J's Core
The shared foundation of the J's Tech Series — and a powerful framework for building technology mods in Minecraft.
J's Core is a library and framework for Minecraft 1.21.1 (NeoForge), providing the systems, utilities and shared content used throughout the J's Tech Series.
Rather than adding a separate gameplay experience, J's Core focuses on providing a common technological foundation, allowing different mods to share materials, communicate through networks, interact with machines and integrate with each other.
Although originally developed for the J's Tech Series, J's Core is also available for other mod developers who want to build their own technology mods using its systems.
What Does J's Core Add?
Shared Materials and Content
J's Core provides the common material system used across the J's Tech Series, avoiding duplicate items between mods.
It also provides the shared cable block and the Technical Reference manual.
The shared materials can be used by different mods without requiring those mods to depend directly on one another.
Technical Reference — In-Game Documentation
J's Core includes the Technical Reference, an interactive manual that brings together documentation from the installed mods of the series.
Features include:
- Chapters dedicated to each installed mod.
- Searchable pages, indexes and tables of contents.
- Detailed explanations of machines, items, recipes and systems.
- Illustrations, technical diagrams, tables and troubleshooting instructions.
- Context-sensitive access to documentation by holding the manual key over supported items.
- Navigation between related entries and manuals.
- Persistent reading positions between sessions.
The Technical Reference is automatically given to players when they first join a world.
Unified Cable and Network Framework
J's Core provides the foundation for the cable systems used throughout the series.
Its modular architecture supports:
- Multiple independent cables inside a single block, using up to nine lanes.
- Data, energy, fluid, heat, gas, motion and peripheral connections.
- Different cable generations, throughput limits and connection rules.
- Cable colouring, junctions and multipart attachments.
- Network topology and device connectivity.
- Point-to-point peripheral connections.
This allows different technological systems to coexist without requiring separate blocks for every connection.
Energy, Fluids and Resource Transfers
The Core includes reusable systems for managing resources between machines and devices.
These include:
- Forge Energy (FE) distribution.
- Energy storage, transfer limits and configurable losses.
- Fluid tanks and fluid transportation.
- Item transfer and filtering.
- Configurable machine input and output faces.
- Support for chemical storage and transfer through optional integrations.
These systems use NeoForge capabilities to support interoperability with other technology mods.
Operations and Task Management
J's Core includes the Operations Framework from J's Computers, providing a common foundation for the tasks executed across technological networks.
It supports:
- Registered operation types and handlers.
- Operation queues and execution states.
- Priorities and priority aging.
- Progress tracking, latency and timeouts.
- Cancellation, failure and completion handling.
- Lifecycle events that other mods can observe.
This framework is particularly important for J's Computers and its network-based automation systems.
Machines, Multiblocks and Automation
J's Core also provides reusable tools for developers to create technological machines and processing systems.
The framework includes:
- Processing machines with inventories, fluid tanks and energy storage.
- Configurable processing recipes and machine upgrades.
- Data-driven multiblock structures and validation.
- Multiblock ports and controller connections.
- Shared machine components and state synchronization.
- Recipe viewer integration with JEI and EMI.
These are framework capabilities for mods built on J's Core, rather than a complete collection of standalone machines.
User Interfaces and Visual Systems
J's Core includes a reusable GUI toolkit for the J's Tech Series and third-party developers.
It provides:
- Custom screens, layouts and interface components.
- Skins and themes based on different technological eras.
- Configurable colour palettes with resource-pack support.
- Font and text rendering utilities.
- Animation curves and configurable motion profiles.
- Pixel-based and GPU-backed rendering surfaces.
- HUD elements, overlays and holographic displays.
The Core also provides a settings interface for configuring supported mods directly in Minecraft.
Advanced Sound System
J's Core includes a shared audio framework for machines, computers and other technological devices.
Features include:
- Independent sound channels and volume controls.
- An in-game Sound Mixer.
