Install

bun install -g @muthuishere/vsync     # or:  npm install -g @muthuishere/vsync
vsync --help

After install, vsync is on your PATH. No shell-rc edits.

Requirements

• Bun ≥ 1.2.21 must be on PATH — the bin file's shebang is #!/usr/bin/env bun, so even if you installed via npm install -g, the OS needs bun to execute the entry point. Most users have Bun anyway; if not, see bun.sh.
• An OS keychain backend — macOS Keychain, Linux libsecret (gnome-keyring, keepassxc-secret-service, etc.), or Windows Credential Manager. Required for storing the per-(repo, env) AES key. No-keychain fallback is intentionally not provided.
• An S3-compatible bucket (AWS S3, Hetzner Object Storage, MinIO, Cloudflare R2, Backblaze B2 via S3 API). vsync only does SDK-level operations — PutObject, GetObject, HeadObject, ListObjectsV2.

Don't want to install?

bunx @muthuishere/vsync <subcommand>

Same code path. Runs from npm cache each time. Slower per-invocation; fine for trying it out.

Platform support

Piece	macOS	Linux	Windows
Global install (npm or bun)	✓	✓	✓
Bun.secrets keychain	✓ Keychain	✓ libsecret	⚠ Credential Manager — supported per Bun docs, less battle-tested
vsync use symlinks	✓	✓	⚠ Requires Developer Mode (Settings → Privacy & security → For developers) or elevated terminal
chmod 0600 on disk config	✓ POSIX bits	✓ POSIX bits	⚠ Maps to read-only attribute — protection comes from %APPDATA% user scope, not mode bits
Git / gh / gcloud shell-outs	✓	✓	✓
S3 push/pull (incl. SigV4 audit append)	✓	✓	✓

The Windows path is conceptually supported but untested in our CI. If you hit issues, file at github.com/muthuishere/vsync/issues.

Develop vsync locally

git clone git@github.com:muthuishere/vsync.git
cd vsync
bun install
bun test                       # 184 tests, ~20s
bun bin/vsync.ts --help        # run the local source

There's no build step. bun test is the only correctness gate.

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Next: What lives in the vault →