Minecraft resource pack converter in one codebase: HTTP server, in-browser WebAssembly, pack repair
Website · Stack · Quick start
What it is
packconv converts Minecraft Java Edition resource packs between versions 1.7.2 and 26.3, in both directions. It also has a repair mode for badly saved files (PNG, JSON, animations) that old versions tolerated and new ones may reject.
It is pure Rust: ZIP and RAR (1.3, 4, 5) archives are unpacked in memory, with no external programs and no C dependencies. The same core runs as an axum HTTP server and as a WebAssembly module in the browser, where the pack is never uploaded.
Technical Stack
| Layer | Technology |
|---|
| Core | Rust 2021, crate packconv-core (zip, image, png, rars, serde_json) |
| Server | packconv-server: axum 0.8, tokio |
| Browser | packconv-wasm: wasm-bindgen 0.2.126, static HTML in web/, converter runs in a Web Worker |
| CI/CD | GitHub Actions builds the wasm and deploys GitHub Pages on every push to main |
Quick start
cargo build --release -p packconv-server # binary: target/release/packconv
target/release/packconv # listens on 0.0.0.0:8080
curl --data-binary @pack.rar "http://localhost:8080/convert?to=26.3" -o out.zip
Browser build (needs the wasm-bindgen CLI 0.2.126):
scripts/build-wasm.sh web && cp -r pkg web/pkg # then serve web/ with any static server
Tests:
cargo test -p packconv-core
scripts/e2e.sh <directory with packs> # end-to-end run on real packs
| Method | Path | Body | Response |
|---|
GET | /health | none | ok |
GET | /versions | none | JSON array of supported versions |
POST | /convert?to=<version>[&from=<version>] | ZIP or RAR as is | ZIP; summary in the x-packconv-report header |
POST | /repair | ZIP or RAR as is | ZIP; summary in the x-packconv-report header |
If from is omitted, the source version is detected from pack.mcmeta. Errors: 413 body over the limit, 422 bad archive or version, 429 queue full, 504 job timed out.
| Variable | Default | Purpose |
|---|
PACKCONV_ADDR | 0.0.0.0:8080 | listen address |
PACKCONV_MAX_JOBS | 1 | concurrent conversions |
PACKCONV_MAX_QUEUE | 4 x jobs | queued requests before 429 |
PACKCONV_MAX_UPLOAD | 128 MiB | request body size |
PACKCONV_MAX_UNPACKED | 512 MiB | total unpacked size |
PACKCONV_MAX_ENTRIES | 100 000 | files per archive |
PACKCONV_TIMEOUT_SECS | 300 | job timeout |
[!NOTE]
Defaults target a small single-core VPS. Cancellation is checked between conversion steps, not inside one.
Conversion limits: shaders (shaders/, post_effect/) are tied to the engine version and are removed with a warning when the version changes. Conversions that cannot keep data are listed in the warnings field of the report. Only vanilla assets are processed (pack.mcmeta, pack.png, assets/minecraft/, assets/realms/); everything else passes through unchanged.
License
Licensed under AGPL-3.0, copyright 2026 hhhhhffd. Mapping tables from MIT-licensed projects keep their own licenses, see THIRD_PARTY_NOTICES.md.
