forge-stems

A local-first DJ stem remix mixer in the browser.

Load stems onto four songs, ride the faders, and export a WAV of the mix. There are no accounts. Nothing is stored: audio stays in memory for the tab and is discarded when you leave.

Run

npm ci
npm run dev

Open the local URL that Vite prints.

npm run typecheck
npm test
npm run build
npm run preview

Vendored engine

The mixer engine is the WebAssembly package in vendor/forge-audio-wasm-v3/ (the .wasm module, the JS glue, and the TypeScript declarations). Imports use the @wasm alias declared in vite.config.ts and tsconfig.json. The deck loads vendor/forge-audio-wasm-v3/forge_audio_wasm_v3_bg.wasm from that folder. Nothing in this tree copies a package out of another workspace.

Provenance

• Front-end source commit: 687695a2
• Audio engine commit: ae41c5a8 (Moonforge sky 0e517012, read_telemetry_into 1dede48b, stem-split DSP 8300cd44, c4b5ba36, and ae41c5a8)
• wasm-pack 0.13.1 (--target web, panic=abort, debug info off)
• wasm-bindgen 0.2.127
• wasm-opt 117 (--dce --remove-unused-module-elements --strip-debug --strip-producers)
• vendor/forge-audio-wasm-v3/forge_audio_wasm_v3_bg.wasm: 627,908 bytes
• sha256: 195ef28309f2133bea0532db97dd5c6d96b42b7ce3469abb3ee0100a3f9d45c0

This build exports stem_split_four (mono PCM in, four packed mono stems out).

Release build of the vendored audio module. Symbols are stripped, and unused C exports that the JS glue does not call were removed (eight support-crate symbols plus the abort and instance-terminated handlers). The glue exposes Engine.read_telemetry_into, and InitOutput matches the exports that remain. Build-time path remapping, plus equal-length rewrites of any panic paths that survived it, keeps machine paths and toolchain locations out of the .wasm. The Moonforge sky shader is in this repo at src/ui/shaders/launcher_sky.wgsl. src/ui/moonforge-sky.ts mounts it behind #app when navigator.gpu can create a device, and stays inert otherwise. vite.config.ts keeps the @wasm alias on vendor/forge-audio-wasm-v3 and does not allow the dev server to read a parent directory.