The manifest

Every mod folder has a kiln.mod.json. Kiln.Sdk writes it from your project file, or add your own. The build checks it with the code that loads it, so a manifest that builds is one Kiln accepts.

{
  "id": "my-mod",                 // lower case, digits, . _ -
  "name": "My Mod",
  "version": "1.4.0",
  "apiVersion": "0.2",
  "side": "server",               // server | client | both
  "clients": "none",              // none | kiln | mod
  "dependencies": {
    "sample-lib": "^1.2",
    "extras": { "version": "*", "optional": true }
  },
  "loadAfter": ["some-mod"],
  "incompatible": { "rival": "<3" },
  "entryAssembly": "MyMod.dll",
  "tests": { "autoRun": true }
}

Comments and trailing commas are allowed.

Where it runs: side

side	Loads on
server (default)	dedicated servers, and the hosted world when a player hosts
client	the game client only
both	both

What players need: clients

clients	A joining player needs	For
none	nothing	server rules, world edits, "journal": "chat" quests
kiln	Kiln: the server sends your definitions	new items from the game’s own models
mod	your mod, from the server’s modpack	quests, NPCs, talents, your own files (icons, models, sounds), client code

Without the key, server mods mean none; client and both mods mean mod.

If you state kiln or mod, the server refuses players without Kiln, unless its modSync is off. The default doesn’t, since many both mods work for everyone. A Kiln player missing a stated mod mod is refused by default and told which mods; modSync set to warn or off lets them in. Needs side: both. These rules pass on test servers, not yet in the real game. See Who can join.

Versions

apiVersion is the mod API you built against (0.2 today). Older APIs of the same major version load.

Range	Means
^1.2 or 1.2	up to, not including, 2.0.0 (for 0.x, ^0.2 stops before 0.3)
~1.2	1.2.x
=1.2.3	exactly that
>=1.0 <2	both conditions
[1.0,2.0)	Forge-style interval
*	any

Load order

Dependencies first, then loadAfter and loadBefore, then by id. A mod that can’t load never stops the others, and kiln.log says why:

mod x 1.0.0 not loaded: missing dependency y ^1.0
mod x 1.0.0 not loaded: dependency cycle: x -> y -> x
mod x 1.0.0 skipped: side 'client': not loaded on a server

A misspelt key only warns (unknown key 'dependecies' (ignored)). kiln lint catches it before you build.

Mods of data only

Since dev.22, entryAssembly is optional. A folder with a kiln.mod.json and a content/*.json data pack is a mod with nothing to run. It has its id, version, dependencies, side and a place in the load order, it shows in the mod list, and its data packs apply.

// kiln/mods/pack-only/kiln.mod.json, with kiln/mods/pack-only/content/items.json beside it
{ "id": "pack-only", "version": "1.0.0", "apiVersion": "0.2", "side": "both", "clients": "kiln" }

[host] mod pack-only 1.0.0 loaded in 0.4 ms (data only: no entryAssembly)

A key that is there must still name a .dll file: an empty entryAssembly is refused. A code project still has to name the assembly it builds (KILN001). Before dev.22 Kiln refused a manifest without it, and the folder’s data packs were skipped. Not yet tried in a real game.