
Modrinth · Minecraft mod
OS Cobblemon Library
A shared foundation for Cobblemon mod development across Fabric and NeoForge.
Quick answer
Which OS Cobblemon Library release should I use?
OS Cobblemon Library 1.5.2 targets 1.21.1 with NeoForge. Installation on the client is optional. Installation on the dedicated server is optional. All 2 required mods have matching files.
Where it goes
Is OS Cobblemon Library required on the client, server, or both?
Installation on the client is optional. Installation on the dedicated server is optional.
The source marks this as usable on both the client and server.
What else does OS Cobblemon Library 1.5.2 need?
1.5.2. Change the file and its required mods may change too.
Install Cobblemon, Kotlin for Forge first. We found matching files for this game-version and loader setup. 1 comes through another mod in the chain.
1 extra mod was pulled in by another dependency. Indented rows show who needs each one. We only count dependency files that match this setup. A file for another loader does not fill the gap.
Before you install it
Add OS Cobblemon Library without breaking your instance.
Built for OS Cobblemon Library 1.5.2. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use 1.5.2. It targets 1.21.1 with NeoForge; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
Install Cobblemon, Kotlin for Forge first. We found matching files for this game-version and loader setup. 1 comes through another mod in the chain.
- 03
Put it on the correct side
Installation on the client is optional. Installation on the dedicated server is optional.
- 04
Pick the file you checked
Use the “Get this file” button beside 1.5.2. It opens that exact file at the source.
About this project
What does OS Cobblemon Library add?
OS Cobblemon Library
A lightweight shared Cobblemon API and compatibility library for Fabric and NeoForge.
About
OS Cobblemon Library is a shared API and compatibility layer for Cobblemon mods.
It centralizes recurring Pokémon, storage, entity, event, battle and Pokédex integrations behind a focused public API, allowing projects to share the same implementation across Fabric and NeoForge instead of maintaining duplicated Cobblemon integration code.
The library intentionally provides infrastructure rather than standalone gameplay systems.
Highlights
- Pokémon identity, forms, aspects and marks
- Reusable Pokémon property matching
- Namespace-aware species resolution
- Command-free Pokémon creation and spawning
- Persistent namespaced Pokémon data
- Natural and effective IV inspection
- Ability classification and type helpers
- Native Pokémon size utilities
- Party and PC storage queries
- Pokémon entity identity, ownership and state
- Reusable Cobblemon event hooks
- Battle inspection and classification
- Pokédex progress and completion queries
- Shared Fabric and NeoForge integration layer
Requirements
Minecraft: 1.21.1
Cobblemon: 1.8.1 to <1.9.0
Java: 21
Loaders: Fabric & NeoForge
Use the file matching your mod loader.
Fabric
- Fabric Loader 0.17.2+
- Fabric API
- Fabric Language Kotlin
- Cobblemon 1.8.1 to <1.9.0
NeoForge
- NeoForge 21.1.182+
- Cobblemon 1.8.1 to <1.9.0
For Players
OS Cobblemon Library is primarily a dependency library.
It does not add standalone gameplay content by itself.
Install it when another mod lists OS Cobblemon Library as a required dependency, and make sure to download the JAR matching your loader.
If none of your installed mods require OS Cobblemon Library, installing it by itself will not add new gameplay features.
For Developers
OS Cobblemon Library provides a focused public API under:
com.ourstory.oscobblemon
The API is organized into reusable Cobblemon-specific domains:
pokemon- identity, matching, creation, persistent data, IVs, abilities, types, labels and sizeentity- Pokémon entity identity, ownership and statestorage- Party and PC access, lookup, matching and countsevent- reusable Cobblemon event subscriptions and lifecycle handlingbattle- battle inspection and classificationpokedex- species, form, variation and completion queries
Shared functionality is designed to remain loader-independent whenever possible, with Fabric and NeoForge modules handling platform-specific integration.
