Vercel has announced the general availability of Vercel Sandbox, an execution layer designed specifically for AI agents. But beyond the AI agent hype, there’s an interesting question: can it be useful for running code safely in different languages like PHP, Node, or Go?
What is Vercel Sandbox?
Vercel Sandbox provides on-demand Linux microVMs. Each sandbox is isolated, with its own filesystem, network, and process space. You get sudo access, package managers, and the ability to run the same commands you’d run on a Linux machine.
The key here is complete isolation. Each sandbox is a Firecracker microVM (the same technology AWS Lambda uses) that spins up in fractions of a second, executes code, and disappears when the task is done.
import { Sandbox } from '@vercel/sandbox';
const sandbox = await Sandbox.create();
await sandbox.runCommand({
cmd: 'node',
args: ["-e", 'console.log("Hello from Vercel Sandbox!")'],
stdout: process.stdout,
});
await sandbox.stop();
The Problem It Solves
AI agents work differently than humans. They need:
- Environments that start in seconds
- Complete isolation for untrusted code
- Ephemeral environments that exist only as long as needed
- Snapshots to instantly restore complex environments
- Active CPU pricing for cost and performance efficiency
Vercel processes over 2.7 million deployments per day. Each spins up an isolated microVM, runs user code, and disappears, often in seconds. Sandbox brings that same infrastructure to agents.
Can It Be Used for PHP?
The short answer is yes. Since Sandbox is a complete Linux microVM with sudo, you can install PHP:
# Install PHP in the sandbox
apt-get update && apt-get install -y php php-cli
# Run PHP code
php -r "echo 'Hello from PHP!';"
However, there’s an important limitation: Sandbox is not persistent. Every time you create a new sandbox, you start from scratch. You’d have to install PHP each time.
The solution is snapshots: once you have an environment configured with PHP, you can save it as a snapshot and restore it instantly in future runs.
What About Node.js?
Node.js is the most natural use case, as it’s the runtime Vercel uses by default. Node is likely already preinstalled in Sandbox’s base images:
await sandbox.runCommand({
cmd: 'node',
args: ['--version'],
stdout: process.stdout,
});
await sandbox.runCommand({
cmd: 'npm',
args: ['install'],
stdout: process.stdout,
});
For Node, Sandbox is especially useful because you can:
- Clone a repository
- Install dependencies with npm/yarn/pnpm
- Run tests
- Execute scripts
- Cleanup and disappear
And Go Binaries?
This is where it gets interesting. Go compiles to static binaries, making it perfect for this environment:
# Install Go
apt-get install -y golang-go
# Or copy a previously compiled binary
./my-go-program
The advantage of Go is that you don’t need to install runtime dependencies. The binary is self-contained. You can compile on your machine and copy the binary to the sandbox, or compile inside the sandbox if needed.
Practical Use Cases
Beyond AI agents, I see several interesting use cases:
1. Untrusted Code Execution
If you need to execute user-submitted code (like in an online code editor), Sandbox offers perfect isolation. The user can run whatever they want, but they’re confined to their microVM.
2. Clean Environment Testing
For integration tests that need a clean environment every time, Sandbox is ideal. There’s no “leakage” between runs.
3. Parallel Processing
You can create multiple sandboxes in parallel to process independent tasks. Each is isolated, no resource contention.
4. Maintenance Scripts
Need to run a maintenance script that requires sudo? Sandbox gives you root access without compromising your main infrastructure.
Limitations to Consider
Ephemeral by Design
Sandboxes are designed to be ephemeral. If you need persistence, you’ll have to:
- Use mounted volumes (if available)
- Save state to external storage (S3, database, etc.)
- Use snapshots to save/restore state
Cold Start
While cold start is fast (sub-second), it’s not instant. For latency-critical tasks, it might not be enough.
Cost
Pricing is by active CPU. If you have tasks that run for a long time, it might not be economical compared to traditional VMs.
Network
Sandboxes have their own isolated network. If you need access to specific resources, you’ll need to configure networking accordingly.
Compared to Alternatives
vs Docker
Docker also gives you isolation, but Sandbox is lighter (Firecracker vs containers) and optimized for fast startup. For ephemeral work, Sandbox wins.
vs AWS Lambda
Lambda is serverless, but it’s limited to specific runtimes and has more restrictions. Sandbox gives you full root access to Linux.
vs Traditional VMs
Traditional VMs are more persistent but take minutes to boot. Sandbox boots in seconds.
Is It Worth It?
It depends on your use case:
Yes, if:
- You need to run untrusted code safely
- Your tasks are ephemeral and last seconds/minutes
- You need complete isolation
- You benefit from parallelism
- You don’t want to manage infrastructure
No, if:
- You need state persistence
- Your tasks run for long periods
- Cold start is a problem
- Active CPU pricing is prohibitive
My Personal Opinion
Vercel Sandbox is interesting, but I think the current hype comes from the AI agent world. For the average developer, it’s probably not the solution unless you have a very specific use case.
That said, the technology behind it (Firecracker microVMs) is solid, and Vercel has proven they can scale it to millions of daily deployments. If it fits your use case, it can be a very powerful tool.
For running PHP, Node, or Go specifically, I would first look at simpler alternatives:
- PHP: Docker containers or Lambdas with PHP runtime
- Node: Serverless functions (Vercel/AWS Lambda) or Docker
- Go: Compiled binaries deployed as containers or Lambda custom runtimes
Sandbox shines when you need the combination of isolation + ephemeral + complete Linux. If you don’t need all three, there’s probably a simpler solution.
Original article: Vercel Sandbox is Now Generally Available Documentation: Vercel Sandbox Docs SDK: @vercel/sandbox
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