Sandboxes

Sandboxes are the execution environments where Neo runs commands and tools and manages workspace files. Depending on your plan, Neo can run with a Neo-managed cloud sandbox, one or more BYOS instances, or both. Accounts with cloud sandbox access receive one automatically. It works without installation and is the default for tasks, terminals, and file sessions. When work must run from your network or use files and tools already on a machine you control, the Bring Your Own Sandbox (BYOS) feature lets you connect a sandbox on a host you control. Some plans can use BYOS as their only execution environment.

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Neo-managed cloud sandbox

When cloud sandbox access is included in your plan, Neo provisions and maintains the environment for you. It provides an isolated Linux environment with a security toolchain, development runtimes, persistent workspace files, and the permissions agents need to install additional packages. Use the cloud sandbox when:

• You want to start immediately without installing anything.
• The target is reachable from the public internet or through a configured VPN.
• You want Neo to manage the operating system, toolchain, updates, and isolation boundary.
• You need an enterprise static egress IP for allowlisting.

On accounts with both options, Neo uses the cloud sandbox automatically unless you select a connected BYOS instance.

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Bring Your Own Sandbox

Bring Your Own Sandbox lets you install Neo’s sandbox service on a laptop, workstation, server, cloud VM, or private VPS that you control. A BYOS instance can complement a Neo-managed sandbox or provide the account’s required execution environment. Use BYOS when:

• Targets are reachable only from a private network, VPN, VPC, or specific network segment.
• Source code or other working files already exist on the host.
• Tests need host-local tools, credentials, browser sessions, or operating system integrations.
• Your organization requires the execution host and workspace storage to remain on infrastructure it controls.

You can install multiple BYOS instances and choose the appropriate network position or toolset for each task.

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Trust boundary

The sandbox daemon, outbound tunnel, file index, file APIs, and computer-use integrations run on the host. Command confinement applies only to /exec command children. It does not move the complete daemon into a container. Workspace files remain on the host’s storage. When an agent reads a file or runs a command, the requested content and command output can travel through the encrypted tunnel to Neo as part of the task. Treat the host as the trust boundary and apply your normal endpoint, identity, and data-handling controls.

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Confine mode

Confine mode controls where /exec commands run on a BYOS instance:

• Docker runs commands in Neo’s managed tool image and is the default on a bare host.
• Native uses Seatbelt on macOS or bubblewrap on Linux.
• Off runs commands directly with the permissions of the sandbox service user.

Confinement does not deny network access by default. Advanced host configuration can deny all egress for confined commands. See Confine mode and network policy.

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Choose a sandbox

When multiple execution environments are available, Neo shows a sandbox selector in supported task, terminal, and files interfaces.

1. Use the Neo-managed sandbox for normal cloud execution when your plan includes one.
2. Select a BYOS instance when the task needs that host’s files, tools, or network position.
3. On a BYOS-only account, connect at least one sandbox before starting a task.
4. Check that the selected sandbox is connected before starting the task.

The selection controls where commands run. It does not copy the complete contents of one sandbox into another.

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VPN, SSH, or BYOS

VPN, SSH connections, and BYOS all extend where Neo can reach, but they solve different problems and put target-facing traffic on a different network path. A VPN adds a hop: traffic leaves the cloud sandbox and crosses the VPN tunnel to reach your network. SSH and BYOS put test traffic on the target’s network directly, since the command runs from a host already positioned there. For a target reachable only from inside your network, that hop count is the main practical difference between VPN and the other two options — not an abstract performance ranking. SSH and BYOS differ in scope rather than network position: SSH runs specific commands on an existing host with no persistent workspace, while BYOS gives Neo a full environment. Reach for BYOS when a task needs more than a few commands, or needs state to persist across a task; reach for SSH when it doesn’t.

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Workspace scope

Personal, project, and team workspaces control who can access files and artifacts. Workspace scope is separate from the execution sandbox you select.

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Sandboxes and SSH

A sandbox is Neo’s persistent execution workspace. An SSH connection is a separate remote host that Neo reaches from a sandbox for targeted command execution. Use BYOS when you want Neo’s workspace, terminal, files, and tools on a host you control. Use SSH when Neo only needs to run specific commands on an existing remote system.