Linking multiple providers to one account.

[danhab99]

We've had alot of discussions about this topic. In my research I noticed this code snippet which describes the creation of a custom adapter. My attention was drawn to the linkAccount field function but their are things I don't understand about it. For one is the first argument the ID of the user returned by the provider or the ID of the currently signed in user trying to link that provider.

I'm fine with doing it like this, but personally it seems abit clunky and difficult to read. I think it would make more sense if we had a linkAccount function imported from "next-auth/client" with the same usage as signIn. The only thing it would require is that you're already signed in, then calling linkAccount would invoke the provider authentication procedure for the indicated provider and the new provider would be linked. Those are just my thoughts. I'm not sure how to go about implementing them.

[balazsorban44]

The linkAccount method signature obviously needed some improvement... In the next major release, the linkAccount method will simply receive an Account object, that you have to create in your accounts table. Depending on the underlying database/ORM you use, it can be as simple as:

https://github.com/nextauthjs/adapters/blob/next/packages/prisma/src/index.ts#L18

The Account interface looks something like this:

interface Account {
  /** The user's id this account belongs to. */
  userId: string
  /** Usually "oauth" */
  type: string
  /** The provider's id this account belongs to. */
  provider: string
  /** The account's user id */
  providerAccountId: string
  /** The raw access token in JWT format */
  access_token?: string;
  /** Usually "Bearer" */
  token_type?: string;
  /** The raw id token in JWT format */
  id_token?: string;
  /** Refresh token, opaque string value */
  refresh_token?: string;
  /** space-separated scope(s) used for the authentication request */
  scope?: string;
  /**
   * When the token set was received the expires_at field was calculated based on the current timestamp
   * and the expires_in value.
   */
  expires_at?: number;
  /** State value passed in the authentication request*/
  session_state?: string;
  [key: string]: unknown;
}