How to Set Up an Assetto Corsa Dedicated Server: The Complete Guide

How an Assetto Corsa dedicated server works

Assetto Corsa is the racing simulator from Kunos Simulazioni, published by 505 Games and released on Steam on 19 December 2014. Its online races run on a separate server program, acServer, which Kunos ships with the game. Kunos' changelogs on Steam show how it grew: since update 1.2 (July 2015) the game's server folder also holds acServerManager, Kunos' own tool for setting a server up, and the folder includes a Linux build of acServer as well (Kunos shipped a corrected one in 1.3.1, October 2015).

What a server is made of

• acServer, the server program. It talks to drivers over a TCP and a UDP port (both 9600 by default) and to the lobby over an HTTP port (8081 by default). The default numbers come from Assetto Server Manager's documentation; every server sets its own in server_cfg.ini.
• server_cfg.ini: the server name, passwords, track, allowed cars, sessions and rules.
• entry_list.ini: the grid, one [CAR_0], [CAR_1] block per slot, with the car model, skin and, for a locked grid, the drivers' Steam IDs.
• The content: the server needs the data of every car and track it runs, and every driver needs the same cars and tracks in their own game. Kunos added checksum checks for tracks in update 1.2, so a driver with different track files cannot simply join.

Pickup mode or booking

A server either runs in pickup mode, where drivers join while a session is open and take a free car from the entry list, or starts with a booking session, where drivers reserve their car before the race. Assetto Server Manager's own help text tells you to use pickup mode. A pickup server can still be closed to strangers: since update 1.13 (March 2017) a locked entry list lets in only the drivers on the list, with no password needed (how to lock the grid).

Assetto Corsa, ACC or EVO?

This guide is about the original Assetto Corsa from 2014. Assetto Corsa Competizione and Assetto Corsa EVO are separate Kunos games with their own servers, settings and content, so nothing here carries over to them. Racing those instead? See our Assetto Corsa Competizione servers and Assetto Corsa EVO servers.

Host it yourself or rent a server: an honest comparison

Running your own Assetto Corsa server costs nothing extra: the server comes with the game. The rough steps on a Windows PC:

1. Open the server folder inside your Assetto Corsa install (in Steam: right-click the game, Manage, Browse local files). It holds acServer and Kunos' acServerManager.
2. Set the server up with Kunos' tool or with a community manager such as Assetto Server Manager, which writes server_cfg.ini and entry_list.ini for you (what goes in them).
3. Make sure the server has every car and track it should run. Server Manager's documentation recommends uploading your whole content/tracks folder, so it knows every layout.
4. Open the ports on your router and firewall: TCP and UDP 9600 and the HTTP port 8081 by default, or the numbers you set. Without them, drivers outside your home cannot connect and the server may not appear in the lobby.
5. Start it, and leave that PC on for as long as the server should be online.

Kunos does not publish hardware figures for the server, and it is light: our own 24-slot demo server used about 160 MB of RAM while idling with Assetto Server Manager running. What a home server really costs is a PC that stays on, your upload bandwidth, and your home IP address shared with everyone who joins. An AI traffic server is heavier, because the server drives every AI car (performance).

Our view after hosting game servers since 2008: for a quick private race with friends, a home server is fine. Rent one when the server should stay online while you are away, when a league or a drift crew drives at different times, or when you want championships, live timings and AI traffic without building it all yourself. Plans and locations are on our Assetto Corsa server hosting page.

Setting up your Assetto Corsa server in the GTX game panel

Assetto Corsa servers on GTX run in our game panel with AC Server Manager (the free version, 1.7.9) already installed and running, and the KissMyRank, Real Penalty, stracker and Sol plugins set up. This is the order we suggest for your first race night:

1. Log in to the game panel at gamepanel.gtxgaming.co.uk and open your server. CONNECTION INFO in the Connection & Controls box shows the server's IP address and port. The ports are assigned for you, so there is nothing to open.
2. Open AC Server Manager with the AC Server Manager button and log in. The default login is in our AC Server Manager guide (in the Server Manager topic above). Server Manager has its own accounts with permission levels, so give each co-admin their own login.
3. Set up the race. Name the server, set a password if you want a private server, choose the track and cars, and start a quick race or a custom race with your own sessions and rules (what Server Manager can do).
4. Join it. Start Assetto Corsa or Content Manager, find the server by its name in the online list or add it by its IP address, and enter the password if you set one. The Web Console shows which track and session the server is running.
5. Plan the upkeep. Add a Scheduled Restart in Scheduled Tasks (restarts and backups) and, if a friend helps you run the server, create a sub-user for them with only the panel permissions they need.

