Valve added Team Fortress 2’s client and server code to Source SDK 2013 on February 18, 2025, giving creators a route to build TF2-based mods ranging from small changes to complete conversions. These are community-made projects, not new Valve games, and the licence requires each mod and its content to be free.
What the TF2 SDK lets creators do
Valve’s TF2 Team described the release as a way for “content creators to build completely new games based on TF2.” The addition puts TF2’s client and server game code in the Source SDK 2013 repository, where creators can modify, extend or rewrite the game rather than simply submit a model for the existing one.
Valve says the code can support changes “from small tweaks to complete conversions.” That describes the range of projects the code can support; it does not mean every project will be a finished standalone game or that creators have unrestricted rights to TF2 assets.
Can you sell a TF2 SDK mod?
No. Valve’s announcement says the SDK is licensed on a non-commercial basis: “any mod created using the SDK must be free, and any content in those mods must be free.” Creators may publish TF2 mods on Steam, where they can appear as separate games in a player’s library, but a Steam listing does not make a paid release permissible.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →#1 Best Overall
- Nine unique character classes, each providing a completely unique play experience for players of varying skills
- Advanced graphics that offers a unique game environment while providing game information within the visuals
- Support for up to 24 players
- Introduces new multiplayer game modes and support for voice chat
- Automatic updates – Stop wasting time looking for patches or new content
For Steam distribution, Valve’s Source Engine mod guidance says creators must complete the usual Steamworks developer onboarding paperwork, even when the mod is free. The guidance also expects mods to be clearly identified as community projects, not as products made or endorsed by Valve. It permits distribution through Steam, a creator’s own website or third-party services when its rules are followed.
TF2 installation and inventory limits
A TF2 mod cannot redistribute TF2’s game files. Valve’s TF2 mod FAQ says the mod must load TF2 content from a local installation, so players need TF2 installed to play a TF2 mod. Steamworks’ general guidance says some total conversions that do not use Valve assets may be able to ship without a base-game dependency, but the TF2-specific FAQ is the relevant rule for TF2 mods.
Rank #2
The SDK can access a read-only view of a player’s TF2 inventory to determine which items they may equip. It cannot change a player’s TF2 inventory, loadout or item properties. Creators may choose or reinterpret equipped items inside their own mod, but Valve says it will not allow TF2 mods focused on manipulating items or the TF2 economy.
What it takes to build a mod
This is a developer toolchain, not a one-click mod installer. The repository’s instructions list separate Windows and Linux build paths; requirements can change, so check the live repository for current setup steps.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Windows
- Install Source SDK 2013 Multiplayer through Steam.
- Install Visual Studio 2022 with the Desktop development with C++ workload.
- Install the MSVC v143 x64/x86 build tools, a Windows 10 or Windows 11 SDK, and Python 3.13 or later.
Linux
- Install Source SDK 2013 Multiplayer and Podman, as listed in the repository’s Linux instructions.
- For Steam distribution, target the Steam Runtime. The repository’s documented Linux build process does this.
In either case, expect to work with a Source codebase and compile a project. The repository is the authority for current dependencies and commands, rather than an old setup guide.
SDK mods versus the TF2 Workshop
The Workshop and SDK serve different purposes. The TF2 Workshop is for submitting finished 3D items for possible selection and incorporation into the existing game. Valve reviews submissions; accepted items may be sold or unlocked in TF2 under Workshop rules. The SDK is for changing game code and creating a separate TF2-based mod or conversion, and its projects must remain free.
| Creator route | What you make | How it is handled | Can it earn money? |
|---|---|---|---|
| TF2 Workshop | 3D items for the existing game | Submit items for developer review and possible selection | Some accepted items can be sold or unlocked in TF2 |
| TF2 SDK | Code changes, mods or a separate TF2-based game | Build and distribute a mod under Valve’s Source mod guidance | No. The mod and all content in it must be free |
Valve’s Workshop page lists Blender as a free, open-source 3D creation tool. It is an optional asset-making tool, not a requirement for compiling the SDK.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.A recent example of what the SDK can support
In a January 31, 2026 report, PC Gamer reported that Team Fortress 2 Classified relaunched on Steam using Valve’s official TF2 SDK. The report describes a pre-hats-era direction alongside additional weapons, modes and a new class. It is an example of a distinct Steam-listed project built with the SDK, not a change to Valve’s licensing terms.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
