Deno Sandbox vs Vercel Sandbox

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.

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.

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

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