Build Template and Sandbox E2B

Learn how to Build Template and Create the Sandbox E2B for Code Interpreter

Overview

E2B is an open-source platform for running secure, isolated code execution environments (sandboxes). It provides a cloud infrastructure specifically designed for AI agents, code interpreters, and automated workflows that need to execute un-trusted code safely.

Think of E2B as a "secure virtual computer on-demand" where you can:

• Execute code safely without risking your main infrastructure

• Run AI-generated code in isolation

• Process data in temporary, disposable environments

• Build and test applications in clean environments

Key Concepts

🏗️ Template

A pre-configured environment (like a Docker image) that defines what software, libraries, and configurations your sandbox will have. Templates are reusable blueprints for creating sandboxes.

🔒 Sandbox

A running instance of a template - an isolated, secure virtual machine where code executes. Each sandbox is temporary and disposable.

Getting Started

Now that you understand what E2B is and how it works, let's get started with the practical steps:

Prerequisites

## Access Requirements
1. E2B API Key: API Key for authentication to create sandbox
2. E2B Access Token:  Access Token for Authentication to create the template
3. E2B Domain: Your self-hosted E2B domain (e.g., poc.glair.id)
4. Network Access: Access to E2B API endpoint (https://api.poc.glair.id)
   Notes: Ask to [e-mail] for E2B API Key and E2B Access Token

## Knowledge Prerequisites
1. Basic understanding of command-line interface (CLI)
2. Familiarity with Docker and Dockerfile syntax
3. Basic understanding of environment variables
4. Knowledge of REST API concepts

## Software Prerequisites
1. docker  --version # Should show minimum  23.x.x 
2. python --version # Should show minimum 3.12.x

Installation

To follow this guide, you will need to install e2b cli.

Linux, or Windows WSL

curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash - && \
sudo apt-get install -y nodejs && \
sudo npm install -g @e2b/cli 

Windows Powershell

MacOS

Checking Version, run this command

Linux, or Windows WSL

node --version && npm --version && e2b --version

Windows Powershell

MacOS

How to Build a Template

Templates are custom sandbox environments built from Dockerfile specifications. They define the software packages, configurations, and startup scripts for your sandboxes.

1

Set Environment Variables

Set these on your local terminal

export E2B_ACCESS_TOKEN="sk_e2b_xyz123xxx"
export E2B_API_KEY="e2b_xyz123xxx"
export E2B_DOMAIN=poc.glair.id

2

Create Project Directory

# Create template project directory
mkdir my-e2b-template
cd my-e2b-template

3

Create Dockerfile

Create a file named e2b.Dockerfile with your custom configuration:

# Use E2B code interpreter base image
FROM e2bdev/code-interpreter:latest

# Install additional Python packages

4

Initialize E2B Template

E2B_DOMAIN=poc.glair.id e2b template init

Expected Output :

🚀 Initializing Sandbox Template...

? Enter template name (alias): dso-template
Using template name: dso-template
? Select target language for template files: Python (sync)

✅ Generated Python (sync) template files:
   ./template.py
   ./build_dev.py
   ./build_prod.py

📝 Added build scripts to Makefile:
   make e2b:build:dev - Build development template
   make e2b:build:prod - Build production template

🎉 Template initialized successfully!

Template created in: ./dso-template/

You can now build your template using:
   make e2b:build:dev (for development)
   make e2b:build:prod (for production)

Learn more about Sandbox Templates: https://e2b.dev/docs

5

Build the Template

Build with Custom Startup Command:

E2B_DOMAIN=poc.glair.id e2b template build -c "/root/.jupyter/start-up.sh"

Expected Output :

✅ Building sandbox template s0gnvgjpiuk8yhjoddt2 finished.

┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│                                                                                                                                                                                                                 │
│  You can now use the template to create custom sandboxes.                                                                                                                                                       │
│  Learn more on https://e2b.dev/docs                                                                                                                                                                             │
│                                                                                                                                                                                                                 │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

 ────────────────────────────────────────────────────────────────────────────────────────────────── Python SDK ───────────────────────────────────────────────────────────────────────────────────────────────────
                                                                                                                                                                                                                  
   from e2b import Sandbox, AsyncSandbox                                                                                                                                                                          
                                                                                                                                                                                                                  
   # Create sync sandbox                                                                                                                                                                                          
   sandbox = Sandbox.create("s0gnvgjpiuk8yhjoddt2")                                                                                                                                                               
                                                                                                                                                                                                                  
