ContainerBox

Minimal docker based sandbox for running generated code and bash commands with uploading files, custom images and donwloading the results.

Usage

Use the context manager when the sandbox belongs to one block of work:

from containerbox import SandboxSession

with SandboxSession() as session:
    result = session.exec("echo hi")
    print(result.stdout)

Use manual lifecycle when you need to pass the same sandbox across functions or modules:

from containerbox import SandboxSession

session = SandboxSession("python:3.13-slim")
session.open()

try:
    result = session.run_code("print('hi')", timeout=5)
    print(result.stdout)
finally:
    session.close()

When using manual lifecycle, always call close(). The context manager does this for you; manual mode makes cleanup your responsibility.

API

with SandboxSession(
    image="ubuntu:24.04",
    runtime="docker",
    session_timeout=300,
    memory="256m",
    cpus=1.0,
    network=False,
) as session:
    result = session.exec("echo ready", timeout=10)

For Python code, use a Python image:

with SandboxSession("python:3.13-slim") as session:
    result = session.run_code("print('hi')", timeout=5)

SandboxResult contains:

• stdout
• stderr
• exit_code
• timed_out
• duration_ms

Files

with SandboxSession("python:3.13-slim") as session:
    session.upload("local_data.csv")
    result = session.run_code("print(open('local_data.csv').read())")
    session.download("main.py", "downloaded_main.py")

Custom Image

Create a Dockerfile in your own project:

FROM node:22-slim

WORKDIR /workspace

RUN npm init -y && npm install slugify

ENV NODE_PATH=/workspace/node_modules

Build it:

docker build -t my-node-sandbox:latest .

Use that image with ContainerBox:

from containerbox import SandboxSession

code = """
const slugify = require("slugify");
console.log(slugify("Hello from Custom Node Image!", { lower: true }));
"""

with SandboxSession("my-node-sandbox:latest") as session:
    result = session.run_code(code, filename="main.js", command=["node", "main.js"])
    print(result.stdout)