nextauthjs
What is the correct way to overwrite the function signIn in Callbacks in v5?
What is the improvement or update you wish to see?
in version 4, you could edit the signIn function inside callbacks, but in version 5 I don't see where to edit this option.
Will this option still be valid in the future?
Is there any context that might help us understand?
examples:
callbacks: {
async signIn({user, account, profile}) {
if (user.email.endsWith('@domain.com')) {
return true;
} else {
return false;
}
},
}
callbacks: {
async signIn({ user, account, profile, email, credentials }) {
const isAllowedToSignIn = true
if (isAllowedToSignIn) {
return true
} else {
// Return false to display a default error message
return false
// Or you can return a URL to redirect to:
// return '/unauthorized'
}
}
}
Does the docs page already exist? Please link to it.
https://next-auth.js.org/configuration/callbacks#sign-in-callback
I have implemented custom sessions with callbacks the following way:
import GitHub from "next-auth/providers/github";
import Google from "next-auth/providers/google";
import CredentialsProvider from "next-auth/providers/credentials";
import {
SignInWithEmailAndPassword,
oauthSignIn,
} from "@/actions/user/user.actions";
const providers = [
Google,
GitHub,
CredentialsProvider({
name: "Credentials",
credentials: {
email: { label: "Email", type: "email" },
password: { label: "Password", type: "password" },
},
async authorize(credentials) {
const user = await SignInWithEmailAndPassword(credentials); // User verification logic
if (user.status === 400) {
return null;
}
return user.data;
},
}),
];
export const providerMap = providers.map((provider) => {
if (typeof provider === "function") {
const providerData = provider();
return { id: providerData.id, name: providerData.name };
} else {
return { id: provider.id, name: provider.name };
}
});
export const { handlers, auth, signIn, signOut, unstable_update } = NextAuth({
providers,
pages: {
signIn: "/auth/sign-in",
},
callbacks: {
async signIn({ user, account }) {
if (account.provider === "google" || account.provider === "github") {
const { name, email, image } = user;
const payload = {
name,
email,
avatar: image,
authType: "Oauth",
};
const res = await oauthSignIn(payload);
user.id = res.data._id.toString();
user.isVerified = res.data.isVerified;
user.image = res.data.avatar;
return user;
}
// Default to allow sign-in
return user;
},
async jwt({ trigger, token, user }) {
// Add user information to the token during sign-in
if (trigger === "update") {
token.isVerified = session.user.isVerified;
}
if (user) {
console.log(user);
const id = user._id?.toString() || user.id;
token.id = id;
token.email = user.email;
token.name = user.name;
token.isVerified = user.isVerified;
token.picture = user.avatar || user.image;
}
return token;
},
async session({ session, token }) {
session.user.id = token.id;
session.user.email = token.email;
session.user.name = token.name;
session.user.image = token.picture;
session.user.isVerified = token.isVerified;
return session;
},
},
});```
If this answers your question please feel free to ask how it works..
I only problem I have faces is with the trigger to update the session when I verify user email and I think it is some of my personal error. For detailed implementation check this repository.
Actually the docs are in migration currently so some features are explained in the old documentation.
@nasatome the signIn callback should work as before. 
@Ali-Raza764 note that returning data in the signIn method was never supported. Just move that logic into the jwt callback. signIn should be only used to decide if the user is allowed to sign in or not.
