Deno Sandbox

Deno Sandbox is an SDK for creating and managing isolated Linux microVMs in the cloud on Deno Deploy. Deno identifies AI agents, copilots, plugin systems, collaborative IDEs, ephemeral CI runners, smoke tests, user-supplied code, and preview environments as use cases. Each sandbox has its own filesystem, network stack, and process tree, with isolation at the hypervisor level. Outbound networking is unrestricted by default, though an allowlist can limit connections to specified hosts. Secrets remain placeholders inside a sandbox and are substituted only for outbound requests to approved hosts. Files are temporary unless a volume is mounted; when a sandbox is killed or its last reference is dropped, the VM is destroyed and its disk wiped. Limits include 2 vCPU, 10 GB of ephemeral disk, configurable memory from 768 MB to 4096 MB, and a maximum 30-minute lifetime. The SDK supports Deno latest stable, Node.js 24+, and Python 3.10 or later, with package and REST API access. Regions listed are Amsterdam and Chicago. The Free plan does not include Sandbox; Pro costs $20 a month and includes it.

Deno Sandbox provides isolated cloud microVMs with configurable networking and temporary storage. Check its runtime, lifetime, region, and concurrency limits against your workload.

Deno Sandbox may suit developers building isolated environments for user-supplied code, AI agents, tests, or preview work. Its SDK and REST API options support teams working with the listed runtimes.

Overview

Deno Sandbox gives developers an SDK for spinning up isolated Linux microVMs in Deno Deploy’s cloud. It suits teams that need to run agents, user-supplied code, tests, or previews in disposable environments. Its isolation and controlled secret handling stand out, but sandbox use starts with a paid plan.

Key features

Each sandbox has its own filesystem, network stack, and process tree, with isolation at the hypervisor level. That makes it a strong fit for workloads such as plugin execution, collaborative IDEs, and ephemeral CI runners where code should not share an ordinary process environment. Deno supports the SDK on Deno latest stable, Node.js 24+, and Python 3.10 or later; developers can use JavaScript packages from npm or JSR, Python packages from PyPI, or call the REST API directly.

Outbound networking is unrestricted by default, with an allowlist available to narrow connections to specified hosts. Secrets remain placeholders inside the sandbox and are substituted only for outbound requests to approved hosts. This helps limit direct credential exposure, though teams that require network access to be blocked by default will need to configure an allowlist.

Sandbox files are temporary unless a volume is mounted. Dropping the last reference or killing a VM destroys it and wipes its disk, which suits short-lived jobs but means persistent work needs mounted storage. Each sandbox supports up to 2 vCPU, 10 GB of ephemeral disk, and configurable memory from 768 MB to 4096 MB, with a maximum 30-minute lifetime. The default prerelease limit is five concurrent sandboxes per organization; Deno invites customers to contact it for a higher limit.

Sandboxes can expose an HTTP development server, provide SSH access, and open an on-demand VS Code editor. The Deno Deploy dashboard traces commands, HTTP requests, and SSH sessions. Amsterdam and Chicago are the supported sandbox regions, so teams needing other locations should look elsewhere.

Pricing

The Free plan costs nothing, billed at $0 /month, and includes 1M requests/month and 10 hr active CPU, but no Sandbox. The separate Deno Sandbox usage charge is $0.20 a month, billed as $0.20/GiB-month for CPU time, memory, and persistent volume usage.

Pro costs $20 a month, billed at $20 /month. It includes Sandbox, three concurrent sandboxes per region, and 5 GiB of volume storage, making it the entry point for teams that need the service. Builder costs $200 a month, billed at $200 /month, and raises those allowances to 20 concurrent sandboxes per region and 50 GiB of volume storage. Enterprise has custom pricing, with custom sandbox concurrency and volume storage; contact sales for a quote.

Community support is included on every listed plan. Pro and Builder add email support, while Enterprise adds an email support SLA. Deno Deploy is SOC2 and ISO27001 certified, and HIPAA BAAs are available for enterprise contracts.

Platforms

Deno Sandbox is available through an API and the web, and its deployment target is edge. Deno Deploy also supports GitHub integration, a dashboard, and CLI deployment, with JavaScript, TypeScript, Deno, and Node.js runtime languages. The deployment service includes 5,000,000 requests/month, 200 GB/month of bandwidth, two edge locations, request processing, response streaming, and cron triggers.

Who it's for

This is a focused choice for developers and teams building AI agents, copilots, plugin systems, or tools that execute user-supplied code. Its short sandbox lifetime and disposable disk also suit smoke tests, preview environments, and temporary CI runners. It is less suitable for workloads needing long-running environments, persistent local state without volumes, or a region beyond Amsterdam and Chicago.

Pros and cons

• Pros: Hypervisor-level isolation gives each sandbox its own filesystem, network stack, and process tree, a useful boundary for untrusted or independently running code.
• Pros: Host allowlists and outbound-only secret substitution help constrain access to services and credentials.
• Pros: SSH, an HTTP development server, an on-demand VS Code editor, and dashboard traces support both interactive work and debugging.
• Cons: The Free plan does not include Sandbox, so trying the core product requires a paid plan.
• Cons: A 30-minute maximum lifetime and ephemeral storage make it a poor fit for persistent or long-running sessions unless the workload can use mounted volumes.
• Cons: The default prerelease concurrency cap is five per organization, and the two supported regions restrict placement choices.

Alternatives

For JavaScript package management rather than cloud microVMs, compare pnpm, JSPM, npm, vlt, Bun, Pantry, Textadept, and Yarn.

Choose pnpm if you want a free package manager available on Android, Linux, macOS, and Windows. JSPM is a free open-source import-map package-management option with API, web, extension, and self-hosted availability. npm is a freemium choice for public package authors, with a free plan for unlimited public packages and access to the public registry. vlt offers a free plan with 2GB storage and delivery, upstream proxy, user management, token management, and community support; its Pro plan is $8 a month, billed annually, for readers seeking a paid package-management option.

Bun is a free, open-source JavaScript runtime and toolkit for Linux, macOS, and Windows. Pantry is a freemium option built and maintained by the Stacks.js team. Textadept is a free, MIT-licensed open-source text editor for Linux, macOS, and Windows. Yarn is a free, open-source package manager with no paid plans or usage limits stated.

Verdict

Deno Sandbox is best for teams that need short-lived, isolated environments to run code they do not fully control. Its strongest reason to choose it is the combination of microVM isolation, network allowlists, and secret substitution; its clearest reason to look elsewhere is the paid entry point, short runtime ceiling, and limited region selection.