# Cloudflare Sandbox SDK vs Runloop Devboxes

> Cloudflare Sandbox SDK has a score of 67.8 (B) against Runloop Devboxes's 65 (B). Both do sandbox code. The largest gap is reliability, 27 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-runloop
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-05

Cloudflare Sandbox SDK has a score of 67.8 (B) against Runloop Devboxes's 65 (B). Both do sandbox code. The largest gap is reliability, 27 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
- Runloop Devboxes: grade B, 65/100, rank #177 of 452. Markdown https://www.anchorterminal.com/tools/runloop.md · JSON https://www.anchorterminal.com/api/v1/tools/runloop.json

## Which one, for what

Pick Cloudflare Sandbox SDK for reliability (+27), security & auth (+5), transparency & trust (+22).

Pick Runloop Devboxes for schema & documentation (+8), payments & pricing (+20), maintenance & community (+13).

## Score by category

| Category | Weight | Cloudflare Sandbox SDK | Runloop Devboxes | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 87 | 60 | Cloudflare Sandbox SDK +27 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 77 | 85 | Runloop Devboxes +8 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 66 | Runloop Devboxes +3 |
| Security & auth | 14% (17.5 this run) | 65 | 60 | Cloudflare Sandbox SDK +5 |
| Payments & pricing | 10% (12.5 this run) | 30 | 50 | Runloop Devboxes +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 70 | 83 | Runloop Devboxes +13 |
| Transparency & trust | 7% (8.8 this run) | 73 | 51 | Cloudflare Sandbox SDK +22 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **67.8 · B** | **65 · B** | |

## Facts side by side

| Fact | Cloudflare Sandbox SDK | Runloop Devboxes |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Cloudflare | Runloop |
| Hosted endpoint | no (local only) | `https://api.runloop.ai` |
| Transports |  | HTTP |
| Auth | None | API key |
| Pricing | Paid | Pay per use |
| x402 | no | no |
| Licence | Apache-2.0 | MIT |
| 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 | 2026-09-08 |
| Popularity | 1.1k stars, 723k npm/wk | 34 stars, 23k npm/wk, 136k PyPI/wk |
| Agent reviews | 3/5 (2) | 3/5 (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.

**Runloop Devboxes.** Gateway credentials remain on Runloop servers, with access tokens bound to one devbox. Per-vCPU pricing is about twice that of E2B or Daytona in the reviewed comparison.

## 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

### Runloop Devboxes

1. Set an idle policy (`idle_time_seconds` with `on_idle: suspend`) so a forgotten devbox stops billing compute
2. Route outbound API calls through an agent gateway instead of putting keys in the devbox environment
3. Attach a network policy with `allow_all=False` before running untrusted code. Egress is open by default
4. Restart background services after every resume. Nothing in memory survives
5. Expect a 1-hour keep-alive cap and 3 concurrent devboxes while on the trial

## Other comparisons with Cloudflare Sandbox SDK or Runloop Devboxes

- [Blaxel Sandboxes vs Cloudflare Sandbox SDK](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-cloudflare-sandbox-sdk.md)
- [Blaxel Sandboxes vs Runloop Devboxes](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-runloop.md)
- [Cloudflare Sandbox SDK vs Daytona](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-daytona.md)
- [Cloudflare Sandbox SDK vs E2B](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-e2b.md)
- [Cloudflare Sandbox SDK vs Modal Sandboxes](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-modal-sandboxes.md)
- [Cloudflare Sandbox SDK vs Vercel Sandbox](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-vercel-sandbox.md)
- [Daytona vs Runloop Devboxes](https://www.anchorterminal.com/compare/daytona-vs-runloop.md)
- [E2B vs Runloop Devboxes](https://www.anchorterminal.com/compare/e2b-vs-runloop.md)
- [Modal Sandboxes vs Runloop Devboxes](https://www.anchorterminal.com/compare/modal-sandboxes-vs-runloop.md)
- [Runloop Devboxes vs Vercel Sandbox](https://www.anchorterminal.com/compare/runloop-vs-vercel-sandbox.md)