Crate map

mcrs is 122 crates under crates/, and you can take them one at a time. This page lists all of them by layer and marks the ones that CI builds without Bevy, without std or for wasm32. Use it to find the crate you need and to see what it brings with it.

WIP

A script made the crate tables from cargo metadata and the three lists in xtask/src/checks.rs, and the result was pasted here by hand. A generator that rebuilds them on every docs build is planned. Until it exists the tables can be out of date, so check the verified date at the bottom of the page.

How to read the tables

The crates are grouped into the seven layers of the README. Each layer should depend only on the layers below it, so you can take the lower layers and pay for nothing above them. A few crates do not follow this yet, because the protocol and network crates still reach into game data. CI checks only one part of the rule, which is that the wire and network crates do not link game data.

The layer of a crate is not stored anywhere in the code. It was assigned by hand from the README table and the crate description, and no check confirms it, so use it as a guide.

Each table has the same five columns. The crate name is the package name, and the other four come from these places:

Column	Where it comes from
Description	description in the Cargo.toml of the crate. Five crates had no description or only their own name, so theirs is written from the source files
No Bevy	NO_BEVY_PACKAGES in checks.rs. CI runs cargo check --no-default-features on these crates and fails if one requires Bevy
no_std	NO_STD_PACKAGES in the same file. CI builds these crates without std
wasm32	WASM32_PACKAGES in the same file. CI builds these crates for the wasm32 target

The no-Bevy list has 100 names. Six of them are tools under tools/, so among the 122 crates of crates/ the count is 94. The no_std list has 9 crates and the wasm32 list has 11. A dash means only that the crate is not on the CI list. The crate may still build that way.

Which crates to start with

The table below names the crates to start with for five kinds of project. None of them is published to crates.io, so every row needs a git dependency, which Use the crates in your project describes. There are no library examples yet, and the first working use is parsing SNBT.¹

You build	Start with	State
A proxy	mcrs_minecraft_protocol and mcrs_minecraft_network. Both are on the no-Bevy list, and xtask checks that they do not link game data	The crates exist. The proxy library itself, with routing and forwarding, is tracked in WIP#296, and online mode in WIP#82
A bot	The same two crates, plus mcrs_minecraft_client_world, which keeps the world state of a client without a window or a renderer. It is not on the no-Bevy list	The client state is split from rendering (Works#301). The walker bot is tracked in WIP#302
A map or a world viewer	mcrs_minecraft_anvil for regions (also on the wasm32 list), mcrs_minecraft_chunk and mcrs_minecraft_block for the data, mcrs_minecraft_mesh for meshes	The crates exist. Top-down tiles without a window are tracked in WIP#297, and a model viewer in WIP#298
A tool for NBT, commands or data packs	mcrs_minecraft_nbt, mcrs_minecraft_snbt, mcrs_command, mcrs_minecraft_datapack	The crates exist. mcrs_command and mcrs_minecraft_snbt read and write what the game reads and writes
A world generator preview	mcrs_minecraft_worldgen_generator and the mcrs_minecraft_worldgen_* crates	A preview by seed through the public API is tracked in WIP#299. The generator itself matches vanilla in parity tests on reference seeds

“The crates exist” means that they build in this repository. None of them promises a stable API, and only six crates have a README.

