Guards

Keep huge shell output out of the context window. A Bash result over a threshold is saved to a file and Claude gets its head and tail plus a slice tool to grep or page the rest on demand.

Stop Claude from retrying the same failing shell command over and over. After N identical failures the next attempt is held, and you choose: stop, or try once more.

Play a sound and post a desktop notification when Claude finishes a turn or needs you to answer a question or a permission prompt.

Limit which paths Claude may edit in a project with one /fence command. Edits outside the fence are refused with a reason Claude can act on.

Know whether your auto-memory index loaded whole. Reports the index's size against a limit you set at every session start, names the entries past the cut, and warns when a session pushes it over.

Hold npm, pnpm, yarn, pip, uv, and cargo installs of packages that don't exist, are brand new, or are barely downloaded, with the registry facts in the question. Catches hallucinated and typosquat packages before they land.

Run the project's tests after any turn that edited files, print pass or fail under Claude's answer, and send the failure back to Claude with one /fix command.

Stop Claude using cat, grep, find, and sed in Bash when the Read, Grep, and Glob tools fit. Each redirected call saves a permission prompt and keeps raw shell output out of context.

Your day, written for you. Every turn is logged; /standup turns today's work across every session on the machine into a three-bullet update, or a Markdown file.

Enforce the style rules Claude keeps ignoring: banned words and phrases, a comment-density cap on added code, and files that must not gain comments. Rules live in .claude/style-cop.md and are both shown to Claude and enforced on edits.

Stop secrets leaving the machine. Holds an edit or command that writes an API key, a private key, or a credential literal, a command that reads a secret file and talks to the network, and a git commit whose staged changes contain a secret. Refuses by default.

Check what Claude claims against what it ran. When an answer says the tests pass, the build is clean, or something was committed, a line under it says whether a matching command actually ran this turn and succeeded.

Undo the file edits a subagent made. /rewind restores your own turns, but not a subagent's edits; this snapshots them and puts the files back with one command.