Sandbox public URL

Every sandbox can be reached by a public URL, which lets you expose and connect to services running inside it. This page covers how to get that URL, connect to a server inside the sandbox, and customize the Host header services receive. To control the sandbox’s outbound internet access, see Internet access. To require authentication on the public URL, see Restricting public access.

Sandbox public URL

Every sandbox has a public URL that can be used to access running services inside the sandbox.

import { Sandbox } from 'e2b'

const sandbox = await Sandbox.create()

// You need to always pass a port number to get the host
const host = sandbox.getHost(3000)
console.log(`https://${host}`)

from e2b import Sandbox

sandbox = Sandbox.create()

# You need to always pass a port number to get the host
host = sandbox.get_host(3000)
print(f'https://{host}')

The code above will print something like this:

https://3000-i62mff4ahtrdfdkyn2esc.e2b.app

https://3000-i62mff4ahtrdfdkyn2esc.e2b.app

The first leftmost part of the host is the port number we passed to the method.

Connecting to a server running inside the sandbox

You can start a server inside the sandbox and connect to it using the approach above. In this example we will start a simple HTTP server that listens on port 3000 and responds with the content of the directory where the server is started.

import { Sandbox } from 'e2b'

const sandbox = await Sandbox.create()

// Start a simple HTTP server inside the sandbox.
const process = await sandbox.commands.run('python -m http.server 3000', { background: true })
const host = sandbox.getHost(3000)
const url = `https://${host}`
console.log('Server started at:', url)

// Fetch data from the server inside the sandbox.
const response = await fetch(url);
const data = await response.text();
console.log('Response from server inside sandbox:', data);

// Kill the server process inside the sandbox.
await process.kill()

import requests
from e2b import Sandbox

sandbox = Sandbox.create()

# Start a simple HTTP server inside the sandbox.
process = sandbox.commands.run("python -m http.server 3000", background=True)
host = sandbox.get_host(3000)
url = f"https://{host}"
print('Server started at:', url)

# Fetch data from the server inside the sandbox.
response = requests.get(url)
data = response.text
print('Response from server inside sandbox:', data)

# Kill the server process inside the sandbox.
process.kill()

This output will look like this:

Server started at: https://3000-ip3nfrvajtqu5ktoxugc7.e2b.app
Response from server inside sandbox: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Directory listing for /</title>
</head>
<body>
<h1>Directory listing for /</h1>
<hr>
<ul>
<li><a href=".bash_logout">.bash_logout</a></li>
<li><a href=".bashrc">.bashrc</a></li>
<li><a href=".profile">.profile</a></li>
</ul>
<hr>
</body>
</html>

Server started at: https://3000-ip3nfrvajtqu5ktoxugc7.e2b.app
Response from server inside sandbox: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Directory listing for /</title>
</head>
<body>
<h1>Directory listing for /</h1>
<hr>
<ul>
<li><a href=".bash_logout">.bash_logout</a></li>
<li><a href=".bashrc">.bashrc</a></li>
<li><a href=".profile">.profile</a></li>
</ul>
<hr>
</body>
</html>

Masking request host headers

You can customize the Host header that gets sent to services running inside the sandbox using the maskRequestHost / mask_request_host option. This is useful when your application expects a specific host format.

import { Sandbox } from 'e2b'

// Create sandbox with custom host masking
const sandbox = await Sandbox.create({
  network: {
    maskRequestHost: 'localhost:${PORT}'
  }
})

// The ${PORT} variable will be replaced with the actual port number
// Requests to the sandbox will have Host header set to for example: localhost:8080

from e2b import Sandbox

# Create sandbox with custom host masking
sandbox = Sandbox.create(
    network={
        "mask_request_host": "localhost:${PORT}"
    }
)

# The ${PORT} variable will be replaced with the actual port number
# Requests to the sandbox will have Host header set to for example: localhost:8080

The ${PORT} variable in the mask will be automatically replaced with the actual port number of the requested service.

Connecting to HTTPS servers inside the sandbox

By default, the E2B proxy connects to the service inside the sandbox over plain HTTP. If the service listening on a port serves HTTPS (TLS) itself, list that port in the httpsPorts / https_ports option so the proxy connects to it over HTTPS instead. The public URL is HTTPS either way.

import { Sandbox } from 'e2b'

// Port 8443 serves HTTPS inside the sandbox
const sandbox = await Sandbox.create({
  network: {
    httpsPorts: [8443]
  }
})

// Generate a self-signed certificate and start an HTTPS server on port 8443
await sandbox.commands.run(
  'openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 1 -nodes -subj "/CN=localhost"'
)
await sandbox.files.write('server.py', `
import http.server, ssl
server = http.server.HTTPServer(('0.0.0.0', 8443), http.server.SimpleHTTPRequestHandler)
context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
context.load_cert_chain('cert.pem', 'key.pem')
server.socket = context.wrap_socket(server.socket, server_side=True)
server.serve_forever()
`)
await sandbox.commands.run('python3 server.py', { background: true })

// The public URL now proxies to the HTTPS server on port 8443
const url = `https://${sandbox.getHost(8443)}`
const response = await fetch(url)
console.log('Response from server inside sandbox:', await response.text())

import requests
from e2b import Sandbox

# Port 8443 serves HTTPS inside the sandbox
sandbox = Sandbox.create(
    network={
        "https_ports": [8443]
    }
)

# Generate a self-signed certificate and start an HTTPS server on port 8443
sandbox.commands.run(
    'openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 1 -nodes -subj "/CN=localhost"'
)
sandbox.files.write("server.py", """
import http.server, ssl
server = http.server.HTTPServer(('0.0.0.0', 8443), http.server.SimpleHTTPRequestHandler)
context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
context.load_cert_chain('cert.pem', 'key.pem')
server.socket = context.wrap_socket(server.socket, server_side=True)
server.serve_forever()
""")
sandbox.commands.run("python3 server.py", background=True)

# The public URL now proxies to the HTTPS server on port 8443
url = f"https://{sandbox.get_host(8443)}"
response = requests.get(url)
print("Response from server inside sandbox:", response.text)

The certificate served by the sandbox is not verified, so self-signed certificates work. Ports not listed in httpsPorts / https_ports keep being proxied over plain HTTP.

This is not TLS passthrough. Requests to the public URL are still terminated at the E2B proxy and re-encrypted on the hop to the sandbox, so public access restrictions and request host masking apply to HTTPS ports as well.

The configured ports are returned in the network field of the sandbox info (getInfo() / get_info()), and cannot be changed after the sandbox is created.