The Mod Manager: one-click extras

• AC Server Manager (Free): installed on every server from day one.
• AC Server Manager (Premium): the paid version, installed with your own licence file (Free or Premium).
• AssettoServer (AI Traffic): the community server for freeroam AI traffic. It replaces AC Server Manager while it is installed (AI traffic).
• Shuto Revival Project, under AI Traffic Tracks: Tokyo's Shuto Expressway with the AI files included, plus a download link for your drivers (Shutoko).

AC Server Manager: races, championships and live timings

Assetto Server Manager (often called AC Server Manager or ACSM) is a third-party web interface for the Assetto Corsa dedicated server. Emperor Servers describe themselves as its developers, and the free versions are published as open source on GitHub. Server Manager writes server_cfg.ini and entry_list.ini for you and starts the server. Its documentation lists what the free version does:

• Quick races: a qualifying session and a race, ready in a few clicks.
• Custom races: your own cars, track, sessions and rules, saved as presets you can run again.
• Race weekends: sequential sessions that can run on different days, for example qualifying on Saturday and the race on Sunday, with the grid worked out from the results and drivers split by results.
• Championships: several events with driver, class and team points.
• Live timings and results: timings while a session runs, and a results page for every session where you can apply penalties.
• Content uploads: cars, tracks and weather (how).
• Sol integration: 24-hour day and night cycles for drivers who launch the game through Content Manager.
• Event looping, accounts and logs: a rotation of events between race nights, logins with different permission levels, and the server logs and options in your browser.

On GTX, the KissMyRank, Real Penalty, stracker and Sol plugins come pre-configured with Server Manager: switch on the ones you want and set them up to suit your rules. KissMyRank, for example, handles driver rankings, rules and penalties.

Free or Premium?

The free 1.7.9 release, from February 2021, is the last free version on GitHub, and that project is now archived. Emperor Servers sell the current Server Manager as a paid licence. Their feature list includes race weekends with advanced grid sorting, driver swaps, scheduled events, advanced weather with Custom Shaders Patch support, a multi-server manager, Discord notifications and Lua plugins. On GTX, Premium is a Mod Manager install with your own licence:

1. Buy the Premium licence from Emperor Servers and download the licence key, a file called ACSM.License.
2. Press STOP. In the Mod Manager, uninstall AC Server Manager (FREE), then install AC Server Manager (PREMIUM).
3. Upload ACSM.License with the File Manager.
4. Press START and open it with the AC Server Manager button.

The rain setup in this guide needs Premium (rain).

server_cfg.ini and entry_list.ini: the settings that matter

Every Assetto Corsa server reads two files when it starts: server_cfg.ini for the server and the race, and entry_list.ini for the grid. On GTX, AC Server Manager writes both for you; with AssettoServer you edit them yourself in Configuration Files, with the server stopped. The key names below are the ones Server Manager writes, taken from its source code.

The server and the race: [SERVER]

• NAME, PASSWORD and ADMIN_PASSWORD: the name in the server list, the join password for a private server, and the password that makes you admin (admin commands).
• TRACK and CONFIG_TRACK: the track folder and its layout, for example TRACK=shuto_revival_project_beta with CONFIG_TRACK=shibaura_pa_traffic.
• CARS: the car models allowed on the server. MAX_CLIENTS: the number of cars, which Server Manager's help says must not be higher than the track's number of pits.
• PICKUP_MODE_ENABLED, LOCKED_ENTRY_LIST and LOOP_MODE: pickup or booking, a grid locked to the entry list, and whether the server starts again from the first track when the last session ends.
• Assists: ABS_ALLOWED and TC_ALLOWED (0 = no car may use it, 1 = only cars that have it, 2 = any car), and STABILITY_ALLOWED, AUTOCLUTCH_ALLOWED and TYRE_BLANKETS_ALLOWED (0 off, 1 on).
• Realism: FUEL_RATE and TYRE_WEAR_RATE (100 is realistic, 0 is none), DAMAGE_MULTIPLIER (0 to 100), ALLOWED_TYRES_OUT for track limits, and LEGAL_TYRES, the tyre compounds drivers may use.
• Time of day: SUN_ANGLE sets the sun's position, and TIME_OF_DAY_MULT speeds time up online (Kunos added the multiplier in update 1.14).
• Network: TCP_PORT, UDP_PORT, HTTP_PORT and REGISTER_TO_LOBBY, which lists the server in the game's online lobby.