All crates by layer

Layer 1: Protocol

Crate	Description	No Bevy	no_std	wasm32
mcrs_command	A command tree, a parser and suggestions that agree with Brigadier, without allocation on the parse	yes	yes	-
mcrs_minecraft_chat	The chat rules that the client and the server share: the characters a message may hold, its length limit and its normal form	yes	yes	-
mcrs_minecraft_core	Directions, numeric operations, shapes, codecs and the version	yes	-	-
mcrs_minecraft_game_mode	The game modes of a player, their names and their wire forms	yes	-	-
mcrs_minecraft_keys	Names of the vanilla registries no crate keys by a type, with their entries and tags	yes	-	yes
mcrs_minecraft_nbt	NBT tags and compounds, the binary read and write in the Java big-endian and the two Bedrock little-endian encodings, and the serde codecs	yes	-	-
mcrs_minecraft_numeric	Bit-exact numeric operations: integer division, comparisons, interpolation, angle wrap, sine tables and the arctangent	yes	-	-
mcrs_minecraft_profile	Game profiles, their properties and the resolvable profile of a player head	yes	-	-
mcrs_minecraft_protocol	Protocol library for Minecraft: Java Edition: framing, compression, and the handshake, status, login and configuration packets	yes	-	yes
mcrs_minecraft_random	The random number generators of the game: legacy, xoroshiro and the worldgen forks	yes	-	-
mcrs_minecraft_resource	Resource locations, resource keys, tag keys, registry keys and registry ids	yes	-	-
mcrs_minecraft_snbt	The read and the write of stringified NBT as the game reads and writes it	yes	-	-
mcrs_minecraft_text	Text components: content, style, click and hover events, JSON and NBT codecs	yes	-	-
mcrs_minecraft_wire	Encode and decode traits, variable-length integers and primitive codecs for the Minecraft: Java Edition protocol	yes	-	yes
mcrs_minecraft_wire_macros	Derive macros for the codec traits of mcrs_minecraft_wire	yes	-	-
mcrs_molang	Molang compiler, scalar and batch evaluator, independent of any game host	yes	yes	-
mcrs_voxel	Block, section, column and local positions and the block state id of a voxel world	yes	yes	-

Layer 2: Network

Crate	Description	No Bevy	no_std	wasm32
mcrs_minecraft_network	Protocol library for Minecraft: Java Edition	yes	-	-

