1-bit bridge

What it is

1-bit bridge is a small Go server you run on a Mac, Windows PC, Linux box, or Raspberry Pi alongside your music library. It serves the iOS app over HTTPS instead of SMB — same files, same bit-exact audio, but a transport designed for the app rather than a decades-old file-sharing protocol.

It's free and open source under the MIT license. The canonical site — setup, troubleshooting, protocol spec, every release note — lives at acoseac.github.io/1-bit-bridge.

Why use it instead of SMB

• Faster. A pre-indexed library manifest replaces the iOS app's two-phase SMB scan. The first sync finishes in seconds, not minutes.
• Reachable remotely. SMB is a LAN protocol. The bridge speaks HTTP/2 over TLS — Tailscale, WireGuard, or any direct route works without extra plumbing.
• Easier to set up. Run the installer, approve the device on the admin console, you're paired. No share permissions, no Samba quirks.
• Same audio path. The bridge ships bytes; the iOS app still owns DSD, DoP, gapless, and everything else. No server-side transcoding, ever.

What's new in 0.1.3

Sixty-two commits since 0.1.2. The wire protocol stays at v1 — every change is additive, and the bit-exact audio path is untouched:

• Library Inspector. A folder-first admin view of your library with FTS5 search, cursor pagination, and a stats drawer. Inline-edit metadata, queue or delete an upscale variant, jump straight to a track. A separate Jobs page tracks upscale runs.
• Classical metadata, properly extracted. Composer, conductor, work, original year, and BPM now come out of FLAC, MP4, AIFF, WAV, DSF, and DFF (via the DIIN container). Multi-value ARTIST / ALBUMARTIST is preserved on FLAC and MP4 instead of being collapsed to a single string.
• Honest ALAC bits. ALAC source bit depth is now read directly from the MP4 alac config atom rather than inferred from the container.
• Variants you can actually manage. A configurable upscale.variantsDir with a source-mirrored layout, a bridge upscale move CLI, per-variant delete from the admin console, symmetric --gc that also clears orphan rows, and external-delete detection.
• Tailscale cert expiry warning. If your Let's Encrypt cert has 30 days or less to live, the bridge surfaces a structured warning at startup — so you don't get caught by Apple's ATS 398-day re-pair cliff on iOS.
• API hardening. Per-route write deadlines, full context.Context propagation through the store, an atomic-pointer config holder that fixes a data race under reload, and pushEventsSupported / pairingEventsSupported advertised in /v1/health.

Full release notes and upgrade guidance: github.com/acoseac/1-bit-bridge/releases.

Bit-exact, by design

The bridge never decodes, resamples, or transcodes the source files. It serves the bytes the iOS app asks for — DSF, DFF, FLAC, ALAC, WAV, AIFF, MP3, AAC — and the iOS app does the rest. The full DSD pre-cache that protects DoP marker alignment still applies; the bridge just gets the bytes there faster. Optional upscaled variants are generated alongside the originals, never in place of them.

Open source, MIT

Source, releases, the protocol spec, and the admin console all live on GitHub under MIT. Issues, PRs, and security reports are welcome.

• Docs: acoseac.github.io/1-bit-bridge
• Source: github.com/acoseac/1-bit-bridge
• Releases: latest tagged build for macOS, Windows, and Linux (arm64 / amd64)