Official tools for vosu by 18-LAB. Install them from the vosu dashboard's Tools page. Each one opens in your browser with Open, and some also run in the background or on the command line (vosux <id>).
The pictures below are real tool pages, running in a vosu with no osu! client attached. Instead of a game, the maps, skins and replays in them are 18-LAB's own generated demo content. See how they are made.
Make practice copies of the map you have selected in osu!: change its rate, difficulty and ruleset transforms, trim it to the sections you want to grind, and preview the result before generating it.
A generated demo map at 1.25× with Mirror and one kept section.
See what the selected map is worth on recorded public Akatsuki and Mamestagram calculator snapshots, or on pp formulas of your own, next to official pp.
A generated demo map with the two built-in profiles and two of the tool's example custom calculators.
One selected-map dashboard for every ruleset: official stars and skills, accuracy-target pp and descriptive section timelines (ours), with the complete mania calculator views retained. Follows the played ruleset, mods and exact rate. The rosu-pp 4.0.1 algorithms match lazer 2025-10-13; newer lazer can differ.
A generated 7K demo chart.
Browse your stable and lazer skins, preview their elements and gameplay in every ruleset, mix parts of several skins into a new one, and edit skin.ini with checks.
The Keymodes tab: a 7K mix of skins exported from render-core's own drawings of the classic and Triangles looks.
Watch the map selected in osu! play out in any of the four rulesets with your skin, mods and the game's clock, or preview any .osu file.
A generated demo map drawn with the built-in Triangles look.
Turn replays into videos: put several replays side by side or overlap them on one playfield, pick skins and an output size, and render MP4 or WebM.
Three generated replays of a demo map in the Overlap layout.
Find maps like the one you have selected (same mapper, similar stars or mania MSD, your recent play history) and download them from a mirror through a polite, validated queue.
Sample data: synthetic search results and queue entries, not real maps.
A background service with no page of its own. It lets the other tools read your osu!lazer library (maps, skins and replays) without changing it.
| Tool | id | UI | Service | CLI |
|---|---|---|---|---|
| osu! practice tool | practice |
yes | backend | vosux practice |
| Server pp calculator | server-pp |
yes | background | vosux server-pp |
| Map analysis | map-analysis |
yes | background | vosux map-analysis |
| Skin studio | skin-studio |
yes | backend | — |
| Map preview | map-preview |
yes | — | — |
| Replay renderer | replay-renderer |
yes | backend | vosux replay-renderer |
| Beatmap downloader | downloader |
yes | backend | — |
| Lazer library | lazer-library |
— | background | — |
Each tool is an out-of-process application hosted by vosu (tool protocol v1). It can have a browser UI under /tools/<id>/, a supervised background service, and a command line run through vosux <id>. vosu installs them from this repository's releases through the dashboard's tool catalog.
UI/CLI tools can have a native backend for local files or rendering. vosu starts it on demand and stops it when idle; it is not a separate service interface. Only background services have Start/Stop/Restart and Start with vosu controls. That per-user setting overrides the manifest default and is available in Details, tool Settings, or vosux --autostart <id> on|off|default. Server pp, map analysis and lazer library default to on-demand; enable startup for whichever background services you use.
crates/vosu-tool-sdk: Rust helpers for the tool protocol (environment, readiness handshake, token checks, vosu/host/dependency clients, CLI output helpers).crates/*: shared Rust libraries.packages/tool-web: shared web tooling (bridge types, Vite preset).packages/*: shared browser libraries.tools/<id>/: one tool per directory:Cargo.toml(binaryvosu-<id>),tool.toml, optionalsettings.json, optionalweb/(Vite project building toweb/dist).scripts/package.py: builds release packages andcatalog.json(contract).
Requirements: the pinned Rust toolchain (rust-toolchain.toml), Bun, and a vosu 1.2.0 build.
bun install
bun run build # build every tool UI into web/dist
cargo build --locked
vosu --tool tools/<id> # run a tool from this checkout; vosu restarts it after rebuilds
vosux <id> --helpBeatmap fixtures use LF on every checkout, including Windows (.gitattributes),
so golden comparisons and section-insertion tests do not depend on Git's
core.autocrlf setting.
With Python 3.11+, the target's native build dependencies, Rust, and Bun installed:
bun install --frozen-lockfile
python scripts/package.py --target x86_64-unknown-linux-gnu \
--base-url https://github.com/18-lab-dev/vosu-tools/releases/download/v0.4.0
python -m unittest discover -s scripts -p test_package.pyPackages and catalog.json are written to dist/. The script builds release binaries with the locked Cargo graph, builds offline UIs with hidden source maps for bundled-package license discovery, and emits verified, deterministic ZIPs. --dry-run validates manifests and prints the build plan; --skip-build packages existing binaries and hidden-sourcemap UI output. Windows releases use x86_64-pc-windows-msvc; the native Windows runner also checks Clippy and tests. Universal UI-only packages are published once from Linux (--native-only omits them on the Windows packaging job). Catalog merging and license provenance are described in the package contract.
Manifest, catalog, lockfile and source-map text, along with Cargo's captured
metadata, is decoded as UTF-8 regardless of the build machine's locale.
The reusable real-package smoke requires a separately built vosu test-harness binary and both generated catalogs:
python scripts/smoke_install.py --vosu /tmp/vosu-int-target/debug/vosu \
--tools /tmp/vosu-tools-evidence/integration/packages/tools \
--overlays /tmp/vosu-tools-evidence/integration/packages/overlays \
--playwright-module /tmp/vosu-tools-evidence/catalog/browser/node_modules/playwright/index.mjs \
--browser-cache /tmp/vosu-tools-evidence/catalog/browser-cacheIt serves test-only loopback catalog copies (package digests/bytes are unchanged), isolates HOME and every XDG root including XDG_RUNTIME_DIR, uses only daemon ports 25150/25151, installs and approves the real tools, starts services, reads their APIs, exercises CLI help, and opens all UIs in a private headless browser. JSON receipts, logs, CLI help, and dark/light screenshots go under /tmp/vosu-tools-evidence/integration/. It never generates practice maps, modifies skins, downloads user beatmaps, or renders to a user's directories.
The pictures in this README come from the packaged tools in an isolated, sandboxed vosu. scripts/screenshots.mjs regenerates them all; docs/screenshots/README.md lists what each one shows and how to run it.
Project code is available under the MIT or Apache-2.0 license, at your option. Ported third-party code keeps its own license, recorded next to it and in THIRD_PARTY_NOTICES.md.