Layer 3: Game data and rules

Crate	Description	No Bevy	no_std	wasm32
mcrs_minecraft_anvil	Anvil region files: reading and writing chunks, palettes, retrogen	yes	-	yes
mcrs_minecraft_assets	Data pack loading: JSON loaders, the registry access and the load state	-	-	-
mcrs_minecraft_biome	Biomes, climate parameters and biome sources	yes	-	-
mcrs_minecraft_biome_file	The biome file as data packs write it, its built-in draft, and the columns it is stored as	yes	-	yes
mcrs_minecraft_block	Block and fluid definitions, block tags and map colours	yes	-	-
mcrs_minecraft_block_entity	Block entities in the typed shape the save, the chunk packet and the anvil reader share	yes	-	-
mcrs_minecraft_block_predicate	Block states, block predicates and block state providers as data packs write them	yes	-	-
mcrs_minecraft_brain	The AI stage of mobs without Bevy: the snapshot replica, the issue and the late application of decisions, keyed random values, the wake schedule and the goal selector	yes	yes	-
mcrs_minecraft_chunk	Chunk sections, palettes, light storage and column heights	yes	-	-
mcrs_minecraft_client_jar	Locates, downloads and unpacks the vanilla client jar	yes	-	-
mcrs_minecraft_collision_table	Builds the collision table of the physics kernel from the block definitions and the block tags	yes	-	-
mcrs_minecraft_command	The command source, permissions, identifiers, and the error text the vanilla argument families share, and the command packets of a player	yes	-	-
mcrs_minecraft_command_argument	The resource, keyword, coordinate, rotation, swizzle and time arguments	yes	-	-
mcrs_minecraft_command_argument_block	The block predicate argument and its test of a block state	yes	-	-
mcrs_minecraft_command_argument_entity	The entity selector argument and the search for the entities that a selector names	yes	-	-
mcrs_minecraft_command_argument_vanilla	The vanilla argument set, its errors, its parsers on the wire and the client command tree	yes	-	-
mcrs_minecraft_command_registry	The registries and the block table that a host lends to the command arguments	yes	-	-
mcrs_minecraft_command_tree	The nodes of the command tree that the commands packet carries	yes	-	-
mcrs_minecraft_damage	The hit procedure of a living entity without Bevy: the damage cooldown, the health change, the start of the death and the hit record	yes	-	-
mcrs_minecraft_datapack	The data pack stack: pack selection, pack.mcmeta, overlays, filters and the files each pack contributes	-	-	-
mcrs_minecraft_dimension	The dimension and dimension type registry values	yes	-	-
mcrs_minecraft_enchantment	The enchantment file and the keys of the enchantment registries	yes	-	yes
mcrs_minecraft_entity	Plain identity types of the entity domain registries and the type data table of the entity types	yes	-	-
mcrs_minecraft_entity_key	The keys of an entity without the physics kernel: its id, its UUID as its order key, the sources of a new UUID, its keyed random stream and the tile that holds it	yes	yes	-
mcrs_minecraft_entity_rows	The rows of the server entities by tile, with a column for the hot state of the mobs: the body grid, the merge point, the rest and wake of tiles and the entity pass over the physics kernel	yes	-	-
mcrs_minecraft_environment	Environment attributes, timelines and world clocks	yes	-	-
mcrs_minecraft_game_registries	Vanilla Minecraft block/item type vocabulary and static registries	yes	-	-
mcrs_minecraft_game_rule	Game rules, their categories, value types, defaults and bounds	yes	-	yes
mcrs_minecraft_goal_world	The read-only block world of the goals of mobs: the ground cell of a block position, the build height, the line of sight and the straight route on walkable ground	yes	yes	-
mcrs_minecraft_goals	The goals of passive mobs for the AI stage: float, panic, random stroll, look at a player and look around, the random position searches, the goal list of the pig and the brain of each mob type with goals	yes	yes	-
mcrs_minecraft_heightmap	The four column heightmaps, the block state predicates they test, and the descent that builds them	yes	-	-
mcrs_minecraft_item	Items, item data components, the component patch, the persistent item stack, enchantments and armour trims	yes	-	-
mcrs_minecraft_lang	A language file of the game: translation patterns by key, and the filler of their placeholders	yes	-	-
mcrs_minecraft_light_color	Light colours of block states and the light a held item emits	yes	-	-
mcrs_minecraft_light_engine	Block and sky light propagation over sections, without Bevy	yes	-	-
mcrs_minecraft_loot	The keys of the loot registries	yes	-	yes
mcrs_minecraft_mob_control	The per-tick controls of a mob without Bevy: the path follower of a straight route, the move control, the jump control, the look control and the body rotation	yes	-	-
mcrs_minecraft_move_predict	The movement checks with a world: the prediction of each client tick of a player from the physics model	yes	-	-
mcrs_minecraft_move_validate	The movement checks without a world: one serverbound packet, and the stream of one connection	yes	-	-
mcrs_minecraft_noise	Perlin, simplex, normal and blended noise and the interval and grid types they sample over	yes	-	-
mcrs_minecraft_particle	Particle types and their options as data packs and attributes write them	yes	-	-
mcrs_minecraft_physics	The entity physics kernel: boxes, block shapes, the collision algorithm, step-up and the move procedure	yes	-	-
mcrs_minecraft_predicate	The keys of the entity predicate and statistic registries	yes	-	yes
mcrs_minecraft_protocol_game	The play-state packets of Minecraft: Java Edition that carry game data: chunks, entities, items, recipes and chat	yes	-	yes
mcrs_minecraft_registries	Registry tables, tags and the registry loader	yes	-	-
mcrs_minecraft_registries_derive	The registry_value attribute and the Resolve derive of mcrs_minecraft_registries	-	-	-
mcrs_minecraft_registry_catalog	The entries of every static registry	yes	-	yes
mcrs_minecraft_save	The files of a world save other than its regions: the level, its world generation settings and each player’s file	-	-	-
mcrs_minecraft_simulation	Block simulation kernels: the step and update chain over a volume, their queues and ordering policies	yes	-	-
mcrs_minecraft_sound	Sound events	yes	-	-
mcrs_minecraft_text_flatten	A text component as flat runs of styled text: translations filled from a language, styles inherited, and the plain and the formatting-code strings made from the runs	yes	-	-
mcrs_minecraft_value_provider	Int, float and height providers and their codecs	yes	-	-
mcrs_minecraft_volume	One block access API over every store of world data: bounds, per-section access, section handles and cursors	yes	-	-
mcrs_minecraft_worldgen	The world generator: the worldgen registries, their loaders and the beardifier	yes	-	-
mcrs_minecraft_worldgen_builtin	The worldgen registry entries the game and the beta preset define, built by code	yes	-	-
mcrs_minecraft_worldgen_carver	Cave and canyon carvers	yes	-	-
mcrs_minecraft_worldgen_density	Density functions, their compiler and evaluator, the noise router and the aquifer	yes	-	-
mcrs_minecraft_worldgen_feature	Configured and placed features, placement modifiers, structure templates and the feature generators	yes	-	-
mcrs_minecraft_worldgen_feature_place	The feature generators: trees, ores, geodes, templates and the rest of what a placed feature writes	yes	-	-
mcrs_minecraft_worldgen_generator	The column pipeline of the noise chunk generator: fill, surface, carvers, features, structures and the read out of the save	yes	-	-
mcrs_minecraft_worldgen_structure	Structures, structure sets, template pools, jigsaw assembly and structure placement	yes	-	-
mcrs_minecraft_worldgen_structure_place	What the hardcoded structure pieces write: the piece canvas, the per-family painters and the after-place hooks	yes	-	-
mcrs_minecraft_worldgen_surface	Surface rules: the material rule compiler and evaluator	yes	-	-
mcrs_minecraft_worldgen_testing	The shipped asset corpus and the oracle dumps, read for tests	yes	-	-

