Sandbox
Without a sandbox an agent can only talk. With one it can run commands, edit files and start services.
Two runtimes
Section titled “Two runtimes”Configure under SandBox in the left menu.
| Runtime | Best for | Characteristics |
|---|---|---|
| Local container | Self-hosted or single-machine setups | You supply the runtime, images and resources |
| E2B | Managed sandboxes | Provide an API key and a template; created on demand |
Both can exist, but only one is active at a time.
Local container
Section titled “Local container”| Field | Notes |
|---|---|
| Server URL | Address of the container service |
| Server auth key | Key required by that service |
| Default image | Image used for new sandboxes |
| CPU / memory / disk | Per-sandbox limits; disk is a hard resource and is required |
| Preview domain | Used to expose sandbox ports |
| Preview scheme | http / https |
| Require signed access | Adds a signature to preview URLs |
| Preview TTL | Expiry in hours |
| Field | Notes |
|---|---|
| Instance key / display name | Distinguish environments |
| E2B domain | Service address |
| Sandbox access domain | Optional custom entry point |
| API key | Your E2B key |
| Template | Which prebuilt template to use |
| Use HTTPS | Recommended in production |
| Environment description | Optional |
| Skills Git repo | Optional; pull skills from a public repo |
After saving you can build the template; built templates appear in the dropdown.
Use it in a session
Section titled “Use it in a session”- Enable the sandbox for the session as prompted.
- Commands run inside the sandbox; output returns to the conversation.
- Inspect execution logs, open previews and discard the sandbox at any time.
Previews
Section titled “Previews”With a preview domain configured, a service started inside the sandbox can be exposed:
- Start the service on a port, e.g.
3000. - Add the port in the sandbox panel.
- Open the generated URL.
With signed access enabled, links carry an expiring signature — suitable for demos.
Sandbox fails to start — check server URL/key, that the image exists, and disk quota.
Commands time out — run long work in the background or raise the tool timeout.
Preview does not open — the service must listen on 0.0.0.0, the port must match, and the preview domain must resolve.
Files disappeared — discarding a sandbox loses its files. Download or commit anything you need to keep.