The kke_ tools¶

Small command-line programs that come with the engine. None of them is needed to play the demos; each one helps with one job. This page says what each is for, whether you need it, and how to use it, with commands you can copy.

Where they are. In your build: build-release/bin/ (the everything-release preset) or build/bin/. In a download: next to the demos. Open a terminal in that folder and start them with ./ in front (./kke_seal). Run one with no arguments and it prints how to use it.

Making the downloads themselves (Linux, AppImage, Windows, Android) is one script in the repository, tools/bake: BAKING.md.

Tool	What it's for	Who needs it
kke_assets	What's in your asset folders, and what each game still needs	Anyone with art packs; before every bake
kke_model_info	What's inside a model file: parts, bones, animations	Anyone adding art to a game
kke_seal	Proves a game's files weren't changed (and makes the keys `kke_license` uses)	Developers releasing a game
kke_license	Licence files for games that want a licence check	Developers who choose to use Kreative DRM
kke_packs	Make and check DLC and mod packs, see their load order	Modders and developers with DLC
kke_server	A server that runs without a window: join codes, server lists, 24/7 worlds	Whoever hosts
`kke_cook`	Encrypts art for a private download	`tools/bake` runs it (COOKED_ART.md)
`kke_bench`, `benchmark/kke_benchmark`	Measure performance	BENCHMARKS.md
`kke_audio_preview`	Listen to the engine's synthesised sounds	AUDIO.md

kke_assets¶

For: checking your art packs. It lists every pack folder, which pack the engine thinks it is, where it belongs, and for every game whether the packs it uses are there. Folder names don't matter: packs are recognised by name in any spelling or by their files.

./kke_assets                     # the folders the games use (KKE_ASSETS_DIR / assets/synty, KKE_SPRITES_DIR / assets/sprites)
./kke_assets ~/Synty             # a folder of your choice
./kke_assets needs               # which packs each game uses, nothing read from disk
./kke_assets needs racing        # one game

Each game's line shows ok or MISSING per pack. A missing pack means blocks in that game, and nothing of it in a bake. The full guide to the folders and names is ASSETS.md.

kke_model_info¶

For: looking inside a model before you use it: how many parts and triangles, which materials and textures, the bones, the animation clips and how long they are. Handy when a model shows up wrong (too big, no texture, no animations), or to find the names of a car's wheels.

./kke_model_info path/to/SM_Veh_Plane_Stunt_01.fbx            # the summary
./kke_model_info path/to/SM_Veh_Plane_Stunt_01.fbx --parts    # every part with where it sits
./kke_model_info assets/animations/UAL1_Standard.fbx --bones  # every bone, its parent and where it rests

What you see (the stunt plane):

SM_Veh_Plane_Stunt_01.fbx
  13 mesh part(s), 3866 triangles, 1 material(s), 0 bone(s), 0 animation(s)
  bounds (-7.41 -2.14 -4.64) .. (7.41 1.35 4.93)
  material 'Plant_Mat' texture ''
  part 'SM_Veh_Plane_Stunt_01_Wheels' 432 tris, material 0, (-1.05 -2.14 2.21) .. (1.05 -1.51 2.85)
  part 'SM_Veh_Plane_Stunt_01_Prop' 438 tris, material 0, (-1.31 -1.62 4.16) .. (1.31 0.68 4.93)

The bounds are in metres: this plane is about 15 m wide. texture '' means the file doesn't name its texture; the engine then uses the pack's atlas (<Pack>_Texture_01). Clips are listed as clip 'Run' 0.80 s.

kke_seal¶

For: proving a game's data (scripts, levels, settings) is exactly what the developer released. You sign the data folder with a secret key; the game, a server or a mod manager checks it with the public key and sees every changed, missing or added file. It also makes the key pair kke_license uses. Players never need it.

Once: make a key pair. Keep the secret file private and out of git (on a USB stick, in your password manager, or as a CI secret).

mkdir -p ~/.kke
./kke_seal keygen ~/.kke/mygame.key

public key: b319d808294cf88dd4f767b3063c1d8d7e2ecb1aa494d93197d4032ea87b2ca5
secret key written to /home/kees/.kke/mygame.key (keep it private, never commit it)

The public key may be shared and compiled into the game.

At every release: sign the data folder. This writes kke.seal into it.

./kke_seal sign games/mygame/data ~/.kke/mygame.key

In CI, put the secret's contents in a secret called KKE_SEAL_KEY and leave out the key file: kke_seal sign games/mygame/data.

Check: anyone can, with the public key.

./kke_seal verify games/mygame/data b319d808...2ca5

seal broken: 1 modified (main.lua)
  modified main.lua

seal ok and exit code 0 when nothing changed.

