🏖️ sandbar

Local-first sandbox for isolated, observable and traceable execution of AI agents.

Install

npm install -g sandbar

Allowed agents

• codex
• opencode

Commands

Create

Create an ubuntu:26.04 Docker sandbox from the current directory with a generated name:

sandbar create

Note: Generated names are unique, so you can create multiple sandboxes from the same workspace.

Or pass a specific name:

sandbar create test

Note: By default, Sandbar uses isolated mode. It copies the current directory (.) to /workspace inside Docker once, so changes are not shared between the host and container.

Create a sandbox in isolated mode:

sandbar create test --mount-mode isolated

Or bind mode:

sandbar create test --mount-mode bind

Note: Use bind mode when you want changes shared between the host and container.

Create a sandbox without copying or mounting the host workspace:

sandbar create test --empty-workspace

Create a sandbox from a compatible Ubuntu-based Docker image:

sandbar create test --empty-workspace --image grepguard/sandbar-agents:latest

Note: Custom images should be based on Ubuntu and include the shell and tooling Sandbar commands expect. The grepguard/sandbar-agents image comes with opencode and codex preinstalled.

Copy or mount a different workspace path or container target:

sandbar create test --workspace . --mount-target /workspace

List

List Sandbar containers:

sandbar list

Start

Start a stopped Sandbar container:

sandbar start test

Stop

Stop a Sandbar container without removing it:

sandbar stop test

Environment variables

Add environment variables in a running Sandbar container (stored in ~/.bashrc):

sandbar env test CODEX_API_KEY=sk-xxx

Note: This appends export KEY="value" to the container's ~/.bashrc, so the var is available on every connection (shell or agent). No need to pass --key.

Set a GitHub personal access token so the agent can push to repositories:

sandbar env test GIT_PAT=ghp_xxx

When GIT_PAT is set, the agent authenticates as Sandbar Agent for git operations.

Install

Install opencode inside a running Sandbar container:

sandbar install test --agent opencode

Or codex:

sandbar install test --agent codex

Note: codex is configured with gpt-5.5 and model_reasoning_effort=xhigh.

Connect

Connect to a running Sandbar container (opens an interactive shell):

sandbar connect test

Note: Docker Desktop may print a Docker Debug hint after you exit the shell. To hide Docker CLI hints, add this to your shell profile:

export DOCKER_CLI_HINTS=false

Run

Run an agent task inside a running Sandbar container:

sandbar run test --agent opencode --prompt "add a new file called hello.js"

Note: Agents run in "yolo mode".

Or pass a file as the prompt:

sandbar run test --agent opencode --file prompt.txt

Pass an API key to an agent one-time (not stored):

sandbar run test --agent codex --prompt "hello" --key sk-xxx

Note: --key passes the key via Docker exec environment for a single run. It is not persisted in the container. Use sandbar env to store it persistently.

Usage

Read token usage for an agent:

sandbar usage test --agent opencode

sandbar usage test --agent codex

Logs

Logs agent conversation from a running Sandbar container:

sandbar logs test --agent codex

sandbar logs test --agent opencode

Kill

Kill and remove a Sandbar container:

sandbar kill test

Contributing

See CONTRIBUTING.md for development setup and contribution guidelines.

License

MIT