The control plane for accelerated, human-in-the-loop development. Run AI coding agents in isolated sandboxes. Review, fork, course-correct — ship 10x faster.
Open source · Self-host on Linux, WSL, or macOS
Handler keeps you in the loop while agents do the heavy lifting. Direct work, review output, fork approaches — ship features faster than ever.
Visual canvas with built-in terminal for every agent. See what each one is doing, check output, review changes — all from one screen. You stay in the loop.
Each agent gets its own secure environment. Firecracker microVMs boot in under 2 seconds with full isolation. No cross-contamination, no shared state, no surprises.
Not sure which approach is right? Fork the environment and try both in parallel. Review the results. Pick the winner. The human makes the call.
Kick off work before bed. Every session persists — terminal output, scrollback, running processes. Come back in the morning and review what they built.
MCP server registry, Git integration, custom Dockerfiles, agent config presets — Handler plugs into the stack you already use. No rip-and-replace.
Claude Code, Codex, Gemini CLI, OpenCode — or whatever ships next. Auto-detected, visually tracked, managed the same way. Use the best agent for each task.
A complete control plane for human-in-the-loop agent development.
Manage isolated Firecracker VMs and Docker containers — each agent gets its own secure environment
Built-in terminals for every sandbox — tmux persistence, scrollback history, and live shell access
Visual canvas with draggable tiles, resource monitoring, and real-time agent tracking
Configure agent presets — model, MCP servers, instructions, permissions, and environment variables
Browse, favorite, and deploy MCP servers from the registry directly into your sandboxes
Custom Dockerfiles with system templates and one-click image builds
10 themes across dark and light modes, keyboard shortcuts, and backend configuration
AI agents are powerful, but they need direction. Handler gives you the visibility to review what agents are doing, the tools to course-correct when needed, and the confidence that nothing ships without your approval.
Self-host on your own hardware. Full power on Linux with Docker + Firecracker microVMs. Docker containers on macOS and WSL. Your code never leaves your machine.
Docker everywhere. Firecracker on Linux and WSL.
AI agents are powerful but imperfect. Handler gives you the visibility and tools to direct their work, review their output, and course-correct before anything ships. You're the handler — agents execute your intent, and you make the final calls.
tmux doesn't detect which agents are running, show you resource usage, let you fork a workspace with one click, or give you a visual overview of all your sessions. Handler is what comes after you outgrow terminal tabs — and it gives you a visual overview of all your sessions.
Yes. Docker containers work on macOS. The full UI, terminal persistence, canvas workspace, and agent detection all work. Firecracker VMs are Linux-only (they require KVM), so VM support is available on Linux and WSL.
Handler includes Docker support, but it's built for a specific workflow: accelerated development with AI coding agents. Agent detection, MCP server registry, config presets, environment forking, and the command centre canvas are features you won't find in a general-purpose container manager.
Self-host for free in 60 seconds.
Requires Node 22+ and pnpm · Full power on Linux (Docker + Firecracker) · Docker on macOS