./kke_seal digest games/mygame/data prints one hash for the whole folder: two players with the same digest have the same data, which is how a server can tell a modded copy apart. Why and how far this goes: ANTI_CHEAT.md "Sealed game data".

kke_license¶

For: developers who want a licence check in their game (optional; see DRM.md for what it does and deliberately doesn't do). A licence is a small signed JSON file: this game, this key, maybe these machines, maybe until this date. The game checks it offline with your public key. It uses the same key pair as kke_seal, so do step 1 of kke_seal first.

The player's machine id. The player runs this (or the game does it for them when they activate) and sends you the result. It's a hash made for this game only, so it doesn't identify their PC anywhere else.

./kke_license machine com.example.mygame

4e8024479e00da63f7caf720bcbbb46c

Issue a licence. You run this (by hand, or your activation service does) and send the file back:

./kke_license issue com.example.mygame KEY-1234 --key ~/.kke/mygame.key \
    --machine 4e8024479e00da63f7caf720bcbbb46c --owner Kees --extra edition=deluxe > license.json

Options: --machine ID (repeat it for more machines; leave it out for any machine), --expires UNIX-SECONDS (date -d 2027-01-01 +%s; leave it out for never), --owner NAME (shown to the player), --extra KEY=VALUE (your own terms: edition, platform, owned DLC as dlc=frost,maps).

Check one (what the game does at start):

./kke_license verify license.json b319d808...2ca5 com.example.mygame

valid: licence KEY-1234

Or why not: for another game, not activated on this machine, expired, bad signature (someone edited the file), unreadable.

End of life. When you stop selling the game or shut your service down, release an unlock licence so every copy keeps working without you:

./kke_license issue com.example.mygame UNLOCK --key ~/.kke/mygame.key --unlock-all > unlock.json

The game id is the id in the game's game.json (kke.tennis, local.starter_game). The code side is in DRM.md.

kke_packs¶

For: DLC and mods. A pack is a folder with a pack.json and files laid out like the game's own data folder; files in a pack replace the game's files with the same path. kke_packs starts a pack, checks it, and shows which packs load in which order and who overrides whom.

Start a pack:

./kke_packs new mods/better_axe com.me.better_axe "Better axe"          # a mod
./kke_packs new dlc/frost com.example.mygame.frost "Frost" --dlc       # a DLC

wrote mods/better_axe/pack.json: put files in mods/better_axe the way they sit in the game's data folder

Then copy your changed files in, for example mods/better_axe/scripts/axe.lua to replace the game's scripts/axe.lua.

Check it:

./kke_packs check mods/better_axe

com.me.better_axe 0.1.0 "Better axe" (mod)
  seal: none (add public_key and run kke_seal sign to prove the files are yours)

To seal a pack, put your public key in its pack.json as "public_key" and run kke_seal sign mods/better_axe your.key; check then says seal: verified.

See the load order (like LOOT for Bethesda games):

./kke_packs order games/mygame/data --dlc games/mygame/dlc --mods mods --list mods.json --own frost

mount order (later wins):
  0. base  games/mygame/data
  1. com.me.better_axe 0.1.0  [mod, mods]
1 files, 1 overridden
  scripts/axe.lua: base < com.me.better_axe

--list mods.json is the player's own order and on/off choices, --own a,b the DLC they own, --shared a,b DLC the host of their session shares. Packs that don't load are listed with the reason.

Everything about pack.json, dependencies, DLC and sharing DLC in a session: MODDING.md.

kke_server¶

For: hosting without keeping a game open. The demos with online play (climb_race, racing, flying_demo, party, tennis, kke_demo) already host from their own menus, so for a quick game with friends you don't need it. Run kke_server for:

Join codes: friends type a short code instead of your address, and nobody forwards ports on their router. Run the relay on a machine with open UDP ports (your server at home, a €5 VPS):

./kke_server --roles relay          # needs UDP 27970-28034 open

Then start a demo with that relay set, and hosting prints a join code:

KKE_NET_RELAY=relay.example.org ./tennis

A server list: --roles directory keeps a list of public servers that the games' Internet servers tab shows.
A world that runs 24/7 for a scripted game (--roles players,scripts), with an admin console, bans, leaderboards and backups.

Start one and type commands into it:

./kke_server --name "Kees's world" --port 27960 --password hunter2

2026-10-03 11:19:47 info kke_server starting: name 'Kees's world', game 'kke', UDP port 27960, 16 players, password ***
2026-10-03 11:19:47 info encryption: every connection; this server's key is e371-c54c-13ce-dcc0
2026-10-03 11:19:47 info ready: players join on UDP port 27960 (type help for commands)

Type help for the console's commands (status, players, kick, ban, say, save, backup, stop); Ctrl+C or stop shuts it down cleanly and saves. ./kke_server --help lists every setting. Settings can also live in server.json next to it or in KKE_SERVER_* environment variables, which is how the Docker setup works:

docker compose -f docker/server/docker-compose.yml up -d

--game ID says which game's players may join (default kke); a game built with another id is turned away with a message saying so. The whole manual, from roles to security: SERVER_HOSTING.md.