Run Claude Code in a Modal Sandbox
This example demonstrates how to run Claude Code in a Modal Sandbox to analyze a GitHub repository. The Sandbox provides an isolated environment where the agent can safely execute code and examine files.
import modal
from modal.container_process import ContainerProcess
app = modal.App.lookup("example-sandbox-agent", create_if_missing=True)First, we create a custom Image that has Claude Code and git installed.
image = (
modal.Image.debian_slim(python_version="3.12")
.apt_install("curl", "git")
.env({"PATH": "/root/.local/bin:$PATH"}) # add claude to path
.run_commands(
"curl -fsSL https://claude.ai/install.sh | bash",
)
)Then we create our Sandbox.
with modal.enable_output():
sandbox = modal.Sandbox.create(app=app, image=image)
print(f"Sandbox ID: {sandbox.object_id}")Next we’ll clone the repository that Claude Code will work on. We’ll use the Modal examples repo that this example is a part of.
We trigger the clone by executing git as a process inside the Sandbox. We then .wait for it to finish.
You can read more about the interface for managing ContainerProcesses in Sandboxes here.
repo_url = "https://github.com/modal-labs/modal-examples"
git_ps: ContainerProcess = sandbox.exec(
"git", "clone", "--depth", "1", repo_url, "/repo"
)
git_ps.wait()
print(f"Cloned '{repo_url}' into /repo.")Finally we’ll use exec again to run Claude Code to analyze the repository.
Here, we pass the pty flag to give the process a pseudo-terminal.
claude_cmd = ["claude", "-p", "What is in this repository?"]
print("\nRunning command:", *claude_cmd)
claude_ps = sandbox.exec(
*claude_cmd,
pty=True, # Adding a PTY is important, since Claude requires it
secrets=[
modal.Secret.from_name("anthropic-secret", required_keys=["ANTHROPIC_API_KEY"])
],
workdir="/repo",
)
claude_ps.wait()Once the command finishes, we read the stdout and stderr.
print("\nAgent stdout:\n")
print(claude_ps.stdout.read())
stderr = claude_ps.stderr.read()
if stderr != "":
print("Agent stderr:", stderr)