---
summary: "How OpenClaw sandboxing works: modes, scopes, workspace access, and images"
title: "Sandboxing"
sidebarTitle: "Sandboxing"
read_when: "You want a dedicated explanation of sandboxing or need to tune agents.defaults.sandbox."
status: active
---

OpenClaw can run tool execution inside a sandbox backend to reduce blast radius. Sandboxing is off by default and controlled by `agents.defaults.sandbox` (global) or `agents.list[].sandbox` (per-agent). The Gateway process always stays on the host; only tool execution moves into the sandbox when enabled.

<Note>
This is not a perfect security boundary, but it materially limits filesystem and process access when the model does something dumb.
</Note>

## What gets sandboxed

- Tool execution: `exec`, `read`, `write`, `edit`, `apply_patch`, `process`, etc.
- The optional sandboxed browser (`agents.defaults.sandbox.browser`).

Not sandboxed:

- The Gateway process itself.
- Any tool explicitly allowed to run outside the sandbox via `tools.elevated`. Elevated exec bypasses sandboxing and runs on the configured escape path (`gateway` by default, or `node` when the exec target is `node`). If sandboxing is off, `tools.elevated` changes nothing since exec already runs on the host. See [Elevated Mode](/tools/elevated).

## Modes, scope, and backend

Three independent settings control sandbox behavior:

| Setting | Key                               | Values                       | Default  |
| ------- | --------------------------------- | ---------------------------- | -------- |
| Mode    | `agents.defaults.sandbox.mode`    | `off`, `non-main`, `all`     | `off`    |
| Scope   | `agents.defaults.sandbox.scope`   | `agent`, `session`, `shared` | `agent`  |
| Backend | `agents.defaults.sandbox.backend` | `docker`, `ssh`, `openshell` | `docker` |

**Mode** controls when sandboxing applies:

- `off`: no sandboxing.
- `non-main`: sandbox every session except the agent's main session. The main session key is always `agent:<agentId>:main` (or `global` when `session.scope` is `"global"`); it is not configurable. Group/channel sessions use their own keys, so they always count as non-main and get sandboxed.
- `all`: every session runs in a sandbox.

**Scope** controls how many containers/environments are created:

- `agent`: one container per agent.
- `session`: one container per session.
- `shared`: one container shared by all sandboxed sessions (per-agent `docker`/`ssh`/`browser` overrides are ignored under this scope).

**Backend** controls which runtime executes sandboxed tools. SSH-specific config lives under `agents.defaults.sandbox.ssh`; OpenShell-specific config lives under `plugins.entries.openshell.config`.

|                     | Docker                           | SSH                            | OpenShell                                           |
| ------------------- | -------------------------------- | ------------------------------ | --------------------------------------------------- |
| **Where it runs**   | Local container                  | Any SSH-accessible host        | OpenShell managed sandbox                           |
| **Setup**           | `scripts/sandbox-setup.sh`       | SSH key + target host          | OpenShell plugin enabled                            |
| **Workspace model** | Bind-mount or copy               | Remote-canonical (seed once)   | `mirror` or `remote`                                |
| **Network control** | `docker.network` (default: none) | Depends on remote host         | Depends on OpenShell                                |
| **Browser sandbox** | Supported                        | Not supported                  | Not supported yet                                   |
| **Bind mounts**     | `docker.binds`                   | N/A                            | N/A                                                 |
| **Best for**        | Local dev, full isolation        | Offloading to a remote machine | Managed remote sandboxes with optional two-way sync |

## Docker backend

Docker is the default backend once sandboxing is enabled. It runs tools and sandbox browsers locally through the Docker daemon socket (`/var/run/docker.sock`); isolation comes from Docker namespaces.

Defaults: `network: "none"` (no egress), `readOnlyRoot: true`, `capDrop: ["ALL"]`, image `openclaw-sandbox:bookworm-slim`.

To expose host GPUs, set `agents.defaults.sandbox.docker.gpus` (or the per-agent override) to a value like `"all"` or `"device=GPU-uuid"`. This is passed to Docker's `--gpus` flag and requires a compatible host runtime such as NVIDIA Container Toolkit.