Pokémon API
The Pokémon API includes helpers for:
- Stable namespaced species identities
- Forms, aspects and marks
- Alpha compatibility
- Immutable identity snapshots
- Reusable
PokemonMatcherpredicates - Species resolution across namespaces
- Pokémon and PokémonEntity creation
- Direct server-side Pokémon spawning
- Namespaced persistent mod data
- Natural and Hyper Trained IV values
- Perfect IV counts and totals
- Common, Hidden, Forced and Unknown ability classification
- Current-form type inspection
- Data-driven labels
- Native size categories and safe scale values
Persistent data uses namespaced keys owned by the consuming mod, allowing projects to attach their own state to a Pokémon without copying Cobblemon integration logic.
Storage, Entities & Battles
PokemonStorage provides shared access to player Party and PC storage with:
- UUID lookup
- Party slot lookup
- Membership snapshots
- Predicate-based searches
- Predicate-based counts
PokemonEntities provides read-only helpers for:
- Underlying Pokémon access
- Pokémon UUIDs
- Owner UUIDs
- Battle state
- Busy state
- Evolution state
- Presence and alive checks
BattleInspector provides reusable battle information including:
- Wild battles
- Trainer battles
- PvP battles
- Battle actors
- Player UUIDs
- Participating Pokémon
- Fainted Pokémon
- Winners and losers
Event API
Version 1.1 expands the library with Java-friendly Cobblemon event hooks.
Supported event areas include:
- Capture calculations and completed captures
- Evolution
- Battle start and victory
- Fainting and fleeing
- Battle gimmick instructions
- Pokémon sending and recalling
- Healing
- Pokémon aspects
- Pokédex updates
- Pokémon spawning
- Entity save and load events
- Hatching
- Trading
- Releasing
- Nicknames
- Level changes
- Experience changes
EventSubscriptionGroup can also track multiple subscriptions and cleanly unsubscribe them together, making it useful for reloadable or optional systems.
Pokédex API
PokedexQueries provides read-only helpers for:
- Seen and caught species
- Form progress
- Aspect progress
- Shiny knowledge
- Global Pokédex counts
- Individual Pokédex counts
- Completion percentages
Documentation
Complete API documentation, integration guides and compatibility information are available online.
The documentation includes:
- Getting Started
- Public API Overview
- Integration Patterns
- Pokémon API
- Storage API
- Event API
- Battle API
- Pokédex API
- API stability policy
- Cobblemon update strategy
- Local development and Maven usage
License & API Use
OS Cobblemon Library itself is All Rights Reserved and distributed under the OS Cobblemon Library Proprietary API License.
Developers may build and distribute independent mods using the documented public API.
Using the API does not require consuming mods to publish or disclose their own source code.
Redistribution, modified builds, rebranding or copying Library source code are not permitted unless separately authorized.
Support the Project
Using OS Cobblemon Library in your project?
Support continued maintenance, compatibility updates and upcoming Our Story projects through Patreon.
For integration help, API suggestions, compatibility reports or bug reports, join the Our Story community on Discord.
Game Hosting
Need a server for your Cobblemon projects?
Host your server with BisectHosting and use code OURSTORY for 25% OFF.
Every purchase helps support the development of Our Story projects.
Project description from Modrinth.
Pick your setup
OS Cobblemon Library by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
1.21.1
2 loader buildsCheck the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
OS Cobblemon Library versions and loaders
1.5.2
os-cobblemon-library-neoforge-1.5.2.jar
10 Nov 2026
1.5.2
os-cobblemon-library-fabric-1.5.2.jar
10 Nov 2026
1.1.0
os-cobblemon-library-neoforge-1.1.0.jar
18 Sept 2026
1.1.0
os-cobblemon-library-fabric-1.1.0.jar
18 Sept 2026
1.0.1
os-cobblemon-library-neoforge-1.0.1.jar
16 Sept 2026
1.0.1
os-cobblemon-library-fabric-1.0.1.jar
16 Sept 2026
Looking for an older file? The official Modrinth project page is in Resources.