The Spice manifest (spice.json)

A Thumper mod is a folder under <game>\Mods\<id>\ with a spice.json at its root. The machine-readable schema is spice-1.schema.json; this page explains the fields and how Thumper uses them. A folder with no spice.json still loads as an implicit, client-only, dependency-free mod named after its folder — every M1-era Mods\ folder keeps working unchanged.

Field reference: every spice.json field with its type, default and allowed values is in the spice.json schema reference.

Minimal example

{
  "spiceVersion": 1,
  "id": "hello-spice",
  "version": "1.0.0",
  "name": "Hello Spice",
  "melange": { "range": ">=0.3.0 <0.4.0" },
  "kind": "client-only",
  "entry": { "client": "client/init.lua" }
}

Fields

Field	Notes
spiceVersion	Must be 1. A manifest with a schema version Thumper doesn’t know is incompatible and never gets a load-order slot.
id	Lowercase, [a-z0-9_-], 1-64 characters. Must equal the folder name — one id, one folder. Used as the dependency-graph key and the wum.storage/wum.config namespace.
version	Semver MAJOR.MINOR.PATCH[-prerelease][+build].
name, authors, description, website	Display only.
melange.range	An npm/Cargo-style semver range (^1.2.0, >=0.5.0 <0.7.0, space = AND) the running Melange version must satisfy, or the mod is incompatible (and the compatibility sweep moves it out of Mods\).
kind	client-only (never touches the simulation, the wire, or Data/Tweak/*; no online handshake) or content (does at least one of those). entry.sim, messages, or permissions.unsafe: true all imply the mod counts as content for the online handshake even if kind says otherwise.
dependencies, optional, conflicts	Arrays of "<id>" or "<id> <comparator><version>" (e.g. "weapon-toolkit >= 2.0.0 <3.0.0"). dependencies are required and order the graph; optional orders the graph only when the id is present and version-compatible; conflicts blocks both mods, whichever side declares it.
loadAfter	Plain mod ids: an ordering-only edge with no existence requirement — nothing breaks if the named mod isn’t installed.
permissions.unsafe	Deep Desert: wum.unsafe.* (raw memory read/write, calling game functions), client VM only. Enabling such a mod opens a consent modal in the overlay; declining still loads the mod, with wum.unsafe calls raising instead of working.
permissions.filesystem	none (default), own-folder (read) or own-folder-write, for Melange-mediated file helpers. Never raw Lua io.
permissions.network	Reserved for a later milestone. Accepted and ignored (with a log warning) by this build.
entry.client	Path, relative to the mod folder, loaded into the always-on Sandbox VM (Lua 5.4).
entry.sim	Path registered into the match’s Lua VM at match start (Lua 5.0 dialect, float numbers). Requires kind: "content".
assets.root / .shaders / .effects	Data-override folders, as M1’s Mods\<id>\ already used (defaults assets, shaders, effects).
contentHash.include	Glob list of files that feed the online content hash (default: entry.sim, assets/**, *.spice.json). Never computed for a client-only mod.
messages	Up to 16 engine message names this content mod registers (pattern Prefix.Sub[.Sub...], 1-5 dotted segments after the first capitalised word). Checked against the live vanilla message registry at start-up, not a fixed list in the schema — a name that collides with a vanilla one is skipped and logged, not a hard error for the rest of the mod. The engine has 73 free slots; Thumper caps registrations at [Thumper] MaxModMessages (48) across every mod combined.
settings	{key, type: bool|int|float|string|enum, default, min?, max?, options?, label}. Drives wum.config.get/set and the per-mod widgets on the Mods page.
weapons	Weapon clones, kind: "content" mods only — see below and weapons.md.
weaponText	New panel names and help text for vanilla weapons, kind: "content" mods only — see weaponText.
weaponIcons	New panel and HUD icons for vanilla weapons, kind: "content" mods only — see weaponIcons.
schemes, factoryWeapons	Game styles and custom-weapon presets from data files, allowed for client-only mods; see schemes and factoryWeapons.
music	MP3 tracks for the sudden-death music, allowed for client-only mods; see music.
meshes	Mesh banks (.xom) under the assets root that give a weapon clone or a wum.sim.weapon():set its own 3D model, kind: "content" mods only — see meshes.
vehicleMeshes	The mesh the Airstrike and Super Airstrike helicopters are drawn with, kind: "content" mods with a meshes bank only — see vehicleMeshes.
defaultEnabled	Honoured only the first time Thumper ever sees this mod id (default true). The shipped samples set it to false.