<Warning>
**Docker-out-of-Docker (DooD) constraints**

If you deploy the OpenClaw Gateway itself as a Docker container, it orchestrates sibling sandbox containers using the host's Docker socket (DooD). This introduces a path mapping constraint:

- **Config requires host paths**: `openclaw.json` `workspace` must contain the **host's absolute path** (e.g. `/home/user/.openclaw/workspaces`), not the internal Gateway container path. The Docker daemon evaluates paths relative to the host OS namespace, not the Gateway's own namespace.
- **Matching volume map required**: The Gateway process also writes heartbeat and bridge files to that `workspace` path. Give the Gateway container an identical volume map (`-v /home/user/.openclaw:/home/user/.openclaw`) so the same host path resolves correctly from inside the Gateway container too. Mismatched mappings surface as `EACCES` when the Gateway tries to write its heartbeat.
- **Codex code mode**: when an OpenClaw sandbox is active, OpenClaw disables Codex app-server native Code Mode, user MCP servers, and app-backed plugin execution for that turn (those run from the Gateway-host app-server process, not the OpenClaw sandbox backend), unless the sandbox tool policy exposes the required tools and you opt into the experimental sandbox exec-server path. Shell access then routes through OpenClaw sandbox-backed tools such as `sandbox_exec` and `sandbox_process`. Do not mount the host Docker socket into agent sandbox containers or custom Codex sandboxes. See [Codex Harness](/plugins/codex-harness) for the full behavior.

On Ubuntu/AppArmor hosts with Docker sandbox mode enabled, Codex app-server `workspace-write` shell execution needs unprivileged user namespaces inside the sandbox container, and this can fail before shell startup when the service user cannot create them. This needs an unprivileged network namespace too when Docker sandbox egress is disabled (`network: "none"`, the default). Common symptoms: `bwrap: setting up uid map: Permission denied` and `bwrap: loopback: Failed RTM_NEWADDR: Operation not permitted`. Run `openclaw doctor`; if it reports a Codex bwrap namespace probe failure, prefer an AppArmor profile that grants the required namespaces to the OpenClaw service process. `kernel.apparmor_restrict_unprivileged_userns=0` is a host-wide fallback with security tradeoffs; use it only when that host posture is acceptable.
</Warning>

### Sandboxed browser

- The sandbox browser auto-starts (ensures CDP is reachable) when the browser tool needs it. Configure via `agents.defaults.sandbox.browser.autoStart` (default `true`) and `autoStartTimeoutMs` (default 12s).
- Sandbox browser containers use a dedicated Docker network (`openclaw-sandbox-browser`) instead of the global `bridge` network. Configure with `agents.defaults.sandbox.browser.network`.
- `agents.defaults.sandbox.browser.cdpSourceRange` restricts container-edge CDP ingress with a CIDR allowlist (for example `172.21.0.1/32`).
- noVNC observer access is password-protected by default; OpenClaw emits a short-lived token URL that serves a local bootstrap page and opens noVNC with the password in the URL fragment (not query string or header logs).
- `agents.defaults.sandbox.browser.allowHostControl` (default `false`) lets sandboxed sessions target the host browser explicitly.
- Optional allowlists gate `target: "custom"`: `allowedControlUrls`, `allowedControlHosts`, `allowedControlPorts`.