Layer 4: Engine

Crate	Description	No Bevy	no_std	wasm32
mcrs_engine_cell	Worlds that tick in lockstep: owned input in, owned output out, each world placed inline or on a thread of its own	yes	-	-
mcrs_engine_link	The link between two parts of the engine: owned messages in, owned messages out, with the far end placed inline or on a thread of its own	yes	-	-
mcrs_engine_muxer	Fans the changes of a world out to its viewers: tiles and tile streams for entities, version streams for chunks, and bytes encoded once and shared	yes	-	-
mcrs_engine_store	The data layer: versioned chunks by key in an in-memory cache over a disk store that the game supplies, reached as a stage on a link	yes	-	-
mcrs_minecraft_chat_server	The chat handling of the server as a plugin that a user can replace	-	-	-
mcrs_minecraft_command_engine	The command tree, the registration of commands and the run of the command lines of the players inside the tick of each dimension world	-	-	-
mcrs_minecraft_dimension_environment	Dimension types and the environment attribute layers of a dimension	yes	-	-
mcrs_minecraft_engine	The packet bus, the bridge between the network and the dimension worlds, sessions, the host side of the dimension channels, the player state that the host and the dimensions share, the world clocks of the host, and heightmap upkeep	-	-	-
mcrs_minecraft_engine_brain	The AI stage of the mobs of a dimension world: the host that publishes the snapshot of the mob rows, runs the stage per tile beside the entity pass, applies the decisions through the mob controls and steers the rows	-	-	-
mcrs_minecraft_engine_mob_replication	The replication projection of the mobs of a dimension world in Bevy: reads the row store and the mob changes of the tick and writes the tile events of the mobs for the muxer	-	-	-
mcrs_minecraft_engine_physics	The entity pass of a dimension world in Bevy: the row store as a resource generic over the mob column, the merge point, the freeze and the pass as systems, the row-only items, and the mob rows with their life cycle and tile events	-	-	-
mcrs_minecraft_engine_registries	Loads the registries, blocks and items of an app from its pack files, walks it to playing, and hands the snapshot to each dimension world	-	-	-
mcrs_minecraft_engine_server	The server plugins of the engine without vanilla behaviour: the core, the dimension worlds, the listener with login, configuration, keep-alive and status, and the server loop	-	-	-
mcrs_minecraft_engine_world	Chunk and column entities, dimensions, tickets, area of interest, sessions, the server loop, block updates and drops, game rules, and the world seed, birth clock and entity ids that new entities take	-	-	-
mcrs_minecraft_replication	The Minecraft side of entity replication: the muxer codec for players and mobs, mob trackers, delta bases for moves, spawn bundles, profile entries and the player list policy, as encoded packets	yes	-	-