Before: unsafe mod switched on	After: the consent modal

weapons: weapon clones

A kind: "content" mod can declare up to 3 weapon clones (schema: spice-1.schema.json), in the free panel cells 29, 39 and 40 — shared across every enabled mod, not per mod. This is checked in two passes, both at every Thumper rescan:

1. Shape, right here in spice.cpp: at most 3 entries, each an object with a known set of keys (name, base, cell, bank, set, panelIcon, hudIcon, text), set values that are a number, a boolean or a string. A shape error refuses the whole mod, naming the bad key or value.
2. Names, bases, cells and field types, in weapons/manifest.cpp — the base whitelist, the resource-name pattern, cell conflicts between mods (later load order loses), and each set field checked against the base’s own container schema. A mod that fails here is Incompatible with the specific reason.

The full field reference, the base whitelist, the Lua side (wum.sim.weapons) and what does and doesn’t work yet are in weapons.md; dist\Mods\mega-bazooka is a complete, working (disabled) example.

weaponText: renaming vanilla weapons

A kind: "content" mod can give vanilla weapons new panel names and help text without changing how they behave:

"weaponText": {
  "kWeaponBazooka": { "name": "Nail Bat", "help": "Swing it at the nearest worm." },
  "kUtilityJetPack": { "name": "Rocket Pack" }
}

The key is the weapon’s container name, ^k(Weapon|Utility)[A-Z][A-Za-z0-9]{2,40}$. name is 1-24 and help 0-160 printable ASCII characters (no control characters); at least one of the two is needed, and an unknown field inside an entry refuses the mod. At most 64 entries per mod. Checked in two passes, like weapons:

1. Shape, in spice.cpp: the kind, the count, the key pattern, the text limits, and that the key is not a clone declared in the same mod’s weapons (a clone has its own text).
2. Across mods, in weapons/manifest.cpp: a key may not be a clone name declared by any mod, and a weapon renamed by an earlier mod in load order refuses the later mod as a whole (the reason names the weapon and the earlier mod).

Whether each container exists is checked when a match starts; an entry for a weapon the game doesn’t have is skipped with a warning. How it works, what it needs online and what is unverified in game are in weapons.md.

weaponIcons: replacing vanilla weapon icons

A kind: "content" mod can replace the weapons-panel icon and the HUD icon of vanilla weapons, the way a clone gets its own with panelIcon and hudIcon:

"weaponIcons": {
  "kWeaponBazooka": { "panelIcon": "icons/ripper.png", "hudIcon": "kindjal.ripper.hud.tga" },
  "kWeaponGrenade": { "panelIcon": "icons/pineapple.png" }
}

The key is the weapon’s container name, as for weaponText (^k(Weapon|Utility)[A-Z][A-Za-z0-9]{2,40}$, a vanilla weapon, never a clone name). At least one of panelIcon and hudIcon is needed per entry, an unknown field refuses the mod, and there are at most 64 entries per mod.

Field	Notes
panelIcon	A PNG path under the assets root (relative, no .., no drive), square, a multiple of 64 pixels up to 4096; larger images are box-filtered to 64x64. Written over the weapon’s own 64x64 slot in the panel’s icon sheet.
hudIcon	A file name (no folder) under assets/loose/, ending .tga and named <modId>.*, so it can never shadow a vanilla file. It is loaded in place of the weapon’s vanilla Data\HUD\Weapons\*.tga.

