internet-access.mdx

title	Internet access

Every sandbox has access to the internet and can be reached by a public URL.

Controlling internet access

You can control whether a sandbox has access to the internet by using the allowInternetAccess parameter when creating a sandbox. By default, internet access is enabled (true), but you can disable it for security-sensitive workloads.

```js JavaScript & TypeScript import { Sandbox } from '@e2b/code-interpreter'

// Create sandbox with internet access enabled (default) const sandbox = await Sandbox.create({ allowInternetAccess: true })

// Create sandbox without internet access const isolatedSandbox = await Sandbox.create({ allowInternetAccess: false })

```python Python
from e2b_code_interpreter import Sandbox

# Create sandbox with internet access enabled (default)
sandbox = Sandbox.create(allow_internet_access=True)

# Create sandbox without internet access
isolated_sandbox = Sandbox.create(allow_internet_access=False)

When internet access is disabled, the sandbox cannot make outbound network connections, which provides an additional layer of security for sensitive code execution.

Setting `allowInternetAccess` to `false` is equivalent to setting `network.denyOut` to `['0.0.0.0/0']` (denying all traffic).

Fine-grained network control

For more granular control over network access, you can use the network configuration option to specify allow and deny lists for outbound traffic.

Allow and deny lists

You can specify IP addresses, CIDR blocks, or domain names that the sandbox is allowed to use:

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Deny all traffic except specific IPs const sandbox = await Sandbox.create({ network: { denyOut: [ALL_TRAFFIC], allowOut: ['1.1.1.1', '8.8.8.0/24'] } })

// Deny specific IPs only const restrictedSandbox = await Sandbox.create({ network: { denyOut: ['8.8.8.8'] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Deny all traffic except specific IPs
sandbox = Sandbox.create(
    network={
        "deny_out": [ALL_TRAFFIC],
        "allow_out": ["1.1.1.1", "8.8.8.0/24"]
    }
)

# Deny specific IPs only
restricted_sandbox = Sandbox.create(
    network={
        "deny_out": ["8.8.8.8"]
    }
)

Domain-based filtering

You can allow traffic to specific domains by specifying hostnames in allow out. When using domain-based filtering, you must include ALL_TRAFFIC in deny out to block all other traffic. Domains are not supported in the deny out list.

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Allow only traffic to google.com const sandbox = await Sandbox.create({ network: { allowOut: ['google.com'], denyOut: [ALL_TRAFFIC] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Allow only traffic to google.com
sandbox = Sandbox.create(
    network={
        "allow_out": ["google.com"],
        "deny_out": [ALL_TRAFFIC]
    }
)

When any domain is used, the default nameserver `8.8.8.8` is automatically allowed to ensure proper DNS resolution.

You can also use wildcards to allow all subdomains of a domain:

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Allow traffic to any subdomain of mydomain.com const sandbox = await Sandbox.create({ network: { allowOut: ['*.mydomain.com'], denyOut: [ALL_TRAFFIC] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Allow traffic to any subdomain of mydomain.com
sandbox = Sandbox.create(
    network={
        "allow_out": ["*.mydomain.com"],
        "deny_out": [ALL_TRAFFIC]
    }
)

You can combine domain names with IP addresses and CIDR blocks:

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Allow traffic to specific domains and IPs const sandbox = await Sandbox.create({ network: { allowOut: ['api.example.com', '*.github.com', '8.8.8.8'], denyOut: [ALL_TRAFFIC] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Allow traffic to specific domains and IPs
sandbox = Sandbox.create(
    network={
        "allow_out": ["api.example.com", "*.github.com", "8.8.8.8"],
        "deny_out": [ALL_TRAFFIC]
    }
)

Domain-based filtering only works for HTTP traffic on port 80 (via Host header inspection) and TLS traffic on port 443 (via SNI inspection). Traffic on other ports uses CIDR-based filtering only. UDP-based protocols like QUIC/HTTP3 are not supported for domain filtering.