- Individual sound muting and alert controls.
- Positional audio, occlusion and sound management.
- Context-sensitive sound cues.
- Procedural sound generation and synthesis.
- WAV and Ogg Vorbis audio support.
- Shared audio recordings with server-side storage and client caching.
The framework allows different mods to use a common audio architecture instead of implementing separate systems.
Additional Framework Features
J's Core also includes many other systems for mod developers, including:
- World generation helpers for ores, structures and dimensions.
- Runtime dimensions and environmental rules.
- Chunk loading and spatial data management.
- Player progression, hardware eras and industrial tiers.
- Ownership, team permissions and access control.
- Entities, vehicles, robots and projectiles.
- Persistent world data, scheduling and state management.
- Programming language registries and extension APIs.
- Data generation tools for blocks, items, recipes, models and translations.
- Unit testing and GameTest utilities.
These systems help reduce duplicated development work and provide a consistent foundation for complex technology mods.
Part of the J's Tech Series
J's Core is the shared code library used by the J's Tech Series.
The series currently includes:
- J's Core — The shared library and technology framework.
- J's Computers — Computers, operating systems, networking, storage and automation.
- J's Industrial — Industrial machinery, energy and processing systems.
More mods are planned as the series expands.
Each mod is designed to remain independently installable, requiring J's Core rather than the other mods in the series. When installed together, they can integrate through their shared foundation without any duplication or other classic problems in tech mods since they all use the exact same foundation.
J's Core is not a standalone technology progression mod. Its primary purpose is to support other mods and provide reusable infrastructure.
For Mod Developers
J's Core is also designed to be useful beyond the J's Tech Series.
Developers can build their own mods on top of its systems, use its documentation and extend supported registries.
The library provides APIs for programming languages, network Operations, rendering and other integration points, alongside broader reusable frameworks.
Please note: J's Core is currently in alpha development. Its versioned API is not yet considered fully stable, and some interfaces may change between releases.
For documentation and examples, visit the J's Core Developer Documentation.
Requirements and Compatibility
- Minecraft: 1.21.1
- Mod Loader: NeoForge 21.1.248 or newer
- Current version: 0.5.2a (Alpha)
- Mod ID:
jscore - License: LGPL-3.0-only
All installed J's Tech Series mods should use matching versions.
J's Core also provides optional integration with other mods and ecosystems, including JEI, EMI, Jade, FTB Teams, Mekanism, KubeJS, Curios and Accessories.
These integrations do not make those mods mandatory dependencies.
Alpha notice: The J's Tech Series is actively developed. Updates may introduce breaking changes, including world incompatibilities. Back up important worlds before updating.
Coming in the Next Version — Carbon (v0.6.0a)
Carbon is a major expansion of J's Core, transforming it from a shared technology library into a much more comprehensive framework for technological, industrial and scientific systems.
The following features have already been introduced in the Carbon development branch and are being prepared for the next release.
Materials, Chemistry and Science
- Expanded Material System: A fully extensible material registry with automatically generated items, blocks, textures, properties and material forms.
- The Periodic Table: Support for all 118 known chemical elements, their isotopes and additional theoretical elements up to atomic number 250.
- Exotic Matter: New material categories including neutronium, strange matter, metallic hydrogen, dark matter, quark-gluon plasma and more.
- Minerals and Ores: Mineral families, chemical compositions, byproducts, geological properties and ore generation.
- Shared Components: Common industrial materials, fuels and technological components, dynamically registered according to the mods installed.
Energy, Machinery and Infrastructure
- J's Energy: A new energy system based on real-world units, with voltage classes, power distribution, electrical losses and compatibility with Forge Energy.
- Electrical Equipment: Batteries, energy converters, fuses, protection devices and diagnostic instruments.
- Advanced Cable Networks: Overhead power lines, improved cable placement, configurable connections, network monitoring and resource transportation.