## SSH backend

Use `backend: "ssh"` to sandbox `exec`, file tools, and media reads on an arbitrary SSH-accessible machine.

```json5
{
  agents: {
    defaults: {
      sandbox: {
        mode: "all",
        backend: "ssh",
        scope: "session",
        workspaceAccess: "rw",
        ssh: {
          target: "user@gateway-host:22",
          workspaceRoot: "/tmp/openclaw-sandboxes",
          strictHostKeyChecking: true,
          updateHostKeys: true,
          identityFile: "~/.ssh/id_ed25519",
          certificateFile: "~/.ssh/id_ed25519-cert.pub",
          knownHostsFile: "~/.ssh/known_hosts",
          // Or use SecretRefs / inline contents instead of local files:
          // identityData: { source: "env", provider: "default", id: "SSH_IDENTITY" },
          // certificateData: { source: "env", provider: "default", id: "SSH_CERTIFICATE" },
          // knownHostsData: { source: "env", provider: "default", id: "SSH_KNOWN_HOSTS" },
        },
      },
    },
  },
}
```

Defaults: `command: "ssh"`, `workspaceRoot: "/tmp/openclaw-sandboxes"`, `strictHostKeyChecking: true`, `updateHostKeys: true`.

- **Lifecycle**: OpenClaw creates a per-scope remote root under `sandbox.ssh.workspaceRoot`. On first use after create or recreate, it seeds that remote workspace from the local workspace once. After that, `exec`, `read`, `write`, `edit`, `apply_patch`, prompt media reads, and inbound media staging run directly against the remote workspace over SSH. OpenClaw does not sync remote changes back to the local workspace automatically.
- **Authentication material**: `identityFile`/`certificateFile`/`knownHostsFile` reference existing local files. `identityData`/`certificateData`/`knownHostsData` accept inline strings or SecretRefs, resolved through the normal secrets runtime snapshot, written to temp files with mode `0600`, and deleted when the SSH session ends. If both a `*File` and `*Data` variant are set for the same item, `*Data` wins for that session.
- **Remote-canonical consequences**: the remote SSH workspace becomes the real sandbox state after the initial seed. Host-local edits made outside OpenClaw after the seed step are not visible remotely until you recreate the sandbox. `openclaw sandbox recreate` deletes the per-scope remote root and seeds again from local on next use. Browser sandboxing is not supported on this backend, and `sandbox.docker.*` settings do not apply to it.

## OpenShell backend

Use `backend: "openshell"` to sandbox tools in an OpenShell-managed remote environment. OpenShell reuses the same SSH transport and remote filesystem bridge as the generic SSH backend, and adds OpenShell lifecycle (`sandbox create/get/delete/ssh-config`) plus an optional `mirror` workspace sync mode.

```json5
{
  agents: {
    defaults: {
      sandbox: {
        mode: "all",
        backend: "openshell",
        scope: "session",
        workspaceAccess: "rw",
      },
    },
  },
  plugins: {
    entries: {
      openshell: {
        enabled: true,
        config: {
          from: "openclaw",
          mode: "remote", // mirror | remote
        },
      },
    },
  },
}
```

`mode: "mirror"` (default) keeps the local workspace canonical: OpenClaw syncs local into the sandbox before `exec` and syncs back after. `mode: "remote"` seeds the remote workspace once from local, then runs `exec`/`read`/`write`/`edit`/`apply_patch` directly against the remote workspace without syncing back; local edits after the seed are invisible until you `openclaw sandbox recreate`. Under `scope: "agent"` or `scope: "shared"`, that remote workspace is shared at the same scope. Current limitations: sandbox browser isn't supported yet, and `sandbox.docker.binds` doesn't apply to this backend.

`openclaw sandbox list`/`recreate`/prune all treat OpenShell runtimes the same as Docker runtimes; prune logic is backend-aware.

For the full prerequisites, configuration reference, workspace-mode comparison, and lifecycle details, see [OpenShell](/gateway/openshell).

## Workspace access

`agents.defaults.sandbox.workspaceAccess` controls what the sandbox can see:

| Value            | Behavior                                                                                  |
| ---------------- | ----------------------------------------------------------------------------------------- |
| `none` (default) | Tools see an isolated sandbox workspace under `~/.openclaw/sandboxes`.                    |
| `ro`             | Mounts the agent workspace read-only at `/agent` (disables `write`/`edit`/`apply_patch`). |
| `rw`             | Mounts the agent workspace read/write at `/workspace`.                                    |

With the OpenShell backend, `mirror` mode still uses the local workspace as the canonical source between exec turns, `remote` mode uses the remote OpenShell workspace as canonical after the initial seed, and `workspaceAccess: "ro"`/`"none"` still restrict write behavior the same way.

