How to Install Mods on an Insurgency Sandstorm Server

To install mods on an Insurgency: Sandstorm server, make a separate mod.io account for the server, subscribe that account to the mods, then authorize it: request a 5 digit code by email and start the server once with -Mods -SecurityCode=<code>, then switch to -SecurityCode=none. The server downloads every subscribed mod on start. For a mod map, keep a vanilla boot map and add -ModDownloadTravelTo=<Map>?Scenario=<Scenario>. Players download mods automatically when they join.

What you are working with

Since update 1.20, Sandstorm servers load mods through a mod.io account that belongs to the server. The old method, an access token pasted into GameUserSettings.ini with mods listed in Mods.txt, is described in many older guides but was replaced, as the mod.io server guide and community threads explain.

The gotcha: the server needs its own mod.io account

Use your normal player account for the server and it silently downloads nothing. Every hosting guide that covers 1.20 repeats this: the server account must be a different mod.io account with a different email. It also helps to think of the account as the mod list itself. Mods are added and removed by subscribing and unsubscribing on the mod.io website while logged in as the server, not by editing a file.

Step 1: Make the server account and subscribe

1. Sign up at mod.io with an email you only use for the server.
2. Open the Insurgency: Sandstorm section and Subscribe to every mod, map and mutator the server should run.
3. Read each mod's page for the exact map name, scenario name or mutator name it needs. You will use them in Step 4.

One server account can serve several servers.

Step 2: Request the security code

mod.io sends the code to the server account's email when you request it through mod.io's email login. The mod.io guide linked above includes a small ServerAuthorization.bat that sends the request for you, and hosts often give you a button for it. Run it with the server account's email and check that inbox for a 5 digit code. It expires, so do Step 3 straight away.

Step 3: Start once with the code, then switch to none

Add these to the launch line (on GamezServers, Additional Switches in the panel):

-Mods -SecurityCode=12345

Start the server and let it finish starting, so the authorization is saved. Then change it to:

-Mods -SecurityCode=none

and restart. From now on the server logs in by itself and downloads or updates subscribed mods on every start. Leaving the old code in place does not keep working, because each code is single use.

Step 4: Add mod maps and mutators

A mod map cannot be the map the server boots on, because the mod is not downloaded yet at that moment. Keep a vanilla Default Map and scenario, and tell the server where to go once downloads finish:

-Mods -SecurityCode=none -ModDownloadTravelTo=MountainPass?Scenario=Scenario_MountainPass_Checkpoint

Use the map and scenario names from the mod's page, exactly as written. Add the same map to MapCycle.txt if it should be part of the rotation. A mutator from a mod goes in -mutators=, for example -mutators=Hardcore,YourModMutator.

Do players need to install the mods?

Usually no manual install. Players who join download the server's mods from mod.io when they connect, which can take a while for big map packs on the first join. If a player gets stuck or keeps failing to load in, have them subscribe to the same mods in the game's own mod browser first, then join again.

Do players still earn XP on a modded server?

XP on a community server depends on stats, not on mods. Stats need a Steam server token (GSLT) and a Game Stats token, and they turn off with cheats enabled or a password in the command line. A modded server with both tokens and no password is set up for stats like any other. Check each mod's page too, since some mods say whether they work with stats.

Common problems

• Server starts vanilla, no mods downloaded: it is using your player account, the security code expired, or -Mods is missing. Request a new code with the server account and repeat Step 3.
• Mod map never loads, server sits on the default map: -ModDownloadTravelTo is missing or the map or scenario name is wrong. A scenario that does not exist on that map also stops the level loading.
• Map rotation keeps restarting the same map: a syntax mistake in MapCycle.txt, usually the scenario part of a line.
• First start takes ages: big mods download on the first boot. Let it finish before restarting.
• Crashes after a game update: an outdated mod. Unsubscribe it with the server account until its author updates it.
• Linux servers ignore subscriptions: some admins running the Linux server report needing -ModList=Mods.txt with the IDs listed in Mods.txt as well. Keep both in sync if mods do not download.

Mods on GamezServers

On an Insurgency: Sandstorm server from GamezServers, the launch options go in Additional Switches, the GSLT is made for you, and Mods.txt, MapCycle.txt and Admins.txt are in the Files tab under Insurgency/Config/Server. Press Backup before adding a big mod pack. For the basics, see how to host an Insurgency Sandstorm server.

FAQ

Why is my Sandstorm server not downloading mods?

Most often it is logged in with your player mod.io account, or the security code was never used. Make a separate server account, subscribe it to the mods and authorize it with a fresh code.

Do I still need Mods.txt?

Since 1.20 the server account's subscriptions decide which mods load. Some Linux setups still pass -ModList=Mods.txt, so keeping the IDs listed there does no harm.

Can a mod map be the default map?

No. Boot on a vanilla map and use -ModDownloadTravelTo so the server switches to the mod map after downloading it.

Do players need mod.io to join?

Normally nothing extra, since the game downloads the server's mods when they connect. Subscribing to the same mods in game first helps if a join keeps failing.