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# Sandbox public URL (/docs/network/public-url)

<!-- agent-signals: reading_time_min: 3 · est_tokens: 1284 · updated: 2026-07-30 -->
Related: [Internet access](/docs/network/internet-access.md), [Restricting public access](/docs/network/restrict-public-access.md), [Proxy tunneling](/docs/network/ip-tunneling.md), [Custom domain](/docs/network/custom-domain.md)

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](/docs/network/internet-access). To require authentication on the public URL, see [Restricting public access](/docs/network/restrict-public-access).

## Sandbox public URL

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

<CodeGroup>
```js title="JavaScript & TypeScript" highlight={6}
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}`)
```

```python title="Python" highlight={6}
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}')
```
</CodeGroup>

The code above will print something like this:

<CodeGroup>
```bash title="JavaScript & TypeScript"
https://3000-i62mff4ahtrdfdkyn2esc.e2b.app
```

```bash title="Python"
https://3000-i62mff4ahtrdfdkyn2esc.e2b.app
```
</CodeGroup>

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.

<CodeGroup>
```js title="JavaScript & TypeScript"
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()
```

```python title="Python"
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()
```
</CodeGroup>

This output will look like this:

<CodeGroup>
```bash title="JavaScript & TypeScript"
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>
```

```bash title="Python"
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>
```
</CodeGroup>

## 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.

<CodeGroup>
```js title="JavaScript & TypeScript"
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
```

```python title="Python"
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
```
</CodeGroup>

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