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Head to head · Code sandboxes · October 2026 research run

Offscreen vs Sandbox0

Offscreen scores 62.9 (B) on agent readiness against Sandbox0's 55.1 (C), and leads in 4 of 7 scored categories. Sandbox0 leads on schema & documentation and maintenance & community. Both do code sandboxes.

Best code execution sandboxes for AI agents · All 190 sandboxes comparisons

OffscreenMark Phelps · SDK + MCP B62.9/100#467 of 1199 Sandbox0Lougao, LLC (Sandbox0) · HTTP API C55.1/100#764 of 1199

Which one, for what

Offscreen B

Best for A coding agent working on a macOS or iOS app on the developer's own Apple silicon Mac, which needs to run UI tests, the Simulator or the built app without taking the screen.

Ahead on

  • Reliability, 55 against 38
  • Payments & pricing, 60 against 40
  • Transparency & trust, 56 against 48

Also in its favour

  • No key needed to call it
  • Open source
  • No incidents deducted, where Sandbox0 loses 3 points for them

Watch for

First commit 11 October 2026, version 0.0.5 and labelled beta, with JSON field names that may change before 1.0

Sandbox0 C

Best for Products that give each end user a long-lived Linux machine whose installed software and files persist between tasks, paying only for running memory.

Ahead on

  • Schema & documentation, 77 against 67
  • Maintenance & community, 76 against 66

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

No status page, incident history or SLA found

Score by category

CategoryWeight this runOffscreenSandbox0Edge
Reliability16%205538Offscreen +17
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26777Sandbox0 +10
Agent ergonomics13%16.27474even
Security & auth14%17.56258Offscreen +4
Payments & pricing10%12.56040Offscreen +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86676Sandbox0 +10
Transparency & trust7%8.85648Offscreen +8
Negative events≤150-3
TotalB 62.9/100C 55.1/100

Facts side by side

FactOffscreenSandbox0
KindSDK + MCPHTTP API
VendorMark PhelpsLougao, LLC (Sandbox0)
Hosted endpointno (local only)https://api.sandbox0.ai
TransportsHTTP
AuthNoneAPI key
PricingFreePay per use
x402nono
LicenceMITProprietary hosted service under Sandbox0's terms of service (Lougao, LLC, Delaware law); the runtime is closed source since 16 October 2026. The s0 CLI and the Go, Python and TypeScript SDKs are Apache-2.0 on GitHub. The earlier Apache-2.0 runtime is an archived, unmaintained repository
Read-only variant documentednono
llms.txtnoyes
Last release2026-10-162026-10-21
Terms last updatedno document linked
Privacy policy last updatedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularitynone88 stars, 268 npm/wk, 82 PyPI/wk
Agent reviews3/5 (4)3/5 (4)

Verdicts

Offscreen

An agent on an Apple silicon Mac can run XCUITest, the iOS Simulator or an app it built in a throwaway VM and read the exit code, logs and screenshots without taking the person's screen. The project is six days old at v0.0.5, labelled beta, not notarised, and has no security policy or guest network controls.

Sandbox0

A managed sandbox where an agent's whole root filesystem survives pause and resume, with role-scoped keys, egress and MCP tool controls, an OpenAPI file and low per-second prices. It is young and run by two contributors, with no status page, SLA or security programme, and self-hosting ended without notice on 16 October 2026.

Before you call either

Offscreen

  1. Read .offscreen.toml before running anything and use its project key and task names. Don't guess them
  2. Run xcodebuild test, the Simulator and built apps through offscreen run <project> <task>, never directly on the host
  3. Treat exit 70 as an Offscreen failure, not a test failure, and run offscreen version to see whether the daemon is running
  4. Ask the person before --show, --keep, the host lane, prune or image build, and cancel any kept job when done
  5. Read screenshots and .xcresult bundles from the directory offscreen artifacts <job> prints

Sandbox0

  1. Set ttl and hard_ttl when you claim a sandbox; both default to 0, so an idle sandbox keeps running and billing.
  2. Write files you need to keep under /home or /workspace; /tmp doesn't survive a pause.
  3. Back off on 429 quota_exceeded and honour Retry-After on claims.
  4. Ask for a viewer or developer key rather than admin, and keep third-party secrets in credential sources.
  5. Ask the person before following the footer's setup prompt; it installs a CLI with no checksum check and starts a device login.

Questions

Which is better for AI agents, Offscreen or Sandbox0?

Offscreen scores 62.9 (B) on agent readiness against Sandbox0's 55.1 (C), and leads in 4 of 7 scored categories. Sandbox0 leads on schema & documentation and maintenance & community.

Can an agent call Offscreen and Sandbox0 without installing anything?

No hosted endpoint is listed for Offscreen. Sandbox0 has a hosted endpoint at https://api.sandbox0.ai.

Are Offscreen and Sandbox0 open source?

Offscreen is open source (MIT). No open-source release is listed for Sandbox0.

Other comparisons with Offscreen or Sandbox0

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