--- summary: "How OpenClaw handles local file access safely, and why the optional fs-safe Python helper is off by default" read_when: - Changing file access, archive extraction, workspace storage, or plugin filesystem helpers title: "Secure file operations" --- OpenClaw uses [`@openclaw/fs-safe`](https://github.com/openclaw/fs-safe) for security-sensitive local file operations: root-bounded reads/writes, atomic replacement, archive extraction, temp workspaces, JSON state, and secret-file handling. It is a **library guardrail** for trusted OpenClaw code that receives untrusted path names, not a sandbox. Host filesystem permissions, OS users, containers, and the agent/tool policy still define the real blast radius. ## Default: no Python helper OpenClaw sets the fs-safe POSIX Python helper to **off** by default: - the gateway should not spawn a persistent Python sidecar unless an operator opts in; - most installs do not need the extra parent-directory mutation hardening; - disabling Python keeps runtime behavior predictable across desktop, Docker, CI, and bundled-app environments. OpenClaw only changes the _default_. An explicit setting always wins: ```bash # Default OpenClaw behavior: Node-only fs-safe fallbacks. OPENCLAW_FS_SAFE_PYTHON_MODE=off # Opt into the helper when available, falling back if unavailable. OPENCLAW_FS_SAFE_PYTHON_MODE=auto # Fail closed if the helper cannot start. OPENCLAW_FS_SAFE_PYTHON_MODE=require # Optional explicit interpreter path. OPENCLAW_FS_SAFE_PYTHON=/usr/bin/python3 ``` The generic fs-safe env names also work: `FS_SAFE_PYTHON_MODE` and `FS_SAFE_PYTHON`. Use `require` (not `auto`) when the helper is part of your security posture; `auto` silently falls back to Node-only behavior if the helper cannot start. ## What stays protected without Python With the helper off, OpenClaw still gets fs-safe's Node-only guardrails: - rejects relative-path escapes (`..`), absolute paths, and path separators where only bare names are allowed; - resolves operations through a trusted root handle instead of ad-hoc `path.resolve(...).startsWith(...)` checks; - refuses symlink and hardlink patterns on APIs that require that policy; - opens files with identity checks where the API returns or consumes file contents; - writes state/config files via atomic sibling-temp + rename; - enforces byte limits for reads and archive extraction; - applies private file modes for secrets and state files where the API requires them. This covers OpenClaw's normal threat model: trusted gateway code handling untrusted model/plugin/channel path input inside a single trusted operator boundary. ## What Python adds On POSIX, the optional helper keeps one persistent Python process and uses fd-relative filesystem operations for parent-directory mutations: rename, remove, mkdir, stat/list, and some write paths. That narrows same-UID race windows where another process swaps a parent directory between validation and mutation — defense in depth on hosts where untrusted local processes can modify the same directories OpenClaw operates in. If your deployment has that risk and Python is guaranteed to exist, set: ```bash OPENCLAW_FS_SAFE_PYTHON_MODE=require ``` ## Plugin and core guidance - Plugin-facing file access should go through `openclaw/plugin-sdk/*` helpers, not raw `fs`, when a path comes from a message, model output, config, or plugin input. - Core code should use the fs-safe wrappers under `src/infra/*` so OpenClaw's process policy applies consistently. - Archive extraction should use the fs-safe archive helpers with explicit size, entry-count, link, and destination limits. - Secrets should use OpenClaw secret helpers or fs-safe secret/private-state helpers; do not hand-roll mode checks around `fs.writeFile`. - For hostile local-user isolation, do not rely on fs-safe alone. Run separate gateways under separate OS users/hosts, or use sandboxing. Related: [Security](/gateway/security), [Sandboxing](/gateway/sandboxing), [Exec approvals](/tools/exec-approvals), [Secrets](/gateway/secrets).