Execute a shell command and return a QUIET, STRUCTURED result: exit code, duration, files changed (git diff), and a token-aware view of stdout/stderr (full on small/failure, head+tail otherwise). Full output is stored and addressable via sh_detail — it is NOT re-emitted into context. Prefer this over a raw Bash call when you care about effects or output is likely verbose.

Retrieve full stored output for a previous sh_run by id WITHOUT re-running it (feature J — addressable output). Use after a condensed result hid lines you need.

Statically predict what a command WOULD do without running it: blast-radius category (read-only | mutating | destructive | network | complex | unknown), whether it's reversible, and predicted file mutations. Use before destructive or unfamiliar commands. Does NOT execute anything.

Snapshot a working directory under a label so you can restore it later with sh_restore. Excludes .git and node_modules. Take one before a risky or irreversible change.

Mirror a directory back to a previous sh_checkpoint (files created since the checkpoint are removed). This is the rollback for an agent's mistakes.

List existing checkpoint labels.