The local sandbox
control plane.
Give every project a dedicated loopback IP and stable .localhost hostnames — zero port conflicts, no container overhead, fully native.
Free and open source · No Docker required · macOS 13+
One IP per project.
Zero port conflicts.
Loopbox assigns a dedicated loopback address to every project on boot. Each service gets a stable .localhost hostname, persisted in /etc/hosts — browser-isolated, stable across reboots.
- Host-based HTTP routing
- gRPC h2c and TCP passthrough
- Browser storage isolated per hostname
- Stable across machine reboots
Your entire stack.
One command.
A persistent supervisor starts, monitors, and restarts every service in your project. Crash detection, per-service log capture, and env file injection — all built in.
- Crash detection and automatic restart
- Per-service log stream capture
- Env file discovery and injection
- Vite intelligence — auto-injects flags
Give your AI agent
eyes on the runtime.
Loopbox runs a local HTTP API at 127.0.0.1:39393. Cursor, Claude, or any custom tool can list projects, tail logs, and control service lifecycle — discovered via agent-api.json.
- List projects and service state
- Tail live log streams
- Start, stop, and restart services
- Auto-discovered by MCP-compatible tools
The new way to manage localhost.
Same port numbers, zero conflict.
Run :5173 in a dozen projects at once. Each lives on its own loopback IP — there's nothing to remember, juggle, or document.
Never restart things by hand.
The built-in supervisor detects crashes and restarts automatically. Your environment stays running while you focus on writing code.
Your AI already knows the state.
Cursor and Claude can read your running services, live logs, and traffic directly — no copy-pasting, no context switching.
Go further with Pro.
See all plans →
Traffic Inspector
Capture every HTTP and gRPC request flowing through your sandbox. Configurable capture modes, per-project retention, and HAR export.
Learn more →
Proto Decode
gRPC payloads decoded from raw bytes using your project's proto files — with a raw fallback when protos aren't available.
Learn more →
Container Management
Bind Docker containers to your sandbox IP. Same port, different sandboxes — multiple databases running simultaneously without conflict.
Learn more →Changelog
v0.1.2
Public release line stabilized; version bumped to 0.1.2 with repository cleanup and private EE adapter separation work.
View release →v0.1.1
Initial public release baseline for the current Loopbox distribution branch.
View release →Loopbox is an independent project focused on native macOS developer tooling.
Built in Rust using the Dioxus framework. The core is MIT-licensed. Paid plans fund continued development and priority support.
[global] domain_suffix = "localhost" ip_base = "127.0.0." [projects.myapp] dir = "/Users/you/dev/myapp" ip = "127.0.0.2" [[projects.myapp.services]] name = "frontend" command = "pnpm dev" [[projects.myapp.services.ports]] port = 5173 protocol = "http1"
One file.
Total definition.
Drop config.toml in ~/.config/loopbox/. Services, ports, and routing — declared once, version-controlled, reproducible across machines.