Coding Sandbox - Fermion

Built for running code in sandbox environments

Secure sandboxed environments 0ms cold start, shell access, and 50+ language support for AI agents and developer tools.

sandbox-example.js

12345678910111213141516171819202122

import { Sandbox } from "@fermion-app/sandbox"

const sandbox = new Sandbox({ apiKey: 'fk-12345' })
const { snippetId } = await sandbox.connect({ shouldBackupFilesystem: true })

await sandbox.setFile({ path: "~/code/app.js", code })
const content = await sandbox.getFile("~/code/app.js")

const { exitCode } = await sandbox.runStreamingCommand({
  cmd: "bun",
  args: ["install", "express", "lodash"],
  onStdout: (stdout) => process.stdout.write(stdout)
})

await sandbox.disconnect()

// some time later

const sandboxAgain = await sandbox.fromSnippet({ snippetId })
const fileContent = await sandbox.getFile("~/code/app.js")

console.log('Older file', fileContent)

Sandboxed container environments with 0ms cold starts, shell access, and pay-per-minute billing. No setup required.

We've built everything you need for your AI-powered coding needs.

Shell Access

Install packages, configure services, or run any command you need in a secure isolated environment.

Zero Second Cold Start

Instant execution with your container readily available, no waiting, just immediate code execution.

Per-Minute Billing

Pay only for actual compute time, no idle costs, no wasted resources, transparent pricing that scales with your usage.

Coding Agents

Securely execute code, access the internet, start terminal commands. Perfect for AI agents that need to write and run code.

Persistent storage

Built in storage persistent to use same sandbox after a few minutes, or a few months.

Vibe Coding

Sandbox to code runtimes for AI-generated apps, support any language and framework with instant preview environments.

Running with full network access and I/O operations

AI Agent

123456789

const express = require('express');
const app = express();

app.get('/api/users', async (req, res) => {
  const users = await db.getUsers();
  res.json(users);
});

app.listen(3000);

AI-generated code in isolated containers

Generate and execute code from AI agents safely. Full network access, filesystem operations, and shell commands—all sandboxed with hardware-level isolation.