Impostor/docs/Server-configuration.md

Server configuration

Some information about all the possible configurations. Click here to see all the possible config options.

Options

Required Server Configuration

Key	Default	Description
PublicIp	127.0.0.1	This needs to the public IPv4 address of the server which you give to others to connect. You can find your IPv4 address on this website. Unless you are only planning to use Impostor privately, on your local network, you should change this to your public ip. It is also possible to use hostnames instead of IPv4 addresses, which will be resolved to IPv4 addresses.
PublicPort	22023	The public port of the server which you give to others to connect. (This is the external port you configure on your router when port forwarding.) Usually 22023.
ListenIp	0.0.0.0	The network interface to listen on. If you do not know what to put here, use 0.0.0.0. Since 1.2.2 it is also possible to use hostnames instead of IPv4 addresses, these must resolve to a valid IPv4 address.
ListenPort	22023	The listen port of the server, usually 22023. For port forwarding purposes: this is an UDP port

HttpServer

Impostor has an Http Server that is used by recent versions of Among Us to connect to. See the Http Server page for more details on how to set this up.

Key	Default	Description
Enabled	true	Whether the http server should be enabled.
ListenIp	0.0.0.0	The network interface to listen on. Use 127.0.0.1 if you use a reverse proxy or just run locally. Use 0.0.0.0 if you are directly exposing this server to the internet
ListenPort	22023	The listen port of this server. For port forwarding purposes, this is an TCP port.

AntiCheat

Impostor has an Anticheat that makes it possible to kick cheaters from games automatically. Note that the anticheat is tuned on the vanilla version of the game, so client-side modifications could trigger the Anticheat if you're playing with them.

Key	Default	Value
Enabled	true	Whether the anticheat should be enabled.
BanIpFromGame	true	When anticheat is enabled and a player is caught hacking, they will be kicked from the server. If this value is set to true, the player will be banned instead and will not be able to rejoin that specific game.
AllowCheatingHosts	"Never"	Configure whether hosts are allowed to cheat. "Never" forbids it, "Always" allows it. "IfRequested" allows hosts to cheat if they connect with the DisableServerAuthorityFlag set.
EnableGameFlowChecks	true	Enable checks that check if certain actions are done in the appropriate order or at the appropriate moment in the game. This includes changing cosmetics while in game or murdering too fast.
EnableMustBeHostChecks	true	Enables checks that check if players are the host before they can do actions that require them to be host of the game. This includes starting the game and spawning objects.
EnableColorLimitChecks	true	Enables checks that checks if players request colors that are already in use.
EnableNameLimitChecks	true	Enables checks that checks if player names have a length that is possible to set using the user interface.
EnableOwnershipChecks	true	Enables checks that check if players are allowed to perform a certain action on themself or another player.
EnableRoleChecks	true	Enables checks that check if players have the correct role when performing certain role abilities like venting or murdering.
EnableTargetChecks	true	Enables checks that check if certain packets to everyone that should only have been sent to certain players or vice versa. This includes sending votes or network objects.

| ForbidProtocolExtensions | true | If disabled allows players to send network packets that go beyond the network packets sent by the vanilla game. This is necessary for most mods that need all players to install it. |

Compatibility

Impostor has two compatibility options which allow some extra flexibility but may not work properly. Enabling either of these options is not recommended.

Key	Default	Value
AllowNewGameVersions	false	Warning: Setting this option to true is unsupported and may cause issues when large updates to Among Us are released. Allow future versions of Among Us to join your server.
AllowVersionMixing	false	Allow players using different game versions to play in one lobby.

Debug

The Debug configuration is used to enable the game recorder. This is mostly useful when developing Impostor.

Key	Default	Value
GameRecorderEnabled	false	Enables the Game Recorder.
GameRecorderPath	empty	Path where the recorded games will be saved.

Serilog (Logging)

Impostor's log framework, Serilog, can be configured in the config file. You can change its default log level and you can add additional sinks.

Key	Default	Value
MinimumLevel	Information	Minimum log level for a message to be printed. If a log entry is as severe or more severe than this level, it will be printed. From most severe to least severe: Fatal,Error, Warning, Information, Debug, Verbose
Using	[]	List of additional Serilog Sinks assemblies to load.
WriteTo	[]	Additional logging sinks. See the Serilog documentation or the example in this section. Serilog

For more information, check the Serilog.Settings.Configuration documentation.

For example, to add logging to a file, you should add the following snippet to your configuration:

"Serilog": {
  "Using": [
    "Serilog.Sinks.File"
  ],
  "WriteTo": [
    {
      "Name": "File",
      "Args": {
        "path": "logs/log.txt",
        "rollingInterval": "Day"
      }
    }
  ]
}

Next to that, you also need to copy over Serilog.Sinks.File.dll from NuGet. See the Serilog.Sinks.File documentation for a list of parameters that can be configured.

Other Serilog sinks are also supported, but are out of scope for this documentation.

Config providers

File

The simplest option to configure is by using the config.json file next to the server executable. For all possible options see the config-full.json file.

Environment variables

If you're unable to edit the config.json file, you can instead set Environment variables to configure Impostor. The general pattern for each variable is IMPOSTOR_SectionName__VariableName. For example, to disable the anticheat, you can set the environment variable IMPOSTOR_AntiCheat__Enabled=false. Here are some more examples:

IMPOSTOR_Server__PublicIp=127.0.0.1
IMPOSTOR_Server__PublicPort=22023
IMPOSTOR_Server__ListenIp=0.0.0.0
IMPOSTOR_Server__ListenPort=22023
IMPOSTOR_AntiCheat__Enabled=true
IMPOSTOR_AntiCheat__BanIpFromGame=true

systemd

Linux users will likely want to create a systemd service definition to manage running the Impostor application. Benefits to using a systemd service include the following:

• The server process can automatically restart if the process dies
• Impostor can be set to start on boot (handy if you do system updates regularly)
• You can use systemd targets to ensure the process doesn't start until the system dependencies are met

Using your favorite text editor, create the following service file:

sudoedit /etc/systemd/system/impostor.service

Modify the following template to your needs and populate the service file.

[Unit]
Description=Impostor private Among Us server - https://github.com/Impostor/Impostor

[Service]
# Directory where Impostor is installed
WorkingDirectory=/opt/impostor
# Path to Impostor binary
ExecStart=/opt/impostor/Impostor.Server
Restart=always
# Restart service after 10 seconds if the dotnet service crashes
RestartSec=10
KillSignal=SIGTERM
SyslogIdentifier=impostor

# User and group that will run the Impostor server process -- ensure that user is allowed to execute the binary
User=impostor
Group=impostor
TimeoutStopSec=10

[Install]
# Wait until most system services have started before starting Impostor
After=multi-user.target
WantedBy=multi-user.target

Reload all systemd unit files to source in the new file you've created.

sudo systemctl daemon-reload

Start the service.

sudo systemctl start impostor.service

Check the log for the service and verify it has started correctly -- Hint: Use the Q key to quit out of journalctl.

sudo journalctl -u impostor.service

If everything has started correctly, ensure the service is set to start on boot.

sudo systemctl enable impostor.service