Checked in two passes, like weaponText: the shape and file-name rules (and that the key is not a clone of the same mod) in spice.cpp and weapons/manifest.cpp, then across mods in load order. A key may not be a clone name declared by any mod, and a weapon that an earlier mod already has icons for refuses the later mod as a whole (the reason names the weapon and the earlier mod). A weapon can have weaponText from one mod and weaponIcons from another. The rules are part of the content identity, so peers with different icons do not play together. How the replacement is applied, when the vanilla icons come back, and what is unverified in game are in weapons.md.

levels: map packs

A kind: "content" mod can ship maps built with Erg, up to 32 per mod and 128 across every enabled mod:

"levels": [{ "slug": "harbour", "title": "Harbour Brawl", "type": "multi", "chunk": true, "source": "src/harbour.ergpatch.json" }]

Field	Notes
slug	[a-z0-9]{1,24}, unique within the mod. The level’s file stem is <prefix>_<slug>, where <prefix> is the mod id with - turned into _.
title	Printable ASCII, 1-40 characters. What players see in the Prebuilt list.
type	multi only — other map types aren’t supported yet.
chunk	true when the pack ships a generated script (assets/levels/<stem>.lub) for spawns, placed objects or a water level.
source	Path to the patch the map was built from (Erg writes this). When the built files are missing, the mod is Incompatible with “not built: open Erg and press Build, or run build.ps1”.
sim	Optional sim/<name>.lua: the map’s level script, run in the sim sandbox only on this map. At most 256 KB of UTF-8 without a byte order mark.
survivor	Optional, default false: also list the map in Survivor’s Prebuilt section as Multi.<stem>.S, on the same files (see Survivor copies). Earlier Melange versions refuse it.

Two mods that resolve to the same prefix (their ids differ only by -/_) can’t both ship maps; the later one in load order is Incompatible. A map’s own files never touch anything under Data\, are never named the same as one of the game’s own map files, and never include the shadow-cache files (.csh) the game itself generates.

schemes and factoryWeapons: game styles and weapon presets

Data only, so both are allowed for a kind: "client-only" mod (a content mod may use them too). Each is an array of { "file": "<path>.json" }; the path is relative to the mod folder, must stay inside it and end in .json.

"schemes": [{ "file": "schemes/kanly.json" }],
"factoryWeapons": [{ "file": "weapons/red.json" }]

At most 8 schemes and 16 factory weapons per mod, and 32 and 64 across every enabled mod. A key used twice (by any mod, or by one of the game’s own entries) is refused with an error in the log ([schemes] <mod>/<file>: ...) and that entry is skipped; the rest of the mod still loads. A shape error in the manifest itself refuses the whole mod, as for levels.

Scheme file: one game style, listed in Versus > Deathmatch > Game Style (and the same list in the other local modes) as a permanent built-in style: the game neither edits nor deletes it, and the list is sorted alphabetically by display text. The scheme is a copy of a built-in one with your changes.

{
  "key": "FETXT.Scheme.Kanly",
  "title": "Kanly",
  "base": "FE.Scheme.Standard",
  "lock": "Lock.Scheme.Standard",
  "fields": { "RoundTime": 300000, "SuddenDeath": 1, "WaterSpeed": 3 },
  "weapons": {
    "*": { "Ammo": 10, "Delay": 0 },
    "ConcreteDonkey": { "Ammo": 1 },
    "HealthMystery": { "Crate": 50 }
  }
}

Field	Notes
key	FETXT.Scheme.<Name>, the name being 2-32 letters or digits starting with a letter. It is the scheme’s Name and the name of its display string.
title	The text shown in the list, 1-24 printable ASCII characters.
base	The Name key of a built-in scheme to copy (default FE.Scheme.Standard; others include FE.Scheme.Pro, FE.Scheme.Beginner, FETXT.Scheme.Darksider).
lock	Optional lock key (default: the base’s, Lock.Scheme.Standard for Standard, which is unlocked from the start). Lock.AllwaysLocked hides the scheme.
fields	Any integer or boolean field of the game’s SchemeData by name, e.g. Wins, WormHealth, RoundTime and TurnTime (milliseconds), SuddenDeath (0 is 1 Health, 1 is Raise Water, 2 is Draw Round), WaterSpeed (1 Slow, 2 Medium, 3 Fast), WindMaxStrength, MineFactoryOn. Integers must fit in int32. Permanent is always true.
weapons	Per-weapon Ammo, Crate and Delay, keyed by the SchemeData field name of the weapon (Bazooka, ConcreteDonkey, …, and the 15 ...Mystery entries). "*" applies to all 58 entries first, then each named entry on top.