Inbound media is copied into the active sandbox workspace (`media/inbound/*`).

<Note>
**Skills**: the `read` tool is sandbox-rooted. With `workspaceAccess: "none"`, OpenClaw mirrors eligible skills into the sandbox workspace (`.../skills`) so they can be read. With `"rw"`, workspace skills are readable from `/workspace/skills`, and eligible managed, bundled, or plugin skills are materialized into the generated read-only path `/workspace/.openclaw/sandbox-skills/skills`.
</Note>

## Custom bind mounts

`agents.defaults.sandbox.docker.binds` mounts additional host directories into the container. Format: `host:container:mode` (e.g., `"/home/user/source:/source:rw"`).

Global and per-agent binds are merged (not replaced). Under `scope: "shared"`, per-agent binds are ignored.

`agents.defaults.sandbox.browser.binds` mounts additional host directories into the **sandbox browser** container only. When set (including `[]`), it replaces `docker.binds` for the browser container; when omitted, the browser container falls back to `docker.binds`.

```json5
{
  agents: {
    defaults: {
      sandbox: {
        docker: {
          binds: ["/home/user/source:/source:ro", "/var/data/myapp:/data:ro"],
        },
      },
    },
    list: [
      {
        id: "build",
        sandbox: {
          docker: {
            binds: ["/mnt/cache:/cache:rw"],
          },
        },
      },
    ],
  },
}
```

<Warning>
**Bind security**

- Binds bypass the sandbox filesystem: they expose host paths with whatever mode you set (`:ro` or `:rw`).
- OpenClaw blocks dangerous bind sources by default: system paths (`/etc`, `/proc`, `/sys`, `/dev`, `/root`, `/boot`), Docker socket directories (`/run`, `/var/run`, and their `docker.sock` variants), and common home-directory credential roots (`~/.aws`, `~/.cargo`, `~/.config`, `~/.docker`, `~/.gnupg`, `~/.netrc`, `~/.npm`, `~/.ssh`).
- Validation normalizes the source path, then resolves it again through the deepest existing ancestor before re-checking blocked paths and allowed roots, so symlink-parent escapes fail closed even when the final leaf doesn't exist yet (e.g. `/workspace/run-link/new-file` still resolves as `/var/run/...` if `run-link` points there).
- Bind targets that shadow the reserved container mount points (`/workspace`, `/agent`) are also blocked by default; override with `agents.defaults.sandbox.docker.dangerouslyAllowReservedContainerTargets: true`.
- Bind sources outside the workspace/agent-workspace allowlisted roots are blocked by default; override with `agents.defaults.sandbox.docker.dangerouslyAllowExternalBindSources: true`. Allowed roots are canonicalized the same way, so a path that only looks inside the allowlist before symlink resolution is still rejected as outside allowed roots.
- Sensitive mounts (secrets, SSH keys, service credentials) should be `:ro` unless absolutely required.
- Combine with `workspaceAccess: "ro"` if you only need read access to the workspace; bind modes stay independent.
- See [Sandbox vs Tool Policy vs Elevated](/gateway/sandbox-vs-tool-policy-vs-elevated) for how binds interact with tool policy and elevated exec.

</Warning>

## Images and setup

Default Docker image: `openclaw-sandbox:bookworm-slim`

<Note>
**Source checkout vs npm install**

The `scripts/sandbox-setup.sh`, `scripts/sandbox-common-setup.sh`, and `scripts/sandbox-browser-setup.sh` helper scripts are only available when running from a [source checkout](https://github.com/openclaw/openclaw). They are not included in the npm package.

