env.json
by MModding
env.json is a small Fabric library for reading env.json files, a sub-JSON format that lets resources redirect by environment context.
What it does
The library converts env.json files into Java objects and provides the parsing step behind that conversion. Resources expose an EnvJson object through a getEnvJson call on the extended resource, and parsing works from either a Path or an InputStream. The format itself does not redirect anything on its own; it only supplies the operations that redirection tools build on, applied during resource reload.
Two official implementations build on the library: Environment Driven Assets (EDA) and Environment Driven Data (EDD). Environment Driven Assets is the one that uses it most often, covering Minecraft asset types and data types. A file must be registered under the format to take part, and a redirected resource is named by its original name with the extension .env.json appended. Files are published for Fabric and Quilt on 1.20.1 – 1.21.1, with Fabric API required on both loaders. The library runs on the client or the server, and neither side strictly needs it. It is not open source and is distributed under a custom license.
Key features
Parsing env.json files
Files are parsed from a Path or an InputStream into an EnvJson object that code can read.
Resource access
Each resource exposes its env.json data through getEnvJson on the extended Resource type.
Asset and data operations
Operations apply to both Minecraft vanilla asset types and vanilla data types during resource reload.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Required by 1 mod
Use cases
Who it’s for: Mod developers writing resource redirection systems on Fabric or Quilt, and anyone installing Environment Driven Assets or Environment Driven Data, which both rely on it.
How it compares
UltraLib is a Fabric library, for 1.20 – 1.21.10, that runs on the client and server together under All rights reserved and is not open source. Data Outside Minecraft Environment is open source under the BSD 3-Clause License, supports Fabric and Quilt, but covers only 1.19.4 – 1.20.1 and is client-side only. env.json itself is not open source and sits on the client or server side, with optional installation.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| env.json | Fabric and Quilt | 1.20.1 – 1.21.1 | Client or server, optional | 2024-09-09 |
| UltraLib | Fabric | 1.20 – 1.21.10 | Client and server | 2025-11-22 |
| Data Outside Minecraft Environment | Fabric and Quilt | 1.19.4 – 1.20.1 | Client-side only | 2023-08-21 |
Questions
Does env.json need Fabric API?
Which loaders does env.json support?
Does env.json have to be installed on the server?
In the catalog
env.json is one of 3,514 Library mods on ModsFinder, and one of 2,348 Library mods for Fabric. 32,366 mods support Minecraft 1.21.1.
More from MModding
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What the author says
env.json is a Minecraft Library introducing a new sub json file extension format, with the goal of redirecting minecraft resources to other ones based on the environment context. env.json doesn't provide these redirections directly, but only the operations around env.json files and their resource reload management.
Official listing
- Modrinth page
- modrinth.com/mod/env.json
- Owner
- MModding
- Published
- 2023-12-30
- Updated on Modrinth
- 2024-09-09
- Facts verified
- 2026-10-15