An unknown field or weapon name, a value that is not an integer or is outside int32, or an unknown key is an error and the scheme is skipped.

Factory weapon file: one custom-weapon preset, listed in the team editor’s weapon list. A team stores only the preset’s key.

{
  "key": "FETXT.Kanly.Red",
  "title": "Red Kanly",
  "base": "FETXT.WipeOut",
  "stock": true,
  "weapon": { "WormDamageMagnitude": 1.2, "FuseTime": 1500, "DetonationFX": "WXP_ExplosionX_Med" },
  "cluster": { "WormDamageMagnitude": 0.6 }
}

Field	Notes
key	FETXT.<Name>[.<Name>...], 6-40 characters, each part letters and digits starting with a letter; not a built-in key. The preset’s Weapon container’s Name is set to it, and it is the display string’s name.
title	The text shown, 1-24 printable ASCII characters.
base	Required: the key of a built-in preset to copy (weapon and cluster): FETXT.AFewProblems, FETXT.ChatterBomb, FETXT.KneeTrembler, FETXT.ThePeaceBreaker, FETXT.TheBrownSofa, FETXT.Factory.Blaster or FETXT.WipeOut.
stock	StockWeapon, default true.
weapon, cluster	Overrides on the two WeaponFactoryContainers by field name: booleans, integers (int32; U32 fields 0 to 4294967295), enums as integers (0-255), floats, strings (printable ASCII) and the string arrays GraphicalResourceID and GraphicalLocatorID. Name cannot be overridden.

Melange rebuilds the game’s DATA.LockedSchemes and DATA.LockedWeapons resources from its own Data\Tweak\LOCAL.XOM with the entries of every enabled mod appended, writes them to Melange\cache\schemes\, and loads them over the originals at the frontend (again whenever the set of enabled mods changes while you are at the menus; a disabled mod’s entries leave the lists without a restart, expected but not yet verified in game). With no enabled mod declaring either key, nothing is touched. [Schemes] Enabled=0 in Melange.ini turns it off.

Both lists are client-side. The lobby names the host’s game style by its position in the host’s list (scheme_code), not by key, so a peer without the mod has no entry for it: the unmodified game reads past the end of its own list and crashes on joining. With [Fixes] SchemeCode=1 (the default) such a peer sees the style as “Unknown game style” instead. Whether the match itself then plays with the host’s settings is not verified. That a preset is listed in the team editor is expected to work like the scheme list but has not been verified in game.

music: sudden-death music

Replaces the music that plays when sudden death starts with MP3s from the mod. Allowed for a kind: "client-only" mod (a content mod may use it too): the music is local, and every player hears their own.

"music": [
  { "slot": "suddenDeath", "file": "music/ash-ridge.mp3", "title": "Ash Ridge", "credit": "Slaughter at Ash Ridge" }
]

Key	Meaning
slot	Required. Only "suddenDeath" for now; another value refuses the mod.
file	Required. A .mp3 path relative to the mod folder, inside it, at most 24 MiB.
title	Required. 1-48 printable ASCII characters, shown in the log.
credit	Optional, at most 96 characters: the original title or author, shown in the log only.

At most 16 entries per mod and 64 tracks per slot across every enabled mod. The audio must be MPEG-1 or MPEG-2 Layer II or III (a normal MP3; ID3 tags are skipped), with at least 50 frames, and one sample rate and channel count throughout the file. All tracks of a slot must share one sample rate and channel count (Melange does not resample): the first track in load order sets them and a track that differs is skipped with an error in the log ([music] <mod>/<file>: ...). A shape error in the manifest itself refuses the whole mod. Only add music you hold the rights to; Melange does not check, and the plugin author is responsible for what a plugin ships.

