YSM Mapping API

Development status: YSM Mapping API is under active development. Breaking changes may occur before a stable release.

YSM Mapping API is a library and dependency mod for other mods that integrate with Yes Steve Model (YSM).

Because YSM's internal classes, methods, and fields are obfuscated, integrations based on hard-coded runtime names can be fragile. During Minecraft startup, YSM Mapping API analyzes the bytecode structure of the installed YSM JAR and exposes verified matches to dependent mods as typed semantic symbols.

This mod does not add items, blocks, models, menus, or standalone gameplay features. Install it when another mod lists YSM Mapping API as a required dependency. Yes Steve Model is required separately and is not bundled.

Supported Versions

• Minecraft 1.20.1 only

  • Fabric Loader 0.16.0 or newer
  • Forge 47.4.10 or newer
  • Java 17

• Minecraft 1.21.1 only

  • Fabric Loader 0.16.0 or newer
  • NeoForge 21.1.235 or newer
  • Java 21

• Yes Steve Model 2.6.0 or newer is required for both versions.

Files are specific to their Minecraft version and mod loader. Use only the JAR matching your exact environment. A newer YSM build may leave individual symbols unresolved if its structure cannot be verified; the API does not guess unknown mappings.

Local Cache and Settings

The following files are generated automatically:

config/ysm_mapping_api/
├─ settings.json
└─ mappings.json

mappings.json stores the last successfully analyzed mappings. It is reused when YSM and the set of requested symbols have not changed, and is replaced only after a new analysis completes successfully.

For Mod Developers

Consumer mods declare their required symbols in:

META-INF/ysm-mapping-api/requests-v1.json

After initialization, mods can resolve typed mappings with YsmMappingApi.resolve(...), use curated semantic keys from YsmSymbols, or define consumer-specific keys.

Mixin integrations can use the supplied plugin and runtime reference-mapper wrapper with source aliases. The current curated registry covers areas such as YSM networking, client/server model synchronization, model and texture access, audio caches, player and animation state, equipment hooks, bones, and renderers.

Manifest documentation and integration examples are available in the source repository. Problems can be reported through the issue tracker.