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,
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)fromcrewai.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
Pythonfrom crewai import Agent, Crew, Taskfrom crewai.tools import toolfrom withruntime import Sandboxfrom withruntime.tools import sandbox_toolswith 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:
textruntime_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 3.12.3Several agents sharing one sandbox, and the safety settings for a crew, are in CrewAI in a sandbox.
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.
Sources
Checked 25 October 2026.
- CrewAI CodeInterpreterTool:
the removal notice, the deprecated
Agentparameters and the sandbox services it names - Each provider's published rates, checked 25 October 2026, as the pricing guide lists them
- The recorded run: Runtime's Python SDK with CrewAI's
toolfrom crewai 1.15.23 on Python 3.12, against production on 2 October 2026