Deno Sandbox vs Offscreen

Deno Sandbox

Secrets stay outside the microVM and are substituted only on outbound requests to approved hosts, and an allowlist limits egress. The service is still in beta, sandboxes need the $20 Pro plan, lifetime is capped at 30 minutes, and no sandbox operation appears in the published OpenAPI document.

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.

Deno Sandbox

1. Set DENO_DEPLOY_TOKEN to an organisation token (prefix ddo_) from Settings in console.deno.com. The organisation must be on Pro or above
2. Pass allowNet on every Sandbox.create(). The Security page says outbound access is unrestricted when it is omitted
3. Pass credentials through secrets with a hosts list, not env, so code in the VM sees only a placeholder
4. The default timeout ends the VM when the client disconnects. Pass a duration such as "10m" and reconnect with Sandbox.connect({ id }), up to 30 minutes
5. Create volumes in ord and start the sandbox in ord. A volume mounts only in its own region
6. exposeHttp URLs are public with no authentication. Treat the random subdomain as a secret

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