Runtm

Open-source sandboxes where coding agents build and deploy.

Spin up isolated environments where Claude Code, Cursor, Codex, and other agents code and ship software. With live URLs, logs, and previews.

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• Sandboxes for yolo agents – Let agents code with full permissions in isolated environments. No risk to your machine or cloud.
• Run any coding agent – Claude Code, Cursor, Codex, Gemini CLI, and more. Bring your favorite.
• Real URLs instantly – Agents deploy to live HTTPS endpoints. Test, share, and iterate.
• Logs and observability – See what your agent built, debug issues, fix and redeploy.

# Install
uv tool install runtm

# Start a local sandbox session
runtm session start

# Your agent builds inside the sandbox...

# Deploy to a live URL
runtm session deploy

You get a live HTTPS endpoint on auto-stopping infrastructure. Machines spin down when idle and wake up on traffic.

Run AI agents in isolated local environments with OS-level sandboxing:

# Start a sandbox (auto-installs deps on first run)
runtm session start

# Start with a template
runtm session start --template web-app

# Use a different agent
runtm session start --agent codex

# List all sandboxes
runtm session list

# Reattach to a sandbox
runtm session attach sbx_abc123

# Deploy from sandbox to live URL
runtm session deploy

What you get:

• OS-level isolation – Uses bubblewrap (Linux) or seatbelt (macOS) for fast, secure sandboxing
• Instant startup – Sandboxes start in <100ms, no containers needed
• Multi-agent support – Works with Claude Code, Codex, Gemini CLI, and more
• Persistent workspaces – Stop and resume sessions, files preserved

┌────────────┐     ┌─────────┐     ┌─────────┐     ┌──────────┐
│ Your Agent │ ──▶ │ Sandbox │ ──▶ │  Runtm  │ ──▶ │ Live URL │
└────────────┘     └─────────┘     └─────────┘     └──────────┘

1. Spin up a sandbox – Your agent gets an isolated workspace
2. Agent builds – Full permissions to code, install deps, run tests
3. Deploy – One command to a real URL with logs and previews
4. Iterate – Agent can see logs, fix bugs, and redeploy

# Recommended
uv tool install runtm

# Alternative
pipx install runtm

# Or with pip
pip install runtm

See the CLI docs for the full reference.

Runtm can be fully self-hosted. See the self-hosting guide.

git clone https://github.com/runtm-ai/runtm.git
cd runtm
cp infra/local.env.example .env

# Install packages (includes sandbox and agents)
./scripts/dev.sh setup

# Start local services
docker compose -f infra/docker-compose.yml up -d

# Use the development CLI
runtm-dev start                    # Start a sandbox session
runtm-dev prompt "Build an API"    # Send prompt to agent

Note: Use runtm-dev (not runtm) when self-hosting. The dev CLI includes sandbox/agents packages.

packages/
  shared/     # Types, manifest schema, errors
  sandbox/    # Local sandbox runtime (OS-level isolation)
  agents/     # AI coding agent adapters (Claude Code, Codex, etc.)
  api/        # FastAPI control plane
  worker/     # Build + deploy pipeline
  cli/        # Python CLI (Typer)

templates/    # Starter projects (backend, static, fullstack)

Full docs at docs.runtm.com:

• Quickstart
• CLI Reference
• API Reference
• Self-Hosting

See CONTRIBUTING.md for development setup and guidelines.

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