If you installed OpenClaw via `npm install -g openclaw`, use the inline `docker build` commands shown below instead.
</Note>

<Steps>
  <Step title="Build the default image">
    From a source checkout:

    ```bash
    scripts/sandbox-setup.sh
    ```

    From an npm install (no source checkout needed):

    ```bash
    docker build -t openclaw-sandbox:bookworm-slim - <<'DOCKERFILE'
    FROM debian:bookworm-slim
    ENV DEBIAN_FRONTEND=noninteractive
    RUN apt-get update && apt-get install -y --no-install-recommends \
      bash ca-certificates curl git jq python3 ripgrep \
      && rm -rf /var/lib/apt/lists/*
    RUN useradd --create-home --shell /bin/bash sandbox
    USER sandbox
    WORKDIR /home/sandbox
    CMD ["sleep", "infinity"]
    DOCKERFILE
    ```

    The default image does **not** include Node. If a skill needs Node (or other runtimes), either bake a custom image or install via `sandbox.docker.setupCommand` (requires network egress + writable root + root user).

    OpenClaw does not silently substitute plain `debian:bookworm-slim` when `openclaw-sandbox:bookworm-slim` is missing. Sandbox runs that target the default image fail fast with a build instruction until you build it, because the bundled image carries `python3` for the sandbox write/edit helpers.

  </Step>
  <Step title="Optional: build the common image">
    For a more functional sandbox image with common tooling (for example `curl`, `jq`, Node 24, pnpm, `python3`, and `git`):

    From a source checkout:

    ```bash
    scripts/sandbox-common-setup.sh
    ```

    From an npm install, build the default image first (see above), then build the common image on top using [`scripts/docker/sandbox/Dockerfile.common`](https://github.com/openclaw/openclaw/blob/main/scripts/docker/sandbox/Dockerfile.common) from the repository.

    Then set `agents.defaults.sandbox.docker.image` to `openclaw-sandbox-common:bookworm-slim`.

  </Step>
  <Step title="Optional: build the sandbox browser image">
    From a source checkout:

    ```bash
    scripts/sandbox-browser-setup.sh
    ```

    From an npm install, build using [`scripts/docker/sandbox/Dockerfile.browser`](https://github.com/openclaw/openclaw/blob/main/scripts/docker/sandbox/Dockerfile.browser) from the repository.

  </Step>
</Steps>

By default, Docker sandbox containers run with **no network**. Override with `agents.defaults.sandbox.docker.network`.

<AccordionGroup>
  <Accordion title="Sandbox browser Chromium defaults">
    The bundled sandbox browser image applies conservative Chromium startup flags for containerized workloads:

    - `--remote-debugging-address=127.0.0.1`
    - `--remote-debugging-port=<derived from OPENCLAW_BROWSER_CDP_PORT>`
    - `--user-data-dir=${HOME}/.chrome`
    - `--no-first-run`
    - `--no-default-browser-check`
    - `--disable-dev-shm-usage`
    - `--disable-background-networking`
    - `--disable-breakpad`
    - `--disable-crash-reporter`
    - `--no-zygote`
    - `--metrics-recording-only`
    - `--password-store=basic`
    - `--use-mock-keychain`
    - `--headless=new` when `browser.headless` is enabled.
    - `--no-sandbox --disable-setuid-sandbox` when `browser.noSandbox` is enabled.
    - `--disable-3d-apis`, `--disable-gpu`, `--disable-software-rasterizer` by default; these graphics-hardening flags help containers without GPU support. Set `OPENCLAW_BROWSER_DISABLE_GRAPHICS_FLAGS=0` if your workload needs WebGL or other 3D features.
    - `--disable-extensions` by default; set `OPENCLAW_BROWSER_DISABLE_EXTENSIONS=0` for extension-reliant flows.
    - `--renderer-process-limit=2` by default; controlled by `OPENCLAW_BROWSER_RENDERER_PROCESS_LIMIT=<N>`, where `0` keeps Chromium's default.

    If you need a different runtime profile, use a custom browser image and provide your own entrypoint. For local (non-container) Chromium profiles, use `browser.extraArgs` to append additional startup flags.

