Bidirectional file sync over SSH.
Zero remote dependencies. Native .gitignore. Content-addressed.
nix run github:andrewgazelka/zsync -- user@server
Tired of:
- rsync re-uploading entire files for tiny changes
- mutagen requiring a 50MB daemon and complex setup
- scp having no idea what
.gitignoreis
zsync fixes this. Your remote server needs nothing installed — a 3MB agent auto-deploys via SSH.
# Nix (recommended) nix run github:andrewgazelka/zsync # Cargo cargo install --git https://github.com/andrewgazelka/zsync# Sync current directory to remote (auto-creates ~/zsync/<dir_name>) zsync root@server # Custom SSH port zsync root@server -p 22222 zsync root@server:22222 # same thing # Explicit remote path zsync root@server:/workspace/project # Watch mode — bidirectional sync as you edit locally or remotely zsync root@server --watch # Delete remote files not present locally zsync root@server --delete| rsync | mutagen | zsync | |
|---|---|---|---|
| Only sends changed bytes | ❌ Often whole file | ❌ Often whole file | ✅ FastCDC chunks |
| Cross-file dedup | ❌ | ❌ | ✅ Content-addressed |
| Zero remote setup | ❌ Must install | ✅ Auto-deploy | ✅ Auto-deploy |
| Agent size | N/A | ~50MB | ~3MB |
| Native .gitignore | ❌ Manual flags | ❌ Partial | ✅ Full support |
| Bidirectional sync | ❌ | ✅ | ✅ Built-in |
| Watch mode | ❌ External tools | ✅ Built-in | ✅ Built-in |
| Port forwarding | ❌ | ❌ | ✅ Built-in |
zsync uses content-addressed storage with FastCDC chunking. Files are split into variable-size chunks based on content, not position. Each chunk is identified by its BLAKE3 hash.
sequenceDiagram participant Local participant Remote Local->>Remote: SSH connect, auto-deploy 3MB agent Local->>Remote: What files do you have? (BLAKE3 hashes) Remote-->>Local: Here's my manifest Local->>Local: Diff, chunk changed files with FastCDC Local->>Remote: Which chunks are you missing? Remote-->>Local: Just these 3 chunks Local->>Remote: Here they are (deduplicated) Remote->>Remote: Reassemble files from chunks Result: If you change one line in a 10MB file, only ~4KB transfers. Sync multiple similar projects and shared code chunks are never re-sent.
Optional .zsync.toml in your project:
# Include files even if gitignored include = [".env", "config/*.local"] # Port forwarding (active in watch mode) [[forward]] local = 8080 remote = 8080 [[forward]] local = 5432 remote = 5432Local: macOS (Apple Silicon, Intel), Linux Remote: Any Linux server with SSH
Production-ready with bidirectional sync in watch mode.
MIT OR Apache-2.0