Internet Access
Sandboxes have full internet access by default.
Overview
All Lelantos sandboxes have unrestricted outbound internet access by default. Sandboxes can make HTTP requests, connect to databases, pull packages, clone repositories, and access any external service.
DNS Configuration
All pre-built templates (base, python, node, bun, playwright, code-interpreter) come with DNS pre-configured. Name resolution works out of the box.
Custom Templates
If you are building a custom template, you need to ensure DNS is configured in your Dockerfile. Add the following line to set up Google's public DNS resolver:
FROM ubuntu:22.04
# Configure DNS for internet access
RUN echo "nameserver 8.8.8.8" > /etc/resolv.conf
# Rest of your Dockerfile...
RUN apt-get update && apt-get install -y curlForgetting to configure DNS in a custom template is the most common cause of network issues inside sandboxes. If your sandbox cannot resolve hostnames, add the nameserver line to your Dockerfile.
Network Details
- Outbound: All TCP/UDP traffic is allowed to any destination.
- Inbound: Sandboxes are accessible via the proxy URL
{port}-{sandboxID}.lelantos.ai. The proxy routes traffic from the internet to the specified port inside the sandbox. - No firewall restrictions: There are no egress firewall rules applied to sandboxes. If your use case requires network isolation, terminate the sandbox when the task is complete.
Accessing Sandbox Services
If your sandbox runs an HTTP server or other network service, you can access it through the sandbox proxy:
https://{port}-{sandboxID}.lelantos.aiFor example, a web server running on port 3000 in sandbox sbx_abc123 would be reachable at:
https://3000-sbx_abc123.lelantos.ai