Layer 5: Vanilla

Crate	Description	No Bevy	no_std	wasm32
mcrs_minecraft_command_vanilla	The vanilla commands execute, gamemode, teleport, locate, summon and time, and the command effects they write	-	-	-
mcrs_minecraft_command_world	The commands that change the world and the server: fill, forceload, gamerule, weather clear, and tick query and sprint	-	-	-
mcrs_minecraft_vanilla_light	Vanilla light wired into the dimension worlds: the block light table, the light engine driver of each dimension and the light updates sent to the players	-	-	-
mcrs_minecraft_vanilla_worldgen	World generation wired into the dimension worlds: the routers, carvers, features and structures of each dimension, and the column scheduler that generates or reads its columns	-	-	-

Layer 6: Rendering

Crate	Description	No Bevy	no_std	wasm32
mcrs_minecraft_entity_animation	Entity animation on the CPU: clips, keyframes, the play list of a client entity, its scripts and the bone pose of a frame	yes	-	-
mcrs_minecraft_entity_model	Entity geometry files of the Bedrock format: reading, baking to a static model and the GPU model records	yes	-	-
mcrs_minecraft_entity_render	GPU-driven entity rendering: persistent slots, the entity cull, the pose and expand passes and the gbuffer draw of the face records	-	-	-
mcrs_minecraft_light_render	Coloured block light for the lighting pass: a paged light volume propagated on the GPU	-	-	-
mcrs_minecraft_mesh	Section meshing: greedy cube faces, fluids, block models, the packed quad layout and the buffer arena	yes	-	-
mcrs_minecraft_model	Block and item models baked from a Minecraft resource pack: the pack, model files, sprite atlas, block catalog and item model trees	-	-	-
mcrs_minecraft_model_file	Block model files, block state files and the face bake of a resource pack, with no Bevy	yes	-	-
mcrs_minecraft_pack_file	Files of an entity pack: lenient JSON, the client entity file, load diagnostics and the compile of Molang fields	yes	-	-
mcrs_minecraft_render	Deferred terrain and sky renderer: a G-buffer, one fullscreen lighting pass and forward translucents, drawn in ordered world pass stages	-	-	-
mcrs_minecraft_render_controller	Render controllers of a client entity: the layers, their geometry, texture and visible bones in a frame	yes	-	-
mcrs_minecraft_render_probe	GPU pass timings, CPU stage timings, draw counters and GPU warm-up for the terrain renderer	-	-	-
mcrs_molang_wgsl	Lowering of pure Molang channels to WGSL and the WGSL math library	yes	yes	-

Layer 7: Applications

Crate	Description	No Bevy	no_std	wasm32
mcrs_minecraft_chat_client	The client chat screen without rendering: the input box, the history, client-side command suggestions, hint lines and the chat log	yes	-	-
mcrs_minecraft_client	Minecraft client: window, asset corpus, environment registries and the voxel renderer	-	-	-
mcrs_minecraft_client_entity	The client state of the entities that the server adds: movement, interpolation, head and body yaw, walk, hurt and death, and the values a renderer reads	-	-	-
mcrs_minecraft_client_gui	The GUI of a Minecraft client: hotbar, inventory and chat screens, game mode switcher, slot item models and the F3 debug screen	-	-	-
mcrs_minecraft_client_world	The world state of a Minecraft client without a window or a renderer: session registries, columns, the local player, game mode and chat	-	-	-
mcrs_minecraft_console	The server console: command lines from the standard input, run as the server, and their answers in the log in English	-	-	-
mcrs_minecraft_server	The server app: the plugin group that puts vanilla behaviour on the engine server	-	-	-
mcrs_minecraft_server_settings	The settings of a server run that the MCRS_ environment variables set, read in one place	yes	-	-

Support

Crate	Description	No Bevy	no_std	wasm32
mcrs_test_alloc	A global allocator that counts the allocations of the calling thread, for tests	yes	-	-

Why some crates need Bevy

Below layer 4, Bevy is an optional feature, and below layer 2 so is tokio. From layer 4 up, Bevy is required, because the engine, the vanilla plugins, the client and the server are Bevy plugins. If you only want data types and codecs, stay in layers 1 to 3 and build with --no-default-features. Layers covers layers 4 and 5.

Footnotes

1. WIP#287 Plans the minimal server, lobby and arena examples. ↩