  </Accordion>
  <Accordion title="Network security defaults">
    - `network: "host"` is blocked.
    - `network: "container:<id>"` is blocked by default (namespace join bypass risk).
    - Break-glass override: `agents.defaults.sandbox.docker.dangerouslyAllowContainerNamespaceJoin: true`.

  </Accordion>
</AccordionGroup>

Docker installs and the containerized gateway live here: [Docker](/install/docker)

For Docker gateway deployments, `scripts/docker/setup.sh` can bootstrap sandbox config. Set `OPENCLAW_SANDBOX=1` (or `true`/`yes`/`on`) to enable that path. Override the socket location with `OPENCLAW_DOCKER_SOCKET`. Full setup and env reference: [Docker](/install/docker#agent-sandbox).

## setupCommand (one-time container setup)

`setupCommand` runs **once** after the sandbox container is created (not on every run). It executes inside the container via `sh -lc`.

Paths:

- Global: `agents.defaults.sandbox.docker.setupCommand`
- Per-agent: `agents.list[].sandbox.docker.setupCommand`

<AccordionGroup>
  <Accordion title="Common pitfalls">
    - Default `docker.network` is `"none"` (no egress), so package installs will fail.
    - `docker.network: "container:<id>"` requires `dangerouslyAllowContainerNamespaceJoin: true` and is break-glass only.
    - `readOnlyRoot: true` prevents writes; set `readOnlyRoot: false` or bake a custom image.
    - `user` must be root for package installs (omit `user` or set `user: "0:0"`).
    - Sandbox exec does **not** inherit host `process.env`. Use `agents.defaults.sandbox.docker.env` (or a custom image) for skill API keys.
    - Values in `agents.defaults.sandbox.docker.env` are passed as explicit Docker container environment variables. Anyone with Docker daemon access can inspect them with Docker metadata commands such as `docker inspect`. Use a custom image, mounted secret file, or another secret delivery path if that metadata exposure is not acceptable.

  </Accordion>
</AccordionGroup>

## Tool policy and escape hatches

Tool allow/deny policies still apply before sandbox rules. If a tool is denied globally or per-agent, sandboxing doesn't bring it back.

`tools.elevated` is an explicit escape hatch that runs `exec` outside the sandbox (`gateway` by default, or `node` when the exec target is `node`). `/exec` directives only apply for authorized senders and persist per session; to hard-disable `exec`, use tool policy deny (see [Sandbox vs Tool Policy vs Elevated](/gateway/sandbox-vs-tool-policy-vs-elevated)).

Debugging:

- `openclaw sandbox list` shows sandbox containers, status, image match, age, idle time, and associated session/agent.
- `openclaw sandbox explain [--session <key>] [--agent <id>]` inspects effective sandbox mode, tool policy, and fix-it config keys.
- `openclaw sandbox recreate [--all | --session <key> | --agent <id>] [--browser] [--force]` removes containers/environments so they get recreated with current config on next use.
- See [Sandbox vs Tool Policy vs Elevated](/gateway/sandbox-vs-tool-policy-vs-elevated) for the "why is this blocked?" mental model.

## Multi-agent overrides

Each agent can override sandbox + tools: `agents.list[].sandbox` and `agents.list[].tools` (plus `agents.list[].tools.sandbox.tools` for sandbox tool policy). See [Multi-Agent Sandbox & Tools](/tools/multi-agent-sandbox-tools) for precedence.

## Minimal enable example

```json5
{
  agents: {
    defaults: {
      sandbox: {
        mode: "non-main",
        scope: "session",
        workspaceAccess: "none",
      },
    },
  },
}
```

## Related

- [Multi-Agent Sandbox & Tools](/tools/multi-agent-sandbox-tools) -- per-agent overrides and precedence
- [OpenShell](/gateway/openshell) -- managed sandbox backend setup, workspace modes, and config reference
- [Sandbox configuration](/gateway/config-agents#agentsdefaultssandbox)
- [Sandbox vs Tool Policy vs Elevated](/gateway/sandbox-vs-tool-policy-vs-elevated) -- debugging "why is this blocked?"
- [Security](/gateway/security)