Sessions, grip and weather

• Sessions: [BOOK], [PRACTICE], [QUALIFY] and [RACE], each with a length in minutes (TIME) or, for a race, LAPS. IS_OPEN decides who may join: 0 nobody, 1 anyone, 2 anyone until 20 seconds before the green light. WAIT_TIME is the wait in seconds before the session starts.
• Dynamic track, [DYNAMIC_TRACK]: SESSION_START is the grip in % at the start, LAP_GAIN the number of laps that add 1% grip, SESSION_TRANSFER how much of the gained grip carries into the next session, and RANDOMNESS a random change to the starting grip.
• Weather, [WEATHER_0], [WEATHER_1] and so on: GRAPHICS must be exactly one folder name from the server's content\weather folder, with air and road temperatures, their variation and wind. Kunos moved weather to the server side in update 1.2.

The grid: entry_list.ini

• One block per slot, [CAR_0], [CAR_1] and onwards, with MODEL and SKIN, and optionally DRIVERNAME, TEAM, GUID (the Steam IDs allowed in that car), BALLAST, RESTRICTOR and FIXED_SETUP.
• Every MODEL must also be in CARS in server_cfg.ini. Kunos made the server stop with an error when the two do not match.
• AssettoServer adds an AI line per slot for traffic servers (AI traffic).

Admin commands, passwords and locked grids

Kunos built admin commands into the in-game chat. Set an ADMIN_PASSWORD first (Kunos made it mandatory in its own acServerManager in update 1.3.4). In a session, type /admin followed by the password in the chat to become admin. If you join the server with the admin password instead of the normal one, you are made admin straight away, and you can join even when a session is closed. These commands come from Kunos' changelogs:

• /help: lists the commands the server knows.
• /next_session and /restart_session: skip to the next session or restart the current one.
• /kick followed by a driver's name, for example /kick The Player.
• /client_list shows the car ID of every driver, and /kick_id kicks by that ID: handy for names with special characters.
• /ban_id: bans a driver by car ID and puts them on the server's blacklist.
• /ballast: gives a car extra weight, up to the server's MAX_BALLAST_KG.

Drivers can vote as well: Kunos' server has votes to kick a driver and to restart or skip a session, and KICK_QUORUM and VOTING_QUORUM in server_cfg.ini set the percentage of votes needed.

Locking the grid to your drivers

For a league, put each driver's Steam ID as the GUID of their car in entry_list.ini and switch on LOCKED_ENTRY_LIST. Since update 1.13 only drivers on the list can then join, and they need no password. A car can list several GUIDs, so team-mates can share a car, and the name on the entry list is shown as the driver name. Server Manager writes the entry list from your race or championship setup.

Admin on an AssettoServer traffic server

AssettoServer has its own admin commands, listed in its documentation, including /pit to send a driver to the pits, /kick and /ban with a reason, /settime, /setweather and /setcspweather, /forcelights, /whois and /restrict for restrictor and ballast. Steam IDs listed in admins.txt are made admin automatically.

Mod cars, tracks and weather: same content for everyone

Mods are what keep Assetto Corsa alive, from Touge mountain roads to full GT grids. Two rules decide whether a mod works online: the server needs the car or track, and every driver needs exactly the same car or track in their own game. Kunos checks track files with checksums, and AssettoServer also checks each car's data.acd, so modified or different versions are turned away.

Adding cars, tracks and weather on GTX

1. Press START: uploads through Server Manager need the server running.
2. Open AC Server Manager with the AC Server Manager button.
3. Open Content and the right menu: Cars and Setups, Tracks or Weather.
4. Read the upload information on that page and drag the car, track or weather folder onto it.
5. Pick the new content when you create or edit a race.

For big content packs, upload with the File Manager or over SFTP instead. If you are moving a league or drift server from another host, upload its content and configuration files the same way and restart.

Getting your drivers the same content

Share the download of every mod car and track with your drivers, and use the same version as the server. Content Manager, the popular third-party launcher for Assetto Corsa, has an online mode that can download missing content, and Server Manager can pass download links for your cars and track to Content Manager in the server's details. Many drivers join servers through Content Manager for exactly that reason.

AI traffic servers with AssettoServer

Cruising a highway full of AI cars with your friends is one of the most popular ways to play Assetto Corsa online, but Kunos' server cannot do it. AI traffic comes from AssettoServer, a free, open-source third-party server built for freeroam, with AI traffic and dynamic weather. Its documentation says race and qualifying sessions and lap times are not supported yet, so it is for freeroam practice servers, not race nights. On GTX it installs from the Mod Manager:

1. Press STOP. In the Mod Manager, uninstall AC Server Manager, then install AssettoServer (AI Traffic).
2. Press START once so the server creates the files AssettoServer needs, then STOP again.
3. In Configuration Files, open server_cfg.ini with the Config Editor, tick Reset file to default and press Save & Exit. Do the same for entry_list.ini.
4. Edit extra_cfg.yml and set EnableAi: true.
5. Edit entry_list.ini with the text editor and add AI=auto to every car slot the AI should drive. Save and press START.