- Mechanical Power: Shafts, gears, gearboxes, flywheels, clutches, motors and dynamos using RPM, torque and real power calculations.
- Thermodynamics: Heat conduction, thermal capacity, temperature simulation, boilers, steam and environmental heat exchange.
- Conveyor Systems: Extensible conveyor belts, including slopes, sorting and item transportation.
Multiblocks, Multipart and Construction
- Advanced Multiblocks: More sophisticated structures with configurable patterns, ports, controllers and formation rules.
- Structure Projector: Preview multiblock structures directly in the world before building them.
- Multiblock Builder: Inspect and diagnose multiblock construction.
- Microblocks and Multipart: Multiple components occupying the same block space, including panels, covers, facades and custom parts.
- Construction Tools: New tools for cutting, configuring, inspecting and assembling technological infrastructure.
- Improved Machines: Shared machine interfaces, configurable inputs and outputs, processing upgrades and more advanced recipe handling.
World Generation and Environmental Simulation
- Advanced World Generation: Geological layers, mineral veins, underground reservoirs, configurable terrain, landforms and structures.
- Dynamic Environments: Extended climate, weather, wind, seasons and dimension-specific environmental rules.
- Atmospheric Simulation: Oxygen, pressure, gas composition, breathing and sealed-room mechanics.
- Radiation and Pollution: Environmental contamination, radiation exposure, radioactive materials, pollution propagation and protective equipment.
- Environmental Hazards: Heat, toxic substances, atmospheric dangers and other hazards affecting players and the world.
- Advanced Fire and Explosions: Energy-based explosions, pressure waves, fire propagation, smoke and firefighting equipment.
- Improved Chunk Loading: The Space Persistor and configurable chunk-loading limits.
Graphics, Interfaces and Audio
- New GUI Framework: Data-driven interfaces with advanced layouts, custom styles and more interactive components.
- Improved Configuration Screens: Searchable settings, presets, import/export, visual controls and server-side configuration management.
- Advanced Rendering: Animated models, connected textures, improved lighting and new model-rendering capabilities.
- Dynamic Lighting: Coloured lights, portable light sources, spotlights and visual glow effects.
- Visual Effects: Data-driven particles, electric arcs, beams, environmental effects and an in-world effects editor.
- Enhanced Audio: Environmental acoustics, sound propagation, echoes and more realistic interactions with surroundings.
- Notification System: Configurable notifications, alerts and notification history.
Developer Framework and Server Improvements
- Expanded API: New developer-facing systems for networking, asynchronous tasks, serialization, optional integrations and UI rendering.
- Improved Development Tools: Automatic resource reloading, data-generation validation and clearer error reporting.
- Performance Diagnostics: Profiling, network bandwidth monitoring, health reports and server performance analysis.
- Permissions and Protection: Improved ownership, team permissions, claim compatibility and audit logging.
- Background Processing: Asynchronous task execution and better management of expensive operations.
- Better Extensibility: More registries and reusable frameworks for developers building their own technology mods.
Development Status
Carbon (v0.6.0a) is currently under active development. These features are present in the development branch but are not yet part of the current stable publication on CurseForge.
Features may be adjusted, expanded or refined before release.
Follow development on GitHub — Carbon Development Branch.
Links and Source Code
J's Core is open source and developed by jvpts11.
- GitHub Repository: https://github.com/jvpts11/js-tech-series
- J's Core Documentation: https://github.com/jvpts11/js-tech-series/tree/main/core/docs
- Changelog: https://github.com/jvpts11/js-tech-series/blob/main/core/CHANGELOG.md
- Releases: https://github.com/jvpts11/js-tech-series/releases
- Issue Tracker: https://github.com/jvpts11/js-tech-series/issues
Licensed under the GNU Lesser General Public License v3.0 only (LGPL-3.0-only).
J's Core — One foundation, an entire technological ecosystem.
J's Core Team