   # Create async sandbox                                                                                                                                                                                         
   sandbox = await AsyncSandbox.create("s0gnvgjpiuk8yhjoddt2")                                                                                                                                                    
 
 ──────────────────────────────────────────────────────────────────────────────────────────────────── JS SDK ─────────────────────────────────────────────────────────────────────────────────────────────────────
                                                                                                                                                                                                                  
   import { Sandbox } from 'e2b'                                                                                                                                                                                  
                                                                                                                                                                                                                  
   // Create sandbox                                                                                                                                                                                              
   const sandbox = await Sandbox.create('s0gnvgjpiuk8yhjoddt2')                                                                                                                                                   
                                                                                                                                                                                                                  
 ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

Save the Template ID (e.g., s0gnvgjpiuk8yhjoddt2) - you'll need it to create sandboxes!

How to Create a Sandbox

Once you have a template ID, you can create sandbox instances using Python SDK.

1

Create .env, here for the environment variables :

E2B_DOMAIN="poc.glair.id"
E2B_API_KEY="e2b_xyz123xxx"
E2B_TEMPLATE_ID="your-template-id"            

2

Create sandbox.py, here for the codes :

from e2b import Sandbox
import os
from dotenv import load_dotenv
load_dotenv()

# Set environment
os.environ['E2B_DOMAIN'] = os.getenv('E2B_DOMAIN')
os.environ['E2B_API_KEY'] = os.getenv('E2B_API_KEY')

# Create sandbox
sandbox = Sandbox.create(os.getenv('E2B_TEMPLATE_ID'))

print(f"Sandbox ID: {sandbox.sandbox_id}")
print(f"Sandbox is running: {sandbox.is_running()}")

# Execute code using commands API
result = sandbox.commands.run("python -c \"print('Hello from E2B!')\"")
print(f"Output: {result.stdout}")
print(f"Error (if any): {result.stderr}")
print(f"Exit code: {result.exit_code}")

# Clean up
sandbox.kill()
print("Sandbox terminated")

3

Execute the python script

1. Install dotenv and e2b first on venv

pip install e2b dotenv

1. Run python script using this command

python sandbox.py

Expected Output :

Sandbox ID: iibheg5bbtos2lsdbwfjv
Sandbox is running: True
Output: Hello from E2B!

Error (if any): 
Exit code: 0
Sandbox terminated                 

Troubleshooting

Issue 1: E2B CLI Not Found

Error

bash: e2b: command not found

Solution

# Check Node.js installation
node --version

# Reinstall E2B CLI globally
npm install -g @e2b/cli

# Verify PATH includes npm global bin
echo $PATH | grep npm

# Add npm global bin to PATH if missing
export PATH="$PATH:$(npm root -g)/../bin"
echo 'export PATH="$PATH:$(npm root -g)/../bin"' >> ~/.bashrc
source ~/.bashrc

Issue 2: Authentication Failed

Error

Error: Authentication failed. Invalid API key.

Solution

# Verify API key is set
echo $E2B_ACCESS_TOKEN

# If empty, set it again
export E2B_ACCESS_TOKEN=sk_e2b_your_actual_token_here

# Test authentication
curl -X GET https://api.${E2B_DOMAIN}/health \
  -H "X-API-Key: ${E2B_ACCESS_TOKEN}"

# If still failing, ask to [e-mail] for regenerate API key

Issue 3: Template Not Found

Error

Error: Template abc123def456 not found

Solution

E2B_DOMAIN=poc.glair.id e2b template list

                                                                   Sandbox templates                                                                    

 Access   Template ID           Template Name         vCPUs  RAM MiB        Created by  Created at  Disk size MiB  Envd version  buildStatus 

 Private  fh2gj24e8qjb6kvhme1d                            2     1024  [e-mail]  10/20/2025           5946         0.4.1     uploaded 
 Private  s0gnvgjpiuk8yhjoddt2                            2     1024  [e-mail]   11/3/2025           5946         0.4.2     uploaded 

Issue 4: Python Command Not Found

Error

$ python sandbox.py
bash: python: command not found

Solution

Use python3 Command (Recommended)
Most modern systems use python3 as the default command:
```
$ python3 sandbox.py
```

Issue 5: External Managed Environment when install e2b dotenv

Error

$ pip install e2b dotenv
error : externally-managed-environment

Solution

$ pip install e2b dotenv --break-system-packages

Congratulations! You have just created your template and sandbox E2B!