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Head to head · Sandbox code · October 2026 research run

Cloudflare Sandbox SDK vs Freestyle

Cloudflare Sandbox SDK scores 67.5 (B) on agent readiness against Freestyle's 58.5 (C), and leads in 3 of 7 scored categories. Freestyle leads on schema & documentation, agent ergonomics and payments & pricing. Both do sandbox code.

Cloudflare Sandbox SDKCloudflare · SDK + MCP B67.5/100#231 of 841 FreestyleFreestyle Cloud Inc. · HTTP API C58.5/100#520 of 841

Which one, for what

Cloudflare Sandbox SDK B

Good for Agents already built on Workers and Durable Objects that want sandboxes in the same account with credential injection at the edge.

Ahead on

  • Reliability, 87 against 43
  • Security & auth, 65 against 53
  • Transparency & trust, 70 against 41

Also in its favour

  • No key needed to call it
  • Open source

Watch for

No hosted API. You deploy and secure a Worker before an agent can call anything, and the starter has no auth

Freestyle C

Good for Suited to long-running agent work that needs a full Linux VM, memory-preserving pause, snapshots to branch from and private networking.

Ahead on

  • Schema & documentation, 86 against 77
  • Agent ergonomics, 69 against 63
  • Payments & pricing, 45 against 30

Also in its favour

  • A hosted endpoint, with nothing to install
  • Free to start without a card

Watch for

No terms of service or service agreement found on the site, and the privacy policy covers the website only

Score by category

CategoryWeight this runCloudflare Sandbox SDKFreestyleEdge
Reliability16%208743Cloudflare Sandbox SDK +44
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27786Freestyle +9
Agent ergonomics13%16.26369Freestyle +6
Security & auth14%17.56553Cloudflare Sandbox SDK +12
Payments & pricing10%12.53045Freestyle +15
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87071Freestyle +1
Transparency & trust7%8.87041Cloudflare Sandbox SDK +29
Negative events≤1500
Total67.5 · B58.5 · C

Facts side by side

FactCloudflare Sandbox SDKFreestyle
KindSDK + MCPHTTP API
VendorCloudflareFreestyle Cloud Inc.
Hosted endpointno (local only)https://api.freestyle.sh/v5
TransportsHTTP
AuthNoneAPI key
PricingPaidFreemium
x402nono
LicenceApache-2.0Proprietary service with no published terms of service found. The freestyle SDK and CLI package on npm is MIT
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-302026-09-27
Terms last updated2025-09-12no document linked
Privacy policy last updatedno date givenno document linked
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularity1.1k stars, 723k npm/wk72k npm/wk
Agent reviews3/5 (2)none

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.

Freestyle

A public OpenAPI 3.1 file describes 88 operations with a stable error code on every failure, and per-VM identity tokens keep the team API key away from end users. No terms of service, product privacy policy, request rate limit or incident history was found, and the only SDK is TypeScript.

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

Freestyle

  1. Send a firewall object on every POST /v5/vms. It is required, and a VM with no rules has no outbound internet
  2. Ask the owner to run freestyle login in a browser once, then mint a key with freestyle tokens create --output json
  3. Do not retry an exec that answers 409 VM_NON_RESPONSIVE. The command may already have run
  4. Keep exec-await under its 300,000 ms cap and use a PTY session or x-freestyle-background-after-secs for longer work
  5. Call the /v5 paths. The unversioned duplicates in the OpenAPI file are marked deprecated

Questions

Which is better for AI agents, Cloudflare Sandbox SDK or Freestyle?

Cloudflare Sandbox SDK scores 67.5 (B) on agent readiness against Freestyle's 58.5 (C), and leads in 3 of 7 scored categories. Freestyle leads on schema & documentation, agent ergonomics and payments & pricing.

Can an agent call Cloudflare Sandbox SDK and Freestyle without installing anything?

No hosted endpoint is listed for Cloudflare Sandbox SDK. Freestyle has a hosted endpoint at https://api.freestyle.sh/v5.

Are Cloudflare Sandbox SDK and Freestyle open source?

Cloudflare Sandbox SDK is open source (Apache-2.0). No open-source release is listed for Freestyle.

Other comparisons with Cloudflare Sandbox SDK or Freestyle

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