Priority rules

When both allow out and deny out are specified, allow rules always take precedence over deny rules. This means if an IP address is in both lists, it will be allowed.

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Even though ALL_TRAFFIC is denied, 1.1.1.1 and 8.8.8.8 are explicitly allowed const sandbox = await Sandbox.create({ network: { denyOut: [ALL_TRAFFIC], allowOut: ['1.1.1.1', '8.8.8.8'] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Even though ALL_TRAFFIC is denied, 1.1.1.1 and 8.8.8.8 are explicitly allowed
sandbox = Sandbox.create(
    network={
        "deny_out": [ALL_TRAFFIC],
        "allow_out": ["1.1.1.1", "8.8.8.8"]
    }
)

ALL_TRAFFIC helper

The ALL_TRAFFIC constant represents the CIDR range 0.0.0.0/0, which matches all IP addresses. Use it to easily deny or allow all network traffic:

```js JavaScript & TypeScript import { Sandbox, ALL_TRAFFIC } from '@e2b/code-interpreter'

// Deny all outbound traffic const sandbox = await Sandbox.create({ network: { denyOut: [ALL_TRAFFIC] } })

```python Python
from e2b_code_interpreter import Sandbox, ALL_TRAFFIC

# Deny all outbound traffic
sandbox = Sandbox.create(
    network={
        "deny_out": [ALL_TRAFFIC]
    }
)

Sandbox public URL

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

```js JavaScript & TypeScript highlight={6} import { Sandbox } from '@e2b/code-interpreter'

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 Python highlight={6}
from e2b_code_interpreter 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:

```bash JavaScript & TypeScript https://3000-i62mff4ahtrdfdkyn2esc.e2b.app ``` ```bash Python https://3000-i62mff4ahtrdfdkyn2esc.e2b.app ```

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

Restricting public access to sandbox URLs

By default, sandbox URLs are publicly accessible. You can restrict access to require authentication using the allowPublicTraffic option:

```js JavaScript & TypeScript import { Sandbox } from '@e2b/code-interpreter'

// Create sandbox with restricted public access const sandbox = await Sandbox.create({ network: { allowPublicTraffic: false } })

// The sandbox has a traffic access token console.log(sandbox.trafficAccessToken)

// Start a server inside the sandbox await sandbox.commands.run('python -m http.server 8080', { background: true })

const host = sandbox.getHost(8080) const url = https://${host}

// Request without token will fail with 403 const response1 = await fetch(url) console.log(response1.status) // 403

// Request with token will succeed const response2 = await fetch(url, { headers: { 'e2b-traffic-access-token': sandbox.trafficAccessToken } }) console.log(response2.status) // 200

```python Python
import requests
from e2b_code_interpreter import Sandbox

# Create sandbox with restricted public access
sandbox = Sandbox.create(
    network={
        "allow_public_traffic": False
    }
)

# The sandbox has a traffic access token
print(sandbox.traffic_access_token)

# Start a server inside the sandbox
sandbox.commands.run("python -m http.server 8080", background=True)

host = sandbox.get_host(8080)
url = f"https://{host}"

# Request without token will fail with 403
response1 = requests.get(url)
print(response1.status_code)  # 403

# Request with token will succeed
response2 = requests.get(url, headers={
    'e2b-traffic-access-token': sandbox.traffic_access_token
})
print(response2.status_code)  # 200

When allowPublicTraffic is set to false, all requests to the sandbox's public URLs must include the e2b-traffic-access-token header with the value from sandbox.trafficAccessToken.

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.

```js JavaScript & TypeScript import { Sandbox } from '@e2b/code-interpreter'

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 Python
import requests
from e2b_code_interpreter 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 option. This is useful when your application expects a specific host format.

```js JavaScript & TypeScript import { Sandbox } from '@e2b/code-interpreter'

// 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 Python
from e2b_code_interpreter 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.