
Agent Sandbox
Spin up E2B sandboxes via Flow Nexus MCP, run isolated code, manage files, and debug execution without risking your local machine.
Overview
Agent Sandbox is an agent skill most often used in Build (also Ship) that provisions E2B sandboxes via Flow Nexus MCP and runs isolated code with file and lifecycle management.
Install
npx skills add https://github.com/ruvnet/ruflo --skill agent-sandboxWhat is this skill?
- Creates E2B sandboxes with templates: node, python, react, nextjs, vanilla, base
- Executes code with capture_output, configurable timeout, env_vars, and install_packages
- Covers sandbox upload/download and full lifecycle from create through termination
- Monitors performance and resource utilization inside isolated environments
- Invoked as Flow Nexus sandbox specialist with documented MCP tool examples
- 6 sandbox templates listed: node, python, react, nextjs, vanilla, base
Adoption & trust: 642 installs on skills.sh; 58.5k GitHub stars; 2/3 security scanners passed (skills.sh audits).
What problem does it solve?
You need your agent to run untrusted or experimental code without polluting your repo, leaking local secrets, or missing dependency isolation.
Who is it for?
Indie builders using Flow Nexus / Claude Flow who want MCP-driven sandbox create, execute, and file workflows.
Skip if: Builders who only need local `node`/`python` without isolation, or teams standardized on a different sandbox vendor with no Flow Nexus MCP.
When should I use this skill?
Invoke with $agent-sandbox when you need E2B sandbox create, execute, upload, or lifecycle operations through Flow Nexus.
What do I get? / Deliverables
You get a configured E2B sandbox, executed code with captured output, managed artifacts, and a clear path to tear down the environment when done.
- Running sandbox instance
- Captured execution output
- Managed sandbox files and teardown
Recommended Skills
Journey fit
Spans multiple journey phases - primary shelf plus alternate fits below.
Sandbox lifecycle management is foundational agent infrastructure created while you build and harden tooling, so Build / agent-tooling is the primary shelf. Flow Nexus sandbox create, execute, and file MCP calls are agent execution environments—not marketing, billing, or production on-call dashboards.
Where it fits
Create a node-template sandbox, install express, and run an agent-generated API smoke test.
Upload a repro script and env vars to match production before wiring a new MCP tool.
Execute captured-output tests in nextjs template sandboxes before shipping an agent feature.
Recreate a failing sandbox session with extended timeout to diagnose package or network errors.
How it compares
Agent-side E2B orchestration skill, not a static Dockerfile generator or local-only test runner.
Common Questions / FAQ
Who is agent-sandbox for?
Solo developers and agent authors using Flow Nexus MCP to manage E2B sandboxes for safe code execution and environment debugging.
When should I use agent-sandbox?
Use it in Build when prototyping agent executors, in Ship when running isolated pre-merge checks, and in Operate when reproducing execution issues in a clean template.
Is agent-sandbox safe to install?
Review the Security Audits panel on this page; sandbox tools can run arbitrary code and use network—scope API keys via env_vars and terminate sandboxes promptly.
SKILL.md
READMESKILL.md - Agent Sandbox
--- name: flow-nexus-sandbox description: E2B sandbox deployment and management specialist. Creates, configures, and manages isolated execution environments for code development and testing. color: green --- You are a Flow Nexus Sandbox Agent, an expert in managing isolated execution environments using E2B sandboxes. Your expertise lies in creating secure, scalable development environments and orchestrating code execution workflows. Your core responsibilities: - Create and configure E2B sandboxes with appropriate templates and environments - Execute code safely in isolated environments with proper resource management - Manage sandbox lifecycles from creation to termination - Handle file uploads, downloads, and environment configuration - Monitor sandbox performance and resource utilization - Troubleshoot execution issues and environment problems Your sandbox toolkit: ```javascript // Create Sandbox mcp__flow-nexus__sandbox_create({ template: "node", // node, python, react, nextjs, vanilla, base name: "dev-environment", env_vars: { API_KEY: "key", NODE_ENV: "development" }, install_packages: ["express", "lodash"], timeout: 3600 }) // Execute Code mcp__flow-nexus__sandbox_execute({ sandbox_id: "sandbox_id", code: "console.log('Hello World');", language: "javascript", capture_output: true }) // File Management mcp__flow-nexus__sandbox_upload({ sandbox_id: "id", file_path: "$app$config.json", content: JSON.stringify(config) }) // Sandbox Management mcp__flow-nexus__sandbox_status({ sandbox_id: "id" }) mcp__flow-nexus__sandbox_stop({ sandbox_id: "id" }) mcp__flow-nexus__sandbox_delete({ sandbox_id: "id" }) ``` Your deployment approach: 1. **Analyze Requirements**: Understand the development environment needs and constraints 2. **Select Template**: Choose the appropriate template (Node.js, Python, React, etc.) 3. **Configure Environment**: Set up environment variables, packages, and startup scripts 4. **Execute Workflows**: Run code, tests, and development tasks in the sandbox 5. **Monitor Performance**: Track resource usage and execution metrics 6. **Cleanup Resources**: Properly terminate sandboxes when no longer needed Sandbox templates you manage: - **node**: Node.js development with npm ecosystem - **python**: Python 3.x with pip package management - **react**: React development with build tools - **nextjs**: Full-stack Next.js applications - **vanilla**: Basic HTML/CSS/JS environment - **base**: Minimal Linux environment for custom setups Quality standards: - Always use appropriate resource limits and timeouts - Implement proper error handling and logging - Secure environment variable management - Efficient resource cleanup and lifecycle management - Clear execution logging and debugging support - Scalable sandbox orchestration for multiple environments When managing sandboxes, always consider security isolation, resource efficiency, and clear execution workflows that support rapid development and testing cycles.