JWT module augmentation in next-auth v5

[SornchaiTheDev]

What is the improvement or update you wish to see?

next-auth v5 can't module augmentation at next-auth/jwt

Is there any context that might help us understand?

I've identified an error in the "Popular Interfaces to Augment" section of Next.js related to the JWT interface. It appears that the correct import should be @auth/core/jwt rather than next-auth/jwt. This correction is crucial because the jwt.d.ts file in the next-auth package includes a deprecated flag, signaling its replacement in version 5.

To illustrate this issue and its resolution, I've included screenshots:

Furthermore, when using next-auth with pnpm, there might be an issue where it can't locate @auth/core/jwt since it's a dependency of the next-auth package and resides in .pnpm within the node_modules directory. To address this, I've implemented the following solution:

// tsconfig.json
{
  "compilerOptions": {
        // Other options...
        "paths": {
         "@auth/core/*" : ["./node_modules/.pnpm/@auth+core@0.18.1/node_modules/@auth/core/*"]
        }
        // Other options...
  }
}

I've also submitted a pull request with these changes (#9563).

Does the docs page already exist? Please link to it.

https://authjs.dev/getting-started/typescript?frameworks=core

[erinnovations]

thanks for the proposed solution. Unfortunately this does not work for me.
I am on v5.Beta4

[Lodimup]

try:

// https://github.com/nextauthjs/next-auth/discussions/8945#discussioncomment-7799831
declare module "@auth/core/jwt" {
  interface JWT {
    accessToken: string;
    refreshToken: string;
    refreshTokenExpiresAt: number;
  }
}

[SornchaiTheDev]

thanks for the proposed solution. Unfortunately this does not work for me.

I am on v5.Beta4

Could you explain the problem you encountered?

[Kinbaum]

thanks for the proposed solution. Unfortunately this does not work for me. I am on v5.Beta4

Make sure that @auth/core is not in your list of dependencies, only next-auth. I encountered something similar, once I removed that and used the tsconfig recommended by @SornchaiTheDev, it started working

[andresgutgon]

For me importing the package fixed it

// This fixed it
import 'next-auth/jwt'

declare module 'next-auth/jwt' {
  interface JWT {
    accessToken?: string
  }
}

declare module 'next-auth' {
  interface Session {
    accessToken?: string
  }
}

I'm following their example here
https://github.com/nextauthjs/next-auth/blob/main/apps/examples/nextjs/auth.ts

[jschuur]

Did JWT/Session overriding change recently?

This used to work for me:

import { DefaultSession, User as DefaultUser } from 'next-auth';

import { UserRole } from '@/lib/types';

declare module 'next-auth' {
  // the sessions callback will add these properties
  interface Session {
    user: {
      roles: UserRole[];
      id: string;
    } & DefaultSession['user'];
  }

  // add the custom roles field from the users DB schema
  interface User extends DefaultUser {
    roles: UserRole[];
    id: string;
  }
}

declare module '@auth/core/jwt' {
  // these get added to the JWT token in the jwt callback
  interface JWT {
    roles: UserRole[];
    id: string;
  }
}

going from @auth/drizzle-adapter 1.2.0 to 1.4.1 and @auth/core 0.32.0 to 0.34.1 now gives me this errdor

Type '({ session, token }: { session: Session; token: JWT; }) => Session' is not assignable to type '(params: { session: { user: AdapterUser; } & AdapterSession; user: AdapterUser; } & { session: Session; token: JWT; } & { newSession: any; trigger?: "update" | undefined; }) => Awaitable<...>'.
  Types of parameters '__0' and 'params' are incompatible.
    Type '{ session: { user: AdapterUser; } & AdapterSession; user: AdapterUser; } & { session: Session; token: JWT; } & { newSession: any; trigger?: "update" | undefined; }' is not assignable to type '{ session: Session; token: JWT; }'.
      Types of property 'token' are incompatible.
        Type 'JWT' is missing the following properties from type 'JWT': roles, idts(2322)

I also get this from where adapter is set:

Type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/adapters").Adapter' is not assignable to type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/adapters").Adapter'.
  Types of property 'createUser' are incompatible.
    Type '((user: import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/adapters").AdapterUser) => import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/types").Awaitabl...' is not assignable to type '((user: import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/adapters").AdapterUser) => import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/types").Awaitabl...'.
      Type '(user: import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/adapters").AdapterUser) => import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/types").Awaitable...' is not assignable to type '(user: import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/adapters").AdapterUser) => import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/types").Awaitable...'.
        Type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/types").Awaitable<import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/adapters").AdapterUser>' is not assignable to type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/types").Awaitable<import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/adapters").AdapterUser>'.
          Type 'AdapterUser' is not assignable to type 'Awaitable<AdapterUser>'.
            Property 'roles' is missing in type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.34.1/node_modules/@auth/core/adapters").AdapterUser' but required in type 'import("/Users/joostschuur/Code/Personal/decent-nextjs-starter-template/node_modules/.pnpm/@auth+core@0.32.0/node_modules/@auth/core/adapters").AdapterUser'.ts(2322)
next.auth.d.ts(16, 5): 'roles' is declared here.

[elksson]

adding this line in my auth.ts fixed the issue for me.
/// <reference types="./auth.d.ts" />

[comxd]

Hello,
I can confirm this problem using the latest beta (v5) version.
Can someone check/review this PR #12472 and confirm that fixes this issue?