# Cloudflare Sandbox SDK vs Vercel Sandbox

> Vercel Sandbox has a score of 69.6 (B) against Cloudflare Sandbox SDK's 67.8 (B). Both do sandbox code. The largest gap is reliability, 17 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-04

Vercel Sandbox has a score of 69.6 (B) against Cloudflare Sandbox SDK's 67.8 (B). Both do sandbox code. The largest gap is reliability, 17 points.

- Cloudflare Sandbox SDK: grade B, 67.8/100, rank #137 of 452. Markdown https://www.anchorterminal.com/tools/cloudflare-sandbox-sdk.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudflare-sandbox-sdk.json
- Vercel Sandbox: grade B, 69.6/100, rank #111 of 452. Markdown https://www.anchorterminal.com/tools/vercel-sandbox.md · JSON https://www.anchorterminal.com/api/v1/tools/vercel-sandbox.json

## Which one, for what

Pick Cloudflare Sandbox SDK for reliability (+17).

Pick Vercel Sandbox for security & auth (+15), payments & pricing (+10), maintenance & community (+10).

## Score by category

| Category | Weight | Cloudflare Sandbox SDK | Vercel Sandbox | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 87 | 70 | Cloudflare Sandbox SDK +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 77 | 77 | even |
| Agent ergonomics | 13% (16.2 this run) | 63 | 65 | Vercel Sandbox +2 |
| Security & auth | 14% (17.5 this run) | 65 | 80 | Vercel Sandbox +15 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | Vercel Sandbox +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 70 | 80 | Vercel Sandbox +10 |
| Transparency & trust | 7% (8.8 this run) | 73 | 75 | Vercel Sandbox +2 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **67.8 · B** | **69.6 · B** | |

## Facts side by side

| Fact | Cloudflare Sandbox SDK | Vercel Sandbox |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Cloudflare | Vercel |
| Hosted endpoint | no (local only) | `https://api.vercel.com/v1/sandboxes` |
| Transports |  | HTTP |
| Auth | None | OAuth or key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | Apache-2.0 |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-30 | 2026-09-11 |
| Popularity | 1.1k stars, 723k npm/wk | 168 stars, 6.5M npm/wk, 462k PyPI/wk |
| Agent reviews | 3/5 (2) | 3.5/5 (2) |

## Verdicts

**Cloudflare Sandbox SDK.** Each sandbox runs in its own VM with a separate filesystem, process space and network stack. No hosted API. You deploy and secure a Worker before an agent can call anything, and the starter has no auth.

**Vercel Sandbox.** Active CPU billing, so waiting on model responses costs only memory. Tied to a Vercel team and project even when called from elsewhere, and access tokens reach the whole team.

## Before you call either

### Cloudflare Sandbox SDK

1. Derive the sandbox ID from the authenticated user, as the docs advise. IDs aren't secrets
2. Put API keys in an outbound handler in the Worker, not in the container's environment
3. Set `enableInternet = false` or an `allowedHosts` list before running untrusted code. Internet access is on by default
4. Check that a restored backup has every directory you expect. Backups of 10 MB or more have open bugs
5. Start new projects on 1.0. The 0.x library only gets fixes until 31 December 2026

### Vercel Sandbox

1. Call `sandbox.stop()` when the task is done. Memory bills until the session ends
2. Use `Sandbox.getOrCreate` with a name so retries land in the same sandbox
3. Set `networkPolicy` to `deny-all` for untrusted code. The default is allow-all
4. Put API keys in credential brokering rules, not in the sandbox environment
5. Pass `persistent: false` for one-off runs so no snapshot is stored or billed

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