RetroAPI
Block, Item, Recipe, Entity, Dimension Registration API for Legacy Minecraft. Supports Ornithe and Babric. Optionally Works with StationAPI.
- Loaders
- OrnitheBabric
- Downloads on Modrinth
- 660
- Followers on Modrinth
- 2
- versions
- 34
- Updated
- August 16, 2026Aug 16
- Published
- in 2026
At a glance
Needed both in the game and on the server
RetroAPI
RetroAPI is a content-registration library for Minecraft Beta 1.7.3 that lets mods add blocks, items, recipes, entities, dimensions and more without requiring StationAPI. It runs on Ornithe (Fabric Loader + OSL) and Babric, and transparently delegates to StationAPI when that mod is also installed.
Developer Portal
To start developing for b1.7.3 with it go here!
https://matthewperiut.github.io/retroapi/index.html
What it implements
Registration
- Custom blocks and items with automatic, stable ID assignment - block IDs are expanded well past the vanilla 256 cap, and assignments persist across loads.
- Block entities without subclassing
BlockWithBlockEntity(RetroBlockEntityType). - Inventory / menu GUIs (chest, furnace and dispenser styles) with automatic slot sync (
@SyncField). - Crafting, smelting and furnace-fuel recipes (
RetroRecipes). - Custom entities with renderers, and custom dimensions reached through walk-in portal blocks.
- Achievements and achievement pages.
- Sound autoloading and automatic lang / translation generation.
Rendering
- Expanded texture atlas plus custom block and item renderers and render types.
Vanilla-safe world storage (sidecar system)
- All modded content is written to
retroapi/sidecar files keyed by string identifiers, so a world can be opened in vanilla without crashing or losing data and reopened in RetroAPI intact. - Covers extended block IDs, modded block entities, modded items inside vanilla containers, and dropped item entities.
Multiplayer
- OSL-based networking with server-to-client ID mapping sync and extended-block chunk sync.
StationAPI compatibility (optional, bundled)
- Ships a
retroapi-stationapicompanion that loads only when StationAPI is also present and delegates registration, rendering, dimensions and world conversion to StationAPI. With it, RetroAPI worlds round-trip through StationAPI's flattened world format without data loss.
Both jars include the StationAPI compatibility layer; it activates automatically if StationAPI is installed and stays dormant otherwise.
FAQ
How to install RetroAPI?
Install Ornithe for your Minecraft version, download RetroAPI for the same version and loader, put the file into the mods folder and launch the game with the loader profile.
Is RetroAPI needed on the server?
Needed in the game and on the server
Which mods is RetroAPI incompatible with?
The author lists it as incompatible with RetroTweaks, Retro Sprint and RetroCommands.