Capability::ALL is 9 with Input; the SDK re-exports command and input;
the API reference is regenerated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The usage line, the docs and the website list `test` with main's
`new --template code|content`; the code template keeps tests/hello.toml.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Both add a Capability variant: the list holds 8 now. The SDK re-exports
both interfaces; the API reference is regenerated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The built-in extras become official mods; these are the calls the FPS
counter and keystrokes overlay need to look and behave the same:
- render.set-corner(corner, w, h, shapes): a box the game places with
its own corner stacking (under the status effects, with the overlays
and hud panels), clear-corner; text-width(text) in the HUD font
(advances for U+0000..U+024F, 6 otherwise); frame-stats(): the game's
FPS counter (fps, min, 1% low).
- input.mapping(name): a movement or click mapping's key label and
whether it is held; clicks-per-second() for attack and use.
- ui: a button widget (200 x 20, select(id, 0)) for settings pages.
- The game keeps its FPS and click counters running while a mod runs,
and refreshes the snapshot every frame for mods with a frame hook.
- The ui test guest gains /corner and /readings, with a sandbox test.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- WIT `input`: claim-items(ids) makes the use button on those items the
mod's: use-start, then use-stop with the ticks held (button up, item
out of the hand, or a screen opening); the game does nothing else
with the click. register-key(name, label, key) for up to 16 keys
(key.keyboard.r), heard as key-down / key-up while playing; the
game's own mapping on the key still runs. held(), poll() (256 kept).
- game/mod_input.rs: play_mouse asks mod_use first (local and remote
windows), the tick ends a use whose item left the hand, the keyboard
and horizon-ctl's key send the physical key to mod_key.
- No claim and no key, no cost: one check each.
- Experimental: the manifest needs experimental = ["input"].
- The ui test guest gains /input_claim, /input_poll and /input_held,
with a sandbox test. Docs: mods.md, stability.md, the changelog, the
regenerated reference.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Mods draw through the game's own renderer, never their own shaders:
- WIT `render`: set-hud(shapes) with fill, quad (any four corners),
sprite (the game's GUI sprites), item (scaled) and text shapes, up
to 1024, kept until replaced; gui-size(); shake(strength, seconds).
- Drawn over the HUD after the extras, under chat and screens, hidden
with F1 (game/mod_render.rs). Colours are 0xAARRGGBB.
- shake turns the view, not the player: jolts fade out squared, add up
to 1, at most 3 degrees of yaw and 2 of pitch, scaled by Distortion
Effects (screenEffectScale; 0 turns it off).
- Experimental: the manifest needs experimental = ["render"].
- No mod drawing, no cost: an empty iterator and an is_empty check.
- cargo horizon-mod check reports shakes and HUD shapes. The ui test
guest gains /render_hud, /render_clear and /render_shake, with a
sandbox test; HudBatch gets fill_quad.
- Docs: mods.md, stability.md, the changelog, the regenerated reference.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Server mods get interface world: get-block(dimension, x, y, z) reads a
loaded chunk's block state as "minecraft:oak_log[axis=y]", get-biome its
biome ("minecraft:plains"), and
set-blocks(dimension, changes) sets up to 4096 blocks per call, checked at
once, made as /setblock makes them (place_state: neighbours, light, block
entities, every client told through the block log) after the call, before
that dimension's next tick.
Reads cost no copy: for a mod call the game lends Mods the levels' chunk
maps (moved out with mem::take and put back after), only while a running
mod has world. Writes for a level that isn't ticking (another dimension,
in-frame) wait for it, up to 65,536.
Test scripts get blocks (setup) and expect.blocks; cargo horizon-mod check
reports a trial run's block writes. Example beacons: /beacon builds a
glowstone pillar beside the player, /ground reads the block underfoot and the biome.
parse_state is now a free function so the mod path shares it.
Docs: docs/mods.md (the capability, script keys), docs/api/mods.md and the
regenerated reference.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The game that simulates a world now starts its server mods (API 0.3,
experimental): single player's server thread, single player in-frame
(beside client mods), a LAN host either way, and the dedicated server.
Windows that are clients of a server never run them.
game/server_mods.rs: tick_server_mods at the end of the tick diffs the
players (player_joined, player_left), delivers the tick's chat and block
events in order, then calls tick. Block events come from players' breaking
and placing (the acting player is the guest during as_guest); chat from the
local chat path and the hub's new HostEvent::PlayerChat; a guest's /command
reaches its mod before vanilla's dispatcher. tell and command replies go to
their player (the window's chat or a SystemChat); broadcast goes to every
player and the log.
