Your first mod

What you need

• The .NET 10 SDK.
• A test server with Kiln, not one people play on. See Run a server.
• Kiln’s matching SDK/MDK download and the kiln command, both under Mod authors on the download page, or a source-built MDK. Unpack the download: the folder holding the .nupkg files is the local package “feed”. Point kiln new at it with --feed or $KILN_FEED. Use the full package version (0.2.0-dev.26 for this release), not the API base 0.2.0. Since 0.2.0-dev.26 the packages are also on a NuGet feed, for dotnet and your IDE: the source is https://frostdev.io/kiln/downloads/0.2.0-dev.26/sdk/feed/index.json. kiln new still takes the unpacked folder.
• The API reference of this release: every public type and member, with the thread and the side it is for, and the modder’s guide next to it.

1. Make the mod

kiln new mod MyMod --server <server folder> --set tests=true
cd MyMod

You get a project file, a mod class and a test class. kiln new --list shows every template.

2. Build it into the server

kiln build && kiln deploy
kiln run                    # or start the server from the launcher

The mod lands in <server>/kiln/mods/my-mod/, and the log says:

mod my-mod 0.1.0 loaded in … ms

If it didn’t load, the log says why: kiln logs --mod my-mod.

3. Change it while the server runs

Edit the code, then:

kiln deploy --reload

The server reloads your mod within a second. See Hot reload.

4. Test it

Tests run at server start and after every reload, or with kiln test. See Testing.

5. Package it

kiln pack

You get my-mod-0.1.0.zip. Players add it to their launcher library. Admins unzip it into kiln/mods.

Without kiln

dotnet new install "<feed>/Kiln.Templates.0.2.0-dev.26.nupkg" # once; use your MDK's full version
dotnet new kiln-mod -n MyMod --feed <feed> --server <folder> --tests
dotnet build -t:KilnDeploy                                 # add -p:KilnReload=true to reload
dotnet build -t:KilnPack