify', 'https://www.googleapis.com/auth/calendar', 'https://www.googleapis.com/auth/gmail.labels',             'https://www.googleapis.com/auth/contacts'],
                    getUserInfo: async ({ accessToken }) => {
                      const response = await fetch(
                        `https://${process.env.NEXT_PUBLIC_NYLAS_API_URI}/v3/grants/me`,
                        { headers: { Authorization: `Bearer ${accessToken}` } }
                      );
                      const userData = await response.json();
                      return {
                        id: userData.data.id,
                            provider: userData.data.provider,                        
                            email: userData.data.email,
                            emailVerified: true,
                            name: userData.data.name,
                      };
                    },
Ah, I figured it out: it requires a combination of setting allowDifferentEmails: true and using genericAuthClient.oauth2.link instead of genericAuthClient.signIn.oauth2.

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