sandboxd: Open-Source Tool to Run Multiple Claude Code Agents in Isolated Containers

A Reddit user found that running Claude Code across multiple projects quickly became chaotic — port collisions, overlapping hot reloads, and juggling git worktrees. They built sandboxd, an open-source (MIT, self-hosted) tool that wraps each project in its own isolated container.

Key Details

• One project = one container with its own workspace, Claude Code session, and preview URL. No port 3000 collisions.
• Parallel agents run without interfering because each container is fully isolated.
• Docker containers (not VMs) with dropped capabilities, read-only root filesystem, and resource limits. Optional gVisor support for stronger isolation.
• Preview URLs via Traefik: project-id.preview.yourhost routes to the correct container, so you never need to remember ports.
• Auto-sleep: idle containers stop automatically and wake on next request. The workspace lives on the host so state persists across sleeps.
• API key security: your key never goes into the container. A local proxy injects the key into requests, keeping credentials out of autonomous agents' reach.
• Stack: Go, SQLite, Docker, Traefik — no Kubernetes or external database.
• One-line install: curl -fsSL https://sandboxd.io/install | bash

Who It's For

Developers running Claude Code (or other AI coding agents) across multiple projects who need workspace isolation, port management, and resource efficiency.