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. Source, releases, and the protocol spec all live at github.com/acoseac/1-bit-bridge.

Why use it instead of SMB

• Faster. A pre-indexed SQLite manifest replaces the iOS app's two-phase scan — folder walk plus tag enrich becomes one paginated HTTP GET. The first scan after pairing finishes in seconds, not minutes.
• Reachable remotely. SMB is a LAN protocol. The bridge speaks HTTP/2 over TLS, which traverses Tailscale, WireGuard, or any direct connection without help.
• Easier to set up. No share permissions to debug, no Samba quirks. Run the installer; scan a QR; you're paired.
• Same audio path. The bridge ships bytes; the iOS app still owns DSD, DoP, gapless, and everything else. No server-side transcoding, ever.

How it works

• Eight versioned endpoints under /v1/ — health, directory listing and stat, byte-range read, full download, paginated library manifest, and album + artist artwork.
• Pre-built library manifest served from a local SQLite database. Tags, sample rate, DSD flag, ReplayGain, MusicBrainz IDs — all resolved server-side, delivered in pages of up to 5,000 tracks.
• Bearer-token auth — every paired device gets its own token. Rotate, expire, or revoke them from the admin console without touching the others.
• TLS fingerprint pinning — the iOS app captures the bridge's certificate on first contact and pins the SHA-256 fingerprint forever after. No public CA, no trust store, no MITM window.
• Bonjour discovery on _onebit-bridge._tcp. The iOS Add Bridge sheet shows nearby servers automatically; you only have to type the bearer token.
• Artwork enrichment against MusicBrainz, Cover Art Archive, and iTunes Search — all rate-limited and respectful of upstream policies, all cached locally.

Pair an iPhone in three steps

1. Run bridge init on your Mac / Windows / Linux / Pi. The installer registers the bridge as a launchd / startup / systemd service and opens the admin console.
2. In the admin console at http://127.0.0.1:7789/, click Devices → Pair new device. The page generates a token and a QR code.
3. On iPhone, open Sources → Add 1-bit Bridge → Scan Pairing QR Code. Tap Save; the iOS app probes the bridge, captures its TLS fingerprint, and pins it. Done.

Out-of-the-box defaults are sensible. If you want the full picture — token lifecycle, TLS rotation, opt-in auto-update with quiet hours, Windows Service install path, backup/restore, protocol spec — the canonical site is acoseac.github.io/1-bit-bridge.

Bit-exact, by design

The bridge never decodes, never resamples, never transcodes. It serves bytes the iOS app asks for — DSF, DFF, FLAC, ALAC, WAV, AIFF, MP3, AAC. The full DSD pre-cache that protects DoP marker alignment on the iOS side still applies; the bridge just gets the bytes there faster.

Open source, MIT

Everything — server, admin console, protocol spec, release builds — lives on GitHub under MIT. Issues, PRs, and security reports are welcome.

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