Account Linking

A Flock player is one account that can hold several credentials. The same player might start on a device ID, add an email and password later, and attach Google after that — signing in with any one of them lands on the same account, with the same progress. This is what makes device-first onboarding safe. A player can start instantly with no sign-up form, then attach a real credential once they’re invested, and keep everything if they lose the device.

Scope: credentials belong to a player; a player belongs to a game.

The credential types

device_id, email, google, apple, facebook, steam, and discord. A player can hold at most one of each — linking a second Google account to the same player is rejected rather than silently replacing the first.

Unity

Linking lives on the authentication provider, beside the login calls, and every method needs a signed-in player.

// What is this player currently able to sign in with?
List<PlayerLinkedAccount> accounts =
    await FlockClient.Instance.Authentication.GetLinkedAccountsAsync();

// Attach an email/password credential to the signed-in player.
accounts = await FlockClient.Instance.Authentication.LinkEmailAsync("[email protected]", "hunter2");

// Attach a social credential using the same token your login flow already obtains.
accounts = await FlockClient.Instance.Authentication.LinkGoogleAsync(idToken);

// Detach one.
accounts = await FlockClient.Instance.Authentication.UnlinkAsync(FlockCredentialProvider.Google);

There is one method per provider — LinkEmailAsync, LinkDeviceAsync, LinkGoogleAsync, LinkAppleAsync, LinkFacebookAsync, LinkSteamAsync, LinkDiscordAsync — each taking the same token your login path already gets from that platform. UnlinkAsync takes a FlockCredentialProvider instead.Every one of these returns the full, updated credential list, so link and unlink double as a refresh — you rarely need to call GetLinkedAccountsAsync again straight afterwards.Each PlayerLinkedAccount carries Provider, ProviderUserId, Email, and EmailVerified.

A player cannot unlink their last credential. Removing it would leave an account nobody can sign in to, so the server refuses with FlockErrorCode.PlayerCannotUnlinkLastCredential. Disable the unlink button when the list has one entry rather than letting the player discover this as an error.

Errors worth handling by name:

Code	Means
`PlayerAccountAlreadyLinked`	That credential is already attached — to this player, or to a different one.
`PlayerAccountNotLinked`	Unlinking something the player doesn’t have.
`PlayerCannotUnlinkLastCredential`	The last remaining sign-in method.
`PlayerInvalidLinkRequest`	The token was rejected by the provider.

There is no account-merge flow. If a credential already belongs to a different player, linking fails with PlayerAccountAlreadyLinked — Flock will not fold two players’ progress together, because there is no safe general answer to which save wins. Decide in your game what to offer: keep the current account, or sign out and into the other one.

Credential state is never cached and never queued offline — it is security state, and a stale answer is worse than no answer. Every call goes to the server.

Password resets on a linked email

Once an email is linked, the player has a password they can reset. ResetPasswordAsync (Unreal: ResetPassword) works signed out, with the email and the code ForgotPasswordAsync sent, so it does not matter how the player signed in this time.

Account linking is available in both the Unity SDK and the Unreal SDK.

See Players & Auth for the sign-in calls themselves.

Getting Started

Concepts

SDKs

Features

Multiplayer

Reference

Account Linking

The credential types

Password resets on a linked email

​The credential types

​Password resets on a linked email

The credential types

Password resets on a linked email