• AI=auto: the AI drives the car while no player uses the slot, and a joining player can take it over. With auto slots, AssettoServer's documentation recommends setting MaxPlayerCount in extra_cfg.yml.
• AI=fixed: the slot is always AI, and players cannot take it.
• No AI line: a normal player slot.

The track needs AI lines

AI cars follow the track's AI fast lane: a fast_lane.ai or fast_lane.aip file in the ai folder of the track or layout. The default tracks have one; some custom tracks do not, and those need the file built first, or you pick a traffic track that ships with it, such as the Shutoko Revival Project.

Denser traffic

AssettoServer's FAQ is clear about the most important setting: more traffic cars in entry_list.ini. Ten traffic cars will never feel busy. After that, lower MinAiSafetyDistanceMeters and MaxAiSafetyDistanceMeters for smaller gaps (not below about 12 m, or AI cars brake right after spawning) and raise AiPerPlayerTargetCount or MaxAiTargetCount to suit your player count. Every AI car is work for the server, so if traffic stutters, use fewer AI slots or a bigger package (performance).

Shutoko Revival Project: a Tokyo expressway traffic server

The Shutoko Revival Project (SRP) recreates Tokyo's Shuto Expressway for Assetto Corsa, and a favourite map for AI traffic servers. In the GTX Mod Manager it is listed as Shuto Revival Project under AI Traffic Tracks, with the AI fast lane files already included. Set up AI traffic first (AssettoServer), then:

1. Press STOP and install Shuto Revival Project from the Mod Manager.
2. In Configuration Files, edit server_cfg.ini with the Text Editor and set TRACK=shuto_revival_project_beta and CONFIG_TRACK=shibaura_pa_traffic.
3. Save and press START.

The track comes with these layouts: daishi_pa, heiwajima_pa_n, heiwajima_pa_s, shibaura_pa, shibaura_pa_traffic, tatsumi_pa and yoyogi_pa. In the version our Mod Manager installs, only shibaura_pa_traffic has the AI lanes: the other layouts load fine but stay empty.

On your drivers' PCs

1. Close Assetto Corsa.
2. Download the tracks with the link under the Shuto Revival Project entry in the Mod Manager, so every PC gets exactly the version the server runs.
3. Unzip them into the game's content\tracks folder, usually C:\Program Files (x86)\Steam\steamapps\common\assettocorsa\content\tracks\.
4. Start the game through Content Manager and join the server.

Rain and dynamic weather online

Out of the box, Assetto Corsa has no rain on a dedicated server. Rain comes from the Custom Shaders Patch (CSP), a third-party extension of the game: its RainFX is part of the CSP Preview version, which its author shares through a paid Patreon. With RainFX, rain works in solo and local sessions; online, every driver needs RainFX and the server needs a race set up for rain. On GTX that means AC Server Manager Premium: when we wrote this, there was no free way to have rain on an Assetto Corsa dedicated server. The setup in short:

1. On each driver's PC: install RainFX in Content Manager under Settings, Custom Shaders Patch with Install from file, and note the Shaders Patch version ID.
2. In Server Manager Premium: under Server, Options, Content Manager Integration, switch on Enable Extra Custom Shaders Patch.
3. Create a custom race: Weather Type Custom Shaders Patch with Transitions, Time Progression Multiplier 1, Graphics Rain (Sol), Custom Rain Preset Rain/Wet, and a CSP weather transition of 240 seconds. Several weather presets in one race let a dry start turn into a wet finish.
4. Require CSP: set the Required Minimum CSP Version to that version ID, choose Enable both custom car and track physics, add [RAIN_PREVIEW] with INTENSITY = 1, REQUIRED = 1 and WITH_PHYSICS = 1 to the extra options, and allow the WET tyres.
5. Save, start and join through Content Manager.

Not every custom track or car supports rain: on those the track feels wet, but drivers do not see the rain. All official tracks and cars support it, so test with one of them first.