Every enabled mod’s tracks for the slot are played back to back in a random order, with hard cuts. The order is new for every match, and the track that led last time does not lead again when there are two or more tracks. With no enabled mod declaring music the game’s own music plays. The game’s own muSuddenDeath.fsb is never modified, and the sudden-death sting and commentary are untouched. [Music] Enabled=0 in Melange.ini turns it off.

meshes: custom 3D models

Loads mesh banks so a weapon can use a model of the mod’s own. kind: "content" mods only.

"meshes": [
  { "file": "assets/meshes/kindjal.NailBat.xom" }
]

Key	Meaning
file	Required, the only key. A .xom path relative to the mod folder, inside it, under the mod’s assets root (assets/ unless assets.root renames it). At most 64 entries per mod, none twice.

A bank is an xomtool convert <mesh.gltf> --bundle <out.xom> --as <modId>.<Name> file (see xomtool.md). Every resource name in a bank must start with <modId>. (the mod’s own id and a dot), so two mods cannot collide and a mod cannot replace a vanilla mesh. Once the bank is loaded, name the mesh from a clone’s set or an entry.sim:

wum.sim.weapon("kWeaponBaseballBat"):set("WeaponGraphicsResourceID", "kindjal.NailBat")

Because the files sit under the assets root they are already part of the content hash: peers must have the same banks, like any other file under assets/**. The mod does not need to re-hash anything by hand.

When the banks load: once per launch, on the main thread, after the game has been at the main menu for about half a second (the same settle the schemes and music features wait for), for every content mod that is active this session, in load order. A bank that cannot be loaded (unreadable, not a mesh bank, a name outside <modId>., a name the game already has, …) is logged as [meshes] <mod>/<file>: <reason> and skipped; the mod stays enabled and its other banks still load. One summary line per launch reports the banks, meshes and sections used. Content-mod changes need a restart anyway, so a mod disabled later keeps its banks for the rest of the session.

Each bank takes one of the engine’s free section numbers (476 to 519). A bank keeps the section it was built with (--section) when that section is in range and still free; otherwise Melange rewrites the section in a copy under Melange\cache\meshes\ and loads that, taking the first free section from 476 up, in load order. At most 44 banks load in one session across all mods, however many each mod declares (up to 64): the banks past the budget in load order are skipped, and the log says so before the first load (only 44 of the 44 mod sections are free: the last N in load order will not load) and for each skipped bank. Put several variants of a model in one bank rather than one bank each if a pack needs many meshes. The engine, the section table and the mechanics are in meshes.md.

vehicleMeshes: the Airstrike helicopters

Replaces the model of the aircraft the Airstrike and Super Airstrike send over. The aircraft is not a weapon field, so set cannot reach it: the engine’s two graphic entities each have a built-in mesh name, and this swaps that name for a match. kind: "content" mods only, and the mod must list at least one meshes bank.

"meshes": [{ "file": "assets/meshes/kindjal.Chopper.xom" }],
"vehicleMeshes": {
  "BomberHelicopter": "kindjal.Chopper",
  "SuperAirstrike": "kindjal.Chopper"
}

Key	The aircraft
BomberHelicopter	The Airstrike’s helicopter (the game’s BomberGraphicEntity).
SuperAirstrike	The Super Airstrike’s helicopter (SuperBomberGraphicEntity).

The key is one of these two, case-sensitive. (Bomber, the third aircraft mesh in the game’s files, is never drawn by this build and is refused with that explanation.) The value is a mesh name <modId>.<Name> (letters, digits, ., _, -, at most 96 characters) that one of the mod’s banks defines. Whether a loaded bank has that mesh is checked when the match starts, not when the manifest is read: if it did not load, that vehicle keeps the vanilla model for the match and the log has a [weapons] vehicleMeshes ... line saying why. Two mods that set the same vehicle: the later one in load order is refused as a whole. The mesh must keep the vanilla helicopter’s node names and animation channels (rear_rotor, top_rotor, trail1, trail2, the perspShape camera and the rest; start from xomtool convert BomberHelicopter --from Bundl09.xom --out ...). A mesh that lacks any of the five names rear_rotor, top_rotor, trail1, trail2, perspShape is not used: the vanilla vehicle is drawn and the log names the missing nodes.

