Muse Code

Muse Code is Meta’s coding agent for the terminal and CI, built on Muse Spark. E2B provides a pre-built muse template with Muse Code already installed.

CLI

Create a sandbox with the E2B CLI.

e2b sbx create muse

Once inside the sandbox, start Muse Code.

muse

Run headless

Use muse exec for non-interactive mode and --yolo to skip approval prompts, disable Muse Code’s own OS sandbox, and trust the workspace. The E2B sandbox is the isolation boundary here, so Muse Code’s built-in sandbox is not needed. The sandbox isolates the agent from your host machine, but sandboxes can reach the open internet by default; restrict outbound traffic with network rules. Muse Code authenticates with an API key from the Meta Model API dashboard via the META_API_KEY environment variable.

Auto-approving tool calls is contained by the sandbox: the agent cannot touch your host machine, local files, or credentials. It can still make outbound network requests, since internet access is enabled by default. To limit where an auto-approved agent can connect, configure outbound network rules (allowInternetAccess, plus allow/deny lists by CIDR or hostname). Hostname rules apply to HTTP(S) traffic only; use CIDR rules for other protocols.

import { Sandbox } from 'e2b'

const sandbox = await Sandbox.create('muse', {
  envs: { META_API_KEY: process.env.META_API_KEY },
})

const result = await sandbox.commands.run(
  `muse exec --yolo "Create a hello world HTTP server in Go"`
)

console.log(result.stdout)
await sandbox.kill()

import os
from e2b import Sandbox

sandbox = Sandbox.create("muse", envs={
    "META_API_KEY": os.environ["META_API_KEY"],
})

result = sandbox.commands.run(
    'muse exec --yolo "Create a hello world HTTP server in Go"',
)

print(result.stdout)
sandbox.kill()

Add --json to emit machine-readable JSONL events instead of plain text, and --max-model-steps to cap a run that would otherwise loop.

Example: work on a cloned repository

import { Sandbox } from 'e2b'

const sandbox = await Sandbox.create('muse', {
  envs: { META_API_KEY: process.env.META_API_KEY },
  timeoutMs: 600_000,
})

await sandbox.git.clone('https://github.com/your-org/your-repo.git', {
  path: '/home/user/repo',
  username: 'x-access-token',
  password: process.env.GITHUB_TOKEN,
  depth: 1,
})

const result = await sandbox.commands.run(
  `cd /home/user/repo && muse exec --yolo "Add error handling to all API endpoints"`,
  { onStdout: (data) => process.stdout.write(data) }
)

const diff = await sandbox.commands.run('cd /home/user/repo && git diff')
console.log(diff.stdout)

await sandbox.kill()

import os
from e2b import Sandbox

sandbox = Sandbox.create("muse", envs={
    "META_API_KEY": os.environ["META_API_KEY"],
}, timeout=600)

sandbox.git.clone("https://github.com/your-org/your-repo.git",
    path="/home/user/repo",
    username="x-access-token",
    password=os.environ["GITHUB_TOKEN"],
    depth=1,
)

result = sandbox.commands.run(
    'cd /home/user/repo && muse exec --yolo "Add error handling to all API endpoints"',
    on_stdout=lambda data: print(data, end=""),
)

diff = sandbox.commands.run("cd /home/user/repo && git diff")
print(diff.stdout)

sandbox.kill()

Build a custom template

If you need to customize the environment (e.g. pre-install dependencies, add config files), build your own template on top of the pre-built muse template.

// template.ts
import { Template } from 'e2b'

export const template = Template()
  .fromTemplate('muse')

# template.py
from e2b import Template

template = (
    Template()
    .from_template("muse")
)

// build.ts
import { Template, defaultBuildLogger } from 'e2b'
import { template as museTemplate } from './template'

await Template.build(museTemplate, 'my-muse', {
  cpuCount: 2,
  memoryMB: 2048,
  onBuildLogs: defaultBuildLogger(),
})

# build.py
from e2b import Template, default_build_logger
from template import template as muse_template

Template.build(muse_template, "my-muse",
    cpu_count=2,
    memory_mb=2048,
    on_build_logs=default_build_logger(),
)

Run the build script to create the template.

npx tsx build.ts

python build.py

Sandbox persistence

Auto-pause, resume, and manage sandbox lifecycle

Git integration

Clone repos, manage branches, and push changes

SSH access

Connect to the sandbox via SSH for interactive sessions

Agents

MCP gateway

CLI

Run headless

Example: work on a cloned repository

Build a custom template

Sandbox persistence

Git integration

SSH access

​CLI

​Run headless

​Example: work on a cloned repository

​Build a custom template

​Related guides

Sandbox persistence

Git integration

SSH access

CLI

Run headless

Example: work on a cloned repository

Build a custom template

Related guides