Weather on an AssettoServer traffic server

AssettoServer has CSP weather built in: set EnableWeatherFx: true in extra_cfg.yml. Its documentation says WeatherFX needs CSP 0.1.76 or newer, and three bundled plugins change the weather for you: RandomWeatherPlugin, LiveWeatherPlugin and VotingWeatherPlugin. Drivers still need RainFX to see rain.

Weather without CSP

Kunos' own weather is set on the server for each race (the [WEATHER_n] blocks in server_cfg.ini), and custom weather folders upload through Server Manager's Content, Weather page. For 24-hour day and night cycles, Server Manager supports Sol for drivers who launch through Content Manager.

Performance, RAM and grid size

• Grid size: a server can never hold more cars than the track has pit boxes, and that number differs between circuits, layouts and mod tracks. Check the tracks you plan to race before you pick a big slot count.
• RAM: Kunos does not publish a memory figure. Our 24-slot demo server used about 160 MB idling with Assetto Server Manager running, so the up to 5 GB included with every GTX server is generous for racing. AI traffic uses more: watch the graph.
• AI traffic: more AI cars means more work for the server. If traffic stutters, use fewer AI slots or a bigger package.
• Network: CLIENT_SEND_INTERVAL_HZ sets how often the server sends updates. Server Manager's help says a higher number means better multiplayer quality but more bandwidth, and really high values can cause connection problems. Its default is 18.
• Distance: in close racing every millisecond counts, so host near your drivers. GTX runs Assetto Corsa servers in 19 locations; the ping test on our hosting page shows the closest.

As a rough guide: 8 or 16 slots for small groups and drift sessions, 24 or 32 for league nights, 48 or 64 for big open servers on tracks with large pit lanes. The live graphs on your server page and Activity and Stats show CPU and memory now and over past days. If you run close to the limit, change slots, RAM, CPU priority or hardware in the Client Area under Upgrade/Downgrade Options.

Updates, restarts and backups

Kunos updates the game and the dedicated server through Steam. On GTX, update the server with the Steam Update button whenever Kunos releases a new version: press STOP, Steam Update, wait for it to finish, then START. Kunos' last announced version update was v1.16 in 2017, so in practice the updates that matter are those of your community tools and mods: keep the server's car and track versions the same as your drivers'.

1. Restart on a schedule. In Scheduled Tasks, create a Scheduled Restart, set it to recur every day and repeat every few hours (every 6 hours for 24 hours gives four restarts a day). Pick quiet hours.
2. Keep backups. Every GTX server has daily automatic backups, and they also run alongside your scheduled restarts.
3. Keep your own copy. Before a big change, such as switching to AssettoServer, download your configuration files and the content you uploaded with the File Manager or SFTP.

If the server files are broken beyond repair, a reinstall from MORE puts the server back to a clean default install: it deletes every server file, including configs and uploaded mods, but keeps your backups. Our 24/7 team can help you get a backup back.

Troubleshooting an Assetto Corsa server

• The server is not in the online list. Check in the Web Console or Log Viewer that it is running, and that REGISTER_TO_LOBBY is on. Drivers can always add it by the IP address and port in CONNECTION INFO.
• The server will not start after a change. Open the Log Viewer: most often a car or track named in the config is not installed on the server. The server also stops when a car in entry_list.ini is not in CARS. And keep the grid within the track's pit boxes.
• A driver gets a checksum or version error. Their car or track files differ from the server's. They reinstall the same version you run; Content Manager can download missing content.
• No AI traffic. Check three things: EnableAi: true is saved in extra_cfg.yml, car slots have AI=auto or AI=fixed, and the track has AI lines. On the Shutoko Revival Project, use the shibaura_pa_traffic layout.
• Stuck on "Initialising AI spline" while loading. AssettoServer's FAQ explains that the game is loading the single-player AI spline from the driver's own track files. Its fix: rename the ai folder of that layout in the game files to ai_off. This switches off AI for that layout in single player and some penalty systems such as track cuts; rename it back to undo.
• AssettoServer refuses to start. It stops on common configuration errors and names them: for example missing car checksums (data.acd) or missing track parameters. Its documentation explains each one and the IgnoreConfigurationErrors setting in extra_cfg.yml.
• AC Server Manager does not open. If AssettoServer is installed, Server Manager is not: the two do not run together. Switch back in the Mod Manager.
• The track feels wet but there is no rain. That track or car does not support rain; test with an official one. A "Game crashed" error, or the Content Manager message that dwrite.dll is missing, means RainFX did not install correctly: unzip it into the Assetto Corsa folder.
• A mod car will not accelerate. Some car mods only work on servers their creators have whitelisted.

Still stuck? Our 24/7 support team reads the logs with you on live chat or a ticket.