# Best sandbox for CrewAI in 2026

CrewAI removed its code interpreter and points to sandbox services; the best one wraps with CrewAI's `tool` and costs little idle.

**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. 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. Three thousand ten-minute crew runs a month,
each busy for 90 CPU-seconds, cost $16.88 on Runtime
against $82.80 on E2B and
$118.98 on Modal, at rates checked 23 September to 2 October 2026.

## What happened to code execution in CrewAI?

CrewAI's [CodeInterpreterTool page](https://docs.crewai.com/en/tools/ai-ml/codeinterpretertool),
read on 1 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 | 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. Give
  them one sandbox and the researcher's downloaded data is where the analyst
  reads it; give each its own and a mistake by one never touches another's
  files.
- **No wrapper to maintain.** Runtime's functions carry type hints and
  docstrings, so `tool(f)` from `crewai.tools` turns them into CrewAI tools
  with nothing in between.
- **A real environment.** An engineer agent fixing tests needs the
  project's toolchain. The default image already has git 2.43, gcc 13 and
  Python 3.12, and Docker starts with `sudo enable-docker`.
- **A machine that waits cheaply.** Crews idle between steps. A sandbox with
  nothing happening pauses itself after 60 seconds and wakes on the next
  tool call.

## 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  | $16.88 |                                  |
| E2B      | $82.80     | 80%   |
| Modal    | $118.98   | 86% |

## 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).

## 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.

## Sources

Checked 1 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 23 September to 2 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