sandbox-output

name	sandbox-output
description	Ensure agents ALWAYS return sandbox_id and endpoint_url when deploying or running applications in a sandbox. Use this skill whenever an application is deployed, a server is started, or a web service is running in a sandbox environment. This skill guarantees consistent output formatting for sandbox deployments.

Sandbox Output

This skill ensures that whenever an application is deployed or running in a sandbox, the agent MUST return a standardized output containing the sandbox identifier and the public endpoint URL.

When to Use

Use this skill:

• After deploying a web application in a sandbox
• After starting a server or service in a sandbox
• After creating a static website hosted in a sandbox
• Whenever a sandbox is running an accessible application

Required Output Format

When a sandbox application is running and accessible, ALWAYS return the following JSON structure:

{
  "sandbox_id": "<sandbox UUID>",
  "endpoint_url": "<public URL to access the application>"
}

Field Definitions

Field	Type	Description
sandbox_id	string (UUID)	The unique identifier of the sandbox returned by sandbox_create or sandbox_connect
endpoint_url	string (URL)	The public URL to access the running application, obtained via sandbox_get_endpoint

Procedure

Step 1: Identify the Sandbox ID

After creating or connecting to a sandbox, capture the sandbox_id from the response.

Step 2: Get the Endpoint URL

Use the sandbox_get_endpoint tool with the appropriate port number to retrieve the public URL.

sandbox_get_endpoint(sandbox_id="<sandbox_id>", port=<port_number>)

Common ports:

• 80 - HTTP web servers
• 443 - HTTPS web servers
• 3000 - Node.js/React development servers
• 5000 - Flask/Python development servers
• 8000 - Django/Python development servers
• 8080 - Alternative HTTP port

Step 3: Return the Standardized Output

Always conclude with the required JSON output format.

Example

Scenario: A static website is deployed in a sandbox on port 80.

Agent Actions:

1. Create sandbox: sandbox_create(image="python:3.11") → returns sandbox_id: "sbx_abc123"
2. Start web server on port 80
3. Get endpoint: sandbox_get_endpoint(sandbox_id="sbx_abc123", port=80) → returns URL

Required Output:

{
  "sandbox_id": "sbx_abc123",
  "endpoint_url": "https://abc123.example.com"
}

Important Rules

1. Never omit this output - Users and other systems depend on this structured response to access the deployed application.

2. Always use valid JSON - The output must be parseable JSON with proper escaping.

3. Verify the endpoint works - Before returning, ensure the endpoint URL is accessible and the application is running.

4. Include in final response - This output should appear in the agent's final message to the user, not buried in intermediate steps.

Success Criteria

• The response contains a valid sandbox_id (UUID format)
• The response contains a valid endpoint_url (accessible URL)
• The JSON is properly formatted and parseable
• The user can immediately access the application using the provided URL