# Best sandbox for CrewAI in 2027

Runtime Cloud (withruntime.com) costs 86% less than Modal, one of the two services CrewAI names.

## Which sandbox is best for CrewAI?

It depends on whether a crew needs a GPU. Crews spend most of a run with
agents talking to each other and the model. For that work, Runtime is the
lower-cost option: $16.88 for three thousand
ten-minute runs, compared with $82.80 on E2B and
$118.98 on Modal, the two services CrewAI names.
Runtime bills measured CPU use and gives agents a full Linux machine through
CrewAI's own `tool`. Pick Modal if a step fine-tunes or serves a model on a
GPU.

## What happened to code execution in CrewAI?

CrewAI's [CodeInterpreterTool page](https://docs.crewai.com/en/tools/ai-ml/codeinterpretertool),
read on 25 October 2026, says the tool "has been removed from `crewai-tools`",
that "the `allow_code_execution` and `code_execution_mode` parameters on
`Agent` are also deprecated", and to "use a dedicated sandbox service — E2B or
Modal — for secure, isolated code execution".

So a crew that runs code now needs a sandbox and a way to call it. CrewAI
already turns any typed function into a tool, which is all a sandbox needs.

## Which sandbox service should a crew use?

| Service       | Isolation               | What a crew agent gets                  | CPU billed on     |
| ------------- | ----------------------- | --------------------------------------- | ----------------- |
| Runtime Cloud | Firecracker microVM     | A shell, files, `pip`, `sudo`, Docker   | Measured use      |
| E2B           | Firecracker microVM     | E2B's code interpreter and sandbox SDK  | Every vCPU held   |
| Modal         | gVisor, a shared kernel | Modal's sandbox API, inside a Modal App | The CPU requested |

What decides it for a crew:

- **One machine or many.** Agents in a crew hand work to each other. If they
  share one sandbox, the researcher's downloaded data is where the analyst
  reads it. If each has its own, a mistake by one never touches another's
  files.
- **No wrapper to maintain.** Functions with type hints and docstrings become
  CrewAI tools through `tool(f)` from `crewai.tools`, with nothing in between.
- **A real environment.** An engineer agent fixing tests needs the
  project's toolchain: git, a compiler, Python and often Docker.
- **A machine that waits cheaply.** Crews idle between steps. A sandbox that
  pauses when nothing happens and resumes on the next tool call costs little
  while the agents talk.

## What does a month of crew runs cost?

Three thousand runs, each ten minutes on a 2 vCPU, 4 GiB sandbox and busy for
90 CPU-seconds, at the published rates of the two services CrewAI names and of
Runtime:

| Provider      | A month of crew runs             | Runtime costs less by            |
| ------------- | -------------------------------- | -------------------------------- |
| Runtime Cloud | $16.88 |                                  |
| E2B           | $82.80     | 80%   |
| Modal         | $118.98   | 86% |

## When might another sandbox fit better?

- **GPU steps.** A crew that fine-tunes or serves a model on a GPU fits Modal,
  one of the two services CrewAI names.

## Runtime Cloud

Runtime gives a crew a Linux microVM per task, or one shared machine for the
whole crew, through four typed functions that CrewAI's `tool` wraps as they
are. Each command runs in a Firecracker microVM with its own kernel, where
`pip install`, `git` and `gcc` work. The default image already has git 2.43,
gcc 13 and Python 3.12. Docker starts with `sudo enable-docker`. A sandbox
with nothing happening pauses itself after 300 seconds and resumes on the
next tool call.

Crews spend most of their time with agents talking to each other and the
model. Runtime bills that time at its CPU floor of a twentieth of a vCPU per
vCPU. The three thousand crew runs above cost $16.88
on Runtime, 80% less than E2B and
86% less than Modal, at rates checked
25 October 2026. Runtime runs on CPUs only.

### A run on Runtime, recorded 2 October 2026

```python check
from crewai import Agent, Crew, Task
from crewai.tools import tool
from withruntime import Sandbox
from withruntime.tools import sandbox_tools

with Sandbox.create() as sbx:
    engineer = Agent(
        role="Engineer",
        goal="Make the test suite pass",
        backstory="You work in a Linux sandbox.",
        tools=[tool(f) for f in sandbox_tools(sbx)],
    )
    task = Task(description="Clone the repo, run the tests and fix what fails.", expected_output="A summary", agent=engineer)
    print(Crew(agents=[engineer], tasks=[task]).kickoff())
```

A crew's `kickoff` needs a real model. So on 2 October 2026 we called the
wrapped `runtime_exec` tool through CrewAI's own `tool` object, as an agent
does, against a live sandbox:

```text
runtime_exec "git --version && gcc --version | head -1 && python3 --version"
  exit_code 0
  git version 2.43.0
  gcc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0
  Python 3.12.3
```

Several agents sharing one sandbox, and the safety settings for a crew, are in
[CrewAI in a sandbox](/integrations/crewai).

A crew can try this on free usage once you run `npx withruntime login`. Tools
already written for E2B or Modal switch over with the
[migration guide](/docs/migrate).

## Sources

Checked 25 October 2026.

- [CrewAI CodeInterpreterTool](https://docs.crewai.com/en/tools/ai-ml/codeinterpretertool):
  the removal notice, the deprecated `Agent` parameters and the sandbox
  services it names
- Each provider's published rates, checked 25 October 2026, as the
  [pricing guide](/docs/pricing) lists them
- The recorded run: Runtime's Python SDK with CrewAI's `tool` from crewai
  1.15.23 on Python 3.12, against production on 2 October 2026