Claude Code / AI Coding Tools
Claude Code sandbox Operation not permitted — slash in denyWithinAllow blocks all file writes on macOS
Fix Claude Code sandbox blocking all write operations on macOS, Operation not permitted error Includes evidence for Claude Code troubleshooting demand.
- Category
- AI Coding Tools
- Error signature
Operation not permitted from the kernel sandbox — write.denyWithinAllow contains "/" which blanket-blocks all write paths- Quick fix
- Compare the failing environment with a known working setup, then change one configuration value at a time.
- Updated
What this error means
Operation not permitted from the kernel sandbox — write.denyWithinAllow contains "/" which blanket-blocks all write paths is a Claude Code failure pattern reported for developers trying to fix claude code sandbox blocking all write operations on macos, operation not permitted error. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.
Why this happens
GitHub issue #59455 reports Claude Code 2.1.132 on macOS injects ”/” into denyWithinAllow sandbox descriptor, causing every write attempt (project dir, /tmp, plans) to fail with kernel sandbox Operation not permitted. Regression from previous versions. No user-configurable setting causes this — Claude Code computes/injects it. Category mapped to AI Coding Tools as this is a Claude Code bug.
Common causes
- GitHub issue #59455 reports Claude Code 2.1.132 on macOS injects ”/” into denyWithinAllow sandbox descriptor, causing every write attempt (project dir, /tmp, plans) to fail with kernel sandbox Operation not permitted. Regression from previous versions. No user-configurable setting causes this — Claude Code computes/injects it. Category mapped to AI Coding Tools as this is a Claude Code bug.
Quick fixes
- Confirm the exact error signature matches
Operation not permitted from the kernel sandbox — write.denyWithinAllow contains "/" which blanket-blocks all write paths. - Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
- Compare the failing environment with a known working setup, then change one configuration value at a time.
Platform/tool-specific checks
- Verify the command, editor, extension, or API client that produced the error.
- Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
- Avoid deleting credentials, local model data, or project settings until the failing scope is clear.
Step-by-step troubleshooting
- Capture the exact error message and the command, editor action, or request that triggered it.
- Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
- Review the source evidence below and compare it with your environment.
- Apply one change at a time and rerun the smallest failing action.
- Keep the working fix documented for the team or deployment environment.
How to prevent it
- Keep provider/tool configuration documented.
- Record non-secret diagnostics such as tool version, provider name, model name, and command path.
- Add a lightweight check before CI or production workflows depend on the tool.
Sources checked
Evidence note: GitHub issue #59455 reports Claude Code 2.1.132 on macOS injects ”/” into denyWithinAllow sandbox descriptor, causing every write attempt (project dir, /tmp, plans) to fail with kernel sandbox Operation not permitted. Regression from previous versions. No user-configurable setting causes this — Claude Code computes/injects it. Category mapped to AI Coding Tools as this is a Claude Code bug.
Related errors
- AI Coding Tools
FAQ
What should I check first?
Start with the exact Operation not permitted from the kernel sandbox — write.denyWithinAllow contains "/" which blanket-blocks all write paths text and the smallest action that reproduces it.
Can I ignore this error?
No. Treat it as a failed Claude Code workflow until the root cause is understood.
Is this guaranteed to have one fix?
No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.
How do I know the fix worked?
Rerun the same command, editor action, or request. The fix is working when that action completes without Operation not permitted from the kernel sandbox — write.denyWithinAllow contains "/" which blanket-blocks all write paths.