Remember Server Password

A client-side Valheim BepInEx quality-of-life plugin that remembers server passwords and adds a Quick Connect button for the last server you successfully joined.

Features

• Remembers a password only after the server accepts it.
• Automatically submits that password on future joins to the same server.
• Passwords are keyed to the server identity:
  • direct/Dedicated joins: host or IP + port
  • Steam joins: Steam server/user ID
  • PlayFab joins: PlayFab server identity
• Adds Quick Connect: <last server> to the Valheim main menu.
• Quick Connect uses Valheim's normal ServerJoinData and character-selection flow.
• If an automatically submitted password is rejected, the stale password is removed automatically and the next join prompts normally.
• Client-side only. The server does not need this mod.
• Password values are never written to the BepInEx log.

How it works

On the first connection to a password-protected server, join normally and type the password into Valheim's standard password dialog. The plugin holds that value only as a pending password until the server completes a successful peer handshake. Only then is it stored.

On later connections, the plugin recognises the server identity during ZNet.RPC_ClientHandshake, places the remembered value into Valheim's existing FejdStartup.ServerPassword path, and lets Valheim perform its normal password hashing and authentication.

The plugin does not bypass or weaken server authentication.

After a successful multiplayer connection, the server identity is also saved as the Quick Connect destination. The next time the main menu is shown, the button connects to that server through Valheim's normal join request flow, including character selection and privilege checks.

Installation

1. Install BepInExPack for Valheim.
2. Copy MagiCorp.RememberServerPassword.dll into: BepInEx/plugins/RememberServerPassword/
3. Launch Valheim normally.

Configuration

Generated file:

BepInEx/config/magicorp.valheim.rememberserverpassword.cfg

General

• Enabled = true Master switch for remembered passwords.
• AutoSubmit = true Automatically use a stored password when its server requests one.
• RememberPasswords = true Save newly entered passwords after a successful connection.

Quick Connect

• ShowQuickConnectButton = true Show the Quick Connect button on the main menu.
• LastServer Automatically managed identity of the last server successfully joined. It can be cleared manually if desired.

Maintenance

• ForgetAllPasswords = false Set to true and restart Valheim to erase all saved passwords. It automatically resets to false.
• ForgetLastServer = false Set to true and restart Valheim to clear the Quick Connect destination. It automatically resets to false.

Password storage

The password database is stored under the local BepInEx config directory as:

MagiCorp.RememberServerPassword.dat

On platforms where .NET protected user storage is available, password values use ProtectedData scoped to the current OS user.

If that API is unavailable, the plugin falls back to AES with a random per-install key stored as MagiCorp.RememberServerPassword.key. This fallback prevents casual plaintext exposure but is not intended to protect against somebody who already has full read access to the local BepInEx directory.

Compatibility

Built against and patch-validated with:

• Valheim l-1.0.12
• network version 40
• BepInExPack Valheim 5.4.2350

The password-handshake patches were runtime validated against 1.0.12. The Quick Connect UI addition is built against the same 1.0.12 assemblies and does not require any server-side component.

Technical details

Relevant vanilla paths used rather than replaced:

• ZNet.RPC_ClientHandshake
• ZNet.OnPasswordEntered
• ZNet.RPC_PeerInfo
• ZNet.RPC_Error
• FejdStartup.SetupGui
• FejdStartup.ProceedJoinRequest

The plugin intentionally delegates authentication, connection setup, character selection and multiplayer privilege validation back to Valheim.

Changelog

1.2.4

• Removed temporary reconnect/password flow diagnostics after validating automatic character selection and password login.
• Disabled the redundant per-frame password-dialog fallback; automatic login now uses the validated RPC_ClientHandshake path only.
• Fixed the fallback ZNet lookup to use Valheim 1.0.12 ZNet.instance, preventing HarmonyX missing-field warning spam.

1.2.3

• Quick Connect now reuses Valheim's last-used character and continues the pending join automatically.
• Remembered passwords are preloaded during ZNet.RPC_ClientHandshake, with an independent password-dialog watcher that auto-submits the stored password if Valheim still opens the prompt.
• Quick Connect uses Valheim's built-in last-used profile, selects it automatically, and invokes the normal OnCharacterStart() continuation.
• Added flow logging around character selection and password auto-submit without logging password values.

1.2.2

• Fixed Quick Connect failing on Valheim 1.0.12 because FejdStartup.ServerPassword has a non-public setter at runtime.
• Password assignment now uses runtime reflection with a backing-field fallback.
• Added connection-flow diagnostics for join identity, password-store lookup, handshake injection, Quick Connect and authentication result. Password values are never logged.

1.2.1

• Fixed the built-in Quick Connect button executing a persistent action inherited from the vanilla menu button used as its visual template.
• Quick Connect now replaces the cloned Button component with a clean one containing only the RememberServerPassword join action.
• Keeps the Valheim 1.0.12 stable ServerJoinData identity tracking used for remembered-password matching.

1.2.0

• Fixed remembered-password matching on Valheim 1.0.12 by pinning the original ServerJoinData identity through DNS/backend resolution and the password handshake.
• Removed unrelated external QuickConnect compatibility work in 1.2.1; Quick Connect is built into this plugin.

1.1.1

• New Thunderstore icon.

1.1.0

• Added Quick Connect for the last successfully joined server.
• Added remembered passwords keyed per server identity.