Like weaponIcons it is presentation only, applied only inside a live content match (the same gate as clones, so every peer runs the same rules), undone at the match end, and part of the content identity, so peers with a different vehicle mesh do not play together. How the name is found and swapped, and what is unverified in the game, is in meshes.md. Melange versions before 0.9.0 do not know the field.

Resolution

Thumper resolves the whole Mods\ folder as one pass, deterministically:

1. Parse and validate every folder. A manifest that fails the schema, has an unknown spiceVersion, or whose melange.range excludes the running build is incompatible and excluded from the graph entirely. Normally such a mod has already left Mods\ (see Compatibility sweep).
2. Build edges from dependencies (required), optional (soft, only when present and compatible) and loadAfter (ordering only).
3. Topologically sort, ties broken by id, ascending — the same mod set always resolves to the same order, regardless of folder creation order or scan order.
4. Conflicts and consent. A conflicts pair blocks both sides. A required dependency on a blocked mod blocks the dependant too (“blocked because X is blocked”). A cycle blocks every mod in it with one shared reason. An unsafe mod without a Deep Desert grant is pending-consent, not blocked — it still loads, with wum.unsafe raising until the user answers the prompt.

Content-mod changes need a restart. Message names are registered once per launch and never unregistered, so enabling or disabling a content-relevant mod takes effect at the next launch (shown as restart-required on the Mods page in the meantime). Client-only mods toggle live.

State

Choices persist in Mods\thumper-state.json (falling back to Documents\Melange\thumper-state.json if the game folder is read-only): which mods are enabled, load-order pins, Deep Desert grants, and whether the Mods pages show local plugins (showLocal, shared by the game and Melange.exe). It is written atomically and is safe to delete — Thumper rebuilds it (re-applying defaultEnabled for every mod as if freshly discovered).

A mod that keeps files of its own inside its folder should keep them in Mods\<id>\user\: the Store carries that folder over when it updates the mod, and a plugin’s release zip may not contain it. Folders starting with . are never mods (the Store keeps its own files in Mods\.store\, the compatibility sweep in Mods\.incompatible\).

Compatibility sweep

A mod this Melange can never load doesn’t stay in Mods\. When the game starts (before Thumper’s first scan, so no file in a mod folder is open yet) and when Melange.exe opens a game folder that the game isn’t running from, every folder is checked: a spice.json that does not parse (including an unknown spiceVersion), a malformed melange.range, or one the running version does not satisfy. A missing dependency, a conflict or a pending consent are not reasons: the user can fix those. A folder without spice.json is never touched.

• Store plugins (a record in Mods\.store\installed.json) are updated to the newest version the Store’s list has for this Melange and game build, or removed when a list fetched just now has none (keeping the map packs an importer made, and [Mod.<id>] settings and saved data). Melange.exe fetches the list for this, and only when such a plugin exists; the game uses the list it cached and never downloads, so there such a plugin only stays unloaded until Melange.exe updates or removes it. Offline, Melange.exe does the same: a cached list may predate the plugin release that supports a new Melange, so it is never reason enough to remove one. A Store plugin the list says is not built for this game build counts too.
• Local plugins move to Mods\.incompatible\<folder>\ (<folder>-2, -3, … when that exists; nothing is overwritten), with a .melange-quarantine.json beside its files saying why, against which version and when. Their thumper-state.json entries go. Move the folder back to try it again (it is moved out again while it still cannot load).

Each action is logged and leaves a notice in Mods\.incompatible\notices.json (the newest 50) that the Plugins page, the Thumper/Mods page and the Oasis Mods panel show until it is dismissed. [Thumper] SweepIncompatible=0 turns the sweep off (in the game and in Melange.exe): such mods then just show as incompatible and never load. While you work on a mod of your own, a typo in its spice.json moves it too: set the key to 0 for that.