--dev-mod now works on the server thread, and servers check a dev mod's
file once a second from their tick. Every hook returns at once when no
server mod runs; without the mods feature they are empty stubs.
Docs: docs/mods.md (where server mods run, when hooks run, not yet),
docs/api/mods.md.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- `new --template content`: a content mod with one block (Glowing Amethyst,
copying vanilla's amethyst block) and its block state, model, item model,
name, loot, recipe and pickaxe tag; `--template code` is the default.
- `build` packs the mod's `assets/` and `data/` (read and checked as the
game reads them) beside the component; a folder without `Cargo.toml` is a
content mod and needs no compiler.
- `check` takes a `.hmod` with no `mod.wasm`: "no code: content only,
nothing to run" instead of the trial run, which refused it, so the
registry can publish content mods.
- The guide (content mods, make a mod) and docs/mods.md, docs/api/mods.md
say so.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Six pages under a "Make a mod" group of the docs: set up and see a mod in
the game (the launcher's Game arguments or cargo horizon-mod run), the
manifest and every capability, the hooks and calls with a worked example
(Playtime, built and checked), content mods, testing and check, and
publishing (minisign signing, the submit form, review, updates). /mods,
the submit page, the docs index, Mods and data packs and the Mod API link
to it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A server mod runs where the world is simulated. Its manifest says side =
"server" and api = "0.3" (only a server mod may), and its component targets
the new WIT world horizon-server-mod:
- imports log and storage as client mods do, and the new capability players:
online() (id, name, position, dimension, game mode, health), tell(id, text),
broadcast(text), 8 lines per call shared with chat;
- exports server-events: init, tick, player-joined, player-left, chat, command
(with the player who typed it; its feedback goes back to that player),
block-broken and block-placed (with the block state as text).
horizon-mods: a second bindgen world sharing log and storage with the first;
a running mod holds either kind of hooks; Mods::load_for(Runs) starts only the
mods a game runs (the window client mods, the world's server server mods,
in-frame single player both) and marks the others Elsewhere. Client and server
commands are owned separately. The game passes Runs::Client for now, so
nothing changes in game until its server code calls these hooks.
The SDK gains horizon_mod_sdk::server (ServerMod, Registration,
export_server_mod!), the example server mod welcome (greets, announces
newcomers kept in storage, /online, /mined), and cargo horizon-mod check's
trial run plays a server mod with a player joining, chatting, typing its
commands and leaving. The manifest refuses client capabilities on a server
mod and players on a client mod. The generated reference, the guide, the
portal and the stability table describe it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A mod's tests/<name>.toml scripts run in the sandbox the game uses, with no game
and no window. The runner plays the game's part (the player and clock the mod
reads, ticks, frames, chat lines, commands, a reload) and each step checks what
the mod did: its commands, chat lines, command feedback and errors, HUD panel
and corner, or that it was turned off. A failing step names itself and prints
expected against got. Each script runs on a scratch copy, so storage starts
empty and is removed afterwards.
horizon_mods::testing (feature runtime) holds TestGame and Script; the cargo
subcommand builds the mod (or takes --hmod), filters scripts by name, and fails
when one does. The template gains tests/hello.toml, coords-hud gains panel and
where scripts, and the sandbox tests run the example's scripts and check the
runner's failures, reload and expected stops. Scripts don't care what language
the mod is written in, so script mods (Lua) get the same runner.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
docs/api/mods.md gets "Ways in": one API (the WIT world) and one sandbox
(WebAssembly) for every language. Rust is first-class; Lua scripts are
planned, run by an interpreter that is itself a WebAssembly mod linked with
the script's capabilities only, with hot reload of the script; C, C++, Zig,
TinyGo, AssemblyScript and JavaScript/TypeScript are to be evaluated, each
listed with its cost measured against Rust.
Server mods are their own line (api 0.3); block entities are no longer
tied to a draft. Promotion to stable: the orchestrator proposes with the
evidence, Ludovic approves.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
docs/api/ gets one page per surface other programs build on (mods,
shaders, agent control, servers, the launcher, data formats), each with an
overview measured from the source, the guide, the generated reference, examples,
its stability, what is not there yet and a changelog, plus the policy every
API follows (docs/api/stability.md): a version per API, semver lines,
experimental / preview / stable, deprecation windows, compatibility tests and
the level of every part today.
The website gets a "Build on Horizon" page (website/docs/apis.md) that
summarises them and links the repository's pages.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Ludovic Marie